Memantine inhibits β-amyloid aggregation and disassembles preformed β-amyloid aggregates.

PubMed

Takahashi-Ito, Kaori; Makino, Mitsuhiro; Okado, Keiko; Tomita, Taisuke

2017-11-04

Memantine, an uncompetitive glutamatergic N-methyl-d-aspartate (NMDA) receptor antagonist, is widely used as a medication for the treatment of Alzheimer's disease (AD). We previously reported that chronic treatment of AD with memantine reduces the amount of insoluble β-amyloid (Aβ) and soluble Aβ oligomers in animal models of AD. The mechanisms by which memantine reduces Aβ levels in the brain were evaluated by determining the effect of memantine on Aβ aggregation using thioflavin T and transmission electron microscopy. Memantine inhibited the formation of Aβ(1-42) aggregates in a concentration-dependent manner, whereas amantadine, a structurally similar compound, did not affect Aβ aggregation at the same concentrations. Furthermore, memantine inhibited the formation of different types of Aβ aggregates, including Aβs carrying familial AD mutations, and disaggregated preformed Aβ(1-42) fibrils. These results suggest that the inhibition of Aβ aggregation and induction of Aβ disaggregation may be involved in the mechanisms by which memantine reduces Aβ deposition in the brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Insulin potentiates the therapeutic effect of memantine against central STZ-induced spatial learning and memory deficit.

PubMed

Bahramian, Abbas; Rastegar, Karim; Namavar, Mohammad Reza; Moosavi, Maryam

2016-09-15

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Memantine has been approved for moderate to severe AD, but evidence indicates that it does not modify disease progression. Recently insulin has been found to exert some beneficial effects on cognition. This study aimed to compare the protective effects of memantine and insulin in an animal model of memory deficit. It also evaluated the effects of combination therapy of these drugs. Adult male Sprague-Dawely rats approximately 8-10 weeks old were used. The canules were implanted bilaterally into lateral ventricles. STZ was administered on days 1 and 3 (3mg/kg in divided doses) and Memantine (5 or 10mg/kg/ip) or/and Insulin (3 or 6mU/icv) were started from day 4 and continued till day 13. The animal's learning and memory capability was assessed on days 14-16 using Morris water maze. On day 17 a visible platform test was done to assess the animals' visuomotor ability. After completion of behavioral studies the brain sections were stained with hematoxylin and eosin for routine histological evaluation. The results show that memantine in doses 5 and 10mg/kg improved memory at day 3 of training and memantine 5mg/kg was more potent than memantine 10mg/kg. Insulin in dose 3mU, but not 6 mU, reversed STZ-induced memory deficit from day 2 of training. When insulin was added to memantine, it increased the potency of memantine 5mg/kg in preventing a memory deficit, but surprisingly was not successful in impeding STZ-induced amnesia, in combination with memantine 10mg/kg. This research work revealed that insulin act more efficiently than memantine in reversing STZ-induced memory impairment. Additionally combination of insulin and memantine seems to act better than memantine alone, providing that a dose adjustment has been done. This study suggests considering the combination therapy of memantine and insulin in dementia and AD. Copyright © 2016 Elsevier B.V. All rights reserved.

Protective effects of NMDA receptor antagonist, memantine, against senescence of PC12 cells: A possible role of nNOS and combined effects with donepezil.

PubMed

Ota, Hidetaka; Ogawa, Sumito; Ouchi, Yasuyoshi; Akishita, Masahiro

2015-12-01

Alzheimer disease (AD) is a neurodegenerative disorder characterized by cognitive dysfunction. The pathology of AD is mainly related to amyloid ß (Aß)-peptides, but glutamate-mediated toxicity is also one of the main processes of memory impairment in AD. Glutamate is the main excitatory neurotransmitter in the central nervous system (CNS) and is particularly involved in synaptic plasticity, memory, and learning. Memantine is a low-affinity voltage-dependent noncompetitive antagonist at glutamatergic NMDA receptors. Here,we investigated whether memantine protects against glutamate-induced senescence. In PC12 cells, treatment with glutamate induced senescent phenotypes as judged by the cell appearance and senescence-associated ß-galactosidase (SA-ßgal) in parallel with decreased SIRT1 and increased p53 expression. However, treatment with memantine decreased glutamate-induced senescent PC12 cells and reversed the changes in SIRT1 and p53 expression. Glutamate is known to stimulate the production of NO and O2(-) and has the capacity to generate ONOO(-) in the CNS. Therefore, we investigated whether glutamate activates nNOS and memantine reverses it. Treatment with glutamate increased nNOS expression, activity, and production of NO,whereas memantine blocked them. Next, the in vivo effects of memantine on cognitive function in senescence-accelerated mouse prone 8 (SAMP8), as a model of AD, were investigated. In the Morris water maze test, SAMP8 showed a marked decline in performance, but memantine administration improved it. Moreover, neuronal senescence and the level of oxidative stress in the hippocampus were decreased by memantine. Finally, the effects of combination treatment with memantine and donepezil, a cholinesterase inhibitor, were investigated. We observed additive effects of memantine and donepezil on the senescent phenotype of PC12 cells and the hippocampus of SAMP8. These results indicate that inhibition of the NMDA receptor by memantine leads to a decrease innNOS activity and results in a reduction of glutamate-induced senescence. Thus, our present study suggests a critical role of memantine in the prevention of neuronal aging, and supports that donepezil has a combined effect with memantine.

Immunomodulation by memantine in therapy of Alzheimer's disease is mediated through inhibition of Kv1.3 channels and T cell responsiveness

PubMed Central

Lowinus, Theresa; Bose, Tanima; Busse, Stefan; Busse, Mandy; Reinhold, Dirk; Schraven, Burkhart; Bommhardt, Ursula H.H.

2016-01-01

Memantine is approved for the treatment of advanced Alzheimer's disease (AD) and reduces glutamate-mediated neuronal excitotoxicity by antagonism of N-methyl-D-aspartate receptors. In the pathophysiology of AD immune responses deviate and infectious side effects are observed during memantine therapy. However, the particular effects of memantine on human T lymphocytes are unresolved. Here, we provide evidence that memantine blocks Kv1.3 potassium channels, inhibits CD3-antibody- and alloantigen-induced proliferation and suppresses chemokine-induced migration of peripheral blood T cells of healthy donors. Concurrent with the in vitro data, CD4+ T cells from AD patients receiving therapeutic doses of memantine show a transient decline of Kv1.3 channel activity and a long-lasting reduced proliferative response to alloantigens in mixed lymphocyte reactions. Furthermore, memantine treatment provokes a profound depletion of peripheral blood memory CD45RO+ CD4+ T cells. Thus, standard doses of memantine profoundly reduce T cell responses in treated patients through blockade of Kv1.3 channels. This may normalize deviant immunopathology in AD and contribute to the beneficial effects of memantine, but may also account for the enhanced infection rate. PMID:27462773

Immunomodulation by memantine in therapy of Alzheimer's disease is mediated through inhibition of Kv1.3 channels and T cell responsiveness.

PubMed

Lowinus, Theresa; Bose, Tanima; Busse, Stefan; Busse, Mandy; Reinhold, Dirk; Schraven, Burkhart; Bommhardt, Ursula H H

2016-08-16

Memantine is approved for the treatment of advanced Alzheimer´s disease (AD) and reduces glutamate-mediated neuronal excitotoxicity by antagonism of N-methyl-D-aspartate receptors. In the pathophysiology of AD immune responses deviate and infectious side effects are observed during memantine therapy. However, the particular effects of memantine on human T lymphocytes are unresolved. Here, we provide evidence that memantine blocks Kv1.3 potassium channels, inhibits CD3-antibody- and alloantigen-induced proliferation and suppresses chemokine-induced migration of peripheral blood T cells of healthy donors. Concurrent with the in vitro data, CD4+ T cells from AD patients receiving therapeutic doses of memantine show a transient decline of Kv1.3 channel activity and a long-lasting reduced proliferative response to alloantigens in mixed lymphocyte reactions. Furthermore, memantine treatment provokes a profound depletion of peripheral blood memory CD45RO+ CD4+ T cells. Thus, standard doses of memantine profoundly reduce T cell responses in treated patients through blockade of Kv1.3 channels. This may normalize deviant immunopathology in AD and contribute to the beneficial effects of memantine, but may also account for the enhanced infection rate.

Post-acute delivery of memantine promotes post-ischemic neurological recovery, peri-infarct tissue remodeling, and contralesional brain plasticity.

PubMed

Wang, Ya-Chao; Sanchez-Mendoza, Eduardo H; Doeppner, Thorsten R; Hermann, Dirk M

2017-03-01

The NMDA antagonist memantine preferentially inhibits extrasynaptic NMDA receptors, which are overactivated upon stroke and thought to disturb neuroplasticity. We hypothesized that memantine enhances post-ischemic neurological recovery, brain remodeling, and plasticity. C57BL6/j mice were exposed to intraluminal middle cerebral artery occlusion. Starting 72 hours post-stroke, vehicle or memantine (4 or 20 mg/kg/day) were subcutaneously delivered over 28 days. Neurological recovery, perilesional tissue remodeling and contralesional pyramidal tract plasticity were evaluated over 49 days. Memantine, delivered at 20 but not 4 mg/kg/day, persistently improved motor-coordination and spatial memory. Secondary striatal atrophy was reduced by memantine. This delayed neuroprotection was associated with reduced astrogliosis and increased capillary formation around the infarct rim. Concentrations of BDNF, GDNF, and VEGF were bilaterally elevated by memantine in striatum and cortex. Anterograde tract tracing studies revealed that memantine increased contralesional corticorubral sprouting across the midline in direction to the ipsilesional red nucleus. In the contralesional motor cortex, the NMDA receptor subunit GluN2B, which is predominantly expressed in extrasynaptic NMDA receptors, was transiently reduced by memantine after 14 days, whereas GluN2A and PSD-95, which preferentially co-localize with synaptic NMDA receptors, were increased after 28 days. Our data suggest the utility of memantine for enhancing post-acute stroke recovery.

Post-acute delivery of memantine promotes post-ischemic neurological recovery, peri-infarct tissue remodeling, and contralesional brain plasticity

PubMed Central

Wang, Ya-chao; Sanchez-Mendoza, Eduardo H; Doeppner, Thorsten R

2016-01-01

The NMDA antagonist memantine preferentially inhibits extrasynaptic NMDA receptors, which are overactivated upon stroke and thought to disturb neuroplasticity. We hypothesized that memantine enhances post-ischemic neurological recovery, brain remodeling, and plasticity. C57BL6/j mice were exposed to intraluminal middle cerebral artery occlusion. Starting 72 hours post-stroke, vehicle or memantine (4 or 20 mg/kg/day) were subcutaneously delivered over 28 days. Neurological recovery, perilesional tissue remodeling and contralesional pyramidal tract plasticity were evaluated over 49 days. Memantine, delivered at 20 but not 4 mg/kg/day, persistently improved motor-coordination and spatial memory. Secondary striatal atrophy was reduced by memantine. This delayed neuroprotection was associated with reduced astrogliosis and increased capillary formation around the infarct rim. Concentrations of BDNF, GDNF, and VEGF were bilaterally elevated by memantine in striatum and cortex. Anterograde tract tracing studies revealed that memantine increased contralesional corticorubral sprouting across the midline in direction to the ipsilesional red nucleus. In the contralesional motor cortex, the NMDA receptor subunit GluN2B, which is predominantly expressed in extrasynaptic NMDA receptors, was transiently reduced by memantine after 14 days, whereas GluN2A and PSD-95, which preferentially co-localize with synaptic NMDA receptors, were increased after 28 days. Our data suggest the utility of memantine for enhancing post-acute stroke recovery. PMID:27170698

Memantine-associated hyperkalaemia in a patient with Alzheimer's disease.

PubMed

Tsukamoto, Tatsuo; Yamada, Hidetaka; Uchimura, Naohisa

2013-09-01

Memantine is an N-methyl-D-aspartate glutamate receptor antagonist that may improve cognitive functions in patients with Alzheimer's disease. It is predominantly excreted unchanged via the kidneys, and patients with decreased creatinine clearance must be treated with lower doses of memantine. However, it is unclear whether memantine itself can lead to renal dysfunction and/or hyperkalaemia. We report a patient with renal impairment and hyperkalaemia possibly associated with memantine administration. © 2013 The Authors. Psychogeriatrics © 2013 Japanese Psychogeriatric Society.

Memantine Attenuates Delayed Vasospasm after Experimental Subarachnoid Hemorrhage via Modulating Endothelial Nitric Oxide Synthase.

PubMed

Huang, Chih-Yuan; Wang, Liang-Chao; Shan, Yan-Shen; Pan, Chia-Hsin; Tsai, Kuen-Jer

2015-06-23

Delayed cerebral vasospasm is an important pathological feature of subarachnoid hemorrhage (SAH). The cause of vasospasm is multifactorial. Impairs nitric oxide availability and endothelial nitric oxide synthase (eNOS) dysfunction has been reported to underlie vasospasm. Memantine, a low-affinity uncompetitive N-methyl-d-aspartate (NMDA) blocker has been proven to reduce early brain injury after SAH. This study investigated the effect of memantine on attenuation of vasospasm and restoring eNOS functionality. Male Sprague-Dawley rats weighing 350-450 g were randomly divided into three weight-matched groups, sham surgery, SAH + vehicle, and SAH + memantine groups. The effects of memantine on SAH were evaluated by assessing the severity of vasospasm and the expression of eNOS. Memantine effectively ameliorated cerebral vasospasm by restoring eNOS functionality. Memantine can prevent vasospasm in experimental SAH. Treatment strategies may help combat SAH-induced vasospasm in the future.

Memantine for the Treatment of Phantom Limb Pain: A Systematic Review.

PubMed

Loy, Brittany M; Britt, Rachel B; Brown, Jamie N

2016-12-01

Phantom limb pain (PLP) occurs in up to 85% of patients who have undergone an amputation and remains difficult to treat. Memantine is a N-Methyl-d-aspartate receptor antagonist that has shown benefit in pain syndromes. The objective of this systematic review is to evaluate the evidence for the use of memantine in the treatment of acute and chronic PLP. MEDLINE (1956 to May 2016) and Embase (1957 to May 2016) were queried for articles that characterized the clinical outcomes of patient(s) treated with memantine for PLP. The initial search identified 185 studies and case reports. After screening, eight articles were included. One prospective study, a case report, and two case series demonstrated benefit with memantine in the treatment of acute PLP. However, in chronic PLP that persisted for over 1 year, four prospective studies failed to demonstrate significant analgesic effects with memantine. Memantine was well tolerated in all studies. Memantine appears to be a reasonable option to trial in a patient with a recent amputation or who has failed or cannot tolerate other analgesics. Additional research is needed to further determine the role of memantine in the treatment and prevention of PLP and to identify the population most likely to gain benefit.

Memantine alters striatal plasticity inducing a shift of synaptic responses toward long-term depression.

PubMed

Mancini, Maria; Ghiglieri, Veronica; Bagetta, Vincenza; Pendolino, Valentina; Vannelli, Anna; Cacace, Fabrizio; Mineo, Desireé; Calabresi, Paolo; Picconi, Barbara

2016-02-01

Memantine is an open channel blocker that antagonizes NMDA receptors reducing the inappropriate calcium (Ca(2+)) influx occurring in presence of moderately increased glutamate levels. At the same time, memantine has the ability to preserve the transient physiological activation of NMDA receptor, essential for learning and memory formation at synaptic level. In the present study we investigated the effects exerted by memantine on striatal synaptic plasticity in rat striatal spiny projection neurons (SPNs). In vitro application of memantine in striatal slices elicited a disruption of long-term potentiation (LTP) induction and maintenance, and revealed, in the majority of the recorded neurons, a long-term depression (LTD), whose amplitude was concentration-dependent (0.3-10 μM). Interestingly, preincubation with the dopamine (DA) D2 receptor antagonist sulpiride (10 μM) prevented memantine-induced LTD and restored LTP. Moreover, the DA D2 agonist quinpirole (10 μM), similarly to memantine, induced LTD in a subgroup of SPNs. In addition, memantine-induced LTD was also prevented by the CB1 endocannabinoid receptor antagonist AM 251 (1 μM). These results suggest that the actions exerted by memantine on striatal synaptic plasticity, and in particular the induction of LTD observed in SPNs, could be attributed to its ability to activate DA D2 receptors. By contrast, blockade of NMDA receptor is not involved in memantine-induced LTD since APV (30 μM) and MK801 (10 μM), two NMDA receptor antagonists, failed to induce this form of synaptic plasticity. Our data indicate that memantine could be used as treatment of neurological disorders in which DA D2 receptor represents a possible therapeutic target. Copyright © 2015 Elsevier Ltd. All rights reserved.

mTOR activation is required for the anti-alcohol effect of ketamine, but not memantine, in alcohol-preferring rats

PubMed Central

Sabino, Valentina; Narayan, Aditi R.; Zeric, Tamara; Steardo, Luca; Cottone, Pietro

2013-01-01

Glutamate NMDA receptors mediate many molecular and behavioral effects of alcohol, and they play a key role in the development of excessive drinking. Uncompetitive NMDA receptor antagonists may, therefore, have therapeutic potential for alcoholism. The first aim was to compare the effects of the NMDA antagonists memantine and ketamine on ethanol and saccharin drinking in alcohol-preferring rats. The second aim was to determine whether the effects of the two NMDA receptor antagonists were mediated by the mammalian target of rapamycin (mTOR). TSRI Sardinian alcohol-preferring rats were allowed to self-administer either 10% w/v ethanol or 0.08% w/v saccharin, and water. Operant responding and motor activity were assessed following administration of either memantine (0–10 mg/kg) or ketamine (0–20 mg/kg). Finally, ethanol self-administration was assessed in rats administered with either memantine or ketamine but pretreated with the mTOR inhibitor rapamycin (2.5 mg/kg). The uncompetitive NMDA receptor antagonists memantine and ketamine dose-dependently reduced ethanol drinking in alcohol-preferring rats; while memantine had a preferential effect on alcohol over saccharin, ketamine reduced responding for both solutions. Neither antagonist induced malaise, as shown by the lack of effect on water intake and motor activity. The mTOR inhibitor rapamycin blocked the effects of ketamine, but not those of memantine. Memantine and ketamine both reduce alcohol drinking in alcohol-preferring rats, but only memantine is selective for alcohol. The effects of ketamine, but not memantine, are mediated by mTOR. The results support the therapeutic potential of uncompetitive NMDA receptor antagonists, especially memantine, in alcohol addiction. PMID:23466691

Memantine in frontotemporal lobar degeneration: A multicenter, randomised, double-blind, placebo-controlled trial

PubMed Central

Boxer, Adam L.; Knopman, David S.; Kaufer, Daniel I.; Grossman, Murray; Onyike, Chiadi; Graf-Radford, Neill; Mendez, Mario; Kerwin, Diana; Lerner, Alan; Wu, Chuang-Kuo; Koestler, Mary; Shapira, Jill; Sullivan, Kathryn; Klepac, Kristen; Lipowski, Kristine; Ullah, Jerin; Fields, Scott; Kramer, Joel H.; Merrilees, Jennifer; Neuhaus, John; Mesulam, M. Marsel; Miller, Bruce L.

2013-01-01

Background Memantine has been used off-label to treat frontotemporal lobar degeneration (FTD). A previous 26 week open label study suggested a transient, modest benefit on neuropsychiatric symptoms as measured by the Neuropsychiatric Inventory (NPI). Methods We performed a randomized, parallel group, double blind, placebo controlled trial of 20 mg memantine taken orally daily for 26 weeks in FTD. Participants met Neary criteria for behavioral variant (bvFTD) or semantic dementia (SD) and had characteristic brain atrophy. Use of cholinesterase inhibitors was prohibited. The objective of the study was to determine whether memantine is an effective treatment for FTD. Individuals were randomized to memantine or matched placebo tablets in blocks of two and four. Primary endpoints were the change in total NPI score and Clinical Global Impression of Change (CGIC) scores after 26 weeks. Secondary outcomes included a neuropsychological battery, and other cognitive, global and activity of daily living measures. Clinicaltrials.gov identifier: NCT00545974 Findings 100 subjects were screened, 81 were randomized, 5 (6%) discontinued and 76 completed all visits. Enrollment numbers were lower than planned due to many subjects’ preference to take memantine or cholinesterase inhibitors off-label rather than participate in a clinical trial. 39 memantine and 42 placebo subjects entered the primary intent to treat analysis. There was no effect of memantine treatment on either the NPI (mean difference [MD] 2.2, 95%CI: −3.9, 8.3, p = 0.47) or CGIC (MD 0, 95%CI: −0.4, 0.4, p = 0.90) after 26 weeks of treatment. Memantine was generally well tolerated, however there were more frequent cognitive adverse events in the memantine group. Interpretation There was no benefit of memantine treatment in bvFTD or SD. These data do not support memantine use in FTD. Funding Forest Research Institute PMID:23290598

Memantine induces manic episode in a 73-year-old patient with vascular neurocognitive disorder: a case report.

PubMed

Duan, Jinfeng; Lao, Chengming; Chen, Jingkai; Pan, Fen; Zhang, Chenlin; Xu, Weijuan; Zhou, Weihua; Hu, Jianbo; Shang, Desheng; Huang, Manli; Xu, Yi

2018-01-01

Memantine, an N -methyl-d-aspartate receptor antagonist, is a well-established treatment option for moderate-to-severe cognitive impairment related to Alzheimer disease. Recently, growing evidence has indicated memantine might also be effective in treatment of affective disorders. The common drug-induced adverse events of memantine include confusion, dizziness, drowsiness, headache, insomnia, and agitation. Herein, we presented a case of a 73-year-old female patient with vascular neurocognitive disorder, who developed a manic episode after taking memantine.

Memantine induces manic episode in a 73-year-old patient with vascular neurocognitive disorder: a case report

PubMed Central

Duan, Jinfeng; Lao, Chengming; Chen, Jingkai; Pan, Fen; Zhang, Chenlin; Xu, Weijuan; Zhou, Weihua; Hu, Jianbo; Shang, Desheng; Huang, Manli; Xu, Yi

2018-01-01

Memantine, an N-methyl-d-aspartate receptor antagonist, is a well-established treatment option for moderate-to-severe cognitive impairment related to Alzheimer disease. Recently, growing evidence has indicated memantine might also be effective in treatment of affective disorders. The common drug-induced adverse events of memantine include confusion, dizziness, drowsiness, headache, insomnia, and agitation. Herein, we presented a case of a 73-year-old female patient with vascular neurocognitive disorder, who developed a manic episode after taking memantine. PMID:29881276

Recent insights into the mode of action of memantine and ketamine

PubMed Central

Johnson, Jon W.; Glasgow, Nathan G.; Povysheva, Nadezhda V.

2014-01-01

The clinical benefits of the glutamate receptor antagonists memantine and ketamine have helped sustain optimism that glutamate receptors represent viable targets for development of therapeutic drugs. Both memantine and ketamine antagonize N-methyl-d-aspartate receptors (NMDARs), a glutamate receptor subfamily, by blocking the receptor-associated ion channel. Although many of the basic characteristics of NMDAR inhibition by memantine and ketamine appear similar, their effects on humans and to a lesser extent on rodents are strongly divergent. Some recent research suggests that preferential inhibition by memantine and ketamine of distinct NMDAR subpopulations may contribute to the drugs' differential clinical effects. Here we review studies that shed light on possible explanations for differences between the effects of memantine and ketamine. PMID:25462293

Memantine extended release (28 mg once daily): a review of its use in Alzheimer's disease.

PubMed

Plosker, Greg L

2015-05-01

Memantine is an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist that is a well-established treatment option for moderate to severe dementia of the Alzheimer's type, either alone or in combination with cholinesterase inhibitors. The immediate-release (IR) formulations of memantine (tablets and oral solution) have been available in numerous countries, including the USA, for more than a decade and are administered orally twice daily at a maximum recommended total daily dosage of 20 mg/day. The memantine extended-release (ER) (Namenda XR(®)) 28 mg once-daily capsule formulation was approved in the USA in 2010 and became available more recently. The potential advantages of memantine ER over the IR formulation include a more convenient dosage regimen and lower pill burden that may improve adherence to therapy; also, memantine ER capsules may be opened and the contents sprinkled on applesauce for patients who have difficulty swallowing. Memantine ER provides a higher total daily dosage than the recommended memantine IR regimen and pharmacokinetic data indicate greater exposure with the ER formulation, but the clinical implications of this are unclear, as the two formulations have not been assessed in a comparative clinical trial. The efficacy of memantine ER 28 mg once daily was demonstrated in a large, multinational, phase III trial, which showed that the addition of memantine ER to ongoing oral cholinesterase inhibitors improved key outcomes compared with cholinesterase inhibitor monotherapy, including measures of cognition and global status, which were the co-primary endpoints of the study. The most common adverse events were headache, diarrhoea and dizziness.

Mechanisms underlying differential effectiveness of memantine and ketamine in rapid antidepressant responses

PubMed Central

Gideons, Erinn S.; Kavalali, Ege T.; Monteggia, Lisa M.

2014-01-01

Ketamine is an NMDA receptor (NMDAR) antagonist that elicits rapid antidepressant responses in patients with treatment-resistant depression. However, ketamine can also produce psychotomimetic effects that limit its utility as an antidepressant, raising the question of whether the clinically tolerated NMDAR antagonist memantine possesses antidepressant properties. Despite its similar potency to ketamine as an NMDAR antagonist, clinical data suggest that memantine does not exert rapid antidepressant actions for reasons that are poorly understood. In this study, we recapitulate the ketamine and memantine clinical findings in mice, showing that ketamine, but not memantine, has antidepressant-like effects in behavioral models. Using electrophysiology in cultured hippocampal neurons, we show that ketamine and memantine effectively block NMDAR-mediated miniature excitatory postsynaptic currents in the absence of Mg2+. However, in physiological levels of extracellular Mg2+, we identified key functional differences between ketamine and memantine in their ability to block NMDAR function at rest. This differential effect of ketamine and memantine extends to intracellular signaling coupled to NMDAR at rest, in that memantine does not inhibit the phosphorylation of eukaryotic elongation factor 2 or augment subsequent expression of BDNF, which are critical determinants of ketamine-mediated antidepressant efficacy. These results demonstrate significant differences between the efficacies of ketamine and memantine on NMDAR-mediated neurotransmission that have impacts on downstream intracellular signaling, which we hypothesize is the trigger for rapid antidepressant responses. These data provide a novel framework on the necessary functional requirements of NMDAR-mediated neurotransmission as a critical determinant necessary to elicit rapid antidepressant responses. PMID:24912158

A Meta-Analysis of Memantine for Depression.

PubMed

Kishi, Taro; Matsunaga, Shinji; Iwata, Nakao

2017-01-01

We conducted a systematic review and meta-analysis on whether memantine was beneficial for the treatment of depressive symptoms in major depressive disorder (MDD) and bipolar disorder (BD). The analysis included double-blind, randomized, placebo-controlled trials of memantine in MDD and BD. The primary outcome measures for efficacy and safety were response rate and all-cause discontinuation, respectively. Risk ratio (RR) and standardized mean difference with 95% confidence intervals (95% CI) were calculated. We identified six trials including 451 patients: MDD, four trials (n = 189), three of which studied memantine augmentation for antidepressants; BD, two trials (n = 262), both on memantine augmentation for mood stabilizers. The mean study duration was 8.33 weeks, and the mean age of patients was 39.9 years. Memantine was not superior to placebo with regard to response rate (RR = 0.92, 95% CI = 0.70-1.20, I2 = 72%), remission rate, improvement of depressive symptoms scale score, all-cause discontinuation (RR = 0.84, 95% CI = 0.60-1.18, I2 = 0%), discontinuation due to inefficacy and adverse events, or incidence of individual adverse events including decreased appetite, dizziness, nausea, and sedation. Although we conducted sensitivity analyses of the response rate to determine the reasons for the heterogeneity (diagnosis, age of patients, memantine dose, memantine augmentation, geographical region, and statistical population), we did not seek confounding factors. Memantine did not improve the treatment efficacy for depressive symptoms in MDD and BD patients. Long-term study of memantine for depression is required.

Clonidine intensifies memantine cutaneous analgesia in response to local skin noxious pinprick in the rat.

PubMed

Wu, Bor-Tsang; Chen, Kuan-Ting; Liu, Kuo-Sheng; Chen, Yu-Wen; Hung, Ching-Hsia; Wang, Jhi-Joung

2015-06-01

The purposes of this study were to evaluate the co-administration of clonidine with memantine and to determine whether it has a peripheral action in intensifying cutaneous analgesia. Cutaneous analgesia was examined through inhibition of the cutaneous trunci muscle reflex in response to the local noxious pinprick in rats. Effect of the added subcutaneous clonidine to memantine on infiltrative cutaneous analgesia was assessed and compared with the local anesthetic lidocaine. On the 50% effective dose (ED50) basis, the rank of drug potency was memantine [4.05 (3.95-4.18) μmol]>lidocaine [5.81 (5.70-5.98) μmol] (p<0.01). Clonidine at a dose of 0.12 μmol did not elicit cutaneous analgesia. Mixtures of clonidine (0.12 μmol) with drug (memantine or lidocaine) at ED50 or ED95 prolonged the duration of action and enhanced the potency as infiltrative cutaneous analgesia. Clonidine enhanced the lidocaine cutaneous analgesia in which had a better effect than added to memantine. Our resulting data showed that memantine displayed more potent cutaneous analgesia than lidocaine. Co-administration of memantine or lidocaine with clonidine increased the potency and duration of the cutaneous analgesia. Clonidine intensified the effects of lidocaine promoting cutaneous analgesia than added to memantine. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Memantine for Lewy body disorders: systematic review and meta-analysis.

PubMed

Matsunaga, Shinji; Kishi, Taro; Iwata, Nakao

2015-04-01

To clarify whether memantine is more efficacious in several outcomes and safer than placebo in patients with Lewy body disorders, we performed a meta-analysis of memantine in patients with Lewy body disorders. The meta-analysis included randomized controlled trials of memantine for Lewy body disorders in all patients with Lewy body disorders. Motor function, activities of daily living, Neuropsychiatric Inventory, Mini-Mental State Exam, discontinuation rate, and individual side effects were evaluated. No significant effects of memantine on motor function scores, Mini-Mental State Exam scores, Neuropsychiatric Inventory scores, and activity of daily living scores were found. However, memantine was superior to placebo in Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change scores (standardized mean difference: -0.26; 95% confidence interval: -0.51 to -0.02; z = 2.08; p = 0.04; two studies; N = 258). Dropout due to all causes, inefficacy, or adverse events were similar in both groups. Moreover, no significant differences in serious adverse events, somnolence/tiredness, stroke, dizziness/vertigo, and confusion were found between the groups. Our results suggest that memantine did not have a benefit for the treatment of Lewy body disorders in cognition and motor function. However, memantine may be superior to placebo for the overall impression of the disorders. Further, memantine is well tolerated. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Regulation of Human Brain Microvascular Endothelial Cell Adhesion and Barrier Functions by Memantine.

PubMed

Wang, Fei; Zou, Zhirong; Gong, Yi; Yuan, Dong; Chen, Xun; Sun, Tao

2017-05-01

Vascular risk factors have been linked to cognitive decline and dementia in the elderly. Microvascular inflammation, especially of the endothelium, may contribute to the progression of neurodegenerative events in Alzheimer's disease (AD). Memantine, an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, is a licensed drug used for the treatment of moderate to severe AD. However, little information is available regarding its anti-inflammatory effects on the endothelium. In this study, we investigated the effects of memantine on human brain microvascular endothelial dysfunction induced by the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Our results show that memantine prevents the attachment of monocyte THP-1 cells to human brain microvascular endothelial cells (HBMVEs). An in vitro BBB model experiment displayed that memantine could rescue TNF-α-induced disruption of the in vitro BBB model. In addition, memantine also interferes with monocyte transmigration across the BBB model. Our results indicate that TNF-α significantly increased the expression of cell adhesion molecules, such as ICAM-1, VCAM-1, and E-selectin, which was prevented by pretreatment with memantine. Mechanistically, memantine reversed activation of the transcription factor NF-κB by preventing the phosphorylation and degradation of its inhibitor IκBα. Our data is the first to describe a novel anti-inflammatory mechanism driven by the endothelial cell-mediated neuroprotective effects of memantine.

Effects of the NMDA antagonist memantine on human methamphetamine discrimination.

PubMed

Hart, Carl L; Haney, Margaret; Foltin, Richard W; Fischman, Marian W

2002-12-01

The discriminative stimulus effects of N-methyl- D-aspartate (NMDA) antagonists have been assessed in laboratory animals. To date, no published study has assessed their ability to alter methamphetamine-related discriminative stimulus effects in humans. This study investigated the discriminative stimulus, subjective (e.g. "Good Drug Effect"), psychomotor performance, and cardiovascular effects (e.g. blood pressure) of oral methamphetamine following acute oral memantine (a non-competitive NMDA antagonist) in humans. Initially, participants were trained to discriminate 10 mg methamphetamine from placebo using a standard two-response procedure (drug versus placebo). Then, the effects of memantine (0, 40 mg) on methamphetamine discrimination were examined across several methamphetamine doses (0, 5, 10, 20 mg) using a novel-response procedure (drug versus placebo versus novel). Following placebo pretreatment, 10 mg methamphetamine produced 99% methamphetamine-appropriate responding and placebo produced 75% placebo-appropriate responding. Following memantine pretreatment, participants responded as if they had been given a novel compound, although memantine did not significantly alter most subjective-effects ratings following methamphetamine. Memantine alone produced "positive" subjective effects and novel drug-appropriate responding. These data indicate that the memantine-methamphetamine combination produced novel discriminative stimulus effects and that memantine produced some stimulant-like subjective effects.

A placebo-controlled study of memantine (Ebixa) in dementia of Wernicke-Korsakoff syndrome.

PubMed

Rustembegović, Avdo; Kundurović, Zlata; Sapcanin, Aida; Sofic, Emin

2003-01-01

We evaluated the responses of 16 patients to preliminarily explore the spectrum of effectiveness and tolerability of the memantine, and NMDA antagonist, in the treatment of dementia in Wernicke-Korsakoff syndrome. In this study, for the first time in dementia of Wernicke-Korsakoff syndrome, the response to memantine was assessed. 16 patients with median age of 64 years and median body weight of 77 kg were treated with memantine 10 mg twice daily for up to 28 weeks. Clinical global impressions (CGI), and Mini Mental Status Examination (MMSE) were performed during the treatment period (after 2, 4, and 28 weeks). Efficacy measures also included the ADCS-Activities of Daily Living scale (ADCS-ADL). At 28 weeks, the ADCS-ADL showed significantly less deterioration in memantine treated patients compared with placebo (-2.3 compared with -4.3: p = 0.005). The results of MMSE demonstrate a significant and clinically relevant benefit for memantine relative to placebo as shown by positive outcomes in cognitive and functional assessments. Memantine (10 mg) was safe and well tolerated. The preliminarily findings of this study with 16 patients suggested that memantine is effective in the treatment of dementia in Wernicke-Korsakoff syndrome.

Effects of Memantine on Aminoglycoside-Induced Apoptosis of Spiral Ganglion Cells in Guinea Pigs.

PubMed

Kim, Bo Young; Bae, Woo Yong; Hur, Dae Young; Kim, Jae-Ryong; Koh, Tae Kyung; Lee, Tae Hoon; Park, Ga Bin

2016-07-01

To explore whether memantine, an N-methyl-D-aspartate receptor antagonist, exerts a neuroprotective effect against apoptosis of spiral ganglion cells (SGCs) induced by gentamicin. An animal experiment. Dong-A University College of Medicine, Busan, Korea. Gentamicin was injected into the left cochleae of guinea pigs to induce apoptosis of SGCs; the contralateral cochleae served as controls. Memantine was intraperitoneally injected 12 hours and 1 hour prior to gentamicin injection. At 1 week after gentamicin and/or memantine injection, the cochleae were removed and stained with hematoxylin and eosin to evaluate morphologic changes and apoptosis. Western blotting was performed to measure FasL expression and the extent of caspase activation in SGCs. SGC numbers remained stable after memantine treatment. Western blotting showed that FasL expression and activation of caspases 3, 8, and 9 were reduced in SGCs after memantine treatment. Memantine attenuated the gentamicin-induced apoptosis of SGCs in guinea pigs. Moreover, memantine may affect Fas-FasL signaling in the receptor-mediated apoptotic pathway and caspase activation involved in the receptor-mediated and mitochondrial apoptotic pathways. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Memantine effects on liver and adrenal gland of rats exposed to cold stress

PubMed Central

2011-01-01

Background Memantine attenuates heart stress due cold stress, however, no study focused its effects on liver and adrenal gland. We evaluated its effects on lipid depletion in adrenal gland and glycogen depletion in liver of rats exposed to cold stress. Methods Male rats divided into 4 groups: 1)Control (CON); 2)Memantine (MEM); 3)Induced cold stress (IH) and; 4)Induced cold stress memantine (IHF). Memantine were administrated by gavage (20 mg/kg/day) during eight days. Cold stress were performed during 4 hours once at - 8°C. Lipid and glycogen depletion were presented as its intensity levels. Results Rats exposed to cold stress presented the highest glycogen (p < 0.001) and lipid depletion (p < 0.001) in liver and adrenal gland, respectively. We noted that memantine significantly reduced lipid depletion in adrenal gland and glycogen depletion in liver. Conclusion Memantine prevented glycogen depletion in liver and lipid depletion in adrenal gland of rats under a cold stress condition. PMID:21255456

Memantine-induced chorea and dystonia.

PubMed

Borges, Letizia Goncalves; Bonakdarpour, Borna

2017-04-01

Memantine is an uncompetitive N -methyl-d-aspartate receptor antagonist and probably also has an indirect dopaminergic action at high concentrations. We describe a person with Alzheimer's disease who developed chorea and dystonia after inadvertently doubling of her daily dose by taking extended-release (XR) memantine twice daily, rather than once daily (planned dose memantine XR, 21 mg once daily), after the drug was switched from immediate release (IR, 10 mg twice daily). Memantine is rarely associated with movement disorders, but this case emphasises the need for awareness of potential problems when switching from memantine IR to XR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Memantine reverses social withdrawal induced by ketamine in rats.

PubMed

Uribe, Ezequiel; Landaeta, José; Wix, Richard; Eblen, Antonio

2013-03-01

The objective of this study was to determine the effect of memantine on schizophrenia-like symptoms in a ketamine-induced social withdrawal model in rats. We examined therapeutic effects of memantine, an NMDA antagonist, and haloperidol, a classic antipsychotic drug, on this behavioral model. Administration of memantine (10 or 15 mg·kg(-1)) significantly reduced ketamine-induced social withdrawal, and this effect was more effective than that of haloperidol (0.25 mg·kg(-1)) by restoring the social interaction between rats with no modification in general motor activity. These results suggest that memantine could have a therapeutic potential for schizophrenia.

Cognitive changes under memantine according to vitamin D status in Alzheimer patients: An exposed/unexposed cohort pilot study.

PubMed

Lemire, Pauline; Brangier, Antoine; Beaudenon, Melinda; Duval, Guillaume T; Annweiler, Cedric

2018-01-01

Memantine is a symptomatic treatment that partially prevents cognitive decline in Alzheimer disease (AD). The neuroprotective effects of memantine and vitamin D may potentiate each other, with benefits for cognition. The objective of this exposed/unexposed pilot study was to determine the cognitive changes among AD patients using memantine according to the presence or absence of vitamin D deficiency (VDD). Fifty-eight AD patients followed in a memory clinic during 6 months between 2009 and 2014 (mean±standard deviation, 82.9±5.0years; 56.9%female) were separated into four groups according to VDD (i.e., serum 25-hydroxyvitamin D≤25nM) at M0 and M6 (i.e., Group 1: no VDD-M0, no VDD-M6; Group 2: VDD-M0, no VDD-M6; Group 3: no VDD-M0, VDD-M6; Group 4: VDD-M0, VDD-M6). The 6-month cognitive change was examined with the Mini-Mental State Examination (MMSE) score in the 4 groups according to the use of memantine. Age, gender, body mass index, IADL score, GDS score, and use of pchychoactive drugs were measured at baseline. We found that participants using memantine had a lower MMSE score at M0 compared to those without memantine (P=0.006). After 6 months of follow-up, there was a memantine-related improvement of the MMSE score only in the participants with VDD-M6. This was significant in Group 3 with no VDD-M0 (P=0.039), but not in Group 4 who already had VDD-M0. Similarly, using memantine was associated with a 6-month improvement of MMSE only in Group 3 in whom VDD appeared during the follow-up (β=8.8, P=0.044). In conclusion, the use of memantine was associated with improved cognitive performance after 6 months of treatment in the presence of VDD at M6. Memantine may prevent the cognitive decline that accompanies the onset of VDD, which prompts to give to AD patients a regimen combining both memantine and vitamin D supplements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of concomitant use of memantine on mortality and efficacy outcomes of galantamine-treated patients with Alzheimer's disease: post-hoc analysis of a randomized placebo-controlled study.

PubMed

Hager, Klaus; Baseman, Alan S; Nye, Jeffrey S; Brashear, H Robert; Han, John; Sano, Mary; Davis, Bonnie; Richards, Henry M

2016-11-15

A large, prospective, 2-year, randomized study in patients with mild-to-moderate Alzheimer's disease or mixed dementia demonstrated reductions in mortality and cognitive/functional decline in galantamine-treated patients. A post-hoc analysis was conducted to study the effect of (the presence or absence of) concomitant memantine use on treatment outcome. Randomized patients (N = 2045) were divided into subgroups based on memantine use. Analyses included demographic and clinical characteristics (age, nursing home placement, Mini-Mental State Examination (MMSE) and Disability Assessment for Dementia (DAD) scores) and mortality endpoints. Overall, 496 (24.3 %) patients were memantine users and were older (mean (SD), 74.0 (8.76) vs 72.8 (8.76), p = 0.008), with lower MMSE scores (18.2 (4.16) vs 19.2 (4.02), p < 0.0001) and DAD scores (58.0 (23.49) vs 62.5 (20.52), p < 0.0001) than nonusers. Mortality rates (per 100 patient-years) in memantine nonusers (n = 1549) were lower for galantamine (1.39) vs placebo-treated patients (4.15). In memantine users, mortality rates were similar for placebo-treated (4.49) and galantamine-treated patients (5.57). In memantine nonusers at 24 months, the decline in MMSE scores (effect size (95 % CI) 0.25 (0.14; 0.36)) and DAD scores (0.17 (0.06; 0.28)) from baseline was lower in galantamine patients vs placebo patients. The absence of these benefits in memantine users could not be explained by baseline age, MMSE, or DAD scores. This post-hoc analysis shows that the beneficial effects of galantamine at 2 years post treatment were not observed in patients who had been placed on background memantine. The reasons for memantine treatment and the possibility of interaction between memantine and galantamine merit further investigation. ClinicalTrials.gov NCT00679627 . Registered 15 May 2008.

Antitussive Effects of Memantine in Guinea Pigs

PubMed Central

Smith, Jaclyn A.; Hilton, Emma C. Y.; Saulsberry, Loren

2012-01-01

Background: The treatment of cough is a significant clinical unmet need because there is little evidence that current therapies are effective. Based on evidence supporting a role for N-methyl d-aspartate receptors (NMDARs) in cough, we hypothesized that memantine, a low-affinity, uncompetitive NMDAR channel blocker in routine use for the treatment of Alzheimer disease, could be an effective, well-tolerated, antitussive therapy. The aim of this study was to establish preclinical evidence that memantine has antitussive effects. Methods: We studied the influence of memantine on experimentally induced coughing in response to citric acid and bradykinin inhalation in guinea pigs. We also compared the potency and efficacy of memantine as an antitussive to other NMDAR antagonists, dextromethorphan and ketamine, and to the γ-aminobutyric acid class B receptor agonist baclofen. Results: Compared with control subjects, 10 mg/kg memantine significantly reduced the cumulative number of coughs evoked by both citric acid (median, 24.0 [interquartile range (IQR), 13.0-25.5] vs 1.5 [IQR, 0.3-10.3] coughs; P = .012) and bradykinin aerosols (median, 16.0 [IQR, 9.5-18.5] vs 0.0 [IQR, 0-0.75] coughs; P = .002). Memantine 10 mg/kg produced a similar reduction in the cumulative number of coughs to baclofen 3 mg/kg and demonstrated comparatively greater cough suppression than 30 mg/kg dextromethorphan or 30 mg/kg ketamine. This dose of memantine produced no sedative or respiratory depressive effects. Conclusions: This study illustrates that memantine has marked antitussive effects in guinea pigs, most likely mediated through NMDAR channel blockade. Memantine, therefore, has the potential to be a safe, effective, and well-tolerated antitussive agent. PMID:22016492

EFFECTS OF LONG-TERM MEMANTINE ON MEMORY AND NEUROPATHOLOGY IN TS65DN MICE, A MODEL FOR DOWN SYNDROME

PubMed Central

Lockrow, Jason; Boger, Heather; Bimonte-Nelson, Heather; Granholm, Ann-Charlotte

2010-01-01

Memantine is a partial NMDA receptor antagonist that has been shown to improve learning and memory in several animal models, and is approved for the treatment of Alzheimer’s disease. Chronic treatments using memantine in animal models of Alzheimer’s disease show disease-modifying effects and suggest a potential neuroprotective function. The present study assessed the effects of both short- and long-term memantine treatment in a mouse model of Down syndrome, the Ts65Dn mouse. The Ts65Dn mouse contains a partial trisomy of murine chromosome 16, and exhibits hippocampal-dependent memory deficits, as well as progressive degeneration of basal forebrain cholinergic neurons. Ts65Dn mice were treated with memantine for a period of six months, beginning at four months of age. At the end of treatment the mice underwent memory testing using novel object recognition and water radial arm maze tasks, and then histologically analyzed for markers of neurodegeneration. Memantine treatment improved spatial and recognition memory performance in the Ts65Dn mice, though not to the level of normosomic littermate controls. Despite these memory improvements, histological analysis found no morphological signs of neuroprotection of basal forebrain cholinergic or locus coeruleus neurons in memantine-treated Ts65Dn mice. However, memantine treatment of Ts65Dn mice gave rise to elevated brain-derived neurotrophic factor expression in the hippocampus and frontal cortex, suggesting a mechanism of behavioral modification. Thus, our findings provide further evidence for memory facilitation of memantine, but suggest pharmacological rather than neuroprotective effects of memantine both after acute and chronic treatment in this mouse model. PMID:20363261

Memantine for the prevention of cognitive dysfunction in patients receiving whole-brain radiotherapy: a randomized, double-blind, placebo-controlled trial

PubMed Central

Brown, Paul D.; Pugh, Stephanie; Laack, Nadia N.; Wefel, Jeffrey S.; Khuntia, Deepak; Meyers, Christina; Choucair, Ali; Fox, Sherry; Suh, John H.; Roberge, David; Kavadi, Vivek; Bentzen, Soren M.; Mehta, Minesh P.; Watkins-Bruner, Deborah

2013-01-01

Background To determine the protective effects of memantine on cognitive function in patients receiving whole-brain radiotherapy (WBRT). Methods Adult patients with brain metastases received WBRT and were randomized to receive placebo or memantine (20 mg/d), within 3 days of initiating radiotherapy for 24 weeks. Serial standardized tests of cognitive function were performed. Results Of 554 patients who were accrued, 508 were eligible. Grade 3 or 4 toxicities and study compliance were similar in the 2 arms. There was less decline in delayed recall in the memantine arm at 24 weeks (P = .059), but the difference was not statistically significant, possibly because there were only 149 analyzable patients at 24 weeks, resulting in only 35% statistical power. The memantine arm had significantly longer time to cognitive decline (hazard ratio 0.78, 95% confidence interval 0.62–0.99, P = .01); the probability of cognitive function failure at 24 weeks was 53.8% in the memantine arm and 64.9% in the placebo arm. Superior results were seen in the memantine arm for executive function at 8 (P = .008) and 16 weeks (P = .0041) and for processing speed (P = .0137) and delayed recognition (P = .0149) at 24 weeks. Conclusions Memantine was well tolerated and had a toxicity profile very similar to placebo. Although there was less decline in the primary endpoint of delayed recall at 24 weeks, this lacked statistical significance possibly due to significant patient loss. Overall, patients treated with memantine had better cognitive function over time; specifically, memantine delayed time to cognitive decline and reduced the rate of decline in memory, executive function, and processing speed in patients receiving WBRT. RTOG 0614, ClinicalTrials.gov number CT00566852. PMID:23956241

Memantine for the prevention of cognitive dysfunction in patients receiving whole-brain radiotherapy: a randomized, double-blind, placebo-controlled trial.

PubMed

Brown, Paul D; Pugh, Stephanie; Laack, Nadia N; Wefel, Jeffrey S; Khuntia, Deepak; Meyers, Christina; Choucair, Ali; Fox, Sherry; Suh, John H; Roberge, David; Kavadi, Vivek; Bentzen, Soren M; Mehta, Minesh P; Watkins-Bruner, Deborah

2013-10-01

To determine the protective effects of memantine on cognitive function in patients receiving whole-brain radiotherapy (WBRT). Adult patients with brain metastases received WBRT and were randomized to receive placebo or memantine (20 mg/d), within 3 days of initiating radiotherapy for 24 weeks. Serial standardized tests of cognitive function were performed. Of 554 patients who were accrued, 508 were eligible. Grade 3 or 4 toxicities and study compliance were similar in the 2 arms. There was less decline in delayed recall in the memantine arm at 24 weeks (P = .059), but the difference was not statistically significant, possibly because there were only 149 analyzable patients at 24 weeks, resulting in only 35% statistical power. The memantine arm had significantly longer time to cognitive decline (hazard ratio 0.78, 95% confidence interval 0.62-0.99, P = .01); the probability of cognitive function failure at 24 weeks was 53.8% in the memantine arm and 64.9% in the placebo arm. Superior results were seen in the memantine arm for executive function at 8 (P = .008) and 16 weeks (P = .0041) and for processing speed (P = .0137) and delayed recognition (P = .0149) at 24 weeks. Memantine was well tolerated and had a toxicity profile very similar to placebo. Although there was less decline in the primary endpoint of delayed recall at 24 weeks, this lacked statistical significance possibly due to significant patient loss. Overall, patients treated with memantine had better cognitive function over time; specifically, memantine delayed time to cognitive decline and reduced the rate of decline in memory, executive function, and processing speed in patients receiving WBRT. RTOG 0614, ClinicalTrials.gov number CT00566852.

Memantine improves memory impairment and depressive-like behavior induced by amphetamine withdrawal in rats.

PubMed

Marszalek-Grabska, M; Gibula-Bruzda, E; Jenda, M; Gawel, K; Kotlinska, J H

2016-07-01

Amphetamine (AMPH) induces deficits in cognition, and depressive-like behavior following withdrawal. The aim of the present study was to investigate whether pre-treatment with memantine (5mg/kg, i.p.), a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, attenuates memory impairment induced by withdrawal from a 1 day binge regimen of AMPH (2mg/kg, four times every 2h, i.p.), in the novel object recognition test in rats. Herein, the influence of scopolamine (0.1mg/kg), an antagonist of the muscarinic cholinergic receptors, and the impact of MK-801 (0.1mg/kg), an antagonist of the NMDA receptors, on the memantine effect, were ascertained. Furthermore, the impact of memantine (5; 10; 20mg/kg, i.p.) was measured on depression-like effects of abstinence, 14 days after the last AMPH treatment (2mg/kg×1×14 days), in the forced swim test. In this test, the efficacy of memantine was compared to that of tricyclic antidepressant imipramine (10; 20; 30mg/kg, i.p.). Our study indicated that withdrawal from a binge regimen of AMPH impaired recognition memory. This effect was attenuated by administration of memantine at both 72h and 7 days of withdrawal. Moreover, prior administration of scopolamine, but not MK-801, decreased the memantine-induced recognition memory improvement. In addition, memantine reversed the AMPH-induced depressive-like behavior in the forced swim test in rats. The antidepressant-like effects of memantine were stronger than those of imipramine. Our study indicates that memantine constitutes a useful approach towards preventing cognitive deficits induced by withdrawal from an AMPH binge regimen and by depressive-like behavior during AMPH abstinence. Copyright © 2016 Elsevier B.V. All rights reserved.

A Stability-Indicating HPLC Method for the Determination of Memantine Hydrochloride in Dosage Forms through Derivatization with 1-Fluoro-2,4-dinitrobenzene

PubMed Central

Jalalizadeh, Hassan; Raei, Mahdi; Tafti, Razieh Fallah; Farsam, Hassan; Kebriaeezadeh, Abbas; Souri, Effat

2014-01-01

Memantine is chemically a tricyclic amine and is used for Parkinson’s disease and movement disorders. Although several HPLC methods with different derivatization reagents have been developed for the determination of memantine in biological fluids, there are some complications which limit the use of these methods in routine analysis of memantine in in vitro tests. We established a simple, sensitive, precise, and accurate HPLC method for the quantification of memantine in dosage forms. Pre-column derivatization of memantine was performed with 1-fluoro-2,4-dinitrobenzene and the reaction product was separated on a Nova-Pak C18 column. A mixture of acetonitrile and sodium dihydrogenphosphate (pH 2.5; 0.05 M) (70: 30, v/v) was used as the mobile phase. UV detection was performed at 360 nm. Forced degradation studies were performed on a powdered tablet sample of memantine hydro-chloride using acidic (0.1 M hydrochloric acid), basic (0.1 M sodium hydroxide), oxidative (10% hydrogen peroxide), thermal (105°C), photolytic, and humidity conditions. Good linearity (r2=0.999) was obtained over the range of 1–12 μg mL−1 of memantine hydrochloride with acceptable within-day and between-day precision values in the range of 0.05–0.95%. The proposed method was used for the assay determination and dissolution rate study of memantine dosage forms with excellent specificity. PMID:24959398

Memantine mediates neuroprotection via regulating neurovascular unit in a mouse model of focal cerebral ischemia.

PubMed

Chen, Zheng-Zhen; Yang, Dan-Dan; Zhao, Zhan; Yan, Hui; Ji, Juan; Sun, Xiu-Lan

2016-04-01

Memantine is a low-moderate affinity and uncompetitive N-methyl-d-aspartate receptor (NMDAR) antagonist, which is also a potential neuroprotectant in acute ischemic stroke for its particular action profiles. The present study was to reveal the mechanisms involved in the neuroprotection of memantine. We used a mouse model of permanent focal cerebral ischemia via middle cerebral artery occlusion to verify our hypothesis. 2,3,5-Triphenyltetrazolium chloride staining was used to compare infarct size. The amount of astrocytes and the somal volume of the microglia cell body were analyzed by immunohistochemistry and stereological estimates. Western blotting was used to determine the protein expressions. Memantine prevented cerebral ischemia-induced brain infarct and neuronal injury, and reduced oxygen-glucose deprivation-induced cortical neuronal apoptosis. Moreover, memantine reduced the amount of the damaged astrocytes and over activated microglia after 24h of ischemia. In the early phase of ischemia, higher production of MMP-9 was observed, and thereby collagen IV was dramatically disrupted. Meanwhile, the post-synaptic density protein 95(PSD-95) was also severely cleavaged. Memantine decreased MMP-9 secretion, prevented the degradation of collagen IV in mouse brain. PSD-95 cleavage was also inhibited by memantine. These results suggested that memantine exerted neuroprotection effects in acute ischemic brain damage, partially via improving the functions of neurovascular unit. Taking all these findings together, we consider that memantine might be a promising protective agent against ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

[Memantine: from the original brand to generics].

PubMed

Titova, N V

Memantine is the first clinically available glutamate antagonist, with an antagonist action at the N-methyl-D-aspartate receptors in the brain, for correction of cognitive and behavioral functions in neurodegenerative disorders. Glutamate mediated excitotoxic neuronal damage has been implicated in Alzheimer's disease (AD) and other parkinsonism-related dementias and, therefore, memantine represents a novel mode of action to counteract the glutamate-mediated excitotoxicity. In moderate to severe AD, 20 mg of memantine shows a positive effect on cognition, mood, behavior and the ability to perform activities of daily living. Long-term studies show good tolerability of memantine with an acceptable side-effect profile. In recent years, there have been a proliferation of a number of companies producing generic memantine with different trade names. In Russia, the first memantine generic drug noojerone was approved in 2010 and its use has since been supported by a growing evidence base of efficacy in real-life clinical practice. Postmarketing studies show that noojerone provides long-term and effective therapy in patients with moderate and severe Alzheimer's dementia. This observation is supported by the clinically significant therapeutic effect of noojerone on cognitive and daily functioning, behavioral and psychotic symptoms of dementia and a reduction of the burden on caregivers. This generic version of memantine is affordable and, therefore, reduces financial burden on patients and improves compliance with treatment.

Pharmacokinetics of Memantine after a Single and Multiple Dose of Oral and Patch Administration in Rats.

PubMed

Lee, Soo-Han; Kim, Seung-Hyun; Noh, Yook-Hwan; Choi, Byung-Moon; Noh, Gyu-Jeong; Park, Woo-Dae; Kim, Eun-Jung; Cho, Ik-Hyun; Bae, Chun-Sik

2016-02-01

Memantine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist used to treat Alzheimer's disease. We investigated memantine pharmacokinetics after oral, IV and patch administration in rats, and compared memantine pharmacokinetics after multiple- or single-dose oral and transdermal administration. Venous blood was collected at preset intervals in single- and multiple-dose studies. Non-compartmental pharmacokinetics was analysed for all formulations. The oral, IV and patch memantine doses were 10 mg/kg, 2 mg/kg and 8.21 ± 0.89 mg/kg, respectively. The maximum plasma concentration was lower and the half-life longer after patch administration than oral and IV administration. Memantine bioavailability was 41 and 63% for oral and patch administration, respectively. Steady state was achieved around 24 hr for oral and patch administration. The mean AUC increased after oral or patch administration from single to multiple dose. The memantine patch formulation displayed a longer duration of action and lower peak plasma concentration. However, drug exposure was similar to the oral formulation at each dose. Additionally, the memantine patch formulation displayed a smaller interindividual variability and lower accumulation than the oral formulation. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Memantine Inhibits α3β2-nAChRs-Mediated Nitrergic Neurogenic Vasodilation in Porcine Basilar Arteries

PubMed Central

Wu, Celeste Yin-Chieh; Chen, Po-Yi; Chen, Mei-Fang; Kuo, Jon-Son; Lee, Tony Jer-Fu

2012-01-01

Memantine, an NMDA receptor antagonist used for treatment of Alzheimer’s disease (AD), is known to block the nicotinic acetylcholine receptors (nAChRs) in the central nervous system (CNS). In the present study, we examined by wire myography if memantine inhibited α3β2-nAChRs located on cerebral perivascular sympathetic nerve terminals originating in the superior cervical ganglion (SCG), thus, leading to inhibition of nicotine-induced nitrergic neurogenic dilation of isolated porcine basilar arteries. Memantine concentration-dependently blocked nicotine-induced neurogenic dilation of endothelium-denuded basilar arteries without affecting that induced by transmural nerve stimulation, sodium nitroprusside, or isoproterenol. Furthermore, memantine significantly inhibited nicotine-elicited inward currents in Xenopous oocytes expressing α3β2-, α7- or α4β2-nAChR, and nicotine-induced calcium influx in cultured rat SCG neurons. These results suggest that memantine is a non-specific antagonist for nAChR. By directly inhibiting α3β2-nAChRs located on the sympathetic nerve terminals, memantine blocks nicotine-induced neurogenic vasodilation of the porcine basilar arteries. This effect of memantine is expected to reduce the blood supply to the brain stem and possibly other brain regions, thus, decreasing its clinical efficacy in the treatment of Alzheimer’s disease. PMID:22792283

Targeting different pathophysiological events after traumatic brain injury in mice: Role of melatonin and memantine.

PubMed

Kelestemur, Taha; Yulug, Burak; Caglayan, Ahmet Burak; Beker, Mustafa Caglar; Kilic, Ulkan; Caglayan, Berrak; Yalcin, Esra; Gundogdu, Reyhan Zeynep; Kilic, Ertugrul

2016-01-26

The tissue damage that emerges during traumatic brain injury (TBI) is a consequence of a variety of pathophysiological events, including free radical generation and over-activation of N-methyl-d-aspartate-type glutamate receptors (NMDAR). Considering the complex pathophysiology of TBI, we hypothesized that combination of neuroprotective compounds, targeting different events which appear during injury, may be a more promising approach for patients. In this context, both NMDAR antagonist memantine and free radical scavenger melatonin are safe in humans and promising agents for the treatment of TBI. Herein, we examined the effects of melatonin administered alone or in combination with memantine on the activation of signaling pathways, injury development and DNA fragmentation. Both compounds reduced brain injury moderately and the density of DNA fragmentation significantly. Notably, melatonin/memantine combination decreased brain injury and DNA fragmentation significantly, which was associated with reduced p38 and ERK-1/2 phosphorylation. As compared with melatonin and memantine groups, SAPK/JNK-1/2 phosphorylation was also reduced in melatonin/memantine combined animals. In addition, melatonin, memantine and their combination decreased iNOS activity significantly. Here, we provide evidence that melatonin/memantine combination protects brain from traumatic injury, which was associated with decreased DNA fragmentation, p38 phosphorylation and iNOS activity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The dichotomy of memantine treatment for ischemic stroke: dose-dependent protective and detrimental effects

PubMed Central

Trotman, Melissa; Vermehren, Philipp; Gibson, Claire L; Fern, Robert

2015-01-01

Excitotoxicity is a major contributor to cell death during the acute phase of ischemic stroke but aggressive pharmacological targeting of excitotoxicity has failed clinically. Here we investigated whether pretreatment with low doses of memantine, within the range currently used and well tolerated for the treatment of Alzheimer's disease, produce a protective effect in stroke. A coculture preparation exposed to modeled ischemia showed cell death associated with rapid glutamate rises and cytotoxic Ca2+ influx. Cell death was significantly enhanced in the presence of high memantine concentrations. However, low memantine concentrations significantly protected neurons and glia via excitotoxic cascade interruption. Mice were systemically administered a range of memantine doses (0.02, 0.2, 2, 10, and 20 mg/kg/day) starting 24 hours before 60 minutes reversible focal cerebral ischemia and continuing for a 48-hour recovery period. Low dose (0.2 mg/kg/day) memantine treatment significantly reduced lesion volume (by 30% to 50%) and improved behavioral outcomes in stroke lesions that had been separated into either small/striatal or large/striatocortical infarcts. However, higher doses of memantine (20 mg/kg/day) significantly increased injury. These results show that clinically established low doses of memantine should be considered for patients ‘at risk' of stroke, while higher doses are contraindicated. PMID:25407270

The Effect of Memantine on Functional Recovery of the Sciatic Nerve Crush Injury in Rats.

PubMed

Ghayour, Mohammad-Bagher; Abdolmaleki, Arash; Behnam-Rassouli, Morteza

2017-01-01

Following severe peripheral nerve injury (PNI), regeneration is often insufficient and functional recovery is incomplete. In this regard, glutamate N-methyl-D-aspartate (NMDA) receptor antagonist such as Memantine have been shown to have neuroprotective effects. We evaluated the effects of Memantine against sciatic nerve crush injury in male Wistar Rats. Memantine or vehicle was given parenteraly to rats for 7 days postoperative. In Memantine treatment groups, a single dose of agent (5 and 10 mg/kg) was administered daily. The control group was given vehicle in the same manner. The rats were subjected to crush injury in the left sciatic nerve with non-serrated clamp for 30 seconds. Behavioural, electrophysiological and morphological alterations were evaluated during the experimental period. Results showed that Memantine has no significant effect on regeneration process rate and functional recovery quality. In the sciatic functional index (SFI) test no significant difference was observed between Memantine treatment groups (5 and 10 mg/ kg) at any week. Since the major neuroprotective effect of Memantine is due to its protective activity against NMDA receptormediated excitotoxicity, it seems that glutamate excitotoxicity is less important in motor impairment due to sciatic nerve crush injury. It is clear that more research is needed to confirm these findings.

Memantine Reverses Social Withdrawal Induced by Ketamine in Rats

PubMed Central

Landaeta, José; Wix, Richard; Eblen, Antonio

2013-01-01

The objective of this study was to determine the effect of memantine on schizophrenia-like symptoms in a ketamine-induced social withdrawal model in rats. We examined therapeutic effects of memantine, an NMDA antagonist, and haloperidol, a classic antipsychotic drug, on this behavioral model. Administration of memantine (10 or 15 mg·kg-1) significantly reduced ketamine-induced social withdrawal, and this effect was more effective than that of haloperidol (0.25 mg·kg-1) by restoring the social interaction between rats with no modification in general motor activity. These results suggest that memantine could have a therapeutic potential for schizophrenia. PMID:23585718

Nursing home placement in the Donepezil and Memantine in Moderate to Severe Alzheimer's Disease (DOMINO-AD) trial: secondary and post-hoc analyses.

PubMed

Howard, Robert; McShane, Rupert; Lindesay, James; Ritchie, Craig; Baldwin, Ashley; Barber, Robert; Burns, Alistair; Dening, Tom; Findlay, David; Holmes, Clive; Jones, Robert; Jones, Roy; McKeith, Ian; Macharouthu, Ajay; O'Brien, John; Sheehan, Bart; Juszczak, Edmund; Katona, Cornelius; Hills, Robert; Knapp, Martin; Ballard, Clive; Brown, Richard G; Banerjee, Sube; Adams, Jessica; Johnson, Tony; Bentham, Peter; Phillips, Patrick P J

2015-12-01

Findings from observational studies have suggested a delay in nursing home placement with dementia drug treatment, but findings from a previous randomised trial of patients with mild-to-moderate Alzheimer's disease showed no effect. We investigated the effects of continuation or discontinuation of donepezil and starting of memantine on subsequent nursing home placement in patients with moderate-to-severe Alzheimer's disease. In the randomised, double-blind, placebo-controlled Donepezil and Memantine in Moderate to Severe Alzheimer's Disease (DOMINO-AD) trial, community-living patients with moderate-to-severe Alzheimer's disease (who had been prescribed donepezil continuously for at least 3 months at a dose of 10 mg for at least the previous 6 weeks and had a score of between 5 and 13 on the Standardised Mini-Mental State Examination) were recruited from 15 secondary care memory centres in England and Scotland and randomly allocated to continue donepezil 10 mg per day without memantine, discontinue donepezil without memantine, discontinue donepezil and start memantine 20 mg per day, or continue donepezil 10 mg per day and start memantine 20 mg per day, for 52 weeks. After 52 weeks, choice of treatment was left to participants and their physicians. Place of residence was recorded during the first 52 weeks of the trial and then every 26 weeks for a further 3 years. A secondary outcome of the trial, reported in this study, was nursing home placement: an irreversible move from independent accommodation to a residential caring facility. Analyses restricted to risk of placement in the first year of follow-up after the patients had completed the double-blind phase of the trial were post-hoc. The DOMINO-AD trial is registered with the ISRCTN Registry, number ISRCTN49545035. Between Feb 11, 2008, and March 5, 2010, 73 (25%) patients were randomly assigned to continue donepezil without memantine, 73 (25%) to discontinue donepezil without memantine, 76 (26%) to discontinue donepezil and start memantine, and 73 (25%) to continue donepezil and start memantine. 162 (55%) patients underwent nursing home placement within 4 years of randomisation, with similar numbers for all groups (36 [49%] in patients who continued donepezil without memantine, 42 [58%] who discontinued donepezil without memantine, 41 [54%] who discontinued donepezil and started memantine, and 43 [59%] who continued donepezil and started memantine). We noted significant (p=0·010) heterogeneity of treatment effect over time, with significantly more nursing home placements in the combined donepezil discontinuation groups during the first year (hazard ratio 2·09 [95% CI 1·29-3·39]) than in the combined donepezil continuation groups, and no difference during the next 3 years (0·89 [0·58-1·35]). We noted no effect of patients starting memantine compared with not starting memantine during the first year (0·92 [0·58-1·45]) or the next 3 years (1·23 [0·81-1·87]). Withdrawal of donepezil in patients with moderate-to-severe Alzheimer's disease increased the risk of nursing home placement during 12 months of treatment, but made no difference during the following 3 years of follow-up. Decisions to stop or continue donepezil treatment should be informed by potential risks of withdrawal, even if the perceived benefits of continued treatment are not clear. Medical Research Council and UK Alzheimer's Society. Copyright © 2015 Elsevier Ltd. All rights reserved.

Morinda citrifolia L. (noni) and memantine attenuate periventricular tissue injury of the fourth ventricle in hydrocephalic rabbits☆

PubMed Central

Köktürk, Sibel; Ceylan, Süreyya; Etus, Volkan; Yasa, Nezih; Ceylan, Savaş

2013-01-01

This study was designed to evaluate the neuroprotective effects of Morinda citrifolia L. (Rubiaceae), commonly known as noni, and memantine (a N-methy-D-aspartate receptor inhibitor) on hydrocephalus-induced neurodegenerative disorders. Kaolin was injected into the cistern magna of male adult New Zealand rabbits to establish a hydrocephalus animal model. Memantine (20 mg/kg, intraperitoneally; memantine-treated group) or noni (5 mL/kg, intragastrically; noni-treated group) was administered daily for 2 weeks. Microtubule-associated protein-2 and caspase-3 immunohistochemistry were performed to detect neuronal degeneration and apoptosis in the periventricular tissue of the fourth ventricle of rabbits. Microtubule-associated protein-2 staining density was significantly decreased in the hydrocephalic group, while the staining density was significantly increased in the memantine- and noni-treated groups, especially in the noni-treated group. Noni treatment decreased the number of caspase-3-positive cells in rabbits with hydrocephalus, while memantine had no effect. These findings suggest that noni exhibits more obvious inhibitory effects on hydrocephalus-induced neurodegenerative disorders than memantine in periventricular tissue of the fourth ventricle. PMID:25206724

Morinda citrifolia L. (noni) and memantine attenuate periventricular tissue injury of the fourth ventricle in hydrocephalic rabbits.

PubMed

Köktürk, Sibel; Ceylan, Süreyya; Etus, Volkan; Yasa, Nezih; Ceylan, Savaş

2013-03-25

This study was designed to evaluate the neuroprotective effects of Morinda citrifolia L. (Rubiaceae), commonly known as noni, and memantine (a N-methy-D-aspartate receptor inhibitor) on hydrocephalus-induced neurodegenerative disorders. Kaolin was injected into the cistern magna of male adult New Zealand rabbits to establish a hydrocephalus animal model. Memantine (20 mg/kg, intraperitoneally; memantine-treated group) or noni (5 mL/kg, intragastrically; noni-treated group) was administered daily for 2 weeks. Microtubule-associated protein-2 and caspase-3 immunohistochemistry were performed to detect neuronal degeneration and apoptosis in the periventricular tissue of the fourth ventricle of rabbits. Microtubule-associated protein-2 staining density was significantly decreased in the hydrocephalic group, while the staining density was significantly increased in the memantine- and noni-treated groups, especially in the noni-treated group. Noni treatment decreased the number of caspase-3-positive cells in rabbits with hydrocephalus, while memantine had no effect. These findings suggest that noni exhibits more obvious inhibitory effects on hydrocephalus-induced neurodegenerative disorders than memantine in periventricular tissue of the fourth ventricle.

Bilateral brain reorganization with memantine and constraint-induced aphasia therapy in chronic post-stroke aphasia: An ERP study.

PubMed

Barbancho, Miguel A; Berthier, Marcelo L; Navas-Sánchez, Patricia; Dávila, Guadalupe; Green-Heredia, Cristina; García-Alberca, José M; Ruiz-Cruces, Rafael; López-González, Manuel V; Dawid-Milner, Marc S; Pulvermüller, Friedemann; Lara, J Pablo

2015-01-01

Changes in ERP (P100 and N400) and root mean square (RMS) were obtained during a silent reading task in 28 patients with chronic post-stroke aphasia in a randomized, double-blind, placebo-controlled trial of both memantine and constraint-induced aphasia therapy (CIAT). Participants received memantine/placebo alone (weeks 0-16), followed by drug treatment combined with CIAT (weeks 16-18), and then memantine/placebo alone (weeks 18-20). ERP/RMS values (week 16) decreased more in the memantine group than in the placebo group. During CIAT application (weeks 16-18), improvements in aphasia severity and ERP/RMS values were amplified by memantine and changes remained stable thereafter (weeks 18-20). Changes in ERP/RMS occurred in left and right hemispheres and correlated with gains in language performance. No changes in ERP/RMS were found in a healthy group in two separated evaluations. Our results show that aphasia recovery induced by both memantine alone and in combination with CIAT is indexed by bilateral cortical potentials. Copyright © 2015 Elsevier Inc. All rights reserved.

Memantine inhibits degradation of the articular cartilage extracellular matrix induced by advanced glycation end products (AGEs).

PubMed

Zhao, Jijun; Yu, Yinghao; Wu, Zhaofeng; Wang, Ling; Li, Wei

2017-07-01

The accumulation of inflammation and cartilage damage induced by advanced glycation end products (AGEs) are important hallmarks of osteoarthritis (OA). Memantine is a clinically licensed drug used for the treatment of moderate and severe Alzheimer's disease. To date, little information has been reported regarding the effects of memantine on cartilage destruction. In this study, we investigated the protective effects of memantine on AGE-induced degradation of collagen II and aggrecans in human SW1353 chondrocytes. Our results indicate that memantine ameliorated AGE-induced degradation of collagen II and aggrecan at the post-translational level in SW1353 cells, which were mediated by matrix metalloproteinase-13 (MMP-13) and A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), respectively. Mechanistically, memantine was found to attenuate the upregulation of the transcriptional factor interferon response factor-1 (IRF-1) induced by AGEs, as well as activation of the JAK2/STAT1 pathway. Our findings suggest that memantine may have a potential therapeutic effect in OA. Copyright © 2017. Published by Elsevier Masson SAS.

Memantine in the prevention or alleviation of electroconvulsive therapy induces cognitive disorders: A placebo controlled trial.

PubMed

Abbasinazari, Mohammad; Adib-Eshgh, Ladan; Rostami, Azin; Beyraghi, Narges; Dabir, Shideh; Jafari, Reyhaneh

2015-06-01

The purpose of this study was to evaluate the effect of memantine administration on the adverse cognitive effects of electroconvulsive therapy (ECT). Forty patients diagnosed with a major depressive disorder for which ECT was indicated as a treatment for their current episode were randomly allocated to either the memantine (5mg/day) group or the placebo group. All patients underwent the same protocol for anaesthesia and ECT procedures. The patients received memantine or the placebo for the whole period of ECT treatment, starting the day before ECT and continuing until the fourth session of ECT. The Modified Mental State Examination (MMSE) was used for the assessment of cognition before and after the trial. Regarding MMSE and item 3 MMSE (related to recent memory), the memantine group scored significantly higher at the end of ECT sessions than the control group (P=0.02, P<0.001, respectively). Our data support the hypothesis that memantine may reduce cognitive impairment following ECT. Memantine could be both a safe and well-tolerated treatment for use with ECT. Copyright © 2015 Elsevier B.V. All rights reserved.

Neuronal Degeneration in the Cingulated Gyrus: NMDC Antagonists and Anticholinesterases

DTIC Science & Technology

2002-10-01

exposure of these compounds to pyridostigmine bromide induce detectable neurotoxicity. 3) The NMDA receptor antagonist, memantine induces a neurotoxic...these drug combinations, suggesting this is a toxic combination. 4) The resultant neuropathology in MK-801 and memantine exposed animals is in good...agreement with the behavioral deficits exhibited by animals exposed to these compounds. 5) Combined exposure of memantine and PB had a greater effect on IPSPs than did memantine or PB alone.

Memantine plus vitamin D prevents axonal degeneration caused by lysed blood.

PubMed

Charier, David; Beauchet, Olivier; Bell, Morgane; Brugg, Bernard; Bartha, Robert; Annweiler, Cedric

2015-03-18

Intracranial hemorrhage, whether due to traumatic brain injury or ruptured cerebral aneurysm, is characterized by major neurological damage and a high mortality rate. Apart from cerebral vasospasm and mass effect, brain injury results from the release of unclotted blood that contacts neurons causing calcic stress. The combination of memantine with vitamin D, a neurosteroid hormone, may prevent blood neurotoxicity. Our purpose was to examine the potential protective effects of memantine + vitamin D against lysed or clotted blood in cortical neuronal cultures. We provide the first evidence that cortical axons in contact with lysed blood degenerate less after exposure to lysed blood in microfluidic neuronal cultures enriched with both memantine and vitamin D compared to control medium and cultures enriched with only memantine or only vitamin D. The reported synergistic neuroprotective effect of memantine + vitamin D, the combination originating an effect stronger than the sum, strongly encourages using both drugs following intracranial hemorrhage.

Memantine in the Treatment of Executive Function Deficits in Adults With ADHD.

PubMed

Biederman, Joseph; Fried, Ronna; Tarko, Laura; Surman, Craig; Spencer, Thomas; Pope, Amanda; Grossman, Rebecca; McDermott, Katie; Woodworth, K Yvonne; Faraone, Stephen V

2017-02-01

To evaluate the efficacy and safety of memantine hydrochloride as an adjunct to stimulant pharmacotherapy for treating executive function deficits (EFDs) in adults with ADHD. This was a 12-week, double-blind, placebo-controlled, randomized clinical trial of memantine added to open-label treatment with stimulant medication. Because of the small sample size, we considered a standardized mean difference (equivalent to effect size) of ≥0.5 and odds ratios ≥2 as indicators of trend improvements. Twelve participants received memantine and 14 received a placebo. Trend improvements favoring memantine were observed on Behavior Rating Inventory of Executive Functions-Adult Inhibition and Self-Monitor subscales when compared with Placebo. No significant changes were noted on the Cambridge Neuropsychological Test Automated Battery. Among adults with ADHD and EFDs, adjunct treatment with memantine to osmotic release oral system-methylphenidate (OROS-MPH) was associated with improvements in selective areas of executive functioning, supporting the need for further research.

Memantine Effects On Sensorimotor Gating and Mismatch Negativity in Patients with Chronic Psychosis.

PubMed

Swerdlow, Neal R; Bhakta, Savita; Chou, Hsun-Hua; Talledo, Jo A; Balvaneda, Bryan; Light, Gregory A

2016-01-01

Patients with chronic psychotic disorders (CPD) exhibit deficient sensorimotor gating (measured by prepulse inhibition (PPI) of startle) and mismatch negativity (MMN). In healthy subjects (HS), N-methyl-D-aspartate (NMDA) antagonists like memantine and ketamine increase PPI, and under some conditions, memantine enhances MMN; these findings present a challenge to understanding the basis for deficient PPI and MMN in psychotic disorders, as reduced NMDA activity is implicated in the pathogenesis of these disorders. Here we assessed for the first time the effects of memantine on PPI and MMN in CPD subjects. Baseline PPI was measured in HS and patients with a diagnosis of schizophrenia or schizoaffective disorder, depressed type. Subjects (total n=84) were then tested twice, in a double-blind crossover design, comparing either: (1) placebo vs 10 mg of memantine or (2) placebo vs 20 mg memantine. Tests included measures of acoustic startle magnitude and habituation, PPI, MMN, autonomic indices, and subjective self-rating scales. Memantine (20 mg) significantly enhanced PPI in CPD subjects, and enhanced MMN across subject groups. These effects on PPI were age dependent and most evident in older CPD patients, whereas those on MMN were most evident in younger subjects. The lower dose (10 mg) either had no detectable effect or tended to degrade these measures. The NMDA antagonist, memantine, has dose-dependent effects on preconscious, automatic measures of sensorimotor gating and auditory sensory processing that are associated with enhanced cognition and function in CPD patients. Ongoing studies will determine whether these memantine-induced changes predict acute pro-cognitive or otherwise clinically beneficial effects in CPD patients.

Effect of co-administration of memantine and sertraline on the antidepressant-like activity and brain-derived neurotrophic factor (BDNF) levels in the rat brain.

PubMed

Amidfar, Meysam; Réus, Gislaine Z; Quevedo, João; Kim, Yong-Ku; Arbabi, Mohammad

2017-01-01

A developing body of data has drawn attention to the N-methyl-d-aspartate (NMDA) receptor antagonists as potential drugs for the treatment of major depressive disorder (MDD). We investigated the possibility of synergistic interactions between the antidepressant sertraline with the uncompetitive NMDA receptor antagonist, memantine. The present study was aimed to evaluate behavioural and molecular effects of the chronic treatment with memantine and sertraline alone or in combination in rats. To this aim, rats were chronically treated with memantine (2.5 and 5mg/kg) and sertraline (5mg/kg) for 14days once a day, and then exposed to the forced swimming test. The brain-derived neurotrophic factor (BDNF) levels were assessed in the hippocampus and prefrontal cortex in all groups by ELISA sandwich assay. Sertraline and memantine (2.5mg/kg) alone did not have effect on the immobility time; however, the effect of sertraline was enhanced by both doses of memantine. Combined treatment with memantine and sertraline produced stronger increases in the BDNF protein levels in the hippocampus and prefrontal cortex. Our results indicate that co-administration of antidepressant memantine with sertraline may induce a more pronounced antidepressant activity than treatment with each antidepressant alone. Antidepressant properties using the combination of memantine and sertraline could be attributed to increased levels of BDNF. This finding may be of particular importance in the case of drug-resistant patients and could suggest a method of obtaining significant antidepressant actions whereas limiting side effects. Copyright © 2016 Elsevier Inc. All rights reserved.

Memantine and Ketamine Differentially Alter NMDA Receptor Desensitization

PubMed Central

Povysheva, Nadezhda V.; Azofeifa, Andrea M.

2017-01-01

Memantine and ketamine are clinically useful NMDA receptor (NMDAR) open channel blockers that inhibit NMDARs with similar potency and kinetics, but display vastly different clinical profiles. This discrepancy has been hypothesized to result from inhibition by memantine and ketamine of overlapping but distinct NMDAR subpopulations. For example, memantine but not ketamine may inhibit extrasynaptic NMDARs more effectively than synaptic NMDARs. However, the basis for preferential NMDAR inhibition depending on subcellular location has not been investigated systematically. We integrated recordings from heterologously expressed single NMDAR subtypes, kinetic modeling, and recordings of synaptically evoked NMDAR responses in acute brain slices to investigate mechanisms by which channel blockers may distinguish NMDAR subpopulations. We found that memantine and ketamine differentially alter NMDAR desensitization and that memantine stabilizes a Ca2+-dependent desensitized state. As a result, inhibition by memantine of GluN1/2A receptors in tsA201 cells and of native synaptic NMDARs in cortical pyramidal neurons from mice of either sex increased in conditions that enhanced intracellular Ca2+ accumulation. Therefore, differential inhibition by memantine and ketamine based on NMDAR location is likely to result from location dependence of the intensity and duration of NMDAR activation. Modulation of Ca2+-dependent NMDAR desensitization is an unexplored mechanism of inhibitory action with the potential to endow drugs with NMDAR selectivity that leads to superior clinical profiles. Our results suggest that designing compounds to target specific receptor states, rather than specific receptor types, may be a viable strategy for future drug development. SIGNIFICANCE STATEMENT Memantine and ketamine are NMDA receptor (NMDAR) channel-blocking drugs with divergent clinical effects. Understanding mechanistically their differential actions may advance our understanding of nervous system disorders and suggest strategies for the design of more effective drugs. Here, we show that memantine and ketamine have contrasting effects on NMDAR desensitization. Ketamine binding decreases occupancy of desensitized states of the GluN1/2B NMDAR subtype. In contrast, memantine binding increases occupancy of GluN1/2A and native NMDAR desensitized states entered after accumulation of intracellular Ca2+, a novel inhibitory mechanism. These properties may contribute to inhibition of distinct NMDAR subpopulations by memantine and ketamine and help to explain their differential clinical effects. Our results suggest stabilization of Ca2+-dependent desensitized states as a new strategy for pharmaceutical neuroprotection. PMID:28877967

Memantine and Ketamine Differentially Alter NMDA Receptor Desensitization.

PubMed

Glasgow, Nathan G; Povysheva, Nadezhda V; Azofeifa, Andrea M; Johnson, Jon W

2017-10-04

Memantine and ketamine are clinically useful NMDA receptor (NMDAR) open channel blockers that inhibit NMDARs with similar potency and kinetics, but display vastly different clinical profiles. This discrepancy has been hypothesized to result from inhibition by memantine and ketamine of overlapping but distinct NMDAR subpopulations. For example, memantine but not ketamine may inhibit extrasynaptic NMDARs more effectively than synaptic NMDARs. However, the basis for preferential NMDAR inhibition depending on subcellular location has not been investigated systematically. We integrated recordings from heterologously expressed single NMDAR subtypes, kinetic modeling, and recordings of synaptically evoked NMDAR responses in acute brain slices to investigate mechanisms by which channel blockers may distinguish NMDAR subpopulations. We found that memantine and ketamine differentially alter NMDAR desensitization and that memantine stabilizes a Ca 2+ -dependent desensitized state. As a result, inhibition by memantine of GluN1/2A receptors in tsA201 cells and of native synaptic NMDARs in cortical pyramidal neurons from mice of either sex increased in conditions that enhanced intracellular Ca 2+ accumulation. Therefore, differential inhibition by memantine and ketamine based on NMDAR location is likely to result from location dependence of the intensity and duration of NMDAR activation. Modulation of Ca 2+ -dependent NMDAR desensitization is an unexplored mechanism of inhibitory action with the potential to endow drugs with NMDAR selectivity that leads to superior clinical profiles. Our results suggest that designing compounds to target specific receptor states, rather than specific receptor types, may be a viable strategy for future drug development. SIGNIFICANCE STATEMENT Memantine and ketamine are NMDA receptor (NMDAR) channel-blocking drugs with divergent clinical effects. Understanding mechanistically their differential actions may advance our understanding of nervous system disorders and suggest strategies for the design of more effective drugs. Here, we show that memantine and ketamine have contrasting effects on NMDAR desensitization. Ketamine binding decreases occupancy of desensitized states of the GluN1/2B NMDAR subtype. In contrast, memantine binding increases occupancy of GluN1/2A and native NMDAR desensitized states entered after accumulation of intracellular Ca 2+ , a novel inhibitory mechanism. These properties may contribute to inhibition of distinct NMDAR subpopulations by memantine and ketamine and help to explain their differential clinical effects. Our results suggest stabilization of Ca 2+ -dependent desensitized states as a new strategy for pharmaceutical neuroprotection. Copyright © 2017 the authors 0270-6474/17/379686-19$15.00/0.

Pharmacological Treatment of Glutamate Excitotoxicity Following Traumatic Brain Injury

DTIC Science & Technology

2009-01-14

31.5%) associated with TBI. In a subsequent study, Rao, et al. (2001) found that treatment with the non-competitive NMDA blocker, memantine ...Dogan A, Todd KG, Bowen KK, Dempsey RJ. Neuroprotection by memantine , a non-competitive NMDA receptor antagonist after traumatic brain injury in...R, Stöffler A, Schmitt F, Ferris S, Möbius HJ; Memantine Study Group. Memantine in moderate-to-severe Alzheimer’s disease. N Engl J Med. 2003 Apr

Inhibitory Effect of NMDA Receptors in the Ventral Tegmental Area on Hormonal and Eating Behavior Responses to Stress in Rats

PubMed Central

Nasihatkon, Zohreh Sadat; Khosravi, Maryam; Bourbour, Zahra; Hassantash, Seyedeh Maryam; Sahraei, Mohammad; Baghlani, Kefayat

2014-01-01

Background. Stress and its consequences are among the causes of accidents. Objective. The effects of intraventral tegmental area (I-VTA) memantine on the plasma corticosterone and eating parameters disturbance induced by acute stress were investigated. Methods. Male Wistar rats (W: 250–300 g) were divided into control and experiential groups, each of which received memantine either intra-VTA or peripherally. One week after bilateral cannulation, the rats received memantine (1 and 5 μg/Rat) five min before electroshock stress. The other experimental groups received memantine (1 and 5 mg/kg) intraperitoneally 30 min before stress. The control groups received saline or memantine but did not experience stress. Food and water intake and plasma corticosterone level were recorded. Results. Results showed that stress decreases food intake but does not change water intake and increase in plasma corticosterone level. Intraperitoneal memantine administration slightly inhibits the stress effects on food intake. However, water intake and plasma corticosterone level were increased. Intra-VTA memantine reduces the effects of stress on corticosterone and water intake. Conclusion. It could be concluded that inhibition of glutamate NMDA receptors in the VTA by memantine leads to the inhibition of the eating behavior parameters and plasma corticosterone level disturbance induced by stress in rats. PMID:25177106

Memantine Improves Attentional Processes in Fragile X-Associated Tremor/Ataxia Syndrome: Electrophysiological Evidence from a Randomized Controlled Trial.

PubMed

Yang, Jin-Chen; Rodriguez, Annette; Royston, Ashley; Niu, Yu-Qiong; Avar, Merve; Brill, Ryan; Simon, Christa; Grigsby, Jim; Hagerman, Randi J; Olichney, John M

2016-02-22

Progressive cognitive deficits are common in patients with fragile X-associated tremor/ataxia syndrome (FXTAS), with no targeted treatment yet established. In this substudy of the first randomized controlled trial for FXTAS, we examined the effects of NMDA antagonist memantine on attention and working memory. Data were analyzed for patients (24 in each arm) who completed both the primary memantine trial and two EEG recordings (at baseline and follow-up) using an auditory "oddball" task. Results demonstrated significantly improved attention/working memory performance after one year only for the memantine group. The event-related potential P2 amplitude elicited by non-targets was significantly enhanced in the treated group, indicating memantine-associated improvement in attentional processes at the stimulus identification/discrimination level. P2 amplitude increase was positively correlated with improvement on the behavioral measure of attention/working memory during target detection. Analysis also revealed that memantine treatment normalized the P2 habituation effect at the follow-up visit. These findings indicate that memantine may benefit attentional processes that represent fundamental components of executive function/dysfunction, thought to comprise the core cognitive deficit in FXTAS. The results provide evidence of target engagement of memantine, as well as therapeutically relevant information that could further the development of specific cognitive or disease-modifying therapies for FXTAS.

Lithium and memantine improve spatial memory impairment and neuroinflammation induced by β-amyloid 1-42 oligomers in rats.

PubMed

Budni, J; Feijó, D P; Batista-Silva, H; Garcez, M L; Mina, F; Belletini-Santos, T; Krasilchik, L R; Luz, A P; Schiavo, G L; Quevedo, J

2017-05-01

Alzheimer's disease (AD) is the most common cause of dementia in the elderly. The main hallmarks of this disease include progressive cognitive dysfunction and an accumulation of soluble oligomers of β-amyloid (Aβ) 1-42 peptide. In this research, we show the effects of lithium and memantine on spatial memory and neuroinflammation in an Aβ1-42 oligomers-induced animal model of dementia in rats. Aβ 1-42 oligomers were administered intrahippocampally to male wistar rats to induce dementia. Oral treatments with memantine (5mg/kg), lithium (5mg/kg), or both drugs in combination were performed over a period of 17days. 14days after the administration of the Aβ1-42 oligomers, the radial arm-maze task was performed. At the end of the test period, the animals were euthanized, and the frontal cortex and hippocampus were removed for use in our analysis. Our results showed that alone treatments with lithium or memantine ameliorate the spatial memory damage caused by Aβ1-42. The animals that received combined doses of lithium and memantine showed better cognitive performance in their latency time and total errors to find food when compared to the results from alone treatments. Moreover, in our study, lithium and/or memantine were able to reverse the decreases observed in the levels of interleukin (IL)-4 that were induced by Aβ1-42 in the frontal cortex. In the hippocampus, only memantine and the association of memantine and lithium were able to reverse this effect. Alone doses of lithium and memantine or the association of lithium and memantine caused reductions in the levels of IL-1β in the frontal cortex and hippocampus, and decreased the levels of TNF-α in the hippocampus. Taken together, these data suggest that lithium and memantine might be a potential therapy against cognitive impairment and neuroinflammation induced by Aβ1-42, and their association may be a promising alternative to be investigated in the treatment of AD-like dementia. Copyright © 2017 Elsevier Inc. All rights reserved.

Population pharmacokinetic study of memantine: effects of clinical and genetic factors.

PubMed

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Wilhelm, Laurence; Michon, Agnès; Thomazic, Valérie; Alnawaqil, Abdel-Messieh; Maurer, Sophie; Zumbach, Serge; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2013-03-01

Memantine, a frequently prescribed anti-dementia drug, is mainly eliminated unchanged by the kidneys, partly via tubular secretion. Considerable inter-individual variability in plasma concentrations has been reported. We aimed to investigate clinical and genetic factors influencing memantine disposition. A population pharmacokinetic study was performed including data from 108 patients recruited in a naturalistic setting. Patients were genotyped for common polymorphisms in renal cation transporters (SLC22A1/2/5, SLC47A1, ABCB1) and nuclear receptors (NR1I2, NR1I3, RXR, PPAR) involved in transporter expression. The average clearance was 5.2 L/h with a 27 % inter-individual variability (percentage coefficient of variation). Glomerular filtration rate (p = 0.007) and sex (p = 0.001) markedly influenced memantine clearance. NR1I2 rs1523130 was identified as the unique significant genetic covariate for memantine clearance (p = 0.006), with carriers of the NR1I2 rs1523130 CT/TT genotypes presenting a 16 % slower memantine elimination than carriers of the CC genotype. The better understanding of inter-individual variability of memantine disposition might be beneficial in the context of individual dose optimization.

Differential regulation of GluA1 expression by ketamine and memantine.

PubMed

Zhang, Ke; Yamaki, Vitor Nagai; Wei, Zhisheng; Zheng, Yu; Cai, Xiang

2017-01-01

Evidence from preclinical and clinical studies shows that ketamine, a noncompetitive NMDA receptor antagonist, exerts rapid and sustained antidepressant responses. However, ketamine's psychotomimetic side effects and abuse liability limit the clinical use of the compound. Interestingly, memantine, another NMDA receptor channel blocker, processes no defined antidepressant property but is much safer and clinical tolerated. Understanding why ketamine but not memantine exhibits rapid antidepressant responses is important to elucidate the cellular signaling underlying the fast antidepressant actions of ketamine and to design a new safer generation of fast-acting antidepressants. Here we show that ketamine but memantine caused a rapid and sustained antidepressant-like responses in forced swim test (FST). Both drugs enhanced GluA1 S845 phosphorylation and potentiated Schaffer collateral-CA1 synaptic transmission. However, ketamine but not memantine elevated the expression of GluA1. Incubating acutely prepared hippocampal slices with ketamine but not memantine enhanced mTOR phosphorylation in a time course parallel to the time course of GluA1 elevation. Our results suggest that distinct properties in regulation of mTOR phosphorylation and synaptic protein expression may underlie the differential effectiveness of ketamine and memantine in their antidepressant responses. Copyright © 2016 Elsevier B.V. All rights reserved.

Memantine for dementia.

PubMed

Areosa, Sastre A; Sherriff, F

2003-01-01

Alzheimer's disease, vascular and mixed dementia are the three commonest forms of dementia affecting older people. There is evidence that the excitatory activity of L-glutamate plays a role in the pathogenesis of Alzheimer's disease and in the damage from an ischaemic stroke. A low affinity antagonist to N-Methyl-D-aspartate (NMDA) type receptors, such as memantine, may prevent excitatory amino acid neurotoxicity without interfering with the physiological actions of glutamate required for memory and learning. To determine the clinical efficacy and safety of memantine for people with Alzheimer's disease, or vascular or mixed dementia. Trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 15 April 2003 using the terms: memantin*, D-145, DMAA, DRG-0267. All major health care databases and trial databases within the scope of the group are searched regularly to keep this Register up to date. Double-blind, parallel group, placebo-controlled, randomized and unconfounded trials in which memantine was administered to people with dementia. Data were extracted, pooled where possible, and weighted mean differences, standardized mean differences or odds ratios were estimated. Intention-to-treat (ITT) and observed cases (OC) analyses are reported, where data were available. Effect of memantine in patients with moderate to severe Alzheimer's disease: analysis of the change from baseline at 28 weeks gave statistically significant results in favour of memantine for 20 mg/day on cognition (MD: 6.1. 95% CI 2.99 to 9.21, P=0.0001) activities of daily living (MD 2.10, 95% CI 0.46 to 3.74, p=0.01) and in the global clinical impression of change measured by the CIBIC-Plus at 28 weeks (MD -0.30, 95% CI -0.58 to -0.02, p=0.04), in all cases the analysis was the ITT-LOCF population (Reisberg 2000). There were no significant differences between memantine and placebo for the number of drop-outs and total number of adverse effects, but a significant difference in favour of memantine for the number who suffer agitation. Effect of memantine in patients with mild to moderate vascular dementia: analysis of the change from baseline at 28 weeks gave statistically significant results in favour of memantine ( 20 mg/day ) for cognition (MD -2.19, 95% CI -3.16 to -1.21, P<0.0001) but there was no benefit for the clinical impression of change, or for global measures of dementia (MMM300, and MMM500). There were no significant differences between memantine and placebo for the number of drop-outs and total number of adverse effects, but a significant difference in favour of memantine for the number who suffer agitation. Effect of memantine in patients with Alzheimer's disease and vascular dementia at 12 weeks: there was no statistically significant difference between memantine (10 mg/day) and placebo in activities of daily living. There was a benefit in favour of memantine (10 mg/day) compared with placebo at 12 weeks, for the numbers improved in terms of clinical impression of change (60/82 compared with 38/84 - OR 3.30, 95% CI 1.72 to 6.33, P=0.0003) (Winblad 1999). Effect of memantine in patients with vascular dementia, Alzheimer's disease and dementia of non-specified type at 6 weeks: there were beneficial effects on cognition (Ditzler 1991), activities of daily living (Ditzler 1991, Pantev 1993), behaviour (Pantev 1993) and global scales (Gortelmeyer 1992; Pantev 1993; Ditzler 1991) and in global impression of change (Gortelmeyer 1992; Ditzler 1991). There were no significant differences between memantine and placebo for the number of drop-outs and total number of adverse effects, but a significant difference in favour of placebo for the number who suffer restlessness. There is a beneficial effect of memantine (20 mg/day) for patients with moderate to severe Alzheimer disease on cognition and functional decline but not in the clinical impression of change. Patifor patients with moderate to severe Alzheimer disease on cognition and functional decline but not in the clinical impression of change. Patients with mild to moderate vascular dementia receiving memantine 20 mg/day had less cognitive deterioration at 28 weeks but again this effect was not clinically discernible. There is a possible beneficial effect on cognition, function and global scales for memantine at 6 weeks in mixed populations. The drug is well tolerated and the incidence of adverse effects is low. More studies are needed.

Effectiveness of memantine on depression-like behavior, memory deficits and brain mRNA levels of BDNF and TrkB in rats subjected to repeated unpredictable stress.

PubMed

Amidfar, Meysam; Kim, Yong-Ku; Wiborg, Ove

2018-06-01

Previous clinical and preclinical studies have indicated that the N-methyl-d-aspartate (NMDA) receptor antagonist, memantine, has neuroprotective properties as well as antidepressant effects. The present study was designed to examine behavioral and molecular effects of memantine administration in rats subjected to the repeated unpredictable stress (RUS) paradigm. Rats were split into four groups at random including control+saline, control+memantine, stressed+saline and stressed+memantine. After 10days of exposure to the RUS paradigm, rats were administered memantine (20mg/kg) intraperitoneally (ip) for 14days. Depression-like behavior and memory performance were assessed by measuring immobility time in the forced swim test and passive avoidance test, respectively. The mRNA levels of BDNF and TrkB in the prefrontal cortex and hippocampus were measured by real-time quantitative PCR. Our results demonstrated that the RUS paradigm caused depression-like behavior and impairment of memory retrieval in rats. We did not find significant changes in BDNF or TrkB mRNA levels in hippocampus, but mRNA levels of TrkB in the prefrontal cortex showed a significant downregulation. Administration of memantine reversed depression-like behavior and memory impairment and significantly increased BDNF and TrkB mRNA levels in both prefrontal cortex and hippocampus of stress exposed rats. Our study supports the hypothesis that drugs with antagonistic properties on the NMDA receptor, such as memantine, might be efficient in treatment of major depression. Our results also suggest that upregulated mRNA levels of BDNF and TrkB in the brain might be essential for antidepressant-like activity of memantine in stress exposed rats. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.

The uncompetitive N-methyl-D-aspartate antagonist memantine reduces binge-like eating, food-seeking behavior, and compulsive eating: role of the nucleus accumbens shell.

PubMed

Smith, Karen L; Rao, Rahul R; Velázquez-Sánchez, Clara; Valenza, Marta; Giuliano, Chiara; Everitt, Barry J; Sabino, Valentina; Cottone, Pietro

2015-03-13

Binge-eating disorder is characterized by excessive, uncontrollable consumption of palatable food within brief periods of time. The role of the glutamatergic N-methyl-D-aspartate (NMDA) receptor system in hedonic feeding is poorly understood. The aim of this study was to characterize the effects of the uncompetitive NMDA receptor antagonist memantine on palatable food-induced behavioral adaptations using a rat model, which mimics the characteristic symptomatology observed in binge-eating disorder. For this purpose, we allowed male Wistar rats to respond to obtain a highly palatable, sugary diet (Palatable group) or a regular chow diet (Chow control group), for 1 h a day, under a fixed-ratio 1 (FR1) schedule of reinforcement. Upon stabilization of food responding, we tested the effects of memantine on the Chow and Palatable food groups' intake. Then, we tested the effects of memantine on food-seeking behavior, under a second-order schedule of reinforcement. Furthermore, we investigated the effects of memantine on the intake of food when it was offered in an aversive, bright compartment of a light/dark conflict test. Finally, we evaluated the effects of memantine on FR1 responding for food, when microinfused into the nucleus accumbens (NAcc) shell or core. Memantine dose-dependently decreased binge-like eating and fully blocked food-seeking behavior and compulsive eating, selectively in the Palatable food group. The drug treatment did not affect performance of the control Chow food group. Finally, intra-NAcc shell, but not core, microinfusion of memantine decreased binge-like eating. Together, these findings substantiate a role of memantine as a potential pharmacological treatment for binge-eating disorder.

Memantine Effects On Sensorimotor Gating and Mismatch Negativity in Patients with Chronic Psychosis

PubMed Central

Swerdlow, Neal R; Bhakta, Savita; Chou, Hsun-Hua; Talledo, Jo A; Balvaneda, Bryan; Light, Gregory A

2016-01-01

Patients with chronic psychotic disorders (CPD) exhibit deficient sensorimotor gating (measured by prepulse inhibition (PPI) of startle) and mismatch negativity (MMN). In healthy subjects (HS), N-methyl-D-aspartate (NMDA) antagonists like memantine and ketamine increase PPI, and under some conditions, memantine enhances MMN; these findings present a challenge to understanding the basis for deficient PPI and MMN in psychotic disorders, as reduced NMDA activity is implicated in the pathogenesis of these disorders. Here we assessed for the first time the effects of memantine on PPI and MMN in CPD subjects. Baseline PPI was measured in HS and patients with a diagnosis of schizophrenia or schizoaffective disorder, depressed type. Subjects (total n=84) were then tested twice, in a double-blind crossover design, comparing either: (1) placebo vs 10 mg of memantine or (2) placebo vs 20 mg memantine. Tests included measures of acoustic startle magnitude and habituation, PPI, MMN, autonomic indices, and subjective self-rating scales. Memantine (20 mg) significantly enhanced PPI in CPD subjects, and enhanced MMN across subject groups. These effects on PPI were age dependent and most evident in older CPD patients, whereas those on MMN were most evident in younger subjects. The lower dose (10 mg) either had no detectable effect or tended to degrade these measures. The NMDA antagonist, memantine, has dose-dependent effects on preconscious, automatic measures of sensorimotor gating and auditory sensory processing that are associated with enhanced cognition and function in CPD patients. Ongoing studies will determine whether these memantine-induced changes predict acute pro-cognitive or otherwise clinically beneficial effects in CPD patients. PMID:26062785

Postmortem memantine concentration in a non-intoxication case, and the possibility of postmortem redistribution: A case report.

PubMed

Nagasawa, Sayaka; Yajima, Daisuke; Torimitsu, Suguru; Chiba, Fumiko; Iwase, Hirotaro

2015-12-01

In this case study, we measured the concentration of memantine in the heart blood, peripheral blood, urine, liver, thigh muscle, and subcutaneous fat of a 64-year-old woman who was prescribed memantine for early-onset Alzheimer's disease. She died in hospital after an altercation with her husband. Cause of death was clearly not drug intoxication or overdose, so we investigated the postmortem redistribution (PMR) of memantine in the various tissues and blood ratios of the postmortem samples. Memantine concentrations detected were 1.31 μg/mL in the peripheral blood, 3.95 μg/mL in central blood, 2.09 μg/mL in the urine, 25.54 μg/g in the liver, 1.16 μg/g in the thigh muscle and 2.13 μg/g in the subcutaneous fat. In all samples, the concentrations were higher than the accepted therapeutic range (which is approximately 0.09-0.15 μg/mL). The central blood to peripheral blood (C/P) memantine ratio was 3.01 while the liver to peripheral blood (L/P) ratio was 19.5. It is documented that a C/P ratio exceeding 2 and L/P ratio exceeding 20 highlight a propensity for significant PMR. Although this is a single case study, our data suggest that memantine exhibits PMR. Additionally, a lowered pH was found in peripheral blood (pH 6.2) and central blood (pH 6.1). This postmortem reduction in blood pH may also promote the PMR of memantine. Because there is very little available postmortem toxicological data on memantine, our case study will serve as a foundation to assist in future forensic investigations. Copyright © 2015. Published by Elsevier Ireland Ltd.

Pharmacokinetic Properties of Memantine after a Single Intraperitoneal Administration and Multiple Oral Doses in Euploid Mice and in the Ts65Dn Mouse Model of Down's Syndrome.

PubMed

Victorino, Daniella B; Bederman, Ilya R; Costa, Alberto C S

2017-11-01

Memantine is a drug approved for the treatment of moderate-to-severe Alzheimer's disease (AD), and there is ongoing research on the potential expansion of its clinical applicability. Published data on the pharmacokinetics of memantine in the mouse are still incomplete, particularly for chronic administration regimens and mouse models of specific genetic disorders. Down's syndrome (DS) is a genetic disorder known to affect multiple organs and systems, with the potential to alter significantly drug pharmacokinetics. Here, we describe a simple, efficient and sensitive GC/MS-based procedure for the determination of memantine concentrations in murine blood and tissue samples. We analysed pharmacokinetic properties of memantine, particularly its distribution in blood, brain and liver in the Ts65Dn mouse model of DS and euploid F1 hybrid mice after single intraperitoneal administrations of increasing doses of this drug. We also determined steady-state memantine concentrations in plasma, brain and liver after chronic oral administration of this drug in adult male Ts65Dn mice, euploid littermate controls and nursing or pregnant Ts65Dn mice. Our results revalidated the acute dose of memantine used in previously published work, determined the appropriate amount of memantine to be mixed into mouse chow to achieve steady and pharmacologically relevant plasma and tissue levels of this drug and demonstrated that memantine can be transferred from mother to offspring via maternal milk and placenta. Most of these findings are potentially applicable not only to the study of DS but also to other neurodevelopmental and neurodegenerative disorders. © 2017 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

The Uncompetitive N-methyl-D-Aspartate Antagonist Memantine Reduces Binge-Like Eating, Food-Seeking Behavior, and Compulsive Eating: Role of the Nucleus Accumbens Shell

PubMed Central

Smith, Karen L; Rao, Rahul R; Velázquez-Sánchez, Clara; Valenza, Marta; Giuliano, Chiara; Everitt, Barry J; Sabino, Valentina; Cottone, Pietro

2015-01-01

Binge-eating disorder is characterized by excessive, uncontrollable consumption of palatable food within brief periods of time. The role of the glutamatergic N-methyl-D-aspartate (NMDA) receptor system in hedonic feeding is poorly understood. The aim of this study was to characterize the effects of the uncompetitive NMDA receptor antagonist memantine on palatable food-induced behavioral adaptations using a rat model, which mimics the characteristic symptomatology observed in binge-eating disorder. For this purpose, we allowed male Wistar rats to respond to obtain a highly palatable, sugary diet (Palatable group) or a regular chow diet (Chow control group), for 1 h a day, under a fixed-ratio 1 (FR1) schedule of reinforcement. Upon stabilization of food responding, we tested the effects of memantine on the Chow and Palatable food groups' intake. Then, we tested the effects of memantine on food-seeking behavior, under a second-order schedule of reinforcement. Furthermore, we investigated the effects of memantine on the intake of food when it was offered in an aversive, bright compartment of a light/dark conflict test. Finally, we evaluated the effects of memantine on FR1 responding for food, when microinfused into the nucleus accumbens (NAcc) shell or core. Memantine dose-dependently decreased binge-like eating and fully blocked food-seeking behavior and compulsive eating, selectively in the Palatable food group. The drug treatment did not affect performance of the control Chow food group. Finally, intra-NAcc shell, but not core, microinfusion of memantine decreased binge-like eating. Together, these findings substantiate a role of memantine as a potential pharmacological treatment for binge-eating disorder. PMID:25381776

Protection from glutamate-induced excitotoxicity by memantine

PubMed Central

Kutzing, Melinda K.; Luo, Vincent; Firestein, Bonnie L.

2014-01-01

This study investigates whether the uncompetitive NMDA receptor antagonist, memantine, is able to protect dissociated cortical neurons from glutamate-induced excitotoxicity (GIE). Treatment with glutamate resulted in a significant loss of synchronization of neuronal activity as well as a significant increase in the duration of synchronized bursting events (SBEs). By administering memantine at the same time as glutamate, we were able to completely prevent these changes to the neuronal activity. Pretreatment with memantine was somewhat effective in preventing changes to the culture synchronization but was unable to fully protect the synchronization of electrical activity between neurons that showed high levels of synchronization prior to injury. Additionally, memantine pretreatment was unable to prevent the increase in the duration of SBEs caused by GIE. Thus, the timing of memantine treatment is important for conferring neuroprotection against glutamate-induced neurotoxicity. Finally, we found that GIE leads to a significant increase in the burst duration. Our data suggest that this may be due to an alteration in the inhibitory function of the neurons. PMID:22203191

The therapeutic effect of memantine through the stimulation of synapse formation and dendritic spine maturation in autism and fragile X syndrome.

PubMed

Wei, Hongen; Dobkin, Carl; Sheikh, Ashfaq M; Malik, Mazhar; Brown, W Ted; Li, Xiaohong

2012-01-01

Although the pathogenic mechanisms that underlie autism are not well understood, there is evidence showing that metabotropic and ionotropic glutamate receptors are hyper-stimulated and the GABAergic system is hypo-stimulated in autism. Memantine is an uncompetitive antagonist of NMDA receptors and is widely prescribed for treatment of Alzheimer's disease treatment. Recently, it has been shown to improve language function, social behavior, and self-stimulatory behaviors of some autistic subjects. However the mechanism by which memantine exerts its effect remains to be elucidated. In this study, we used cultured cerebellar granule cells (CGCs) from Fmr1 knockout (KO) mice, a mouse model for fragile X syndrome (FXS) and syndromic autism, to examine the effects of memantine on dendritic spine development and synapse formation. Our results show that the maturation of dendritic spines is delayed in Fmr1-KO CGCs. We also detected reduced excitatory synapse formation in Fmr1-KO CGCs. Memantine treatment of Fmr1-KO CGCs promoted cell adhesion properties. Memantine also stimulated the development of mushroom-shaped mature dendritic spines and restored dendritic spine to normal levels in Fmr1-KO CGCs. Furthermore, we demonstrated that memantine treatment promoted synapse formation and restored the excitatory synapses to a normal range in Fmr1-KO CGCs. These findings suggest that memantine may exert its therapeutic capacity through a stimulatory effect on dendritic spine maturation and excitatory synapse formation, as well as promoting adhesion of CGCs.

Antagonism of NMDA receptors as a potential treatment for Down syndrome: a pilot randomized controlled trial

PubMed Central

Boada, R; Hutaff-Lee, C; Schrader, A; Weitzenkamp, D; Benke, T A; Goldson, E J; Costa, A C S

2012-01-01

Down syndrome (DS) is the most common genetic cause of intellectual disability. The N-methyl-D-aspartate (NMDA) receptor uncompetitive antagonist, memantine hydrochloride (memantine), has been shown to improve learning/memory and rescue one form of hippocampus synaptic plasticity dysfunction in the best-studied mouse model of DS available, the Ts65Dn mouse. Given the status of memantine as a treatment for Alzheimer's disease (AD) approved by the Food and Drug Administration, the preclinical evidence of potential efficacy in Ts65Dn mice, and the favorable safety profile of memantine, we designed a study to investigate whether the findings in the mouse model could be translated to individuals with DS. In this pilot, proof-of-principle study we hypothesized that memantine therapy would improve test scores of young adults with DS on measures of episodic and spatial memory, which are generally considered to be hippocampus dependent. Accordingly, in this randomized, double-blind, placebo-controlled trial, we compared the effect of 16-week treatment with either memantine or placebo on cognitive and adaptive functions of 40 young adults with DS using a carefully selected set of neuropsychological outcome measures. Safety and tolerability were also monitored. Although no significant differences were observed between the memantine and placebo groups on the two primary outcome measures, we found a significant improvement in the memantine group in one of the secondary measures associated with the primary hypothesis. Only infrequent and mild adverse events were noted. PMID:22806212

Memantine attenuates cell apoptosis by suppressing the calpain-caspase-3 pathway in an experimental model of ischemic stroke.

PubMed

Chen, Bin; Wang, Guoxiang; Li, Weiwei; Liu, Weilin; Lin, Ruhui; Tao, Jing; Jiang, Min; Chen, Lidian; Wang, Yun

2017-02-15

Ischemic stroke, the second leading cause of death worldwide, leads to excessive glutamate release, over-activation of N-methyl-D-aspartate receptor (NMDAR), and massive influx of calcium (Ca 2+ ), which may activate calpain and caspase-3, resulting in cellular damage and death. Memantine is an uncompetitive NMDAR antagonist with low-affinity/fast off-rate. We investigated the potential mechanisms through which memantine protects against ischemic stroke in vitro and in vivo. Middle cerebral artery occlusion-reperfusion (MCAO) was performed to establish an experimental model of ischemic stroke. The neuroprotective effects of memantine on ischemic rats were evaluated by neurological deficit scores and infarct volumes. The activities of calpain and caspase-3, and expression levels of microtubule-associated protein-2 (MAP2) and postsynaptic density-95 (PSD95) were determined by Western blotting. Additionally, Nissl staining and immunostaining were performed to examine brain damage, cell apoptosis, and neuronal loss induced by ischemia. Our results show that memantine could significantly prevent ischemic stroke-induced neurological deficits and brain infarct, and reduce ATP depletion-induced neuronal death. Moreover, memantine markedly suppressed the activation of the calpain-caspase-3 pathway and cell apoptosis, and consequently, attenuated brain damage and neuronal loss in MCAO rats. These results provide a molecular basis for the role of memantine in reducing neuronal apoptosis and preventing neuronal damage, suggesting that memantine may be a promising therapy for stroke patients. Copyright © 2017 Elsevier Inc. All rights reserved.

In vitro effects of the anti-Alzheimer drug memantine on the human erythrocyte membrane and molecular models.

PubMed

Zambrano, Pablo; Suwalsky, Mario; Villena, Fernando; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2017-01-29

Memantine is a NMDA antagonist receptor clinically used for treating Alzheimer's disease. NMDA receptors are present in the human neurons and erythrocyte membranes. The aim of the present study was to investigate the effects of memantine on human erythrocytes. With this purpose, the drug was developed to in vitro interact with human red cells and bilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE). The latter represent lipids respectively present in both outer and inner monolayers of the red cell membrane. Results obtained by scanning electron microscopy (SEM) showed that memantine changed the normal biconcave shape of red cells to cup-shaped stomatocytes. According to the bilayer-couple hypothesis the drug intercalated into the inner monolayer of the erythrocyte membrane. Experimental results obtained by X-ray diffraction on multibilayers of DMPC and DMPE, and by differential scanning calorimetry on multilamellar vesicles indicated that memantine preferentially interacted with DMPC in a concentration-dependent manner. Thus, it can be concluded that in the low therapeutic plasma concentration of circa 1 μM memantine is located in NMDA receptor channel without affecting the erythrocyte shape. However, at higher concentrations, once the receptors became saturated excess of memantine molecules (20 μM) would interact with phosphoinositide lipids present in the inner monolayer of the erythrocyte membrane inducing the formation of stomatocytes. However, 40-50 μM memantine was required to interact with isolated phosphatidylcholine bilayers. Copyright © 2016 Elsevier Inc. All rights reserved.

The Therapeutic effect of Memantine through the Stimulation of Synapse Formation and Dendritic Spine Maturation in Autism and Fragile X Syndrome

PubMed Central

Wei, Hongen; Dobkin, Carl; Sheikh, Ashfaq M.; Malik, Mazhar; Brown, W. Ted; Li, Xiaohong

2012-01-01

Although the pathogenic mechanisms that underlie autism are not well understood, there is evidence showing that metabotropic and ionotropic glutamate receptors are hyper-stimulated and the GABAergic system is hypo-stimulated in autism. Memantine is an uncompetitive antagonist of NMDA receptors and is widely prescribed for treatment of Alzheimer's disease treatment. Recently, it has been shown to improve language function, social behavior, and self-stimulatory behaviors of some autistic subjects. However the mechanism by which memantine exerts its effect remains to be elucidated. In this study, we used cultured cerebellar granule cells (CGCs) from Fmr1 knockout (KO) mice, a mouse model for fragile X syndrome (FXS) and syndromic autism, to examine the effects of memantine on dendritic spine development and synapse formation. Our results show that the maturation of dendritic spines is delayed in Fmr1-KO CGCs. We also detected reduced excitatory synapse formation in Fmr1-KO CGCs. Memantine treatment of Fmr1-KO CGCs promoted cell adhesion properties. Memantine also stimulated the development of mushroom-shaped mature dendritic spines and restored dendritic spine to normal levels in Fmr1-KO CGCs. Furthermore, we demonstrated that memantine treatment promoted synapse formation and restored the excitatory synapses to a normal range in Fmr1-KO CGCs. These findings suggest that memantine may exert its therapeutic capacity through a stimulatory effect on dendritic spine maturation and excitatory synapse formation, as well as promoting adhesion of CGCs. PMID:22615862

Open-Label Memantine in Fragile X Syndrome

ERIC Educational Resources Information Center

Erickson, Craig A.; Mullett, Jennifer E.; McDougle, Christopher J.

2009-01-01

Glutamatergic dysfunction is implicated in the pathophysiology of fragile X syndrome (FXS). The purpose of this pilot study was to examine the effectiveness and tolerability of memantine for a number of target symptoms associated with FXS. Medical records describing open-label treatment with memantine in 6 patients with FXS and a comorbid…

Memantine for dementia?

PubMed

2003-10-01

Memantine (Ebixa--Lundbeck Ltd), an oral medicine, is available in the UK for treating "patients with moderately severe to severe Alzheimer's disease". It differs from other licensed dementia medicines in that it is an N-methyl-D-aspartate (NMDA) receptor antagonist. The company has claimed that, with memantine therapy, "improvements in activities of daily living help patients to maintain a degree of independence and be easier to care for, potentially avoiding the need for nursing home care". We assess the efficacy of memantine for dementia and discuss its place in the management of patients with Alzheimer's disease.

A comparative first-principles study of structural and electronic properties among memantine, amantadine and rimantadine

NASA Astrophysics Data System (ADS)

Middleton, Kirsten; Zhang, G. P.; Nichols, Michael R.; George, Thomas F.

2012-05-01

Memantine, amantadine and rimantadine are structurally derived from the same diamondoid, adamantane. These derivatives demonstrate therapeutic efficacy in human diseases: memantine for Alzheimer's disease and amantadine and rimantadine for influenza. In order to better understand some of the properties that distinguish these three compounds, we conduct first-principles calculations on their structure and electronic properties. Our results indicate that protonation has a significant effect on the dipole moment, where the dipole moment in protonated memantine is over eight times larger than in the deprotonated form.

Synaptic plasticity in glutamatergic and GABAergic neurotransmission following chronic memantine treatment in an in vitro model of limbic epileptogenesis

PubMed Central

He, Shuijin; Bausch, Suzanne B.

2013-01-01

Chronic N-methyl-D-aspartate receptor (NMDAR) blockade with high affinity competitive and uncompetitive antagonists can lead to seizure exacerbation, presumably due to an imbalance in glutamatergic and GABAergic transmission. Acute administration of the moderate affinity NMDAR antagonist memantine in vivo has been associated with pro- and anticonvulsive properties. Chronic treatment with memantine can exacerbate seizures. Therefore, we hypothesized that chronic memantine treatment would increase glutamatergic and decrease GABAergic transmission, similar to high affinity competitive and uncompetitive antagonists. To test this hypothesis, organotypic hippocampal slice culture were treated for 17–21 days with memantine and then subjected to electrophysiological recordings. Whole-cell recordings from dentate granule cells revealed that chronic memantine treatment slightly, but significantly increased sEPSC frequency, mEPSC amplitude and mEPSC charge transfer, consistent with minimally increased glutamatergic transmission. Chronic memantine treatment also increased both sIPSC and mIPSC frequency and amplitude, suggestive of increased GABAergic transmission. Results suggest that a simple imbalance between glutamatergic and GABAergic neurotransmission may not underlie memantine’s ictogenic properties. That said, glutamatergic and GABAergic transmission were assayed independently of one another in the current study. More complex interactions between glutamatergic and GABAergic transmission may prevail under conditions of intact circuitry. PMID:24184417

Memantine for Prophylactic Treatment of Migraine Without Aura: A Randomized Double-Blind Placebo-Controlled Study.

PubMed

Noruzzadeh, Rezvan; Modabbernia, Amirhossein; Aghamollaii, Vajiheh; Ghaffarpour, Majid; Harirchian, Mohammad Hossein; Salahi, Sarvenaz; Nikbakht, Nikta; Noruzi, Nahid; Tafakhori, Abbas

2016-01-01

Uncontrolled studies in human have suggested that memantine might be a suitable option for migraine prophylaxis. To assess the efficacy and tolerability of memantine for migraine prophylaxis. This was a 12-week randomized double-blind placebo-controlled parallel-group study. Sixty patients with migraine without aura were randomized using a computer-generated list to receive memantine (10 mg/day) or placebo for 12 weeks. The primary outcome was the difference in change from baseline in the monthly attack frequency at week 12 between the two groups (using migraine diary). Secondary efficacy measures were assessed using several clinical, functional, and psychological instruments. We performed both complete case (CC) and intention-to-treat analyses (ITT). Twenty-five patients in the memantine group and 27 patients in the placebo group completed the study. Patients in the memantine group showed significantly greater reduction (mean change; 3.4; 95%CI, 2.3-4.4) in the monthly attack frequency than the placebo group (mean change, 1.0; 95%CI, 0.3-1.7) (mean difference [MD], 2.3; 95%CI, 1.1-3.5, P < .001). Both CC (MD, 4.9; 95%CI, 2.6-7.2 days), and ITT analyses (MD, 5.2; 95%CI, 2.0-8.5) showed significantly higher reduction in the mean number of migraine days in the memantine group than the placebo group (P < .01). Patients in the memantine group experienced greater reduction in the number of work absence days, severity, and disability score than the patients in the placebo group in both ITT and CC analyses. Changes in quality of life, sleep, depression, and anxiety did not differ between the two groups. Three patients in the memantine group complained of sedation, mild vertigo and nausea, and drowsiness. In the placebo group, one patient complained of nausea and another patient discontinued treatment after 2 weeks due to vertigo. Memantine might be a tolerable and efficacious option for prophylaxis in patients with migraine without aura. Tolerability, short duration required for titration, and safety profile in pregnancy might give memantine an advantage over other antimigraine medications. The study was registered in the Iranian Registry of Clinical Trials (Registration number: IRCT2013120115616N1). © 2015 American Headache Society.

Low-dose memantine attenuated morphine addictive behavior through its anti-inflammation and neurotrophic effects in rats.

PubMed

Chen, Shiou-Lan; Tao, Pao-Luh; Chu, Chun-Hsien; Chen, Shih-Heng; Wu, Hsiang-En; Tseng, Leon F; Hong, Jau-Shyong; Lu, Ru-Band

2012-06-01

Opioid abuse and dependency are international problems. Studies have shown that neuronal inflammation and degeneration might be related to the development of opioid addiction. Thus, using neuroprotective agents might be beneficial for treating opioid addiction. Memantine, an Alzheimer's disease medication, has neuroprotective effects in vitro and in vivo. In this study, we evaluated whether a low dose of memantine prevents opioid-induced drug-seeking behavior in rats and analyzed its mechanism. A conditioned-place-preference test was used to investigate the morphine-induced drug-seeking behaviors in rats. We found that a low-dose (0.2-1 mg/kg) of subcutaneous memantine significantly attenuated the chronic morphine-induced place-preference in rats. To clarify the effects of chronic morphine and low-dose memantine, serum and brain levels of cytokines and brain-derived neurotrophic factor (BDNF) were measured. After 6 days of morphine treatment, cytokine (IL-1β, IL-6) levels had significantly increased in serum; IL-1β and IL-6 mRNA levels had significantly increased in the nucleus accumbens and medial prefrontal cortex, both addiction-related brain areas; and BDNF levels had significantly decreased, both in serum and in addiction-related brain areas. Pretreatment with low-dose memantine significantly attenuated chronic morphine-induced increases in serum and brain cytokines. Low-dose memantine also significantly potentiated serum and brain BDNF levels. We hypothesize that neuronal inflammation and BDNF downregulation are related to the progression of opioid addiction. We hypothesize that the mechanism low-dose memantine uses to attenuate morphine-induced addiction behavior is its anti-inflammatory and neurotrophic effects.

Memantine reduces alcohol drinking but not relapse in alcohol-dependent rats.

PubMed

Alaux-Cantin, Stéphanie; Buttolo, Romain; Houchi, Hakim; Jeanblanc, Jérôme; Naassila, Mickaël

2015-09-01

Alcoholism is a chronic relapsing disorder with consequences on health and that requires more effective treatments. Among alternative therapies, the therapeutic potential of the non-competitive N-methyl-D-aspartate receptor antagonist memantine has been suggested. Despite promising results, its efficiency in the treatment of alcoholism remains controversial. Currently, there is no pre-clinical data regarding its effects on the motivation for ethanol in post-dependent (PD) animals exposed to intermittent ethanol vapor, a validated model of alcoholism. Thus, the objectives of this study were to evaluate the effects of acute injections of memantine (0, 12.5, 25 and 50 mg/kg) on operant ethanol self-administration in non-dependent (ND) and PD rats tested either during acute withdrawal or relapse after protracted abstinence. Our results showed that memantine (25 mg/kg) abolished ethanol self-administration in ND rats and reduced by half the one of PD rats during acute withdrawal. While this effect was observed only 6 hours after treatment in ND rats, it was long lasting in PD rats (at least 30 hours after injection). Furthermore, our results indicated that memantine did not modify the breaking point for ethanol. This suggests that memantine probably act by potentiating the pharmacological effect of ethanol but not by reducing motivation for ethanol. Finally, memantine was also ineffective in reducing relapse after protracted abstinence. Altogether, our pre-clinical results highlighted a potential therapeutic use of memantine that may be used as a replacement therapy drug but not as relapse-preventing drug. © 2014 Society for the Study of Addiction.

The impact of RTOG 0614 and RTOG 0933 trials in routine clinical practice: The US Survey of Utilization of Memantine and IMRT planning for hippocampus sparing in patients receiving whole brain radiotherapy for brain metastases.

PubMed

Slade, Alexander N; Stanic, Sinisa

2016-03-01

Two recent clinical trials, phase III RTOG 0614 and phase II RTOG 0933, showed some effectiveness of Memantine and IMRT planning for hippocampus sparing, among patients receiving whole brain radiotherapy (WBRT) for brain metastases; however, their use in routine clinical practice is unknown. A survey was sent to 1933 radiation oncologists in the US. Data collected included utilization of Memantine and hippocampus sparing, reasons for adoption and non-adoption, and demographic variables. A total of 196 radiation oncologists responded to the survey, with 64% reporting using Memantine in almost none of the patients receiving WBRT for brain metastases, and only 11% considering Memantine for <10% of their patients. The most common reason for not using Memantine was a poor patient performance status, and limited life expectancy. Likewise, 56% of radiation oncologists would not change their clinical practice to include hippocampus sparing IMRT in patients receiving WBRT based on the results of RTOG 0933. Further validation of hippocampus sparing in a phase III trial was supported by 71% of radiation oncologists, whereas further exploration of Memantine for this purpose in a phase III trial was supported by 42%. At this time, the majority of surveyed radiation oncologists in the US do not use Memantine, or IMRT planning for hippocampus sparing in patients receiving WBRT. Further validation of the hippocampus sparing concept in a phase III trial was supported, before adopting it in routine clinical practice. Copyright © 2015 Elsevier Inc. All rights reserved.

Memantine transport by a proton-coupled organic cation antiporter in hCMEC/D3 cells, an in vitro human blood-brain barrier model.

PubMed

Higuchi, Kei; Kitamura, Atsushi; Okura, Takashi; Deguchi, Yoshiharu

2015-04-01

Memantine is clinically used for the treatment of patients with Alzheimer's disease and is highly distributed to the brain. The aim of this study is to characterize memantine transport at the blood-brain barrier (BBB) using hCMEC/D3 cells, a human BBB model. The initial uptake velocity of memantine in hCMEC/D3 cells was concentration-dependent, and was reduced by metabolic inhibitors, but was independent of extracellular sodium ion and membrane potential. Intracellular alkalization and intracellular acidification markedly reduced and enhanced the uptake, respectively. The uptake was strongly inhibited by quinidine, pyrilamine and verapamil, and was moderately inhibited by TEA (substrate of OCTs and OCTNs) and l-carnitine (substrate of OCTN2), but was not inhibited by MPP(+) (substrate of OCTs and PMAT) or ergothioneine (substrate of OCTN1). Although relatively abundant expression of OCTN2 gene has been observed in hCMEC/D3 cells, knockdown of OCTN2 with siRNA did not decrease memantine uptake. Memantine and diphenhydramine each showed inhibition of the other's uptake in a competitive manner. Thus, proton-coupled organic cation antiporter(s) appears to be involved in the transport of memantine in hCMEC/D3 cells, at least in part. Our results indicate that the in vivo BBB permeability of memantine in humans can be predicted from the in vitro uptake clearance in hCMEC/D3 cells. Copyright © 2014 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

Effect of memantine on C-reactive protein and lipid profiles in bipolar disorder.

PubMed

Chang, Hui Hua; Chen, Po See; Wang, Tzu-Yun; Lee, Sheng-Yu; Chen, Shiou-Lan; Huang, San-Yuan; Hong, Jau-Shyong; Yang, Yen Kuang; Lu, Ru-Band

2017-10-15

Balance in the immune system plays roles in bipolar disorder (BD) and its metabolic co-morbidities. Memantine is an NMDA receptor antagonist with anti-inflammatory effects. However, the effects of memantine adjunct treatment on metabolic status of BD are unclear. During the 12 weeks period, a total of 191 BD patients were enrolled and split into valproate (VPA) + placebo and VPA + memantine (5mg/day) arms. The fasting plasma levels of high-sensitivity C-reactive protein (CRP) and metabolic indices were assessed. BD patients were stratified according to their initial CRP level. A cut-off value of initial CRP level of 2322ng/mL discriminated the waist circumference in these BD patients after 12-week VPA treatment. In the high CRP (> 2322ng/mL) group, patients in the VPA + memantine arm had a significantly decreased in their CRP (p= 0.009), total cholesterol (p= 0.002), LDL (p= 0.002) levels, BMI (p= 0.001), and waist circumference (p< 0.001), compared to those in the VPA + placebo arm. However, analysis of the low CRP group did not showed the effect. We recruited BD patients in depressed states and the sample size was relative small. The effects of the fixed dose of memantine on metabolic indices were 12-week follow up in BD patients treated with VPA. BD patients with high initial CRP levels receiving memantine adjunct treatment have a reduced risk of inflammation and metabolic imbalance. Prospective studies are needed to confirm the long-term outcome for memantine adjunct therapy in BD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Memantine: targeting glutamate excitotoxicity in Alzheimer's disease and other dementias.

PubMed

Molinuevo, José L; Lladó, Albert; Rami, Lorena

2005-01-01

The management of dementia has changed since the development of new antidementia drugs. The benefits observed in Alzheimer's disease (AD) with selective cholinergic transmission treatments are mainly symptomatic, without clear evidence of neuroprotection. The hypothesis that glutamate-mediated neurotoxicity is involved in the pathogenesis of AD is finding increasingly more acceptance in the scientific community. Glutamate receptors are overactive, and N-methyl-D-aspartate (NMDA) receptor antagonists have therapeutic potential for the treatment of AD and other neurological disorders. Memantine is a noncompetitive NMDA antagonist that is considered a neuroprotective drug. Memantine's capacity has been demonstrated in preclinical studies, and it is considered a useful symptomatic treatment for AD. Memantine has been shown to benefit cognition, function, and global outcome in patients with moderate to severe AD, and it is currently approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe AD. Recently, memantine has also demonstrated efficacy in the initial stages of AD, although FDA authorization is pending. This review highlights the important pharmacological and clinical aspects of memantine, as well as some basic mechanisms mediating glutamatergic neurodegeneration.

Dual action of memantine in Alzheimer disease: a hypothesis.

PubMed

Wu, Tzong-Yuan; Chen, Chih-Ping

2009-09-01

In this study, we proposed a hypothesis to explain the mechanisms of memantine action in treating Alzheimer disease (AD). Memantine may reduce the expression of amyloid precursor protein and tau protein, as well as acting as an antagonist of N-methyl-D-aspartate receptors in the brain. Two neuropathologic characteristics of AD are neuritic plaques and neurofibrillary tangles. The major molecular components of the plaques and tangles are amyloid-beta peptide and tau, respectively. Drugs able to reduce the expression of amyloid-beta and tau protein provide potential pharmaceutical treatments for AD. We found that memantine inhibited internal ribosome entry site-mediated translation initiation in COS-1 cells. This suggests that the memantine may not only inhibit neuronal excitotoxicity, but also act as an inhibitor of the internal ribosome entry site, to block the expression of amyloid precursor protein and tau in neurons. Memantine may function not only as an antagonist of N-methyl-D-aspartate receptors, but also as an inhibitor of the internal ribosome entry site to block the expression of amyloid precursor protein and tau, and so ameliorate the symptoms of AD.

Trends in the Prescription and Long-Term Utilization of Antidementia Drugs Among Patients with Alzheimer's Disease in Spain: A Cohort Study Using the Registry of Dementias of Girona.

PubMed

Calvó-Perxas, Laia; Turró-Garriga, Oriol; Vilalta-Franch, Joan; Lozano-Gallego, Manuela; de Eugenio, Rosa; Márquez, Fabián; Carmona, Olga; Gich, Jordi; Manzano, Anna; Viñas, Marta; Roig, Anna Mª; Garre-Olmo, Josep

2017-04-01

Acetylcholinesterase inhibitors (AChEIs) and the N-methyl D-aspartate-antagonist memantine are indicated for the symptomatic treatment of Alzheimer's disease (AD). Our aims were to describe the baseline characteristics of patients with AD according to prescription of these treatments after the diagnostic work-up to describe long-term trends in the use of these medications and to identify baseline characteristics associated with the frequency of use of each treatment. This was a cohort study with a sample of 2992 patients with AD recorded in the Registry of Dementias of Girona (ReDeGi) between 2007 and 2014. Consumption of AChEIs and memantine was assessed using the Pharmacy Unit database from the Public Catalan Healthcare Service. We used generalized estimating equation analyses to identify the baseline characteristics associated with the consumption of AChEIs and memantine over time. Most of the patients (70.4%; 95% confidence interval [CI] 68.7-72.0) were prescribed antidementia medication at the time of diagnosis. Of these, 75.0% (95% CI 73.1-76.8) were prescribed AChEIs, 14.7% (95% CI 13.2-16.3) were prescribed an AChEI plus memantine, and 10.3% (95% CI 9.0-11.6) were prescribed memantine. Advanced age reduced the likelihood of AChEI consumption. Mild dementia severity increased the use of AChEIs, and moderate-advanced dementia increased the likelihood of memantine consumption. After diagnosis, the likelihood of AChEI consumption decreased from the first year until the fifth, whereas the likelihood of memantine consumption, either alone or in combination with AChEIs, increased. Antidementia drug use in this study showed the initial use of AChEIs alone with later use of AChEIs in combination with memantine and memantine alone in older patients with severe AD. Our findings are in agreement with current clinical practice guidelines for the pharmacological treatment of AD.

Contra-directional Coupling of Nur77 and Nurr1 in Neurodegeneration: A Novel Mechanism for Memantine-Induced Anti-inflammation and Anti-mitochondrial Impairment.

PubMed

Wei, Xiaobo; Gao, Huimin; Zou, Jing; Liu, Xu; Chen, Dan; Liao, Jinchi; Xu, Yunqi; Ma, Long; Tang, Beisha; Zhang, Zhuohua; Cai, Xiang; Jin, Kunling; Xia, Ying; Wang, Qing

2016-11-01

Recent evidence suggests that nerve growth factor IB (Nur77) and nuclear receptor related1 (Nurr1) are differentially involved in dopaminergic neurodegeneration. Since memantine has shown clinically relevant efficacy in Parkinson's disease (PD) and displayed a potent protective effect on dopaminergic neurons in experimental PD models, we asked if it exerts its neuroprotection by regulating Nur77 and Nurr1 signaling. We adopted a well-established in vitro PD model, 6-hydroxydopamine (OHDA)-lesioned PC12 cells, to test our hypothesis. Different concentrations of memantine were incubated with 6-OHDA-lesioned PC12 cells, and Nur77/Nurr1 and their related signaling molecules were examined by Western blot and immunocytochemistry. Nur77-deficient PC12 cells were used to verify the influences of Nur77 on neurodegeneration and memantine-mediated neuroprotection. We found that memantine reversed Nur77 upregulation and restored Nurr1 downregulation in 6-OHDA-lesioned PC12 cells. 6-OHDA incubation caused Nur77 translocation from the nucleus to cytosol and induced co-localization of Cyt c/HSP60/Nur77 in the cytosol. Memantine strongly reduced the sub-cellular translocations of Nur77/Cyt c/HSP60 under 6-OHDA-induced oxidative condition. Knockdown of Nur77 enhanced the viability of PC12 cells exposed to 6-OHDA, while memantine-induced neuroprotection was much less in the cells with Nur77 knockdown than in those without it. We conclude that Nur77 plays a crucial role in modulating mitochondrial impairment and contributes to neurodegeneration under the experimental PD condition. Memantine effectively suppresses such Nur77-mediated neurodegeneration and promotes survival signaling through post-translational modification of Nurr1. Nur77 and Nurr1 present a contra-directionally coupling interaction in memantine-mediated neuroprotection.

Long-lasting effect of NMDA receptor antagonist memantine on ethanol-cue association and relapse.

PubMed

Vengeliene, Valentina; Olevska, Anastasia; Spanagel, Rainer

2015-12-01

It is well known that the glutamatergic system plays a crucial role in alcohol addiction and especially in relapse-like behaviour. However, results of clinical studies on compounds that influence the activity of the glutamatergic system have been disappointing so far. The aim of our study was to establish treatment conditions under which the N-methyl-d-aspartate receptor (NMDAR) antagonist memantine may produce more reliable treatment effect with respect to alcohol relapse-like behaviour. For this purpose, male Wistar rats were trained to associate several discrete stimuli with ethanol delivery. Thereafter, half of the animals received a brief memory reactivation session followed by two administrations of 20 mg/kg of memantine, while the other half received the same treatment without memory reactivation. Afterwards, a cue-induced ethanol-seeking behaviour test was performed followed by repeated extinction sessions and a reacquisition test. Our data show that administration of memantine reduced responding on the ethanol-associated lever in a cue-induced ethanol-seeking test. This reduction did not depend on whether or not a memory reactivation session was introduced prior to memantine administration. Following extinction, however, reacquisition of ethanol self-administration was only impaired in the group where memantine was given after a short memory reactivation session, showing that this schedule of drug administration produced a long-lasting disruption of the association between the conditioned stimuli and the delivery of ethanol. In conclusion, we show that memantine disrupted the drug-cue association, which consequently interfered with relapse-like behaviour supporting the possibility that memantine is a treatment option for alcoholism. Our data supports the possibility that memantine is a treatment option for alcoholism. However, the effectiveness of this drug seems to lie in its ability to disrupt conditioned behaviours and should be given in conjunction with exposure to conditioned drug stimuli. © 2015 International Society for Neurochemistry.

Cost effectiveness of memantine in Alzheimer's disease: an analysis based on a probabilistic Markov model from a UK perspective.

PubMed

Jones, Roy W; McCrone, Paul; Guilhaume, Chantal

2004-01-01

Clinical trials with memantine, an uncompetitive moderate-affinity NMDA antagonist, have shown improved clinical outcomes, increased independence and a trend towards delayed institutionalisation in patients with moderately severe-to-severe Alzheimer's disease. In a randomised double-blind, placebo-controlled, 28-week study conducted in the US, reductions in resource utilisation and total healthcare costs were noted with memantine relative to placebo. While these findings suggest that, compared with placebo, memantine provides cost savings, further analyses may help to quantify potential economic gains over a longer treatment period. To evaluate the cost effectiveness of memantine therapy compared with no pharmacological treatment in patients with moderately severe-to-severe Alzheimer's disease over a 2-year period. A Markov model was constructed to simulate patient progression through a series of health states related to severity, dependency (determined by patient scores on the Alzheimer's Disease Cooperative Study-Activities of Daily Living [ADCS-ADL] inventory and residential status ('institutionalisation') with a time horizon of 2 years (each 6-month Markov cycle was repeated four times). Transition probabilities from one health state to another 6 months later were mainly derived from a 28-week, randomised, double-blind, placebo-controlled clinical trial. Inputs related to epidemiological and cost data were derived from a UK longitudinal epidemiological study, while data on quality-adjusted life-years (QALYs) were derived from a Danish longitudinal study. To ensure conservative estimates from the model, the base case analysis assumed drug effectiveness was limited to 12 months. Monte Carlo simulations were performed for each state parameter following definition of a priori distributions for the main variables of the model. Sensitivity analyses included worst case scenario in which memantine was effective for 6 months and one-way sensitivity analyses on key parameters. Finally, a subgroup analysis was performed to determine which patients were most likely to benefit from memantine. Informal care was not included in this model as the costs were considered from National Health Service and Personal Social Services perspective. The base case analysis found that, compared with no treatment, memantine was associated with lower costs and greater clinical effectiveness in terms of years of independence, years in the community and QALYs. Sensitivity analyses supported these findings. For each category of Alzheimer's disease patient examined, treatment with memantine was a cost-effective strategy. The greatest economic gain of memantine treatment was in independent patients with a Mini-Mental State Examination score of > or =10. This model suggests that memantine treatment is cost effective and provides cost savings compared with no pharmacological treatment. These benefits appear to result from prolonged patient independence and delayed institutionalisation for moderately severe and severe Alzheimer's disease patients on memantine compared with no pharmacological treatment.

Involvement of NMDA glutamate receptors in the acquisition and reinstatement of the conditioned place preference induced by MDMA.

PubMed

García-Pardo, Maria P; Escobar-Valero, Carla; Rodríguez-Arias, Marta; Miñarro, Jose; Aguilar, Maria A

2015-08-01

Some 3,4-methylenedioxymethamphetamine (MDMA) users become dependent as a result of chronic consumption. A greater understanding of the neurobiological basis of the rewarding effects of MDMA could contribute to developing effective pharmacotherapies for MDMA-related problems. The present study evaluated the role of N-methyl-D-aspartate (NMDA) glutamate receptors (NMDARs) in the acquisition and reinstatement of conditioned place preference (CPP) induced by MDMA. Adolescent male mice were conditioned with 1 or 10 mg/kg MDMA and pretreated with 5 or 10 mg/kg of the NMDAR antagonist memantine during acquisition of conditioning (experiment 1), or before a reinstatement test (experiment 2). In addition, the effects of memantine on acquisition of chocolate-induced CPP and the effects of memantine and MDMA on a passive avoidance task were evaluated. Memantine did not exert any motivational effects, but blocked the acquisition of MDMA-induced CPP. Moreover, following acquisition and extinction of MDMA-induced CPP, memantine did not induce reinstatement but blocked reinstatement of the CPP induced by priming with MDMA. Memantine did not block the CPP induced by chocolate, and it partially reversed the impairing effects of MDMA on memory. Our results demonstrate that NMDARs are involved in acquisition of the conditioned rewarding effects of MDMA and in priming-induced reinstatement of CPP following extinction. Moreover, they suggest the validity of memantine for the treatment of MDMA abuse.

Memantine prevents hypoglycemia-induced decrements of the cerebral energy status in healthy subjects.

PubMed

Willenborg, B; Schmoller, A; Caspary, J; Melchert, U H; Scholand-Engler, H G; Jauch-Chara, K; Hohagen, F; Schweiger, U; Oltmanns, K M

2011-02-01

The risk to develop dementia is significantly increased in diabetes mellitus. Memantine, an N-methyl-D-aspartate receptor antagonist, which is clinically applied in dementia, has been shown to exert neuroprotective effects under hypoglycemic conditions in rats. We hypothesized that memantine may prevent hypoglycemia-induced decrements in the cerebral high-energy phosphate, i.e. ATP, metabolism to exert its neuroprotective action under these conditions. In a randomized, double-blind crossover design, we applied memantine vs. placebo in 16 healthy male subjects and examined the cerebral high-energy phosphate metabolism by (31)phosphor magnetic resonance spectroscopy, hormonal counterregulation, and neurocognitive performance during hypoglycemic glucose clamp conditions. We found increments in hormonal counterregulation and reduced neurocognitive performance during hypoglycemia (P < 0.05). Cerebral ATP levels increased upon hypoglycemia in the memantine condition as compared with placebo (P = 0.006) and remained higher after renormalizing blood glucose concentrations (P = 0.018), which was confirmed by ATP to inorganic phosphate ratio (P = 0.046). Phosphocreatine levels and phosphocreatine to inorganic phosphate ratio remained stable throughout the experiments and did not differ between conditions (P > 0.1 for both). Our data demonstrate that memantine preserves the cerebral energy status during experimentally induced hypoglycemia in healthy subjects. An improved neuronal energy status may thus be involved in the neuroprotective effect under these conditions and may qualify memantine as potential future option to combat cognitive impairments and dementia in diabetes.

Transdermal absorption of memantin--effect of chemical enhancers, iontophoresis, and role of enhancer lipophilicity.

PubMed

del Rio-Sancho, S; Serna-Jiménez, C E; Calatayud-Pascual, M A; Balaguer-Fernández, C; Femenía-Font, A; Merino, V; López-Castellano, A

2012-09-01

The transdermal administration of memantine may have advantages with respect to oral therapy when treating advanced stages of Alzheimer's disease. With the ultimate objective of administrating memantine through a transdermal patch, the absorption of the drug across skin was evaluated by means of in vitro permeation studies. The effect of several chemical enhancers was studied in order to enhance percutaneous absorption of the memantine. The iontophoretic transdermal transport of memantine hydrochloride using a current density of 0.5 mA/cm(2) was also investigated. Results demonstrated that pre-treatment of the skin with R-(+)-limonene, laurocapram, decenoic acid, or oleic acid produced a statistically significant increment in the transdermal flux of memantine hydrochloride with respect to the control. Iontophoresis exhibited the greatest ability to enhance the flux of drug with respect to the control; nevertheless, the results obtained with R-(+)-limonene indicate that this compound could be of great use as a percutaneous enhancer in a memantine transdermal delivery system. In this study, the relationship between enhancement activity and lipophilicity was also studied. Satisfactory correlations have been obtained between the optimum lipophilicity of the enhancer and n-octanol/water partition coefficients of drugs. This relationship is a very useful tool that could allow to reduce time and to optimize the selection of appropriate enhancers for transdermal formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

Memantine, an NMDA receptor antagonist, differentially influences Go/No-Go performance and fMRI activity in individuals with and without a family history of alcoholism

PubMed Central

DeVito, E. E.; Jiantonio, R. E.; Meda, S. A.; Stevens, M. C.; Potenza, M. N.; Krystal, J. H.; Pearlson, G. D.

2013-01-01

Rationale Individuals with a family history of alcoholism (family history positive [FHP]) show higher alcoholism rates and are more impulsive than those without such a family history (family history negative [FHN]), possibly due to altered N-methyl-D-aspartate (NMDA) receptor function. Objectives We investigated whether memantine, an NMDA receptor antagonist, differentially influences impulsivity measures and Go/No-Go behavior and fMRI activity in matched FHP and FHN individuals. Methods On separate days, participants received a single dose of 40 mg memantine or identical-appearing placebo. Results No group performance differences were observed on placebo for Go correct hit or No-Go false alarm reaction time on the Go/No-Go task. During fMRI, right cingulate activation differed for FHP vs. FHN subjects during No-Go correct rejects. Memantine had attenuated effects in FHP vs. FHN subjects: For No-Go false alarms, memantine was associated with limited reduction in subcortical, cingulate, and temporal regions in FHP subjects and reduced activity in fronto-striatal–parietal networks in FHN subjects. For No-Go correct rejects, memantine (relative to placebo) reduced activity in left cingulate and caudate in FHP but not FHN subjects. Conclusions Lower sensitivity to the effects of memantine in FHP subjects is consistent with greater NMDA receptor function in this group. PMID:22311382

Efficacy and safety of memantine in patients with moderate-to-severe Alzheimer's disease: results of a pooled analysis of two randomized, double-blind, placebo-controlled trials in Japan

PubMed Central

Nakamura, Yu; Kitamura, Shin; Homma, Akira; Shiosakai, Kazuhito; Matsui, Daiju

2014-01-01

Background: With the increase in the aging population, there is a pressing need to provide effective treatment options for individuals with Alzheimer's disease (AD). Memantine is an N-methyl-D-aspartate receptor antagonist used to treat AD in > 80 countries worldwide, and studies in the USA and Europe have shown it to be effective in improving language deficits; however, there are currently no data on language improvements in Japanese patients treated with memantine. Objectives: To clarify the efficacy and safety of memantine in Japanese outpatients with moderate to severe AD, using a pooled analysis of two multicenter randomized placebo-controlled trials, a phase 2 dose-finding study and a phase 3 study. Results: The final analysis comprised 633 patients (318 receiving memantine and 315 placebo). Memantine produced better outcomes in terms of Severe Impairment Battery-Japanese version, Clinician's Interview-Based Impression of Change plus-Japanese version, Behavioral Pathology in AD Rating Scale, and language scores, versus placebo. The overall incidence of adverse events and adverse reactions was similar between groups. Conclusion: In this pooled analysis of Japanese patients, memantine achieved better outcomes than placebo in terms of cognition, including attention, praxis, visuospatial ability and language, and behavioral and psychological symptoms, including activity disturbances and aggressiveness. PMID:24673497

Memantine for dementia.

PubMed

Areosa Sastre, A; McShane, R; Sherriff, F

2004-10-18

Alzheimer's disease, vascular and mixed dementia are the three commonest forms of dementia affecting older people. There is evidence that the excitatory activity of L-glutamate plays a role in the pathogenesis of Alzheimer's disease and in the damage from an ischaemic stroke. A low affinity antagonist to N-Methyl-D-aspartate (NMDA) type receptors, such as memantine, may prevent excitatory amino acid neurotoxicity without interfering with the physiological actions of glutamate required for memory and learning. To determine the clinical efficacy and safety of memantine for people with Alzheimer's disease, or vascular or mixed dementia. Trials were identified from a search of the Trial-based Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 7 April 2004 using the terms: memantin*, namenda*, ebixa*, axura*, D-145, DMAA, DRG-0267. All major health care databases and many ongoing trial databases are searched regularly to keep this Register up to date. Double-blind, parallel group, placebo-controlled, randomised and unconfounded trials in which memantine was administered to people with dementia. Data were extracted, pooled where possible, and weighted mean differences, standardized mean differences or odds ratios were estimated. Intention-to-treat (ITT) and observed cases (OC) analyses are reported, where data were available. The evidence suggests that memantine has a positive effect on cognition, mood and behaviour and the ability to perform activities of daily living in patients with moderate to severe Alzheimer's disease. The results in patients with mild to moderate vascular dementia, suggest a beneficial effect of 20mg/day of memantine on cognitive function measured at 28 weeks. However, these results are neither supported by an effect on ability to perform activities of daily living nor by an effect on the clinical impression of change. This suggests that, in patients with mild to moderate vascular dementia, the effect on cognitive function is not translated into clinically detectable changes. :Memantine 20 mg/day caused a clinically noticeable reduction in deterioration over 28 weeks in patients with moderate to severe Alzheimer disease. This was supported by less functional and cognitive deterioration. Patients taking memantine were less likely to become agitated. The effect in mild to moderate AD is unknown. Patients with mild to moderate vascular dementia receiving memantine 20 mg/day had less cognitive deterioration at 28 weeks but the effects were not clinically discernible. There is an early beneficial effect on cognition, mood, behaviour and clinical impression for memantine at 6 weeks. The drug is well tolerated in general and the incidence of adverse effects is low.

Memory and mood during MDMA intoxication, with and without memantine pretreatment.

PubMed

de Sousa Fernandes Perna, E B; Theunissen, E L; Kuypers, K P C; Heckman, P; de la Torre, R; Farre, M; Ramaekers, J G

2014-12-01

Previous studies have shown that single doses of MDMA can affect mood and impair memory in humans. The neuropharmacological mechanisms involved in MDMA-induced memory impairment are not clear. Memantine, an NMDA and alpha 7 nicotinic acetylcholine (ACh) receptor antagonist, was able to reverse MDMA-induced memory impairment in rats. This study investigated whether treatment with memantine can prevent MDMA-induced memory impairment in humans. 15 subjects participated in a double-blind, placebo controlled, within-subject design. Subjects received both pre-treatment (placebo/memantine 20 mg) (T1) and treatment (placebo/MDMA 75 mg) (T2) on separate test days. T1 preceded T2 by 120 min. Memory function was assessed 90 min after T2 by means of a Visual Verbal Learning Task, a Prospective Memory Task, the Sternberg Memory Task and the Abstract Visual Pattern Learning Task. Profile of Mood State and psychomotor performance were also assessed to control whether MDMA and memantine interactions would selectively pertain to memory or transfer to other domains as well. MDMA significantly impaired performance in the visual verbal learning task and abstract visual pattern learning task. Pre-treatment with memantine did not prevent MDMA-induced memory impairment in these two tasks. Both positive (vigour, arousal, elation) and negative mood effects (anxiety) were increased by MDMA. The responses were not altered by pretreatment with memantine which had no effect on memory or mood when given alone. These preliminary results suggest that memantine does not reverse MDMA-induced memory impairment and mood in humans. This article is part of the Special Issue entitled 'CNS Stimulants'. Copyright © 2014 Elsevier Ltd. All rights reserved.

Long-term effects of the concomitant use of memantine with cholinesterase inhibition in Alzheimer disease

PubMed Central

Lopez, O L; Becker, J T; Wahed, A S; Saxton, J; Sweet, R A; Wolk, D A; Klunk, W; DeKosky, S T

2010-01-01

Background Patients using cholinesterase inhibitors (ChEIs) have a delay in nursing home (NH) admission compared with those who were not using the medication. There are no long-term studies of the effects of memantine in combination with ChEIs use in Alzheimer disease (AD). This study was conducted to examine the effects of ChEIs and memantine on time to death and time to NH admission. Methods Time to NH admission and death was examined in 943 probable AD patients who had at least a 1-year follow-up evaluation. Of these patients, 140 (14.9%) used both ChEIs and memantine, 387 (45.0%) used only ChEIs, and 416 (40.1%) used neither. The mean (SD) follow-up time was 62.3 (35.8) months. The analysis was conducted with multivariable Cox proportional hazard models controlling for critical covariates (ie, age, education level, gender, severity of the dementia, hypertension, diabetes mellitus, heart disease, psychiatric symptoms and use of psychotropic medications). Results Compared with those who never used cognitive enhancers, patients who used ChEIs had a significant delay in NH admission (HR: 0.37, 95% CI 0.27 to 0.49); this effect was significantly augmented with the addition of memantine (HR: 0.29, 95% CI 0.11 to 0.72) (memantine+ChEI vs ChEI alone). ChEIs alone, or in combination with memantine had no significant association on time to death. Conclusions This observational study revealed that the addition of the NMDA receptor antagonist memantine to the treatment of AD with ChEI significantly altered the treated history of AD by extending time to nursing home admission. PMID:19204022

A novel once-daily fixed-dose combination of memantine extended release and donepezil for the treatment of moderate to severe Alzheimer's disease: two phase I studies in healthy volunteers.

PubMed

Boinpally, Ramesh; Chen, Laishun; Zukin, Stephen R; McClure, Natalie; Hofbauer, Robert K; Periclou, Antonia

2015-07-01

Combining two standard-of-care medications for Alzheimer's disease (AD) into a single once-daily dosage unit may improve treatment adherence, facilitate drug administration, and reduce caregiver burden. A new fixed-dose combination (FDC) capsule containing 28 mg memantine extended release (ER) and 10 mg donepezil was evaluated for bioequivalence with co-administered commercially available memantine ER and donepezil, and for bioavailability with regard to food intake. Two phase I, single-dose, randomized, open-label, crossover studies were conducted in 18- to 45-year-old healthy individuals. In MDX-PK-104 study, fasting participants (N = 38) received co-administered memantine ER and donepezil or the FDC. In MDX-PK-105 study, participants (N = 36) received three treatments: intact FDC taken while fasting or after a high-fat meal, or FDC contents sprinkled on applesauce while fasting. Standard pharmacokinetic parameters for memantine and donepezil were calculated from the plasma concentration time-curve using non-compartmental analyses. Linear mixed-effects models were used to compare: (a) FDC versus co-administered individual drugs; (b) FDC fasted versus with food; and (c) FDC sprinkled on applesauce versus FDC intact, both fasted. Safety parameters were also evaluated. The FDC capsule was bioequivalent to co-administered memantine ER and donepezil. There was no significant food effect on the bioavailability of the FDC components. There were no clinically relevant differences in time to maximum plasma concentration or safety profiles across treatments. An FDC capsule containing 28 mg memantine ER and 10 mg donepezil is bioequivalent to commercially available memantine ER and donepezil, and bioavailability is not affected by food intake or sprinkling of capsule contents on applesauce.

Modification of hippocampal markers of synaptic plasticity by memantine in animal models of acute and repeated restraint stress: implications for memory and behavior.

PubMed

Amin, Shaimaa Nasr; El-Aidi, Ahmed Amro; Ali, Mohamed Mostafa; Attia, Yasser Mahmoud; Rashed, Laila Ahmed

2015-06-01

Stress is any condition that impairs the balance of the organism physiologically or psychologically. The response to stress involves several neurohormonal consequences. Glutamate is the primary excitatory neurotransmitter in the central nervous system, and its release is increased by stress that predisposes to excitotoxicity in the brain. Memantine is an uncompetitive N-methyl D-aspartate glutamatergic receptors antagonist and has shown beneficial effect on cognitive function especially in Alzheimer's disease. The aim of the work was to investigate memantine effect on memory and behavior in animal models of acute and repeated restraint stress with the evaluation of serum markers of stress and the expression of hippocampal markers of synaptic plasticity. Forty-two male rats were divided into seven groups (six rats/group): control, acute restraint stress, acute restraint stress with Memantine, repeated restraint stress, repeated restraint stress with Memantine and Memantine groups (two subgroups as positive control). Spatial working memory and behavior were assessed by performance in Y-maze. We evaluated serum cortisol, tumor necrotic factor, interleukin-6 and hippocampal expression of brain-derived neurotrophic factor, synaptophysin and calcium-/calmodulin-dependent protein kinase II. Our results revealed that Memantine improved spatial working memory in repeated stress, decreased serum level of stress markers and modified the hippocampal synaptic plasticity markers in both patterns of stress exposure; in ARS, Memantine upregulated the expression of synaptophysin and brain-derived neurotrophic factor and downregulated the expression of calcium-/calmodulin-dependent protein kinase II, and in repeated restraint stress, it upregulated the expression of synaptophysin and downregulated calcium-/calmodulin-dependent protein kinase II expression.

Inhibitory Effect of Memantine on Streptozotocin-Induced Insulin Receptor Dysfunction, Neuroinflammation, Amyloidogenesis, and Neurotrophic Factor Decline in Astrocytes.

PubMed

Rajasekar, N; Nath, Chandishwar; Hanif, Kashif; Shukla, Rakesh

2016-12-01

Our earlier studies showed that insulin receptor (IR) dysfunction along with neuroinflammation and amyloidogenesis played a major role in streptozotocin (STZ)-induced toxicity in astrocytes. N-methyl-D-aspartate (NMDA) receptor antagonist-memantine shows beneficial effects in Alzheimer's disease (AD) pathology. However, the protective molecular and cellular mechanism of memantine in astrocytes is not properly understood. Therefore, the present study was undertaken to investigate the effect of memantine on insulin receptors, neurotrophic factors, neuroinflammation, and amyloidogenesis in STZ-treated astrocytes. STZ (100 μM) treatment for 24 h in astrocytes resulted significant decrease in brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and insulin-degrading enzyme (IDE) expression in astrocytes. Treatment with memantine (1-10 μM) improved STZ-induced neurotrophic factor decline (BDNF, GDNF) along with IR dysfunction as evidenced by a significant increase in IR protein expression, phosphorylation of IRS-1, Akt, and GSK-3 α/β in astrocytes. Further, memantine attenuated STZ-induced amyloid precursor protein (APP), β-site APP-cleaving enzyme-1 and amyloid-β 1-42 expression and restored IDE expression in astrocytes. In addition, memantine also displays protective effects against STZ-induced astrocyte activation showed by reduction of inflammatory markers, nuclear factor kappa-B translocation, glial fibrillary acidic protein, cyclooxygenase-2, tumor necrosis factor-α level, and oxidative-nitrostative stress. The results suggest that besides the NMDA receptor antagonisic activity, effect on astroglial IR and neurotrophic factor may also be an important factor in the beneficial effect of memantine in AD pathology. Graphical Abstract Novel neuroprotective mechanisms of memenatine in streptozotocin-induced toxicity in astrocytes.

The Effects of Memantine on Glutamic Receptor-Associated Nitrosative Stress in a Traumatic Brain Injury Rat Model.

PubMed

Wang, Che-Chuan; Wee, Hsiao-Yue; Hu, Chiao-Ya; Chio, Chung-Ching; Kuo, Jinn-Rung

2018-04-01

The main aim of this study is to elucidate whether the neuroprotective effect of memantine, a noncompetitive N-methyl-d-aspartate receptor 2B (NR2B) antagonist, affects neuronal nitrosative stress, apoptosis, and NR2B expression and improves functional outcomes. Immediately after the onset of fluid percussion traumatic brain injury (TBI), anesthetized male Sprague-Dawley rats were divided into sham-operated, TBI + vehicle, and TBI + memantine groups. TBI rats were treated with a memantine intraperitoneal injection dose of 20 mg/kg intraperitoneally and then 1 mg/kg every 12 hours intraperitoneally for 6 doses. The motor function, proprioception, infarction volume, and neuronal apoptosis were then measured. Immunofluorescence was used to evaluate astrogliosis, microgliosis, nitrosative stress, and NR2A and NR2B expression in cortical cells. All the parameters were assessed 72 hours after TBI. Compared with the sham-operated controls, the TBI-induced motor and proprioception deficits, and increased infraction volume after TBI were significantly attenuated by memantine therapy. The TBI-induced neuronal apoptosis, astrogliosis, and microgliosis, the numbers of neuronal NO synthase and 3-nitro-l-tyrosine expression in neurons, and inducible NO synthase expression in microglia and astrocyte cells in the ischemic cortex after TBI were significantly improved by memantine therapy. Simultaneously, without affecting the NR2A expression in neuronal cells, the NR2B expression significantly decreased after memantine therapy, as evaluated by an immunofluorescence stain. Intraperitoneal injection of memantine in the acute stage may ameliorate TBI in rats by affecting NR2B expression and decreasing neuronal apoptosis and nitrosative stress in the injured cortex. These effects might represent 1 mechanism by which functional recovery occurred. Copyright © 2018 Elsevier Inc. All rights reserved.

Neuroprotective Treatment of Laser-Induced Retinal Injuries

DTIC Science & Technology

2001-10-01

to evaluate the neuroprotective effect of dextromethorphan, memantine and brimonidine in our rat model of laser- induced retinal-lesions Methods: Argon...dextromethorphan, memantine or brimonidine. The control groups (18 rats for each compound) received the solvent at the same volume and schedule as...size and the magnitude of photoreceptor nuclei loss within the lesions. Conclusions: Systemic treatments with dextromethorphan, memantine or brimonidine

Memantine and reduced time with dyskinesia in Parkinson's Disease.

PubMed

Wictorin, K; Widner, H

2016-05-01

The partial glutamate antagonist amantadine is currently used in clinical practice, to reduce dyskinesia developing as a side-effect of levodopa treatment in patients suffering from Parkinson's disease (PD). This study was aimed at evaluating the antidyskinetic effect of another glutamate antagonist, memantine. We performed a randomized, double-blind and placebo-controlled crossover clinical trial of memantine (20 mg), with a 3-week treatment period, and 15 patients completed the study. The primary outcome measure, a change in observed dyskinesia ratings, did not reach significance. Seven of the 15 patients reduced the L-dopa-induced dyskinesias by 32%, whereas for three patients, they increased by 33%, and for five patients, they did not change. Data from the self-administered diaries, as a secondary outcome measure, did show a significant 35% reduction in the percentage of time of the day spent with dyskinesia, from 25% (placebo) to 16% (memantine). Memantine was well tolerated, without any serious adverse events, or worsening in the parkinsonian motor score. The results suggest that memantine may be a useful antidyskinetic drug, and a larger clinical study is warranted. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Memantine Enhances the Effect of Olanzapine in Patients With Schizophrenia: A Randomized, Placebo-Controlled Study.

PubMed

Fakhri, Ahmad; Pakseresht, Sirous; Haghdoost, Mohammad Reza; Hekmatkhah, Nasihat; Torkashvand, Maria; Ghorbanzadeh, Behnam

2016-11-01

Glutamate dysregulation may be involved in the neuropathology of schizophrenia. Memantine, a drug approved by the FDA for the treatment of moderate to severe Alzheimer's disease, acts as a partial uncompetitive NMDA receptor antagonist. The aim of this study was to examine the efficacy of memantine as an adjunctive treatment to olanzapine in patients with schizophrenia. In this double-blind, placebo-controlled studies, patients with schizophrenia according to DSM-IV clinical criteria were selected. Patients were randomly assigned to receive either memantine (week 1:10 mg/day; weeks 2-6:20 mg/day) plus olanzapine (15-20 mg/day) or olanzapine plus placebo. At baseline, no statistically significant difference regarding the mean total PANSS scores between treatment groups was found. Results showed that memantine significantly improved the positive and negative PANSS score in patients maintained on olanzapine after six weeks compared to olanzapine alone (P<0.001). Furthermore, female patients showed significantly better response than males, especially in positive PANSS score. No significant changes in extrapyramidal symptoms were observed.These findings indicate that olanzapine efficacy might be augmented with memantine. Furthermore, this effect is more remarkable in female patients with schizophrenia.

Comparing Efficacy and Side Effects of Memantine vs. Risperidone in the Treatment of Autistic Disorder.

PubMed

Nikvarz, Nikvarz; Alaghband-Rad, Javad; Tehrani-Doost, Mehdi; Alimadadi, Abbas; Ghaeli, Padideh

2017-01-01

Introduction: This study was aimed to compare the efficacy and side effects of memantine, an antagonist of the NMDA receptor of glutamate, with risperidone given the fact that glutamate has been noted for its possible effects in the pathogenesis of autism. Risperidone, an atypical antipsychotic, has been approved by FDA for the management of irritability associated with autism. Methods: 30 children, aged 4-17 years, entered an 8-week, randomized trial. Patients were randomly assigned to receive either risperidone or memantine. Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS), Clinical Global Impressions - Improvement (CGI-I) and Clinical Global Impression-Severity (CGI-S) scales were used to assess behavioral symptoms of the patients. Results: Both risperidone and memantine reduced the scores of 4 subscales of ABC as well as the 10-item and the total score of CARS significantly. However, differences between the 2 drugs in the scores of each evaluating scale were not found to be significant. Relatively, larger number of patients on risperidone showed "very much improvement" when assessed by CGI-I scale when compared with those on memantine. Discussion and conclusion: The present study suggests that memantine may have beneficial effects in the treatment of many core symptoms of autism. Therefore, memantine may be considered as a potential medication in the treatment of those autistic children who do not respond or cannot tolerate side effects of risperidone. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of the NMDA receptor antagonist memantine on the expression and development of acute opiate dependence as assessed by withdrawal-potentiated startle and hyperalgesia.

PubMed

Harris, Andrew C; Rothwell, Patrick E; Gewirtz, Jonathan C

2008-03-01

While the N-methyl-D: -aspartate (NMDA) glutamate receptor has been strongly implicated in chronic opiate dependence, relatively few studies have examined the effects of NMDA receptor antagonists on withdrawal from acute opiate exposure. The current study examined the effects of memantine, a well-tolerated NMDA receptor antagonist, on acute opiate dependence as assessed by elevations in rodent startle responding (i.e., "withdrawal-potentiated startle") and increased pain sensitivity (i.e., hyperalgesia). Administration of memantine either attenuated (5 mg/kg) or blocked (10 mg/kg) the expression of withdrawal-potentiated startle during naloxone (2.5 mg/kg)-precipitated withdrawal from a single dose of morphine sulfate (10 mg/kg). Pre-treatment with the NMDA receptor antagonist also inhibited the exacerbation of withdrawal-potentiated startle across repeated acute opiate exposures. Memantine blocked the expression of acute dependence, but was less effective in inhibiting its escalation, when hyperalgesia was used as a measure of withdrawal. These doses of memantine did not affect startle responding or nociception in otherwise drug-free animals. Data from additional control groups indicated that the effects of memantine on the expression of withdrawal were not influenced by nonspecific interactions between the NMDA antagonist and either morphine or naloxone. These findings suggest that the NMDA receptor may play a key role in the earliest stages of opiate dependence and provide further evidence that memantine may be useful for the treatment of opiate withdrawal.

Memantine Protects Rats Treated with Intrathecal Methotrexate from Developing Spatial Memory Deficits

PubMed Central

Cole, Peter D.; Vijayanathan, Veena; Ali, Nafeeza F.; Wagshul, Mark E.; Tanenbaum, Eric J.; Price, Jeremy; Dalal, Vidhi; Gulinello, Maria E.

2014-01-01

Purpose To test whether memantine can prevent methotrexate-induced cognitive deficits in a preclinical model. Experimental Design After noting that methotrexate exposure induces prolonged elevations of the glutamate analog homocysteic acid (HCA) within cerebrospinal fluid, we tested whether intrathecal injection of HCA would produce memory deficits similar to those observed after intrathecal methotrexate. We then tested whether memantine, an antagonist of the N-methyl-D-aspartate (NMDA) subclass of glutamate receptors, could protect animals treated with clinically relevant doses of intrathecal methotrexate against developing memory deficits. Finally, we asked whether memantine affected this pathway beyond inhibiting the NMDA receptor by altering expression of the NMDA receptor or affecting concentrations of HCA or glutamate within the central nervous system. Results Four intrathecal doses of methotrexate induced deficits in spatial memory, persisting at least one month following the final injection. Intrathecal HCA was sufficient to reproduce this deficit. Concurrent administration of memantine during the period of methotrexate exposure was protective, decreasing the incidence of methotrexate-induced spatial memory deficits from 56% to 20% (P < 0.05). Memantine neither altered expression of NMDA receptors within the hippocampus nor blunted the methotrexate-induced increases in glutamate or HCA. Conclusions Excitotoxic glutamate analogs including HCA contribute to cognitive deficits observed after intrathecal methotrexate. Memantine, an NMDA receptor antagonist, reduces the incidence of cognitive deficits in rats treated with intrathecal methotrexate, and may therefore benefit patients with cancer receiving similar treatment. PMID:23833301

Combining hypobaric hypoxia or hyperbaric oxygen postconditioning with memantine reduces neuroprotection in 7-day-old rat hypoxia-ischemia.

PubMed

Gamdzyk, Marcin; Ziembowicz, Apolonia; Bratek, Ewelina; Salinska, Elzbieta

2016-10-01

Perinatal hypoxia-ischemia causes brain injury in neonates, but a fully successful treatment to prevent changes in the brain has yet to be developed. The aim of this study was to evaluate the effect of combining memantine treatment with HBO (2.5 ATA) or HH (0.47 ATA) on neonatal hypoxia-ischemia brain injury. 7-day old rats were subjected to hypoxia-ischemia (H-I) and treated with combination of memantine and HBO or HH. The brain damage was evaluated by examination of infarct area and the number of apoptotic cells in CA1 region of hippocampus. Additionally, the level of reactive oxygen species (ROS) was measured. Memantine, HBO or HH postconditioning applied at short time (1-6h) after H-I, and repeated for two subsequent days, resulted in significant neuroprotection. The reduction in ipsilateral hemisphere weight deficit and in the size of infarct area was observed 14days after H-I. A reduction in apoptosis and ROS level was also observed. Combining memantine with HBO or HH resulted in a loss of neuroprotection. Our results show that, combining HBO or HH postconditioning with memantine produce no additive increase in the neuroprotective effect. On the contrary, combining the treatments resulted in lower neuroprotection in comparison to the effects of memantine, HBO or HH alone. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Memantine improves buprenorphine/naloxone treatment for opioid dependent young adults.

PubMed

Gonzalez, Gerardo; DiGirolamo, Gregory; Romero-Gonzalez, Mauricio; Smelson, David; Ziedonis, Douglas; Kolodziej, Monika

2015-11-01

Opioid use disorders are considered a serious public health problem among young adults. Current treatment is limited to long-term opioid substitution therapy, with high relapse rates after discontinuation. This study evaluated the co-administration of memantine to brief buprenorphine pharmacotherapy as a treatment alternative. 13-week double-blind placebo-controlled trial evaluating 80 young adult opioid dependent participants treated with buprenorphine/naloxone 16-4mg/day and randomized to memantine (15mg or 30mg) or placebo. Primary outcomes were a change in the weekly mean proportion of opioid use, and cumulative abstinence rates after rapid buprenorphine discontinuation on week 9. Treatment retention was not significantly different between groups. The memantine 30mg group was significantly less likely to relapse and to use opioids after buprenorphine discontinuation. Among participants abstinent on week 8, those in the memantine 30mg group (81.9%) were significantly less likely to relapse after buprenorphine was discontinued compared to the placebo group (30%) (p<0.025). Also, the memantine 30mg group had significantly reduced opioid use (mean=0, SEM±0.00) compared to the placebo group (mean=0.33, SEM±0.35; p<0.004) during the last 2 weeks of study participation. Memantine 30mg significantly improved short-term treatment with buprenorphine/naloxone for opioid dependent young adults by reducing relapse and opioid use after buprenorphine discontinuation. Combined short-term treatment with buprenorphine/naloxone may be an effective alternative treatment to long-term methadone or buprenorphine maintenance in young adults. Published by Elsevier Ireland Ltd.

Effect of Gabapentin/Memantine on the Infantile Nystagmus Syndrome in the Zebrafish Model: Implications for the Therapy of Ocular Motor Diseases.

PubMed

Bögli, Stefan Yu; Afthinos, Maresa; Huang, Melody Ying-Yu

2017-06-01

Infantile nystagmus syndrome (INS) is a disorder characterized by typical horizontal eye oscillations. Due to the uncertain etiology of INS, developing specific treatments remains difficult. Single reports demonstrated, on limited measures, alleviating effects of gabapentin and memantine. In the current study, we employed the zebrafish INS model belladonna (bel) to conduct an in-depth study of how gabapentin and memantine interventions alleviate INS signs, which may further restore visual conditions in affected subjects. Moreover, we described the influence of both medications on ocular motor functions in healthy zebrafish, evaluating possible iatrogenic effects. Ocular motor function and INS characteristics were assessed by eliciting optokinetic response, spontaneous nystagmus, and spontaneous saccades in light and in dark, in 5- to 6-day postfertilization bel larvae and heterozygous siblings. Single larvae were recorded before and after a 1-hour drug treatment (200 mM gabapentin/0.2 mM memantine). Both interventions significantly reduced nystagmus intensity (gabapentin: 59.98%, memantine: 39.59%). However, while the application of gabapentin affected all tested ocular motor functions, memantine specifically reduced nystagmus amplitude and intensity, and thus left controls completely unaffected. Finally, both drug treatments resulted in specific changes in nystagmus waveform and velocity. Our study provides deeper insight into gabapentin and memantine treatment effect in the zebrafish INS model. Moreover, this study should establish zebrafish as a pharmacologic animal model for treating nystagmus and ocular motor disease, serving as a basis for future large-scale drug screenings.

Novel Therapeutic Targets for Chronic Migraine

DTIC Science & Technology

2012-09-01

investigation of amiloride and related drugs as treatments for chronic migraine. We have also found that the drug memantine inhibits cortical...spreading depression, but acute treatment with memantine does not inhibit nociceptive signaling in the brainstem. These results are consistent with the...potential efficacy of memantine as a preventive therapy, but not as an acute therapy for migraine. We have also found that delta opioid receptor

Anti-dementia drugs and changes in gait: a pre-post quasi-experimental pilot study.

PubMed

Beauchet, Olivier; Launay, Cyrille P; Allali, Gazan; Watfa, Gilles; Gallouj, Karim; Herrmann, François R; Annweiler, Cédric

2013-11-21

Anti-dementia drugs may improve gait performance. No comparison between acetylcholinesterase inhibitors (CEIs) and memantine-related changes in gait variability has been reported. The objectives of this study were to 1) quantify and compare the mean values and coefficients of variation (CoV) of stride time in demented patients with Alzheimer's disease and related disorders (ADRD) before and after the use of CEIs or memantine, and in age- and gender-matched controls patients with ADRD using no anti-dementia drugs; and 2) to determine whether changes in CoV of stride time differed between CEIs or memantine. A total of 120 demented patients with mild-to-moderate ADRD were prospectively included in this pre-post quasi-experimental study with two intervention groups (43 patients taking CEIs, and 41 taking memantine) and a control group (36 age- and gender matched patients without any anti-dementia drugs). CoV of stride time and walking speed were measured with GAITRite® system while usual walking at steady state. Age, gender, number of drugs daily taken, use of psychoactive drugs, body mass index and time between the two visits were also recorded. There was no difference between groups for the time between baseline and follow-up assessments (232.9 ± 103.7 days for patients without anti-dementia drugs, 220.0 ± 67.5 days for patients with CEIs, 186.7 ± 96.2 days for patients with memantine, P = 0.062). Patients with memantine had a lower (i.e., better) CoV of stride time at follow-up assessment compared to those with CEIs (4.2 ± 2.4% versus 5.8 ± 4.2%, P = 0.010). Patients with memantine had a greater decrease in CoV of stride time compared to those with CEIs (-1.90% versus 0.93%, P = 0.010) and mixed-effects linear regressions showed that this decrease was specifically explained by memantine (P = 0.028). Our results showed that patients with ADRD and treated with memantine, but not those with CEIs, decreased their gait variability, and thus improved their gait safety (Trial registration number: NCT01315704).

Memantine Monotherapy for Alzheimer’s Disease: A Systematic Review and Meta-Analysis

PubMed Central

Matsunaga, Shinji; Kishi, Taro; Iwata, Nakao

2015-01-01

Background We performed an updated meta-analysis of randomized placebo-controlled trials testing memantine monotherapy for patients with Alzheimer’s disease (AD). Methods The meta-analysis included randomized controlled trials of memantine monotherapy for AD, omitting those in which patients were also administered a cholinesterase inhibitor. Cognitive function, activities of daily living, behavioral disturbances, global function, stage of dementia, drug discontinuation rate, and individual side effects were compared between memantine monotherapy and placebo groups. The primary outcomes were cognitive function and behavioral disturbances; the others were secondary outcomes. Results Nine studies including 2433 patients that met the study’s inclusion criteria were identified. Memantine monotherapy significantly improved cognitive function [standardized mean difference (SMD)=−0.27, 95% confidence interval (CI)=−0.39 to −0.14, p=0.0001], behavioral disturbances (SMD=−0.12, 95% CI=−0.22 to −0.01, p=0.03), activities of daily living (SMD=−0.09, 95% CI=−0.19 to −0.00, p=0.05), global function assessment (SMD=−0.18, 95% CI=−0.27 to −0.09, p=0.0001), and stage of dementia (SMD=−0.23, 95% CI=−0.33 to −0.12, p=0.0001) scores. Memantine was superior to placebo in terms of discontinuation because of inefficacy [risk ratio (RR)=0.36, 95% CI=0.17¬ to 0.74, p=0.006, number needed to harm (NNH)=non significant]. Moreover, memantine was associated with less agitation compared with placebo (RR=0.68, 95% CI=0.49 to 0.94, p=0.02, NNH=non significant). There were no significant differences in the rate of discontinuation because of all causes, all adverse events, and individual side effects other than agitation between the memantine monotherapy and placebo groups. Conclusions Memantine monotherapy improved cognition, behavior, activities of daily living, global function, and stage of dementia and was well-tolerated by AD patients. However, the effect size in terms of efficacy outcomes was small and thus there is limited evidence of clinical benefit. PMID:25860130

Anti-autophagic and anti-apoptotic effects of memantine in a SH-SY5Y cell model of Alzheimer's disease via mammalian target of rapamycin-dependent and -independent pathways

PubMed Central

SONG, GUIJUN; LI, YU; LIN, LULU; CAO, YUNPENG

2015-01-01

Memantine non-competitively blocks the N-methyl-d-aspartate receptor in order to inhibit beta-amyloid (Aβ) secretion, and has been used to treat moderate-to-severe Alzheimer's disease (AD). However, the mechanisms underlying the role of memantine in the autophagy and apoptosis of neuronal cells in AD, as well as the association between neuronal autophagy and apoptosis have yet to be elucidated. The present study aimed to establish an AD cell model overexpressing the 695-amino-acid Swedish mutant of Aβ precursor protein (APP695swe) in order to observe the effects of memantine on the cell viability, autophagy and apoptosis of SH-SY5Y cells in the AD model, and to investigate the associated underlying mechanisms. A pcDNA3.1-APP695 plasmid was transfected into the SH-SY5Y cells. Reverse transcription-quantitative polymerase chain reaction and western blot analyses demonstrated that the AD cell model was successfully established. MTT assays demonstrated that memantine was able to upregulate neuronal cell survival, and acridine orange staining and flow cytometry demonstrated that memantine (5 µM) was able to inhibit neuronal autophagy and apoptosis. Following neuronal autophagy induction by rapamycin, cell apoptosis rates increased significantly. Further experiments revealed that memantine was able to upregulate the expression of signaling molecules phosphorylated (p)-phosphoinositide 3-kinase, p-Akt and p-mammalian target of rapamycin (mTOR), and also inhibited the phosphorylation of the B-cell lymphoma 2/Beclin-1 complex via mitogen-activated protein kinase 8. In conclusion, the results of the present study demonstrated that in the AD cell model, autophagy was able to promote apoptosis. Memantine exerted anti-autophagic and anti-apoptotic functions, and mTOR-dependent as well as-independent autophagic signaling pathways were involved in this process. Therefore, these results of the present study strongly supported the use of memantine as a potential therapeutic strategy for AD treatment. PMID:26459718

Efficacy and safety profile of memantine in patients with cognitive impairment in multiple sclerosis: A randomized, placebo-controlled study.

PubMed

Peyro Saint Paul, Laure; Creveuil, Christian; Heinzlef, Olivier; De Seze, Jerome; Vermersch, Patrick; Castelnovo, Giovanni; Cabre, Philippe; Debouverie, Marc; Brochet, Bruno; Dupuy, Benoit; Lebiez, Pierre; Sartori, Éric; Clavelou, Pierre; Brassat, David; Lebrun-Frenay, Christine; Daplaud, David; Pelletier, Jean; Coman, Irène; Hautecoeur, Patrick; Tourbah, Ayman; Defer, Gilles

2016-04-15

Memantine, an uncompetitive antagonist of N-methyl-D-aspartate (NMDA)-type glutamate receptors that was approved for the treatment of moderate to severe Alzheimer's disease, has been negatively evaluated for the treatment of cognitive disorders of multiple sclerosis, but these studies were conducted only during short-term administration and on a heterogeneous group of patients with different forms of the disease. In addition, many adverse reactions were observed in these patients. The purpose of the "EMERITE" (NCT01074619) study was to examine the efficacy and safety of the long-term administration of memantine as a symptomatic treatment for cognitive disorders in patients with relapsing-remitting multiple sclerosis (RR-MS). The study was supported by the French Ministry of Health and received additional support from Lundbeck. In this double-blind, placebo-controlled, parallel group, randomized trial, the participants were assigned to receive memantine (20 mg/day) or a placebo for 52 weeks. The participants included males and females, 18-60 years of age, with a diagnosis of RR-MS and presenting with a cognitive complaint and/or demonstrating moderate cognitive impairment. The data were collected in the Department of Neurology in 19 French centers. The primary outcome was the Paced Auditory Serial Addition Test (PASAT) score at week 52. Secondary measurements included additional neuropsychological tests and the annualized relapse rate. The scores were adjusted according to the baseline scores in the analysis. The safety was assessed by the number of adverse events. The random sequence was generated using the Excel software. At each center, only the pharmacist had access to the allocation sequence and could be asked to unblind the trial. Fifty patients were allocated to the memantine group, and 43 to the placebo group. The intent-to-treat (ITT) population included 31 patients in each group. After adjusting for the PASAT scores at baseline, the PASAT scores at the end point did not differ between the memantine and the placebo groups (p=0.88). Adjusted mean score difference (memantine minus placebo), was -0.40 (95% confidence interval: -5.5; +4.7). No significant differences were observed for the secondary outcomes (short term memory and attention scores, EDSS, and relapse rate). The findings remained unchanged after multiple imputation of the missing values. Neurological and psychiatric adverse events were significantly higher in the memantine group than in the placebo group, and these parameters were higher than those reported in the product literature of memantine. No differences between the placebo and memantine groups were observed. Nevertheless, the tolerability of memantine was significantly worse than expected. Copyright © 2016 Elsevier B.V. All rights reserved.

Synergistic effects of galantamine and memantine in attenuating scopolamine-induced amnesia in mice.

PubMed

Busquet, Perrine; Capurro, Valeria; Cavalli, Andrea; Piomelli, Daniele; Reggiani, Angelo; Bertorelli, Rosalia

2012-01-01

We investigated a possible drug efficacy enhancement obtained by combining inactive doses of galantamine and memantine in the scopolamine-induced amnesia model in mice. We evaluated the effects of the two drugs, either alone or in combination, using the spontaneous alternation and object recognition tasks. In both tests, combination of low doses of galantamine (0.1 mg/kg, s.c.) and memantine (0.5 mg/kg, i.p.), which were sub-active per se, rescued the memory impairment induced by scopolamine (1 mg/kg, i.p.). The results suggest that combinations of galantamine and memantine might provide a more effective treatment of memory impairments in cognitive disorders than either drug used alone.

Effect of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity.

PubMed

Topdag, M; Iseri, M; Gelenli, E; Yardimoglu, M; Yazir, Y; Ulubil, S A; Topdag, D O; Ustundag, E

2012-11-01

This study aimed to contribute to the literature on the prevention and treatment of ototoxicity due to various drugs and chemicals. This study compared the histological effects of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity, in 36 rats. Dexamethasone and memantine had significant effects on the stria vascularis, organ of Corti and spiral ganglion (p < 0.05). Although piracetam decreased the apoptosis rate, this effect was not statistically significant (p > 0.05). Dexamethasone and memantine were found superior to piracetam in reducing apoptosis due to cisplatin ototoxicity. Further studies of this subject are needed, incorporating electron microscopy and auditory brainstem response testing.

Comparison of Pharmacological Potency and Safety of Glutamate Blocker IEM-1913 and Memantine.

PubMed

Gmiro, V E; Serdyuk, S E; Veselkina, O S

2015-11-01

Adamantane-containing glutamate blocker IEM-1913 (1-amino-4-(1-adamantane-amino)-butane dihydrochloride) equals to memantine in antiparkinsonian potency, but surpasses it in anticonvulsive, antidepressant, and analgesic activities. Moreover, its use is less toxic and safer. IEM-1913 produces significant pharmacological effects at a wide concentration diapason (0.03-1.00 mg/kg), while memantine is effective within a narrow range only (15-20 mg/kg). High pharmacological efficacy and low toxicity of IEM-1913 can be explained by the fact that in contrast to monocationic selective NMDA antagonist memantine, the dicationic glutamate blocker IEM-1913 produces a combined block of cerebral NMDA and AMPA receptors.

Effect of memantine on cue-induced alcohol craving in recovering alcohol-dependent patients.

PubMed

Krupitsky, Evgeny M; Neznanova, Olga; Masalov, Dimitry; Burakov, Andrey M; Didenko, Tatyana; Romanova, Tatyana; Tsoy, Marina; Bespalov, Anton; Slavina, Tatyana Y; Grinenko, Alexander A; Petrakis, Ismene L; Pittman, Brian; Gueorguieva, Ralitza; Zvartau, Edwin E; Krystal, John H

2007-03-01

Ethanol blocks N-methyl-d-aspartic acid (NMDA) glutamate receptors. Increased NMDA receptor function may contribute to motivational disturbances that contribute to alcoholism. The authors assessed whether the NMDA receptor antagonist memantine reduces cue-induced alcohol craving and produces ethanol-like subjective effects. Thirty-eight alcohol-dependent inpatients participated in three daylong testing sessions in a randomized order under double-blind conditions. On each test day, subjects received 20 mg of memantine, 40 mg of memantine, or placebo, and subjective responses to treatment were assessed. The level of alcohol craving was assessed before and after exposure to an alcohol cue. Memantine did not stimulate alcohol craving before exposure to an alcohol cue, and it attenuated alcohol cue-induced craving in a dose-related fashion. It produced dose-related ethanol-like effects without adverse cognitive or behavioral effects. These data support further exploration of whether well-tolerated NMDA receptor antagonists might have a role in the treatment of alcoholism.

Response to rivastigmine transdermal patch or memantine plus rivastigmine patch is affected by apolipoprotein E genotype in Alzheimer patients.

PubMed

Han, Hyun Jeong; Kim, Byeong C; Lee, Jun-Young; Ryu, Seung-Ho; Na, Hae Ri; Yoon, Soo Jin; Park, Hyun Young; Shin, Joon Hyun; Cho, Soo-Jin; Yi, Hyon-Ah; Choi, Mun Seong; Heo, Jae-Hyeok; Park, Kyung Won; Kim, Kwang K; Choi, Seong Hye

2012-01-01

The apolipoprotein E (APOE) genotype in response to pharmacological treatments in patients with Alzheimer's disease (AD) remains a matter of controversy. This analysis investigated the effect of the APOE genotype on the clinical response to rivastigmine transdermal patch monotherapy or memantine plus rivastigmine patch in patients with mild to moderate AD. Two hundred and six (n = 206) patients with probable AD and Mini-Mental State Examination (MMSE) scores of 10-20 were randomized to rivastigmine patch monotherapy or memantine plus rivastigmine patch for 24 weeks. Of the 206 patients with probable AD, 146 patients who consented to genetic testing for APOE were included and assessed for this subgroup study. There were no significant differences on MMSE, NPI, ADAS-cog, ADCS-ADL, CDR-SB, NPI and FAB between rivastigmine patch monotherapy and memantine plus rivastigmine patch according to the APOE genotype. However, patients with moderately severe AD (MMSE ≤15) who were APOE ε4 carriers showed higher responder rates on ADCS-ADL with memantine plus rivastigmine patch compared to rivastigmine patch monotherapy. Moderately severe AD patients with the APOE ε4 allele may respond more favorably to memantine plus rivastigmine patch than ε4 noncarriers. Copyright © 2012 S. Karger AG, Basel.

MEMANTINE ATTENUATES THE OKADAIC ACID INDUCED SHORT-TERM SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS IN RATS.

PubMed

Dashniani, M; Chighladze, M; Burjanadze, M; Beselia, G; Kruashvili, L

2016-03-01

In the present study, the possible beneficial effect of memantine on the Okadaic Acid (OA) induced spatial short-term memory impairment was examined in spatial alternation task, and the neuroprotective potential of memantine on OA-induced structural changes in the hippocampus was evaluated by Nissl staining. OA was dissolved in artificial cerebrospinal fluid (aCSF) and injected intracerebroventriculary (ICV) 200 ng in a volume of 10 μl bilaterally. Vehicle control received aCSF ICV bilaterally. Control and OA injected rats were divided into 2 subgroups injected i.p. with saline or memantine (5 mg/kg). Memantine or saline were given daily for 13 days starting from the day of OA injection. Behavioral study showed that bilateral ICV microinjection of OA induced impairment in spatial short-term memory. Nissl staining in the present study showed that the ICV microinjection of OA significantly decreased the number of surviving pyramidal neurons in the CA1 region of the hippocampus. Chronic administration of memantine effectively attenuated OA induced spatial short-term memory impairment and the OA-induced neuropathological changes in the hippocampus. Therefore, ICV injection of OA can be used as an experimental model to study mechanisms of neurodegeneration and define novel therapeutics targets for AD pathology.

Cost-effectiveness of memantine in moderate and severe Alzheimer's disease in Norway.

PubMed

Rive, B; Aarsland, D; Grishchenko, M; Cochran, J; Lamure, M; Toumi, M

2012-06-01

The cost-effectiveness of memantine for the treatment of moderate and severe Alzheimer's disease has been assessed in several European countries. Objective of the study was to assess it in Norwegian settings. This cost-utility analysis used a Markov modelling approach to simulate the evolution of patients until their need for full-time care (FTC) over a 5-year period. FTC was defined as a patient becoming either dependent or institutionalised. Transition probabilities were estimated using a newly developed predictive equation of time to FTC. Health resource use and utilities were obtained from the Scandinavian Study of Cost and Quality of Life in Alzheimer's Disease study, and mortality was obtained from the Oslo study. Memantine efficacy was based on a meta-analysis of six large trials. The model compared memantine with its alternative in this population, that is no pharmacological treatment or background therapy with acetylcholinesterase inhibitors. The model underwent extensive sensitivity analyses. In Norway, memantine was found to delay the need for FTC by 4.4 weeks compared with standard care and was associated with increased quality-adjusted life years. Memantine was the dominant strategy with cost savings of €3739 (30 041 NOK) per patient. The probability of being the dominant strategy was 98.8%. This result was confirmed across multiple sensitivity analyses. The model suggests that memantine prolongs time to FTC for no additional cost to the healthcare system and society. It can be regarded as a cost-effective choice in the management of moderate and severe Alzheimer's disease. Copyright © 2011 John Wiley & Sons, Ltd.

Memantine augmentation in clozapine-refractory schizophrenia: a randomized, double-blind, placebo-controlled crossover study.

PubMed

Veerman, S R T; Schulte, P F J; Smith, J D; de Haan, L

2016-07-01

Dysfunction of neuroplasticity due to N-methyl-d-aspartate (NMDA) receptor hypofunction may be a causal factor for memory and executive dysfunctioning in schizophrenia. Deregulation of NMDA transmission in the prefrontal cortex may also explain negative and positive symptoms. Clozapine augmentation with memantine targets altered NMDA receptor-mediated neurotransmission in schizophrenia and showed substantial beneficial effects on several symptom domains in a small proof-of-concept study. We evaluate effects of memantine add-on treatment to clozapine for memory and executive function, and negative and positive symptoms in schizophrenia. Clozapine-treated patients with refractory schizophrenia were randomly assigned to 12 weeks of double-blind adjunctive treatment with memantine (n = 26) or placebo (n = 26). Crossover occurred after a 2-week placebo wash-out period. Primary endpoints were change from baseline to 12 weeks treatment and 14 weeks to 26 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Side effects were assessed using the Liverpool University Neuroleptic Side-Effect Rating Scale. When compared with placebo, memantine improved a composite memory score comprising verbal recognition memory and paired associates learning task scores on the CANTAB (effect size = 0.30) and PANSS negative subscale score (effect size = 0.29). Side effects were mild and transient. In patients with clozapine-treated refractory schizophrenia, memantine addition significantly improved verbal and visual memory and negative symptoms without serious adverse effects. These results justify further investigations on long-term memantine augmentation to clozapine in treatment-resistant schizophrenia.

The effect of memantine on sleep architecture and psychiatric symptoms in patients with Alzheimer's disease.

PubMed

Ishikawa, Ichiro; Shinno, Hideto; Ando, Nobuo; Mori, Takahiro; Nakamura, Yu

2016-06-01

Behavioural and psychological symptoms of dementia (BPSD) are commonly present in patients with Alzheimer's disease (AD). Disturbed sleep quality is also observed in AD patients. However, the effects of memantine on sleep architecture have not been investigated. The purpose of this study was to investigate the effects of memantine on polysomnography (PSG) variables and BPSD. In total, 12 patients with AD (mean age: 79.0±4.1 years old) were enrolled in this study. The following tests were performed: the Neuropsychiatric Inventory for the assessment of BPSD, the Mini-Mental State Examination (MMSE) for cognitive function, and PSG for evaluation of sleep architecture. After baseline examinations, patients were treated with memantine according to a standard prescription protocol. After being treated with 20 mg/day of memantine for 4 weeks, examinations were carried out again. All subjects completed the trial. The mean MMSE and NPI scores were 22.6±3.4 and 13.8±12.9, respectively. Treatment with memantine significantly decreased the NPI score (5.8±4.3, p<0.01). There were significant decreases in the scores of subscales for anxiety (p=0.04) and irritability/lability (p=0.04). PSG demonstrated a longer total sleep time (TST) (p<0.01), increases in sleep efficiency (p<0.01) and time spent in stage II (% TST, p=0.02), and decreases in nocturnal awakening (p<0.01), the periodic limb movement index (p<0.01), and time spent in stage I (% TST, p=0.02). Memantine was effective for reducing fragmented sleep and improving BPSD, and was well tolerated.

Memantine as an Adjuvant Treatment for Obsessive Compulsive Symptoms in Manic Phase of Bipolar Disorder: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

PubMed

Sahraian, Ali; Jahromi, Leila Razeghian; Ghanizadeh, Ahmad; Mowla, Arash

2017-04-01

The aim of this study is to examine the effects of memantine as an adjuvant treatment for obsessive compulsive (OC) symptoms in patients with bipolar disorder (BD) type I, manic phase. In this 16-week double-blind placebo-controlled randomized clinical trial, 58 patients in the manic phase of BD who had OC symptoms were randomly allocated to receive memantine or placebo plus their routine medications (lithium + olanzapine + clonazepam). The Yale Brown Obsessive Compulsive Behavior Scale was used to assess the outcomes. Adverse effects were also recorded. Thirty-eight patients (19 in the memantine group and 19 in the placebo group) completed the trial. Throughout the trial, the mean score decreased from 20.26 ± 5.91 to 9.73 ± 5.44 in the memantine group (P < 0.000) and from 22.89 ± 5.70 to 16.63 ± 4.00 in the placebo group (P < 0.000). At the end of the study, 15 (78.94%) patients in the memantine group and 7 (36.84%) patients in the placebo group demonstrated more than 34% decline in the Yale Brown Obsessive Compulsive Behavior Scale score (P < 0.01). No serious adverse effects were reported. Our double-blind controlled clinical trial showed that memantine is an effective adjuvant agent for reducing OC symptoms in patients with BD. However, it needs to be noted that our study is preliminary, and larger double-blind controlled studies are needed to confirm the results.

Memantine before Mastectomy Prevents Post-Surgery Pain: A Randomized, Blinded Clinical Trial in Surgical Patients.

PubMed

Morel, Véronique; Joly, Dominique; Villatte, Christine; Dubray, Claude; Durando, Xavier; Daulhac, Laurence; Coudert, Catherine; Roux, Delphine; Pereira, Bruno; Pickering, Gisèle

2016-01-01

Neuropathic pain following surgical treatment for breast cancer with or without chemotherapy is a clinical burden and patients frequently report cognitive, emotional and quality of life impairment. A preclinical study recently showed that memantine administered before surgery may prevent neuropathic pain development and cognitive dysfunction. With a translational approach, a clinical trial has been carried out to evaluate whether memantine administered before and after mastectomy could prevent the development of neuropathic pain, the impairment of cognition and quality of life. A randomized, pilot clinical trial included 40 women undergoing mastectomy in the Oncology Department, University Hospital, Clermont-Ferrand, France. Memantine (5 to 20 mg/day; n = 20) or placebo (n = 20) was administered for four weeks starting two weeks before surgery. The primary endpoint was pain intensity measured on a (0-10) numerical rating scale at three months post-mastectomy. Data analyses were performed using mixed models and the tests were two-sided, with a type I error set at α = 0.05. Compared with placebo, patients receiving memantine showed at three months a significant difference in post-mastectomy pain intensity, less rescue analgesia and a better emotional state. An improvement of pain symptoms induced by cancer chemotherapy was also reported. This study shows for the first time the beneficial effect of memantine to prevent post-mastectomy pain development and to diminish chemotherapy-induced pain symptoms. The lesser analgesic consumption and better well-being of patients for at least six months after treatment suggests that memantine could be an interesting therapeutic option to diminish the burden of breast cancer therapy. Clinicaltrials.gov NCT01536314.

Comparison of behavioral effects of the NMDA receptor channel blockers memantine and ketamine in rats

PubMed Central

Kotermanski, Shawn E.; Johnson, Jon W.; Thiels, Edda

2013-01-01

Memantine and ketamine block N-methyl-D-aspartate (NMDA) receptors with similar affinity and kinetics, yet their behavioral consequences differ: e.g., memantine is used to alleviate symptoms of Alzheimer’s disease, whereas ketamine reproduces symptoms of schizophrenia. The two drugs exhibit different pharmacokinetics, which may play a principal role in their differential behavioral effects. To gain insight into the drugs’ behavioral consequences, we treated adult male rats acutely with varying doses (0–40 mg/kg i.p.) of memantine or ketamine and assessed exploratory behavior and spatial working memory. To examine the importance of pharmacokinetics, we assessed behavior either 15 or 45 min after drug administration. Both drugs decreased ambulation, fine movements, and rearing at the beginning of the exploratory activity test; however, at the end of the test, high doses of only memantine increased ambulation and fine movements. High doses of both drugs disrupted spontaneous alternation, a measure of working memory, but high doses of only memantine elicited perseverative behavior. Surprisingly, ketamine’s effects were influenced by the delay between drug administration and testing no more frequently than were mematine’s. Our findings show that, regardless of test delay, memantine and ketamine evoke similar behavioral effects at lower doses, consistent with NMDA receptors being both drugs’ principal site of action, but can have divergent effects at higher doses. Our results suggest that the divergence of mematine’s and ketamine’s behavioral consequences is likely to result from differences in mechanisms of NMDA receptor antagonism or actions at other receptors. PMID:23665480

Safety and Efficacy of Memantine in Children with Autism: Randomized, Placebo-Controlled Study and Open-Label Extension.

PubMed

Aman, Michael G; Findling, Robert L; Hardan, Antonio Y; Hendren, Robert L; Melmed, Raun D; Kehinde-Nelson, Ola; Hsu, Hai-An; Trugman, Joel M; Palmer, Robert H; Graham, Stephen M; Gage, Allyson T; Perhach, James L; Katz, Ephraim

2017-06-01

Abnormal glutamatergic neurotransmission is implicated in the pathophysiology of autism spectrum disorder (ASD). In this study, the safety, tolerability, and efficacy of the glutamatergic N-methyl-d-aspartate (NMDA) receptor antagonist memantine (once-daily extended-release [ER]) were investigated in children with autism in a randomized, placebo-controlled, 12 week trial and a 48 week open-label extension. A total of 121 children 6-12 years of age with Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR)-defined autistic disorder were randomized (1:1) to placebo or memantine ER for 12 weeks; 104 children entered the subsequent extension trial. Maximum memantine doses were determined by body weight and ranged from 3 to 15 mg/day. There was one serious adverse event (SAE) (affective disorder, with memantine) in the 12 week study and one SAE (lobar pneumonia) in the 48 week extension; both were deemed unrelated to treatment. Other AEs were considered mild or moderate and most were deemed not related to treatment. No clinically significant changes occurred in clinical laboratory values, vital signs, or electrocardiogram (ECG). There was no significant between-group difference on the primary efficacy outcome of caregiver/parent ratings on the Social Responsiveness Scale (SRS), although an improvement over baseline at Week 12 was observed in both groups. A trend for improvement at the end of the 48 week extension was observed. No improvements in the active group were observed on any of the secondary end-points, with one communication measure showing significant worsening with memantine compared with placebo (p = 0.02) after 12 weeks. This trial did not demonstrate clinical efficacy of memantine ER in autism; however, the tolerability and safety data were reassuring. Our results could inform future trial design in this population and may facilitate the investigation of memantine ER for other clinical applications.

Safety and Efficacy of Memantine in Children with Autism: Randomized, Placebo-Controlled Study and Open-Label Extension

PubMed Central

Findling, Robert L.; Hardan, Antonio Y.; Hendren, Robert L.; Melmed, Raun D.; Kehinde-Nelson, Ola; Hsu, Hai-An; Trugman, Joel M.; Palmer, Robert H.; Graham, Stephen M.; Gage, Allyson T.; Perhach, James L.; Katz, Ephraim

2017-01-01

Abstract Objective: Abnormal glutamatergic neurotransmission is implicated in the pathophysiology of autism spectrum disorder (ASD). In this study, the safety, tolerability, and efficacy of the glutamatergic N-methyl-d-aspartate (NMDA) receptor antagonist memantine (once-daily extended-release [ER]) were investigated in children with autism in a randomized, placebo-controlled, 12 week trial and a 48 week open-label extension. Methods: A total of 121 children 6–12 years of age with Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR)-defined autistic disorder were randomized (1:1) to placebo or memantine ER for 12 weeks; 104 children entered the subsequent extension trial. Maximum memantine doses were determined by body weight and ranged from 3 to 15 mg/day. Results: There was one serious adverse event (SAE) (affective disorder, with memantine) in the 12 week study and one SAE (lobar pneumonia) in the 48 week extension; both were deemed unrelated to treatment. Other AEs were considered mild or moderate and most were deemed not related to treatment. No clinically significant changes occurred in clinical laboratory values, vital signs, or electrocardiogram (ECG). There was no significant between-group difference on the primary efficacy outcome of caregiver/parent ratings on the Social Responsiveness Scale (SRS), although an improvement over baseline at Week 12 was observed in both groups. A trend for improvement at the end of the 48 week extension was observed. No improvements in the active group were observed on any of the secondary end-points, with one communication measure showing significant worsening with memantine compared with placebo (p = 0.02) after 12 weeks. Conclusions: This trial did not demonstrate clinical efficacy of memantine ER in autism; however, the tolerability and safety data were reassuring. Our results could inform future trial design in this population and may facilitate the investigation of memantine ER for other clinical applications. PMID:26978327

PubMed Central

RALLI, M.; TROIANI, D.; PODDA, M.V.; PACIELLO, F.; ERAMO, S.L.M.; DE CORSO, E.; SALVI, R.; PALUDETTI, G.; FETONI, A.R.

2014-01-01

SUMMARY Short-term tinnitus develops shortly after the administration of a high dose of salicylate. Since salicylate selectively potentiates N-methyl- D-aspartate (NMDA) currents in spiral ganglion neurons, it may play a vital role in tinnitus by amplifying NMDA-mediated neurotransmission. The aim of this study was to determine whether systemic treatment with a NMDA channel blocker, memantine, could prevent salicylate-induced tinnitus in animals. Additional experiments were performed to evaluate the effect of memantine on the auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) to test for changes in hearing function. Thirty-six rats were divided into 3 groups and treated daily for four consecutive days. One group (n = 12) was injected with salicylate (300 mg/kg/d, IP), the second (n = 12) was treated with memantine (5 mg/kg/d, IP) and the third group (n = 12) was injected with salicylate and memantine. All rats were tested for tinnitus and hearing loss at 2, 24, 48 and 72 h after the first drug administration and 24 h post treatment; tinnituslike behaviour was assessed with gap prepulse inhibition of acoustic startle (GPIAS), and hearing function was measured with DPOAE, ABR and noise burst prepulse inhibition of acoustic startle (NBPIAS). Rats in the salicylate group showed impaired GPIAS indicative of transient tinnitus-like behaviour near 16 kHz that recovered 24 h after the last salicylate treatment. Memantine did not cause a significant change in GPIAS. Combined injection of salicylate and memantine significantly attenuated GPIAS tinnitus-like behaviour at 48 hours after the first injection. None of the treatments induced permanent threshold shifts in the ABR and DPOAE, which recovered completely within one day post treatment. Animals treated with salicylate plus memantine showed results comparable to animals treated with salicylate alone, confirming that there is no effect of memantine on DPOAE which reflects OHC function. The present study confirms the role of cochlear NMDA receptors in the induction of salicylate-induced tinnitus. PMID:24882929

Antenatal blockade of N-methyl-D-aspartate receptors by Memantine reduces the susceptibility to diabetes induced by a high-fat diet in rats with intrauterine growth restriction.

PubMed

Huang, Xiao-Ting; Yue, Shao-Jie; Li, Chen; Guo, Jia; Huang, Yan-Hong; Han, Jian-Zhong; Feng, Dan-Dan; Luo, Zi-Qiang

2017-05-01

Intrauterine growth retardation (IUGR) is closely related to the later development of type 2 diabetes in adulthood. Excessive activation of N-methly-D-aspartate receptors (NMDARs) causes excitatory neurotoxicity, resulting in neuronal injury or death. Inhibition of NMDARs enhances the glucose-stimulated insulin secretion and survival of islet cells in type 2 diabetic mouse and human islets. Here, we examined whether antenatal blockade of NMDARs by Memantine could decrease the risk of diabetes induced by a high-fat (HF) diet at adulthood in IUGR rats. Pregnant SD rats were assigned to four groups: control, IUGR, Memantine, and Memantine + IUGR. The pregnant rats were exposed to hypoxic conditions (FiO2 = 0.105) for 8 h/day (IUGR group) or given a daily Memantine injection (5 mg/kg, i.p.) before hypoxia exposure from embryonic day (E) 14.5 to E 20.5 (Memantine + IUGR). The offspring were fed an HF diet with 60% of the calories from age 4 to 12 weeks. We found that NMDAR mRNAs were expressed in the fetal rat pancreas. An HF diet resulted in a high rate of diabetes at adulthood in the IUGR group. Antenatal Memantine treatment decreased the risk of diabetes at adulthood of rats with IUGR, which was associated with rescued glucose tolerance, increased insulin release, improved the insulin sensitivity, and increased expression of genes related to beta-cell function in the pancreas. Together, our results suggest that antenatal blockade of NMDARs by Memantine in pregnant rats improves fetal development and reduces the susceptibility to diabetes at adulthood in offspring. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cross-Over Trial of Gabapentin and Memantine as Treatment for Acquired Nystagmus

PubMed Central

Thurtell, Matthew J.; Joshi, Anand C.; Leone, Alice C.; Tomsak, Robert L.; Kosmorsky, Gregory S.; Stahl, John S.; Leigh, R. John

2010-01-01

We conducted a masked, cross-over, therapeutic trial of gabapentin (1200mg/day) versus memantine (40mg/day) for acquired nystagmus in 10 patients (28–61 years; 7 female; MS: 3, post-stroke: 6, post-traumatic: 1). Nystagmus was pendular in 6 patients (oculopalatal tremor: 4, MS: 2) and jerk upbeat, hemi-seesaw, torsional, or upbeat-diagonal in each of the others. Both drugs reduced median eye speed (p<0.001), gabapentin by 32.8% and memantine by 27.8%, and improved visual acuity (p<0.05). Each patient improved with one or both drugs. Side-effects included unsteadiness with gabapentin and lethargy with memantine. Both drugs should be considered as treatment for acquired forms of nystagmus. PMID:20437565

Classics in Chemical Neuroscience: Memantine.

PubMed

Alam, Shahrina; Lingenfelter, Kaelyn Skye; Bender, Aaron M; Lindsley, Craig W

2017-09-20

Memantine was the first breakthrough medication for the treatment of moderate to severe Alzheimer's disease (AD) patients and represents a fundamentally new mechanism of action (moderate-affinity, uncompetitive, voltage-dependent, N-methyl-d-aspartate (NMDA) receptor antagonist that exhibits fast on/off kinetics) to modulate glutamatergic dysfunction. Since its approval by the FDA in 2003, memantine, alone and in combination with donepezil, has improved patient outcomes in terms of cognition, behavioral disturbances, daily functioning, and delaying time to institutionalization. In this review, we will highlight the historical significance of memantine to AD (and other neuropsychiatric disorders) as well as provide an overview of the synthesis, pharmacology, and drug metabolism of this unique NMDA uncompetitive antagonist that clearly secures its place among the Classics in Chemical Neuroscience.

A study of potential pharmacokinetic and pharmacodynamic interactions between dextromethorphan/quinidine and memantine in healthy volunteers.

PubMed

Pope, Laura E; Schoedel, Kerri A; Bartlett, Cynthia; Sellers, Edward M

2012-08-01

Dextromethorphan/quinidine (DMQ) is the first agent indicated for the treatment of pseudobulbar affect. Dextromethorphan, the active ingredient, is a low-affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. This study evaluated the potential for a drug-drug interaction (DDI) of DMQ with memantine, which is also an NMDA receptor antagonist. This open-label, randomized, parallel-group study enrolled healthy adults who were randomized into one of two treatment groups. Group 1 subjects were administered memantine at a starting dose of 5 mg once daily, which was titrated over a 3-week period to a dose of 10 mg twice daily (every 12 hours) and continued for another 11 days to attain steady state; DMQ 30 mg (dextromethorphan 30 mg/quinidine 30 mg) every 12 hours was then added for a further 8 days. Group 2 subjects received DMQ 30 mg every 12 hours for 8 days to attain steady state; memantine was then added, titrated on the same schedule as in group 1, and continued at 10 mg every 12 hours for an additional 11 days. Pharmacokinetic blood sampling was performed to assess the primary endpoints of the 90% confidence intervals (CIs) for the geometric mean ratios of the areas under the plasma concentration-time curves (AUCs) for memantine, dextromethorphan, dextrorphan - the dextromethorphan metabolite - and quinidine during concomitant therapy versus monotherapy. Safety/tolerability and pharmacodynamic variables were also assessed. A total of 52 subjects were randomized. In both group 1 (n = 23) and group 2 (n = 29), the 90% CIs for the ratios of the AUCs during concomitant therapy versus monotherapy were within the predefined range to indicate similarity (0.8-1.25) for memantine, dextromethorphan and dextrorphan, indicating no pharmacokinetic DDI. The 90% CI for the AUC ratio for quinidine was slightly above the predefined range; however, the mean AUC increased by only 25%. In both groups, incidence of adverse events was similar, and pharmacodynamic variables were either similar or slightly improved with DMQ added to memantine and memantine added to DMQ, compared to monotherapy with either agent. Minimal pharmacokinetic and pharmacodynamic interactions were observed between memantine and DMQ, suggesting they can be coadministered without dose adjustment.

Memantine for Alzheimer's Disease: An Updated Systematic Review and Meta-analysis.

PubMed

Kishi, Taro; Matsunaga, Shinji; Oya, Kazuto; Nomura, Ikuo; Ikuta, Toshikazu; Iwata, Nakao

2017-01-01

The clinical benefit of memantine for Alzheimer's disease (AD) remains inconclusive. We performed an updated systematic review and meta-analysis of the efficacy/safety of memantine in AD. We included randomized trials of memantine for AD patients. Cognitive function scores (CF), behavioral disturbances scores (BD), and all-cause discontinuation were used as primary measures. Effect size based on a random-effects model was evaluated in the meta-analyses. Thirty studies (n = 7,567; memantine versus placebo: N = 11, n = 3,298; memantine + cholinesterase inhibitors (M+ChEIs) versus ChEIs: N = 17, n = 4,175) were identified. Memantine showed a significant improvement in CF [standardized mean difference (SMD) = -0.24, 95% confidence intervals (95% CIs) = -0.34, -0.15, p < 0.00001, I2 = 35% ] and BD (SMD = -0.16, 95% CIs = -0.29, -0.04, p = 0.01, I2 = 52%) compared with placebo. In the sensitivity analysis including only patients with moderate-severe AD, memantine was superior to the placebo in reducing BD without considerable heterogeneity (SMD = -0.20, 95% CIs = -0.34, -0.07, p = 0.003, I2 = 36%). Compared with ChEIs, M+ChEIs showed a greater reduction in BD (SMD = -0.20, 95% CIs = -0.36, -0.03, p = 0.02, I2 = 77%) and a trend of CF improvement (SMD = -0.11, 95% CIs = -0.22, 0.01, p = 0.06, I2 = 56%). However, in the sensitivity analysis of double-blind, placebo-controlled studies only, M+ChEIs showed a significant reduction in BD compared with ChEIs without considerable heterogeneity (SMD = -0.11, 95% CIs = -0.21, -0.01, p = 0.04, I2 = 40%). When performing the sensitivity analysis of donepezil studies only, M+ChEIs was superior to ChEIs in improving CF without considerable heterogeneity (SMD = -0.18, 95% CIs = -0.31, -0.05, p = 0.006, I2 = 49%). No differences were detected in all-cause discontinuation between the groups. The meta-analyses suggest the credible efficacy and safety of memantine in treating AD when used alone or in combination with ChEIs.

Memantine effects on behaviour in moderately severe to severe Alzheimer's disease: a post-marketing surveillance study.

PubMed

Clerici, Francesca; Vanacore, Nicola; Elia, Antonietta; Spila-Alegiani, Stefania; Pomati, Simone; Da Cas, Roberto; Raschetti, Roberto; Mariani, Claudio

2012-02-01

The aim of this study is to evaluate memantine effectiveness on behavioural and psychological symptoms of dementia (BPSD) in clinical practice and to identify variables that may predict the therapy effects. The effects of memantine on behaviour were analysed in the database of a post-marketing surveillance study promoted by the Lombardy Region Health Office and involving 43 Alzheimer's disease (AD) Units. From July to December 2005, 399 moderately severe-to-severe AD patients free of cholinergic medications were enrolled, treated with memantine and followed-up for 6 months. BPSD were assessed in a subgroup of 297 patients [mean age 77 ± 8 years; 73% females; mean neuropsychiatric inventory (NPI) score 28 ± 24] for whom the 12-item NPI subscores at baseline, and at 3 and 6 months were available. The 12 BPSD were clustered as follows: affect, physical behaviour, psychosis and hypomania. The main outcome measure was the proportion of individual cluster responders at 6 months of therapy. The proportion of individual cluster responders was 30% affect, 24% physical behaviour, 29% psychosis, 27% hypomania. Patients taking 20 mg memantine daily during the study period had a statistically significant higher probability to experience behavioural improvement than those who discontinued treatment or did not complete memantine titration (affect OR 9.0; 95% CI 3.8-21.6; physical behaviour OR 17.8; 95% CI 5.9-53.6; psychosis OR 23.6; 95% CI 5.1-110.8). The logistic regression analysis was not applicable to the hypomania subsyndrome because of the low cluster prevalence. The standard 20 mg daily memantine treatment regimen was found to be associated with a modest 6-month behavioural improvement in the affect, physical behaviour and psychosis domains in 24-30% of patients.

Memantine may affect pseudobulbar affect in patients with Alzheimer's disease.

PubMed

Prokšelj, Tatjana; Jerin, Aleš; Kogoj, Aleš

2013-12-01

Behavioural symptoms are common in moderate to severe Alzheimer's disease (AD) and are improved by memantine with the most pronounced effect on agitation/aggression. Dextromethorphan in combination with quinidine is the only drug approved by US Food and Drug Administration for the treatment of pseudobulbar affect (PBA) on the basis of efficacy in patients with multiple sclerosis or amyotrophic lateral sclerosis. The aim of our study was to evaluate the efficacy of memantine on PBA in patients with AD. In a prospective, double-blind, case-control study to assess PBA with pathological laughter and crying scale patients were administered memantine (final dose of 20 mg daily) or citalopram (20 mg once daily), each for 10 weeks. The number of episodes of involuntary emotional expression, Neuropsychiatric Inventory (NPI) and Overt Aggression Scale-Modified (OAS-M) total scores were also recorded. Furthermore, the platelet serotonin (5-HT) concentration was measured. Although memantine had beneficial effects on PBA, it also had a crucial impact on behavioural symptoms, especially aggression and agitation (to an average of 3.5 times higher end-point scores on OAS-M and increase of NPI total scores for an average of 114% of initial value). Therefore, the study was prematurely stopped. In addition, we had evidenced a drop of platelet 5-HT concentration (to an average of 73% of initial value). Surprisingly, our research showed the opposite action of memantine on neuropsychiatric symptoms as expected. In a limited number of AD patients with PBA, memantine had a beneficial effect on involuntary emotional expression, but it potentiated agitation/aggression, irritability and caused a crucial drop of the platelet 5-HT concentration.

MPTP-induced changes in hippocampal synaptic plasticity and memory are prevented by memantine through the BDNF-TrkB pathway

PubMed Central

Zhu, Guoqi; Li, Junyao; He, Ling; Wang, Xuncui; Hong, Xiaoqi

2015-01-01

Background and Purpose Mild cognitive deficit in early Parkinson's disease (PD) has been widely studied. Here we have examined the effects of memantine in preventing memory deficit in experimental PD models and elucidated some of the underlying mechanisms. Experimental Approaches I.p. injection of 1-methyl-4- phenyl-1,2,3,6-tetrahydro pyridine (MPTP) in C57BL/6 mice was used to produce models of PD. We used behavioural tasks to test memory. In vitro, we used slices of hippocampus, with electrophysiological, Western blotting, real time PCR, elisa and immunochemical techniques. Key Results Following MPTP injection, long-term memory was impaired and these changes were prevented by pre-treatment with memantine. In hippocampal slices from MPTP treated mice, long-term potentiation (LTP) –induced by θ burst stimulation (10 bursts, 4 pulses) was decreased, while long-term depression (LTD) induced by low-frequency stimulation (1 Hz, 900 pulses) was enhanced, compared with control values. A single dose of memantine (i.p., 10 mg·kg−1) reversed the decreased LTP and the increased LTD in this PD model. Activity-dependent changes in tyrosine kinase receptor B (TrkB), ERK and brain-derived neurotrophic factor (BDNF) expression were decreased in slices from mice after MPTP treatment. These effects were reversed by pretreatment with memantine. Incubation of slices in vitro with 1-methyl-4-phenylpyridinium (MPP+) decreased depolarization-induced expression of BDNF. This effect was prevented by pretreatment of slices with memantine or with calpain inhibitor III, suggesting the involvement of an overactivated calcium signalling pathway. Conclusions and Implications Memantine should be useful in preventing loss of memory and hippocampal synaptic plasticity in PD models. PMID:25560396

N-Methyl D-Aspartate (NMDA) Receptor Antagonists and Memantine Treatment for Alzheimer’s Disease, Vascular Dementia and Parkinson’s Disease

PubMed Central

Olivares, David; Deshpande, Varun K.; Shi, Ying; Lahiri, Debomoy K.; Greig, Nigel H.; Rogers, Jack T.; Huang, Xudong

2016-01-01

Memantine, a partial antagonist of N-methyl-D-aspartate receptor (NMDAR), approved for moderate to severe Alzheimer’s disease (AD) treatment within the US and Europe under brand name Namenda (Forest), Axura and Akatinol (Merz), and Ebixa and Abixa (Lundbeck), may have potential in alleviating additional neurological conditions, such as vascular dementia (VD) and Parkinson’s disease (PD). In various animal models, memantine has been reported to be a neuroprotective agent that positively impacts both neurodegenerative and vascular processes. While excessive levels of glutamate result in neurotoxicity, in part through the over-activation of NMDARs, memantine—as a partial NMDAR antagonist, blocks the NMDA glutamate receptors to normalize the glutamatergic system and ameliorate cognitive and memory deficits. The key to memantine’s therapeutic action lies in its uncompetitive binding to the NMDAR through which low affinity and rapid off-rate kinetics of memantine at the level of the NMDAR-channel preserves the physiological function of the receptor, underpinning memantine’s tolerability and low adverse event profile. As the biochemical pathways evoked by NMDAR antagonism also play a role in PD and since no other drug is sufficiently effective to substitute for the first-line treatment of L-dopa despite its side effects, memantine may be useful in PD treatment with possibly fewer side effects. In spite of the relative modest nature of its adverse effects, memantine has been shown to provide only a moderate decrease in clinical deterioration in AD and VD, and hence efforts are being undertaken in the design of new and more potent memantine-based drugs to hopefully provide greater efficacy. PMID:21875407

A Prospective Open-Label Trial of Memantine Hydrochloride for the Treatment of Social Deficits in Intellectually Capable Adults With Autism Spectrum Disorder.

PubMed

Joshi, Gagan; Wozniak, Janet; Faraone, Stephen V; Fried, Ronna; Chan, James; Furtak, Stephannie; Grimsley, Emily; Conroy, Kristina; Kilcullen, J Ryan; Woodworth, K Yvonne; Biederman, Joseph

2016-06-01

This prospective 12-week open-label trial evaluates the tolerability and efficacy of memantine hydrochloride for the treatment of core social and cognitive deficits in adults with high-functioning autism spectrum disorder (ASD). Measures for assessment of therapeutic response included the Social Responsiveness Scale-Adult Research Version (SRS-A), disorder-specific Clinical Global Impression scales, Behavior Rating Inventory of Executive Functioning-Adult Self-Report, Diagnostic Analysis of Nonverbal Accuracy Scale, and Cambridge Neuropsychological Test Automated Battery. Eighteen adults (mean age, 28 ± 9.5 years) with high-functioning ASD (SRS-A raw score, 99 ± 17) were treated with memantine (mean dose, 19.7 ± 1.2 mg/d; range, 15-20 mg), and 17 (94%) completed the trial. Treatment with memantine was associated with significant reduction on informant-rated (SRS-A, -28 ± 25; P < 0.001) and clinician-rated (Clinical Global Impression-Improvement subscale ≤2, 83%) measures of autism severity. In addition, memantine treatment was associated with significant improvement in ADHD and anxiety symptom severity. Significant improvement was noted in nonverbal communication on the Diagnostic Analysis of Nonverbal Accuracy Scale test and in executive function per self-report (Behavior Rating Inventory of Executive Functioning-Adult Self-Report Global Executive Composite, -6 ± 8.8; P < 0.015) and neuropsychological assessments (Cambridge Neuropsychological Test Automated Battery). Memantine treatment was generally well tolerated and was not associated with any serious adverse events. Treatment with memantine appears to be beneficial for the treatment of ASD and associated psychopathology and cognitive dysfunction in intellectually capable adults. Future placebo-controlled trials are warranted.

Memantine before Mastectomy Prevents Post-Surgery Pain: A Randomized, Blinded Clinical Trial in Surgical Patients

PubMed Central

Morel, Véronique; Joly, Dominique; Villatte, Christine; Dubray, Claude; Durando, Xavier; Daulhac, Laurence; Coudert, Catherine; Roux, Delphine; Pereira, Bruno; Pickering, Gisèle

2016-01-01

Background Neuropathic pain following surgical treatment for breast cancer with or without chemotherapy is a clinical burden and patients frequently report cognitive, emotional and quality of life impairment. A preclinical study recently showed that memantine administered before surgery may prevent neuropathic pain development and cognitive dysfunction. With a translational approach, a clinical trial has been carried out to evaluate whether memantine administered before and after mastectomy could prevent the development of neuropathic pain, the impairment of cognition and quality of life. Method A randomized, pilot clinical trial included 40 women undergoing mastectomy in the Oncology Department, University Hospital, Clermont-Ferrand, France. Memantine (5 to 20 mg/day; n = 20) or placebo (n = 20) was administered for four weeks starting two weeks before surgery. The primary endpoint was pain intensity measured on a (0–10) numerical rating scale at three months post-mastectomy. Results Data analyses were performed using mixed models and the tests were two-sided, with a type I error set at α = 0.05. Compared with placebo, patients receiving memantine showed at three months a significant difference in post-mastectomy pain intensity, less rescue analgesia and a better emotional state. An improvement of pain symptoms induced by cancer chemotherapy was also reported. Conclusions This study shows for the first time the beneficial effect of memantine to prevent post-mastectomy pain development and to diminish chemotherapy-induced pain symptoms. The lesser analgesic consumption and better well-being of patients for at least six months after treatment suggests that memantine could be an interesting therapeutic option to diminish the burden of breast cancer therapy. Trial Registration Clinicaltrials.gov NCT01536314 PMID:27050431

Memantine as adjunctive treatment to risperidone in children with autistic disorder: a randomized, double-blind, placebo-controlled trial.

PubMed

Ghaleiha, Ali; Asadabadi, Mahtab; Mohammadi, Mohammad-Reza; Shahei, Maryam; Tabrizi, Mina; Hajiaghaee, Reza; Hassanzadeh, Elmira; Akhondzadeh, Shahin

2013-05-01

Autism is a neurodevelopmental disorder that causes significant impairment in socialization and communication. It is also associated with ritualistic and stereotypical behaviour. Recent studies propose both hyper-and hypoglutamatergic ideologies for autism. The objective of this study was to assess the effects of memantine plus risperidone in the treatment of children with autism. Children with autism were randomly allocated to risperidone plus memantine or placebo plus risperidone for a 10-wk, double-blind, placebo-controlled study. The dose of risperidone was titrated up to 3 mg/d and memantine was titrated to 20 mg/d. Children were assessed at baseline and after 2, 4, 6, 8 and 10 wk of starting medication protocol. The primary outcome measure was the irritability subscale of Aberrant Behavior Checklist-Community (ABC-C). Difference between the two treatment arms was significant as the group that received memantine had greater reduction in ABC-C subscale scores for irritability, stereotypic behaviour and hyperactivity. Eight side-effects were observed over the trial, out of the 25 side-effects that the checklist included. The difference between the two groups in the frequency of side-effects was not significant. The present study suggests that memantine may be a potential adjunctive treatment strategy for autism and it was generally well tolerated. This trial is registered with the Iranian Clinical Trials Registry (IRCT1138901151556N10; www.irct.ir).

Cost-effectiveness of donepezil and memantine in moderate to severe Alzheimer's disease (the DOMINO-AD trial).

PubMed

Knapp, Martin; King, Derek; Romeo, Renée; Adams, Jessica; Baldwin, Ashley; Ballard, Clive; Banerjee, Sube; Barber, Robert; Bentham, Peter; Brown, Richard G; Burns, Alistair; Dening, Tom; Findlay, David; Holmes, Clive; Johnson, Tony; Jones, Robert; Katona, Cornelius; Lindesay, James; Macharouthu, Ajay; McKeith, Ian; McShane, Rupert; O'Brien, John T; Phillips, Patrick P J; Sheehan, Bart; Howard, Robert

2017-12-01

Most investigations of pharmacotherapy for treating Alzheimer's disease focus on patients with mild-to-moderate symptoms, with little evidence to guide clinical decisions when symptoms become severe. We examined whether continuing donepezil, or commencing memantine, is cost-effective for community-dwelling, moderate-to-severe Alzheimer's disease patients. Cost-effectiveness analysis was based on a 52-week, multicentre, double-blind, placebo-controlled, factorial clinical trial. A total of 295 community-dwelling patients with moderate/severe Alzheimer's disease, already treated with donepezil, were randomised to: (i) continue donepezil; (ii) discontinue donepezil; (iii) discontinue donepezil and start memantine; or (iv) continue donepezil and start memantine. Continuing donepezil for 52 weeks was more cost-effective than discontinuation, considering cognition, activities of daily living and health-related quality of life. Starting memantine was more cost-effective than donepezil discontinuation. Donepezil-memantine combined is not more cost-effective than donepezil alone. Robust evidence is now available to inform clinical decisions and commissioning strategies so as to improve patients' lives whilst making efficient use of available resources. Clinical guidelines for treating moderate/severe Alzheimer's disease, such as those issued by NICE in England and Wales, should be revisited. © 2016 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons Ltd. © 2016 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons Ltd.

Altered Actions of Memantine and NMDA-Induced Currents in a New Grid2-Deleted Mouse Line

PubMed Central

Kumagai, Ayako; Fujita, Akira; Yokoyama, Tomoki; Nonobe, Yuki; Hasaba, Yasuhiro; Sasaki, Tsutomu; Itoh, Yumi; Koura, Minako; Suzuki, Osamu; Adachi, Shigeki; Ryo, Haruko; Kohara, Arihiro; Tripathi, Lokesh P.; Sanosaka, Masato; Fukushima, Toshiki; Takahashi, Hiroyuki; Kitagawa, Kazuo; Nagaoka, Yasuo; Kawahara, Hidehisa; Mizuguchi, Kenji; Nomura, Taisei; Matsuda, Junichiro; Tabata, Toshihide; Takemori, Hiroshi

2014-01-01

Memantine is a non-competitive antagonist of the N-methyl-d-aspartate (NMDA) receptor, and is an approved drug for the treatment of moderate-to-severe Alzheimer’s disease. We identified a mouse strain with a naturally occurring mutation and an ataxic phenotype that presents with severe leg cramps. To investigate the phenotypes of these mutant mice, we screened several phenotype-modulating drugs and found that memantine (10 mg/kg) disrupted the sense of balance in the mutants. Moreover, the mutant mice showed an attenuated optokinetic response (OKR) and impaired OKR learning, which was also observed in wild-type mice treated with memantine. Microsatellite analyses indicated that the Grid2 gene-deletion is responsible for these phenotypes. Patch-clamp analysis showed a relatively small change in NMDA-dependent current in cultured granule cells from Grid2 gene-deleted mice, suggesting that GRID2 is important for correct NMDA receptor function. In general, NMDA receptors are activated after the activation of non-NMDA receptors, such as AMPA receptors, and AMPA receptor dysregulation also occurs in Grid2 mutant mice. Indeed, the AMPA treatment enhanced memantine susceptibility in wild-type mice, which was indicated by balance sense and OKR impairments. The present study explores a new role for GRID2 and highlights the adverse effects of memantine in different genetic backgrounds. PMID:25513882

Treatment effects between monotherapy of donepezil versus combination with memantine for Alzheimer disease: A meta-analysis.

PubMed

Chen, Ruey; Chan, Pi-Tuan; Chu, Hsin; Lin, Yu-Cih; Chang, Pi-Chen; Chen, Chien-Yu; Chou, Kuei-Ru

2017-01-01

This is the first meta-analysis to compare the treatment effects and safety of administering donepezil alone versus a combination of memantine and donepezil to treat patients with moderate to severe Alzheimer Disease, particularly regarding cognitive functions, behavioral and psychological symptoms in dementia (BPSD), and global functions. PubMed, Medline, Embase, PsycINFO, and Cochrane databases were used to search for English and non-English articles for inclusion in the meta-analysis to evaluate the effect size and incidence of adverse drug reactions of different treatments. Compared with patients who received donepezil alone, those who received donepezil in combination with memantine exhibited limited improvements in cognitive functions (g = 0.378, p < .001), BPSD (g = -0.878, p < .001) and global functions (g = -0.585, p = .004). Gradual titration of memantine plus a fixed dose and gradual titration of donepezil as well as a fixed dose and gradual titration of memantine resulted in limited improvements in cognitive functions(g = 0.371, p = .005), BPSD(g = -0.913, p = .001), and global functions(g = -0.371, p = .001). Both in the 24th week and at the final evaluation point, the combination of donepezil and memantine led to greater improvement in cognitive functions, BPSD, and global functions than did donepezil alone in patients with moderate to severe Alzheimer Disease.

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2010-09-01

control group and low (300 mg load) and high dose (600 mg load) DU exposure conditions, but utilized a vehicle and three drug-treated groups ( memantine ...applied long after exposure was initiated. The minipumps were filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day dose) and/or 10 mg/ml...riluzole (1.2 mg/kg/day dose). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been reported to have

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2009-09-01

utilizes a vehicle and three drug-treated groups ( memantine or riluzole or a combination) for each exposure level. This design results in a 3 exposure... memantine (3.6 mg/kg/day) and/or 10 mg/ml riluzole (1.2 mg/kg/day). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist... memantine also has been reported to have neuroprotectant value via induction of brain-derived neurotrophic factor and its receptor (4-6), making the

Histopathologic Changes in the Brain, Heart, and Skeletal Muscle of Rhesus Macaques, Ten Days After Exposure to Soman (An Organophosphorus Nerve Agent)

DTIC Science & Technology

2000-04-01

Center, Washington DC. 2. Koplovitz, I., S. Schulz, M. Shutz, et al. 1997. Memantine ef- fects on soman-induced seizures and seizure-related brain dam...neuronal culture as a model for soman-in- duced neurotoxicity and effectiveness of memantine as a neuroprotective drug. Arch. Toxicol. 69:384-390...for soman induced neurotoxicity and effectiveness of memantine as a neuroprotective drug. Drug Dev. Rev. 30:45-53. 27. Bredlow, J. D., G. F

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2008-09-01

treated groups ( memantine or riluzole or a combination) for each exposure level. This design results in a 3 exposure level × 4 drug condition...concentration is greater during this period than prior to 6 months exposure. The minipumps are filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day...and/or 10 mg/ml riluzole (1.2 mg/kg/day). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2011-03-01

600 mg load) DU exposure conditions, but also utilized a vehicle and three drug-treated groups ( memantine or riluzole or a combination) for each...exposure was initiated. The minipumps were filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day dose) and/or 10 mg/ml riluzole (1.2 mg/kg...day dose). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been reported to have neuroprotectant

Design, synthesis, and evaluation of polyamine-memantine hybrids as NMDA channel blockers.

PubMed

Kumamoto, Takuya; Nakajima, Marie; Uga, Reina; Ihayazaka, Naoko; Kashihara, Haruna; Katakawa, Kazuaki; Ishikawa, Tsutomu; Saiki, Ryotaro; Nishimura, Kazuhiro; Igarashi, Kazuei

2018-02-01

N-Methyl-d-aspartate (NMDA) receptors have been implicated in learning and memory, and may also play a central role in various conditions leading to neuronal degradation. NMDA receptor antagonists could therefore be of therapeutic benefit for a number of neurological disorders. We have designed hybrid compounds of polyamines and memantine, both of which function as NMDA channel blockers. The triamine derivative with a guanidine moiety showed more potent antagonistic activity than memantine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of memantine combination therapy on symptoms in patients with moderate-to-severe depressive disorder: randomized, double-blind, placebo-controlled study.

PubMed

Amidfar, M; Khiabany, M; Kohi, A; Salardini, E; Arbabi, M; Roohi Azizi, M; Zarrindast, M-R; Mohammadinejad, P; Zeinoddini, A; Akhondzadeh, S

2017-02-01

Current treatments for depressive disorders are far from optimum. This study was planned to evaluate possible antidepressant effects and safety of memantine, a selective N-methyl-d-aspartate receptor antagonist, in humans. Sixty-six outpatients with the diagnosis of moderate-to-severe major depressive disorder, based on DSM-V diagnostic criteria, were recruited to participate in a parallel, randomized, controlled trial. Sixty-two participants completed 6 weeks of treatment with either memantine (20 mg/day) plus sertraline (200 mg/day) or placebo plus sertraline (200 mg/day). Patients were evaluated using the Hamilton Depression Rating Scale (HDRS) at baseline and at weeks 2, 4 and 6. Comparison of treatment efficacy in improving depressive symptoms between the two groups was the principal outcome measure. A repeated-measures analysis demonstrated significant time × treatment interaction on HDRS score [F (2·09, 125·67) = 5·09, P = 0·007]. Significantly greater improvement was seen at all three follow-up sessions as well as significantly greater response rates at weeks 4 and 6 (P = 0·018 and P < 0·001, respectively) in the memantine group. Significantly more early improvers and more rapid response to treatment were observed in the memantine group (P = 0·001 and P < 0·001, respectively). A significant reduction was observed in HDRS score from baseline to the study endpoint in both memantine (P < 0·001, Cohen's d = 12·71) and placebo groups (P < 0·001, Cohen's d = 5·13). No serious adverse event occurred. No significantly greater remission rate was seen in the adjunctive memantine therapy. A 6-week course of treatment with memantine as adjunct to sertraline showed a favourable safety and efficacy profile in patients with major depressive disorder. Nonetheless, larger controlled studies of longer duration are necessary to assess long-term safety, efficacy and optimal dosing. © 2016 John Wiley & Sons Ltd.

Memantine and donepezil: a fixed drug combination for the treatment of moderate to severe Alzheimer's dementia.

PubMed

Owen, R T

2016-04-01

Donepezil (and other cholinesterase inhibitors [ChEIs]) and memantine are the mainstays of treatment in Alzheimer's dementia, addressing respectively, the cholinergic and glutamatergic dysregulation which underlies or results from its pathophysiology. To alleviate the pill burden and swallowing difficulties associated with the condition, a fixed drug combination of extended-release memantine and donepezil was developed. This combination was shown to be both bioequivalent to the components administered separately and could be administered sprinkled over soft food. The mode of action, pharmacokinetics, clinical efficacy and safety and tolerability of the combination are discussed together with the wider, often conflicting trial literature of combination versus monotherapy with memantine and ChEIs, their meta-analyses and treatment guidelines. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

A pilot study using dynamic contrast enhanced-MRI as a response biomarker of the radioprotective effect of memantine in patients receiving whole brain radiotherapy

PubMed Central

Wong, Philip; Leppert, Ilana R.; Roberge, David; Boudam, Karim; Brown, Paul D.; Muanza, Thierry; Pike, G. Bruce; Chankowsky, Jeffrey; Mihalcioiu, Catalin

2016-01-01

Purpose This pilot prospective study sought to determine whether dynamic contrast enhanced MRI (DCE-MRI) could be used as a clinical imaging biomarker of tissue toxicity from whole brain radiotherapy (WBRT). Method 14 patients who received WBRT were imaged using dynamic contrast enhanced DCE-MRI prior to and at 8-weeks, 16-weeks and 24-weeks after the initiation of WBRT. Twelve of the patients were also enrolled in the RTOG 0614 trial, which randomized patients to the use of placebo or memantine. After the unblinding of the treatments received by RTOG 0614 patients, DCE-MRI measures of tumor tissue and normal appearing white matter (NAWM) vascular permeability (Initial Area Under the Curve (AUC) Blood Adjusted) was analyzed. Cognitive, quality-of-life (QOL) assessment and blood samples were collected according to the patient's ability to tolerate the exams. Circulating endothelial cells (CEC) were measured using flow cytometry. Results Following WBRT, there was an increasing trend in the vascular permeability of tumors (p=0.09) and NAWM (p=0.06) with time. Memantine significantly (p=0.01) reduced NAWM AUC changes following radiotherapy. Patients on memantine retained (COWA p= 0.03) better cognitive functions than those on placebo. No association was observed between the level of CEC and DCE-MRI changes, time from radiotherapy or memantine use. Conclusions DCE-MRI can detect vascular damage secondary to WBRT. Our data suggests that memantine reduces WBRT-induced brain vasculature damages. PMID:27248467

A pilot study using dynamic contrast enhanced-MRI as a response biomarker of the radioprotective effect of memantine in patients receiving whole brain radiotherapy.

PubMed

Wong, Philip; Leppert, Ilana R; Roberge, David; Boudam, Karim; Brown, Paul D; Muanza, Thierry; Pike, G Bruce; Chankowsky, Jeffrey; Mihalcioiu, Catalin

2016-08-09

This pilot prospective study sought to determine whether dynamic contrast enhanced MRI (DCE-MRI) could be used as a clinical imaging biomarker of tissue toxicity from whole brain radiotherapy (WBRT). 14 patients who received WBRT were imaged using dynamic contrast enhanced DCE-MRI prior to and at 8-weeks, 16-weeks and 24-weeks after the initiation of WBRT. Twelve of the patients were also enrolled in the RTOG 0614 trial, which randomized patients to the use of placebo or memantine. After the unblinding of the treatments received by RTOG 0614 patients, DCE-MRI measures of tumor tissue and normal appearing white matter (NAWM) vascular permeability (Initial Area Under the Curve (AUC) Blood Adjusted) was analyzed. Cognitive, quality-of-life (QOL) assessment and blood samples were collected according to the patient's ability to tolerate the exams. Circulating endothelial cells (CEC) were measured using flow cytometry. Following WBRT, there was an increasing trend in the vascular permeability of tumors (p=0.09) and NAWM (p=0.06) with time. Memantine significantly (p=0.01) reduced NAWM AUC changes following radiotherapy. Patients on memantine retained (COWA p= 0.03) better cognitive functions than those on placebo. No association was observed between the level of CEC and DCE-MRI changes, time from radiotherapy or memantine use. DCE-MRI can detect vascular damage secondary to WBRT. Our data suggests that memantine reduces WBRT-induced brain vasculature damages.

Combined Memantine and Donepezil Treatment Improves Behavioral and Psychological Symptoms of Dementia-Like Behaviors in Olfactory Bulbectomized Mice.

PubMed

Yabuki, Yasushi; Matsuo, Kazuya; Hirano, Koga; Shinoda, Yasuharu; Moriguchi, Shigeki; Fukunaga, Kohji

2017-01-01

Memantine, an uncompetitive N-methyl-D-aspartate receptor antagonist, and the cholinesterase inhibitor, donepezil, are approved in most countries for treating moderate-to-severe Alzheimer's disease (AD). These drugs have different molecular targets; thus, it is expected that the effects of combined treatment would be synergistic. Some reports do show memantine/donepezil synergy in ameliorating cognition in AD model animals, but their combined effects on behavioral and psychological symptoms of dementia (BPSD)-like behaviors have not been addressed. Here, we investigate combined memantine/donepezil effects on cognitive impairment and BPSD-like behaviors in olfactory bulbectomized (OBX) mice. Interestingly, combined administration synergistically improved both depressive-like behaviors and impaired social interaction in OBX mice, whereas only weak synergistic effects on cognitive performance were seen. To address mechanisms underlying these effects, we used in vivo microdialysis study and observed impaired nicotine-induced serotonin (5-HT) release in OBX mouse hippocampus. Combined memantine/donepezil administration, but not single administration of either, significantly antagonized the decrease in nicotine-induced 5-HT release seen in OBX mouse hippocampus. Furthermore, decreased autophosphorylation of calcium/calmodulin dependent protein kinase II (CaMKII) was rescued in hippocampal CA1 and dentate gyrus of OBX mice by combined memantine/donepezil administration. These results suggest that improvement of BPSD-like behaviors by the co-administration of both drugs is in part mediated by enhanced 5-HT release and CaMKII activity in OBX mouse hippocampus. © 2016 S. Karger AG, Basel.

DNA damage, DNA susceptibility to oxidation and glutathione redox status in patients with Alzheimer's disease treated with and without memantine.

PubMed

Akkaya, Çağlayan; Yavuzer, Serap Sahin; Yavuzer, Hakan; Erkol, Gökhan; Bozluolcay, Melda; Dinçer, Yıldız

2017-07-15

The aim of the current study was to compare oxidative DNA damage, DNA susceptibility to oxidation, and ratio of GSH/GSSG in patients with Alzheimer's disease (AD) treated with acetylcholinesterase inhibitor (AChEI) and combined AChEI+memantine. The study included 67 patients with AD and 42 volunteers as control. DNA damage parameters (strand breaks, oxidized purines, H 2 O 2 -induced DNA damage) in lymphocyte DNA and GSH/GSSG ratio in erythrocytes were determined by the comet assay and spectrophotometric assay, respectively. DNA damage was found to be higher, GSH/GSSG ratio was found to be lower in the AD group than those in the control group. DNA strand breaks and H 2 O 2 -induced DNA damage were lower in the patients taking AChEI+memantine than those in the patients taking AChEI but no significant difference was determined between the groups for oxidized purines and GSH/GSSG ratio. In conclusion, increased systemic oxidative DNA damage and DNA susceptibility to oxidation may be resulted from diminished GSH/GSSG ratio in AD patients. Although DNA strand breaks and H 2 O 2 -induced DNA damage are lower in the AD patients treated with combined AChEI and memantine, this may not indicate protective effect of memantine against DNA oxidation due to similar levels of oxidized purines in the patients treated with AChEI and AChEI+memantine. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Vitamin E and Memantine on Functional Decline in Alzheimer Disease

PubMed Central

Dysken, Maurice W.; Sano, Mary; Asthana, Sanjay; Vertrees, Julia E.; Pallaki, Muralidhar; Llorente, Maria; Love, Susan; Schellenberg, Gerard D.; McCarten, J. Riley; Malphurs, Julie; Prieto, Susana; Chen, Peijun; Loreck, David J.; Trapp, George; Bakshi, Rajbir S.; Mintzer, Jacobo E.; Heidebrink, Judith L.; Vidal-Cardona, Ana; Arroyo, Lillian M.; Cruz, Angel R.; Zachariah, Sally; Kowall, Neil W.; Chopra, Mohit P.; Craft, Suzanne; Thielke, Stephen; Turvey, Carolyn L.; Woodman, Catherine; Monnell, Kimberly A.; Gordon, Kimberly; Tomaska, Julie; Segal, Yoav; Peduzzi, Peter N.; Guarino, Peter D.

2014-01-01

Importance Although vitamin E and memantine have been shown to have beneficial effects in moderately severe Alzheimer disease (AD), evidence is limited in mild to moderate AD. Objective To determine if vitamin E (alpha tocopherol), memantine, or both slow progression of mild to moderate AD in patients taking an acetylcholinesterase inhibitor. Design, Setting, and Participants Double-blind, placebo-controlled, parallel-group, randomized clinical trial involving 613 patients with mild to moderate AD initiated in August 2007 and concluded in September 2012 at 14 Veterans Affairs medical centers. Interventions Participants received either 2000 IU/d of alpha tocopherol (n = 152), 20 mg/d of memantine (n = 155), the combination (n = 154), or placebo (n = 152). Main Outcomes and Measures Alzheimer's Disease Cooperative Study/Activities of Daily Living (ADCS-ADL) Inventory score (range, 0-78). Secondary outcomes included cognitive, neuropsychiatric, functional, and caregiver measures. Results Over the mean (SD) follow-up of 2.27 (1.22) years, participants receiving alpha tocopherol had slower decline than those receiving placebo as measured by the ADCS-ADL. The change translates into a delay in clinical progression of 19% per year compared with placebo (approximately 6.2 months over the follow-up period). Caregiver time increased least in the alpha tocopherol group. All-cause mortality and safety analyses showed a difference only on the serious adverse event of “infections or infestations” with greater frequencies in the memantine (31 events in 23 participants) and combination groups (44 events in 31 participants) compared with placebo (13 events in 11 participants). ADCS-ADL InventoryVitamin E (n = 140)Memantine (n = 142)Vitamin E + Memantine (n = 139)Placebo (n = 140)Baseline score, mean (SD)57.20 (14.38)57.77 (13.78)57.16 (13.59)56.93 (13.61)Least squares mean (SE) change from baseline−13.81 (1.11)−14.98 (1.10)−15.20 (1.11)−16.96 (1.11)Mean change difference compared with placebo (95% CI)3.15 (0.92 to 5.39)1.98 (−0.24 to 4.20)1.76 (−0.48 to 4.00) Conclusions and Relevance Among patients with mild to moderate AD, 2000 IU/d of alpha tocopherol compared with placebo resulted in slower functional decline. There were no significant differences in the groups receiving memantine alone or memantine plus alpha tocopherol. These findings suggest benefit of alpha tocopherol in mild to moderate AD by slowing functional decline and decreasing caregiver burden. Trial Registration clinicaltrials.gov Identifier: NCT00235716 PMID:24381967

Memantine improves attention and episodic memory in Parkinson's disease dementia and dementia with Lewy bodies.

PubMed

Wesnes, Keith A; Aarsland, Dag; Ballard, Clive; Londos, Elisabet

2015-01-01

In both dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), attentional dysfunction is a core clinical feature together with disrupted episodic memory. This study evaluated the cognitive effects of memantine in DLB and PDD using automated tests of attention and episodic memory. A randomised double-blind, placebo-controlled, 24-week three centre trial of memantine (20 mg/day) was conducted in which tests of attention (simple and choice reaction time) and word recognition (immediate and delayed) from the CDR System were administered prior to dosing and again at 12 and 24 weeks. Although other results from this study have been published, the data from the CDR System tests were not included and are presented here for the first time. Data were available for 51 patients (21 DLB and 30 PDD). In both populations, memantine produced statistically significant medium to large effect sized improvements to choice reaction time, immediate and delayed word recognition. These are the first substantial improvements on cognitive tests of attention and episodic recognition memory identified with memantine in either DLB or PDD. Copyright © 2014 John Wiley & Sons, Ltd.

Memantine reduces stealing behavior and impulsivity in kleptomania: a pilot study.

PubMed

Grant, Jon E; Odlaug, Brian L; Schreiber, Liana R N; Chamberlain, Samuel R; Won Kim, Suck

2013-03-01

Kleptomania is characterized by repetitive stealing behavior and has been associated with deleterious unwanted outcomes including forensic contact and increased rates of suicidal behavior. Very few trials have been conducted to investigate pharmacological treatment options for this neglected condition. Memantine is an NMDA-receptor antagonist that has shown promising results in the treatment of other behavioral addictions and substance addictions. Twelve individuals with kleptomania received memantine (10 mg/day, titrated to 30 mg/day maximum depending on clinical response and tolerability) over the course of 8 weeks, in an open-label trial. The effects of treatment were quantified using well-validated measures and select neurocognitive tests (last observation carried forward analyses). Kleptomania disease severity scores decreased across all measures considered, and 11 (91.7%) of the participants met the responder criteria (35% improvement on the primary effectiveness measure plus CGI improved/very much improved; significant improvements were also observed in terms of mood, anxiety, and disability scores along with a significant improvement in stop-signal response inhibition. Memantine was generally well tolerated. This study shows the effectiveness of memantine in reducing urges to shoplift and shoplifting behavior along with improving impulsivity, mood, anxiety, and psychosocial functioning.

The effect of memantine on trinitrobenzene sulfonic acid-induced ulcerative colitis in mice.

PubMed

Motaghi, Ehsan; Hajhashemi, Valiollah; Mahzouni, Parvin; Minaiyan, Mohsen

2016-12-15

Previous reports suggest a significant role for N-Methyl-D-aspartate (NMDA) activation in inflammatory processes. So, this study was conducted to investigate the effect of memantine, a commonly used NMDA receptor antagonist, on inflammatory changes in mice model of colitis. Colitis was induced by intracolonic instillation of trinitrobenzene sulfonic acid (TNBS) (40mg/kg). Animals received memantine (12.5, 25 and 50mg/kg, i.p.), glutamate (2g/kg, p.o.) or dexamethasone (1mg/kg, i.p.) 24h before TNBS instillation and daily thereafter for 4 days. The colonic injury was measured by clinical, macroscopic, microscopic and biochemical analysis. Memantine significantly attenuated the body weight loss, colon weight, the plasma levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and colon level of tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO); as well as macroscopic and microscopic signs of colitis. Oral administration of glutamate had no significant effect on investigated parameters. Memantine as a NMDA antagonist may provide a novel venue for the development of strategies for the treatment of ulcerative colitis. Copyright © 2016 Elsevier B.V. All rights reserved.

Combinatorial Strategies and High Throughput Screening in Drug Discovery Targeted to the Channel of Botulinum Neurotoxin

DTIC Science & Technology

2006-09-01

block the HC channel. memantine NH2 amantadine H2N quinacrine NH O N lidocaine NH O N QX-222 S N Cl chlorpromazine N NCl O HN N Our objective was to...M2 protein2 and its derivative, memantine , which blocks the NMDA receptor channel3, and is approved by the FDA for the treatment of dementia...intracellular processing of BoNTs by collapsing the pH gradient across endosomes6,7. Chlorpromazine, quinacrine and memantine , in addition, cross the blood

A fixed-dose combination of memantine extended-release and donepezil in the treatment of moderate-to-severe Alzheimer's disease.

PubMed

Deardorff, William James; Grossberg, George T

2016-01-01

Currently available therapies for the treatment of Alzheimer's disease (AD) consist of cholinesterase inhibitors (ChEIs), such as donepezil, and the N -methyl-D-aspartate receptor antagonist memantine. In December 2014, the US Food and Drug Administration approved Namzaric™, a once-daily, fixed-dose combination (FDC) of memantine extended-release (ER) and donepezil for patients with moderate-to-severe AD. The FDC capsule is bioequivalent to the coadministered individual drugs, and its bioavailability is similar when taken fasting, with food, or sprinkled onto applesauce. The combination of memantine and ChEIs in moderate-to-severe AD provides additional benefits to ChEI monotherapy across multiple domains and may delay the time to nursing home admission. A dedicated study of memantine ER compared to placebo in patients on a stable dose of a ChEI found statistically significant benefits on cognition and global status but not functioning. Treatment with memantine ER and donepezil is generally well tolerated, although higher doses of ChEIs are associated with more serious adverse events such as vomiting, syncope, and weight loss. Potential advantages of the FDC include a simpler treatment regimen, reduction in pill burden, and the ability to sprinkle the capsule onto soft foods. Patients who may benefit from the FDC include those with significant dysphagia, a history of poor compliance, or limited caregiver interaction. However, available evidence that these advantages would increase treatment adherence and persistence is conflicting, meaning that the added cost of switching patients from generic options to an FDC may not always be justified.

Memantine ameliorates autistic behavior, biochemistry & blood brain barrier impairments in rats.

PubMed

Kumar, Hariom; Sharma, Bhupesh

2016-06-01

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, commonly characterized by altered social behavior, communication, biochemistry and pathological conditions. One percent of the worldwide population suffers from autism and males suffer more than females. NMDA receptors have the important role in neurodevelopment, neuropsychiatric and neurodegenerative disorders. This study has been designed to investigate the role of memantine, a NMDA receptor modulator, in prenatal valproic acid-induced autism in rats. Animals with prenatal valproic acid have shown the reduction in social interaction (three-chamber social behavior apparatus), spontaneous alternation (Y-Maze), exploratory activity (Hole board test), intestinal motility, serotonin levels (both in prefrontal cortex and ileum) and prefrontal cortex mitochondrial complex activity (complex I, II, IV). Furthermore, prenatal valproic acid-treated animals have shown an increase in locomotion (actophotometer), anxiety (elevated plus maze), brain oxidative stress (thiobarbituric acid reactive species, glutathione, catalase), nitrosative stress (nitrite/nitrate), inflammation (both in brain and ileum myeloperoxidase activity), calcium and blood-brain barrier permeability. Treatment with memantine has significantly attenuated prenatal valproic acid-induced reduction in social interaction, spontaneous alteration, exploratory activity intestinal motility, serotonin levels and prefrontal cortex mitochondrial complex activity. Furthermore, memantine has also attenuated the prenatal valproic acid-induced increase in locomotion, anxiety, brain oxidative and nitrosative stress, inflammation, calcium and blood-brain barrier permeability. Thus, it may be concluded that prenatal valproic acid has induced autistic behavior, biochemistry and blood-brain barrier impairment in animals, which were significantly attenuated by memantine. NMDA receptor modulators like memantine should be explored further for the therapeutic benefits in autism. Copyright © 2016 Elsevier Inc. All rights reserved.

Treatment With Cholinesterase Inhibitors and Memantine of Patients in the Alzheimer’s Disease Neuroimaging Initiative

PubMed Central

Schneider, Lon S.; Insel, Philip S.; Weiner, Michael W.

2011-01-01

Objectives To assess the clinical characteristics and course of patients with mild cognitive impairment (MCI) and mild Alzheimer disease (AD) treated with cholinesterase inhibitors (ChEIs) and memantine hydrochloride. Design Cohort study. Setting The 59 recruiting sites for the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Participants Outpatients with MCI and AD in ADNI. Main Outcome Measures The AD Assessment Scale–cognitive subscale (ADAS-cog), Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) scale, and Functional Activities Questionnaire (FAQ). Results A total of 177 (44.0%) of 402 MCI patients and 159 (84.6%) of 188 mild-AD patients were treated with ChEIs and 11.4% of MCI patients and 45.7% of AD patients with memantine at entry. Mild-cognitive-impairment patients who received ChEIs with or without memantine were more impaired, showed greater decline in scores, and progressed to dementia sooner than patients who did not receive ChEIs. Alzheimer-disease patients who received ChEIs and memantine took them longer, were more functionally impaired, and showed greater decline on the MMSE and CDR (but not on the ADAS-cog or FAQ) than those who received ChEIs only. Conclusions Academic physicians frequently prescribe ChEIs and memantine earlier than indicated in the US Food and Drug Administration–approved labeling to patients who are relatively more severely impaired or who are rapidly progressing toward cognitive impairment. The use of these medications in ADNI is associated with clinical decline and may affect the interpretation of clinical trial outcomes. Study Registration clinicalTrials.gov Identifier: NCT00106899 PMID:21220675

A fixed-dose combination of memantine extended-release and donepezil in the treatment of moderate-to-severe Alzheimer’s disease

PubMed Central

Deardorff, William James; Grossberg, George T

2016-01-01

Currently available therapies for the treatment of Alzheimer’s disease (AD) consist of cholinesterase inhibitors (ChEIs), such as donepezil, and the N-methyl-D-aspartate receptor antagonist memantine. In December 2014, the US Food and Drug Administration approved Namzaric™, a once-daily, fixed-dose combination (FDC) of memantine extended-release (ER) and donepezil for patients with moderate-to-severe AD. The FDC capsule is bioequivalent to the coadministered individual drugs, and its bioavailability is similar when taken fasting, with food, or sprinkled onto applesauce. The combination of memantine and ChEIs in moderate-to-severe AD provides additional benefits to ChEI monotherapy across multiple domains and may delay the time to nursing home admission. A dedicated study of memantine ER compared to placebo in patients on a stable dose of a ChEI found statistically significant benefits on cognition and global status but not functioning. Treatment with memantine ER and donepezil is generally well tolerated, although higher doses of ChEIs are associated with more serious adverse events such as vomiting, syncope, and weight loss. Potential advantages of the FDC include a simpler treatment regimen, reduction in pill burden, and the ability to sprinkle the capsule onto soft foods. Patients who may benefit from the FDC include those with significant dysphagia, a history of poor compliance, or limited caregiver interaction. However, available evidence that these advantages would increase treatment adherence and persistence is conflicting, meaning that the added cost of switching patients from generic options to an FDC may not always be justified. PMID:27757016

A bioequivalence study of two memantine formulations in healthy Chinese male volunteers
.

PubMed

Deng, Ying; Zhuang, Jialang; Wu, Jingguo; Chen, Jiangying; Ding, Liang; Wang, Xueding; Huang, Lihui; Zeng, Guixiong; Chen, Jie; Ma, Zhongfu; Chen, Xiao; Zhong, Guoping; Huang, Min; Zhao, Xianglan

2017-10-01

The aim of the current study is to evaluate the bioequivalence between the test and reference formulations of memantine in a single-dose, two-period and two-sequence crossover study with a 44-day washout interval. A total of 20 healthy Chinese male volunteers were enrolled and completed the study, after oral administration of single doses of 10 mg test and reference formulations of memantine. The blood samples were collected at different time points and memantine concentrations were determined by a fully validated HPLC-MS/MS method. The evaluated pharmacokinetic parameters (test vs. reference) including C_max (18 ± 3.2 vs. 17.8 ± 3.4), AUC_0-t (1,188.5 ± 222.2 vs. 1,170.9 ± 135.7), and AUC_0-∞ (1,353.3 ± 258.6 vs. 1,291.3 ± 136.7) values were assessed for bioequivalence based on current guidelines. The observed pharmacokinetic parameters of memantine test drug were similar to those of the reference formulation. The 90% confidence intervals of test/reference ratios for C_max, AUC_0-t, and AUC_0-∞ were within the bioequivalence acceptance range of 80 - 125%. The results obtained from the healthy Chinese subjects in this study suggests that the test formulation of memantine 10 mg tablet is bioequivalent to the reference formulation (Ebixa^®10 mg tablet).
.

The combination of memantine and galantamine improves cognition in rats: The synergistic role of the α7 nicotinic acetylcholine and NMDA receptors.

PubMed

Nikiforuk, Agnieszka; Potasiewicz, Agnieszka; Kos, Tomasz; Popik, Piotr

2016-10-15

The combination of memantine and acetylcholinesterase inhibitors (AChEIs) is used as a therapeutic strategy to improve cognition in Alzheimer's disease. Among AChEIs, galantamine, which is also a positive allosteric modulator (PAM) of nicotinic acetylcholine receptors (nAChRs), including α7-nAChRs, may be particularly beneficial. The α7-nAChR is involved in interactions between the cholinergic and glutamatergic systems. In the present study, we investigated the potential role of α7-nAChRs in the pro-cognitive effects of this drug combination. To this aim, cognitive performance in rats was assessed using the attentional set shifting task (ASST) and novel object recognition task (NORT). Co-administration of inactive doses of memantine with galantamine facilitated the rats' set-shifting performance and reversed delay-induced deficits in object recognition. These effects were blocked by the α7-nAChR antagonist methyllycaconitine, suggesting that the observed cognitive enhancement is α7-nAChR dependent. Moreover, combined administration of memantine with inactive doses of selective α7-nAChRs PAMs, CCMI and PNU-120596, also improved ASST and NORT performance in a methyllycaconitine-dependent manner. Stimulation of α7-nAChRs may underlie the pro-cognitive effects of combining memantine and galantamine. Our results suggest that memantine, when given with enhancers of α7-nAChRs, may represent an effective strategy for cognitive improvement. Copyright © 2016 Elsevier B.V. All rights reserved.

Withdrawal Study of Memantine in Pediatric Patients With Autism, Asperger's Disorder, or Pervasive Developmental Disorder Not Otherwise Specified Previously Treated With Memantine

ClinicalTrials.gov

2013-10-31

Autism Spectrum Disorder (ASD); Autism; Autistic Disorder; Asperger's Disorder; Asperger's; Pediatric Autism; Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS); Pervasive Child Development Disorder

Effect of vitamin E and memantine on functional decline in Alzheimer disease: the TEAM-AD VA cooperative randomized trial.

PubMed

Dysken, Maurice W; Sano, Mary; Asthana, Sanjay; Vertrees, Julia E; Pallaki, Muralidhar; Llorente, Maria; Love, Susan; Schellenberg, Gerard D; McCarten, J Riley; Malphurs, Julie; Prieto, Susana; Chen, Peijun; Loreck, David J; Trapp, George; Bakshi, Rajbir S; Mintzer, Jacobo E; Heidebrink, Judith L; Vidal-Cardona, Ana; Arroyo, Lillian M; Cruz, Angel R; Zachariah, Sally; Kowall, Neil W; Chopra, Mohit P; Craft, Suzanne; Thielke, Stephen; Turvey, Carolyn L; Woodman, Catherine; Monnell, Kimberly A; Gordon, Kimberly; Tomaska, Julie; Segal, Yoav; Peduzzi, Peter N; Guarino, Peter D

2014-01-01

Although vitamin E and memantine have been shown to have beneficial effects in moderately severe Alzheimer disease (AD), evidence is limited in mild to moderate AD. To determine if vitamin E (alpha tocopherol), memantine, or both slow progression of mild to moderate AD in patients taking an acetylcholinesterase inhibitor. Double-blind, placebo-controlled, parallel-group, randomized clinical trial involving 613 patients with mild to moderate AD initiated in August 2007 and concluded in September 2012 at 14 Veterans Affairs medical centers. Participants received either 2000 IU/d of alpha tocopherol (n = 152), 20 mg/d of memantine (n = 155), the combination (n = 154), or placebo (n = 152). Alzheimer's Disease Cooperative Study/Activities of Daily Living (ADCS-ADL) Inventory score (range, 0-78). Secondary outcomes included cognitive, neuropsychiatric, functional, and caregiver measures. Data from 561 participants were analyzed (alpha tocopherol = 140, memantine = 142, combination = 139, placebo = 140), with 52 excluded because of a lack of any follow-up data. Over the mean (SD) follow-up of 2.27 (1.22) years, ADCS-ADL Inventory scores declined by 3.15 units (95% CI, 0.92 to 5.39; adjusted P = .03) less in the alpha tocopherol group compared with the placebo group. In the memantine group, these scores declined 1.98 units less (95% CI, -0.24 to 4.20; adjusted P = .40) than the placebo group's decline. This change in the alpha tocopherol group translates into a delay in clinical progression of 19% per year compared with placebo or a delay of approximately 6.2 months over the follow-up period. Caregiver time increased least in the alpha tocopherol group. All-cause mortality and safety analyses showed a difference only on the serious adverse event of "infections or infestations," with greater frequencies in the memantine (31 events in 23 participants) and combination groups (44 events in 31 participants) compared with placebo (13 events in 11 participants). Among patients with mild to moderate AD, 2000 IU/d of alpha tocopherol compared with placebo resulted in slower functional decline. There were no significant differences in the groups receiving memantine alone or memantine plus alpha tocopherol. These findings suggest benefit of alpha tocopherol in mild to moderate AD by slowing functional decline and decreasing caregiver burden. clinicaltrials.gov Identifier: NCT00235716.

Open-label pilot study of memantine in the treatment of compulsive buying.

PubMed

Grant, Jon E; Odlaug, Brian L; Mooney, Marc; O'Brien, Robert; Kim, Suck Won

2012-05-01

Although compulsive buying (CB) is relatively common, pharmacotherapy research for CB is limited. Memantine, an N-methyl-D-aspartate receptor antagonist, appears to reduce glutamate excitability and improve impulsive behaviors, suggesting it may help individuals with CB. Nine patients (8 females) with CB were enrolled in a 10-week open-label treatment study of memantine (dose ranging from 10 to 30 mg/d). Participants were enrolled from December 2008 until May 2010. The primary outcome measure was change from baseline to study endpoint on the Yale-Brown Obsessive Compulsive Scale-Shopping Version (Y-BOCS-SV). Of the 9 participants, 8 (88.9%) completed the 10-week study. Y-BOCS-SV scores decreased from a mean of 22.0 ± 1.3 at baseline to 11.0 ± 5.3 at endpoint (P < .001). Hours spent shopping per week and money spent shopping both decreased significantly (P < .001). The mean effective dose of memantine was 23.4 ± 8.1 mg/d. Memantine treatment was associated with diminished impulsive buying and improvements on cognitive tasks of impulsivity. In addition, the medication was well-tolerated. These findings suggest that pharmacologic manipulation of the glutamate system may target the impulsive behavior underlying CB. Placebo-controlled, double-blind studies are warranted in order to confirm these preliminary findings in a controlled design.

Memantine shows promise in reducing gambling severity and cognitive inflexibility in pathological gambling: a pilot study

PubMed Central

Chamberlain, Samuel R.; Odlaug, Brian L.; Potenza, Marc N.; Kim, Suck Won

2012-01-01

Rationale Although pathological gambling (PG) is relatively common, pharmacotherapy research for PG is limited. Memantine, an N-methyl d-aspartate receptor antagonist, appears to reduce glutamate excitability and improve impulsive decision making, suggesting it may help individuals with PG. Objective This study sought to examine the safety and efficacy of Memantine in PG. Methods Twenty-nine subjects (18 females) with DSM-IV PG were enrolled in a 10-week open-label treatment study of memantine (dose ranging from 10 to 30 mg/day). Subjects were enrolled from January 2009 until April 2010. Change from baseline to study endpoint on the Yale Brown Obsessive Compulsive Scale Modified for Pathological Gambling (PG-YBOCS) was the primary outcome measure. Subjects underwent pre- and post-treatment cognitive assessments using the stop-signal task (assessing response impulsivity) and the intra-dimensional/extra-dimensional (ID/ED) set shift task (assessing cognitive flexibility). Results Twenty-eight of the 29 subjects (96.6%) completed the 10-week study. PG-YBOCS scores decreased from a mean of 21.8±4.3 at baseline to 8.9±7.1 at study endpoint (p<0.001). Hours spent gambling per week and money spent gambling both decreased significantly (p<0.001). Subjects also demonstrated a significant improvement in ID/ED total errors (p=0.037) at study endpoint. The mean effective dose of memantine was 23.4±8.1 mg/day. The medication was well-tolerated. Memantine treatment was associated with diminished gambling and improved cognitive flexibility. Conclusions These findings suggest that pharmacological manipulation of the glutamate system may target both gambling and cognitive deficits in PG. Placebo-controlled, double-blind studies are warranted in order to confirm these preliminary findings in a controlled design. PMID:20721537

Effect of Memantine on Serum Levels of Neuron-Specific Enolase and on the Glasgow Coma Scale in Patients With Moderate Traumatic Brain Injury.

PubMed

Mokhtari, Majid; Nayeb-Aghaei, Hossein; Kouchek, Mehran; Miri, Mir Mohammad; Goharani, Reza; Amoozandeh, Arash; Akhavan Salamat, Sina; Sistanizad, Mohammad

2018-01-01

Traumatic brain injury (TBI) is a major cause of disability and death globally. Despite significant progress in neuromonitoring and neuroprotection, pharmacological interventions have failed to generate favorable results. We examined the effect of memantine on serum levels of neuron-specific enolase (NSE), a marker of neuronal damage, and the Glasgow Coma Scale (GCS) in patients with moderate TBI. Patients were randomly assigned to the control group (who received standard TBI management) and the treatment group (who, alongside their standard management, received enteral memantine 30 mg twice daily for 7 days). Patients' clinical data, GCS, findings of head computed tomography, and serum NSE levels were collected during the study. Forty-one patients were randomized into the control and treatment groups, 19 and 22 patients respectively. Baseline characteristics and serum NSE levels were not significantly different between the 2 groups. The mean serum NSE levels for the memantine and the control groups on day 3 were 7.95 ± 2.86 and 12.33 ± 7.09 ng/mL, respectively (P = .05), and on day 7 were 5.03 ± 3.25 and 10.04 ± 5.72 ng/mL, respectively (P = .003). The mean GCS on day 3 was 12.3 ± 2.0 and 10.9 ± 1.9 in the memantine and control groups, respectively (P = .03). Serum NSE levels and GCS changes were negatively correlated (r = -0.368, P = .02). Patients with moderate TBI who received memantine had significantly reduced serum NSE levels by day 7 and marked improvement in their GCS scores on day 3 of the study. © 2017, The American College of Clinical Pharmacology.

Rationale and design of a multicenter randomized clinical trial with memantine and dextromethorphan in ketamine-responder patients.

PubMed

Pickering, Gisèle; Pereira, Bruno; Morel, Véronique; Tiberghien, Florence; Martin, Elodie; Marcaillou, Fabienne; Picard, Pascale; Delage, Noémie; de Montgazon, Géraldine; Sorel, Marc; Roux, Delphine; Dubray, Claude

2014-07-01

The N-methyl-D-aspartate receptor plays an important role in central sensitization of neuropathic pain and N-methyl-D-aspartate receptor antagonists, such as ketamine, memantine and dextromethorphan may be used for persistent pain. However, ketamine cannot be repeated too often because of its adverse events. A drug relay would be helpful in the outpatient to postpone or even cancel the next ketamine infusion. This clinical trial evaluates if memantine and/or dextromethorphan given as a relay to ketamine responders may maintain or induce a decrease of pain intensity and have a beneficial impact on cognition and quality of life. This trial is a multi-center, randomized, controlled and single-blind clinical study (NCT01602185). It includes 60 ketamine responder patients suffering from neuropathic pain. They are randomly allocated to memantine, dextromethorphan or placebo. After ketamine infusion, 60 patients received either memantine (maximal dose 20 mg/day), or dextromethorphan (maximal dose 90 mg/day), or placebo for 12 weeks. The primary endpoint is pain measured on a (0-10) Numeric Rating Scale 1 month after inclusion. Secondary outcomes include assessment of neuropathic pain, sleep, quality of life, anxiety/depression and cognitive function at 2 and 3 months. Data analysis is performed using mixed models and the tests are two-sided, with a type I error set at α=0.05. This study will explore if oral memantine and/or dextromethorphan may be a beneficial relay in ketamine responders and may diminish ketamine infusion frequency. Preservation of cognitive function and quality of life is also a central issue that will be analyzed in these vulnerable patients. Copyright © 2014. Published by Elsevier Inc.

Dementia Medications and Risk of Falls, Syncope, and Related Adverse Events Meta-Analysis of Randomized Controlled Trials

PubMed Central

Kim, Dae Hyun; Brown, Rebecca T.; Ding, Eric L.; Kiel, Douglas P.; Berry, Sarah D.

2012-01-01

Background Conflicting evidence exists on whether cholinesterase inhibitors and memantine increase the risk of falls, syncope, and related events, defined as fracture and accidental injury. Objectives To evaluate the effect of cholinesterase inhibitors and memantine on the risk of falls, syncope, and related events Design, Setting, Participants, and Intervention Meta-analysis of 54 placebo-controlled randomized trials and extension studies of cholinesterase inhibitors and memantine that reported falls, syncope, and related events in cognitively impaired older adults. Trials were identified from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (no language restriction, through July 2009), and manual search. Measurements Falls, syncope, fracture, and accidental injury Results Compared to placebo, cholinesterase inhibitor use was associated with an increased risk of syncope (odds ratio [95% confidence interval]: 1.53 [1.02-2.30]), but not with other events (falls: 0.88 [0.74-1.04]; fracture: 1.39 [0.75-2.56]; accidental injury: 1.13 [0.87-1.45]). Memantine use was associated with fewer fractures (0.21 [0.05-0.85]), but not with other events (fall: 0.92 [0.72-1.18]; syncope: 1.04 [0.35-3.04]; accidental injury: 0.80 [0.56-1.12]). There was no differential effect by type and severity of cognitive impairment, residential status, nor length of follow-up. However, due to underreporting and small number of events, a potential benefit or risk cannot be excluded. Conclusion Cholinesterase inhibitors may increase the risk of syncope, with no effects on falls, fracture, and accidental injury in cognitively impaired older adults. Memantine may have a favorable effect on fracture, with no effects on other events. More research is needed to confirm the reduction in fractures observed for memantine. PMID:21649634

Memantine shows promise in reducing gambling severity and cognitive inflexibility in pathological gambling: a pilot study.

PubMed

Grant, Jon E; Chamberlain, Samuel R; Odlaug, Brian L; Potenza, Marc N; Kim, Suck Won

2010-12-01

Although pathological gambling (PG) is relatively common, pharmacotherapy research for PG is limited. Memantine, an N-methyl D-aspartate receptor antagonist, appears to reduce glutamate excitability and improve impulsive decision making, suggesting it may help individuals with PG. This study sought to examine the safety and efficacy of Memantine in PG. Twenty-nine subjects (18 females) with DSM-IV PG were enrolled in a 10-week open-label treatment study of memantine (dose ranging from 10 to 30 mg/day). Subjects were enrolled from January 2009 until April 2010. Change from baseline to study endpoint on the Yale Brown Obsessive Compulsive Scale Modified for Pathological Gambling (PG-YBOCS) was the primary outcome measure. Subjects underwent pre- and post-treatment cognitive assessments using the stop-signal task (assessing response impulsivity) and the intra-dimensional/extra-dimensional (ID/ED) set shift task (assessing cognitive flexibility). Twenty-eight of the 29 subjects (96.6%) completed the 10-week study. PG-YBOCS scores decreased from a mean of 21.8 ± 4.3 at baseline to 8.9 ± 7.1 at study endpoint (p < 0.001). Hours spent gambling per week and money spent gambling both decreased significantly (p < 0.001). Subjects also demonstrated a significant improvement in ID/ED total errors (p = 0.037) at study endpoint. The mean effective dose of memantine was 23.4 ± 8.1 mg/day. The medication was well-tolerated. Memantine treatment was associated with diminished gambling and improved cognitive flexibility. These findings suggest that pharmacological manipulation of the glutamate system may target both gambling and cognitive deficits in PG. Placebo-controlled, double-blind studies are warranted in order to confirm these preliminary findings in a controlled design.

The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia.

PubMed

Emik, Ulku; Unal, Yusuf; Arslan, Mustafa; Demirel, Cengiz Bekir

2016-01-01

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia. The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups. The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001). In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Effects on agitation with rivastigmine patch monotherapy and combination therapy with memantine in mild to moderate Alzheimer's disease: a multicenter 24-week prospective randomized open-label study (the Korean EXelon Patch and combination with mEmantine Comparative Trial study).

PubMed

Yoon, Soo J; Choi, Seong H; Na, Hae R; Park, Kyung-Won; Kim, Eun-Joo; Han, Hyun J; Lee, Jae-Hong; Shim, Young S; Na, Duk L

2017-03-01

Memantine is known to be effective in the treatment of the behavioral symptoms of dementia, especially agitation in moderate to severe Alzheimer's disease (AD). However, memantine and rivastigmine patch combination therapy has not been well studied in determining treatment effectiveness with mild to moderate AD patients. This was a multicenter, 24-week, prospective, randomized, open-label study design. A total 147 AD patients with Mini-Mental State Examination scores from 10 to 20 were randomly assigned to rivastigmine patch monotherapy and combination therapy with memantine groups. Agitation symptoms, using the Korean Version of the Cohen Mansfield Agitation Inventory were evaluated at baseline and at study end. Suppression and emergence of agitation symptoms were also evaluated. We carried out factor analyses to evaluate the interrelationship of agitation symptoms and to investigate treatment response in these symptoms. Factor analyses showed two symptom clusters: factor A - aggressive agitated behaviors - versus factor B - non-aggressive agitated behaviors. The rivastigmine patch monotherapy group showed significantly decreased factor B scores and had a tendency of decreased Korean Version of the Cohen Mansfield Agitation Inventory total scores and factor A scores. Conversely, the combination therapy group showed significantly increased Korean Version of the Cohen Mansfield Agitation Inventory total scores and factor B scores. Neither monotherapy nor combination therapy reduced the emergence of new agitation symptoms. In this trial of mild to moderate AD patients, the rivastigmine patch monotherapy group experienced a reduction of non-aggressive agitated behaviors. However, combination therapy with memantine did not show any benefit on the agitation associated with mild to moderate AD. Geriatr Gerontol Int 2017; 17: 494-499. © 2016 Japan Geriatrics Society.

Acetylcholinesterase inhibitors and memantine in bipolar disorder: A systematic review and best evidence synthesis of the efficacy and safety for multiple disease dimensions.

PubMed

Veronese, Nicola; Solmi, Marco; Luchini, Claudio; Lu, Ru-Band; Stubbs, Brendon; Zaninotto, Leonardo; Correll, Christoph U

2016-06-01

Acetylcholinesterase inhibitors (AceI) and memantine might prove useful in bipolar disorder (BD) given their neuroprotective and pro-cognitive effects, as highlighted by several case reports. We aimed to systematically review the efficacy and safety of AceI and memantine across multiple outcome dimensions in BD. Systematic PubMed and SCOPUS search until 04/17/2015 without language restrictions. Included were randomized controlled trials (RCTs), open label studies and case series of AceI or memantine in BD patients reporting quantitative data on depression, mania, psychotic symptoms, global functioning, or cognitive performance. We summarized results using a best-evidence based synthesis. Out of 214 hits, 12 studies (RCTs=5, other designs=7, total n=422) were included. Donepezil (studies=5; treated=102 vs. placebo=21): there was strong evidence for no effect on mania and psychotic symptoms; low evidence indicating no effect on depression. Galantamine (studies=3; treated=21 vs. controls=20) (placebo=10, healthy subjects=10): there was strong evidence for no effect on mania; moderate evidence for no effect on depression; low evidence for no effect on global functioning. Memantine (studies=4; treated=152 vs. placebo=88): there was conflicting evidence regarding efficacy for mania, depression and global functioning. Paucity of RCTs; small sample size studies; heterogeneous design, outcome and patient characteristics. There is limited but converging evidence of no effect of AceI in BD, and conflicting evidence about memantine in BD. Too few studies of mostly medium/low quality and lacking sufficient numbers of patients in specific mood states, especially mania, contributed data, focusing solely on short-term/medium-term treatment, necessitating additional high-quality research to yield more definite results. Copyright © 2016 Elsevier B.V. All rights reserved.

Glioprotection of Retinal Astrocytes After Intravitreal Administration of Memantine in the Mouse Optic Nerve Crush Model.

PubMed

Maciulaitiene, Ruta; Pakuliene, Giedre; Kaja, Simon; Pauza, Dainius Haroldas; Kalesnykas, Giedrius; Januleviciene, Ingrida

2017-03-07

BACKGROUND In glaucoma, non-intraocular pressure (IOP)-related risk factors can result in increased levels of extracellular glutamate, which triggers a cascade of neurodegeneration characterized by the excessive activation of N-methyl-D-aspartate (NMDA). The purpose of our study was to evaluate the glioprotective effects of memantine as a prototypic uncompetitive NMDA blocker on retinal astrocytes in the optic nerve crush (ONC) mouse model for glaucoma. MATERIAL AND METHODS Optic nerve crush was performed on all of the right eyes (n=8), whereas left eyes served as contralateral healthy controls (n=8) in Balb/c/Sca mice. Four randomly assigned mice received 2-µl intravitreal injections of memantine (1 mg/ml) after ONC in the experimental eye. One week after the experiment, optic nerves were dissec-ted and stained with methylene blue. Retinae were detached from the sclera. The tissue was immunostained. Whole-mount retinae were investigated by fluorescent microscopy. Astrocyte counts for each image were performed manually. RESULTS Histological sections of crushed optic nerves showed consistently moderate tissue damage in experimental groups. The mean number of astrocytes per image in the ONC group was significantly lower than in the healthy control group (7.13±1.5 and 10.47±1.9, respectively). Loss of astrocytes in the memantine-treated group was significantly lower (8.83±2.2) than in the ONC group. Assessment of inter-observer reliability showed excellent agreement among observations in control, ONC, and memantine groups. CONCLUSIONS The ONC is an effective method for investigation of astrocytic changes in mouse retina. Intravitreally administered memantine shows a promising glioprotective effect on mouse retinal astrocytes by preserving astrocyte count after ONC.

The safety, tolerability, and efficacy of once-daily memantine (28 mg): a multinational, randomized, double-blind, placebo-controlled trial in patients with moderate-to-severe Alzheimer's disease taking cholinesterase inhibitors.

PubMed

Grossberg, George T; Manes, Facundo; Allegri, Ricardo F; Gutiérrez-Robledo, Luis Miguel; Gloger, Sergio; Xie, Lei; Jia, X Daniel; Pejović, Vojislav; Miller, Michael L; Perhach, James L; Graham, Stephen M

2013-06-01

Immediate-release memantine (10 mg, twice daily) is approved in the USA for moderate-to-severe Alzheimer's disease (AD). This study evaluated the efficacy, safety, and tolerability of a higher-dose, once-daily, extended-release formulation in patients with moderate-to-severe AD concurrently taking cholinesterase inhibitors. In this 24-week, double-blind, multinational study (NCT00322153), outpatients with AD (Mini-Mental State Examination scores of 3-14) were randomized to receive once-daily, 28-mg, extended-release memantine or placebo. Co-primary efficacy parameters were the baseline-to-endpoint score change on the Severe Impairment Battery (SIB) and the endpoint score on the Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus). The secondary efficacy parameter was the baseline-to-endpoint score change on the 19-item Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL19); additional parameters included the baseline-to-endpoint score changes on the Neuropsychiatric Inventory (NPI) and verbal fluency test. Data were analyzed using a two-way analysis of covariance model, except for CIBIC-Plus (Cochran-Mantel-Haenszel test). Safety and tolerability were assessed through adverse events and physical and laboratory examinations. A total of 677 patients were randomized to receive extended-release memantine (n = 342) or placebo (n = 335); completion rates were 79.8 and 81.2 %, respectively. At endpoint (week 24, last observation carried forward), memantine-treated patients significantly outperformed placebo-treated patients on the SIB (least squares mean difference [95 % CI] 2.6 [1.0, 4.2]; p = 0.001), CIBIC-Plus (p = 0.008), NPI (p = 0.005), and verbal fluency test (p = 0.004); the effect did not achieve significance on ADCS-ADL19 (p = 0.177). Adverse events with a frequency of ≥5.0 % that were more prevalent in the memantine group were headache (5.6 vs. 5.1 %) and diarrhea (5.0 vs. 3.9 %). Extended-release memantine was efficacious, safe, and well tolerated in this population.

A double-blind randomized placebo-controlled withdrawal trial comparing memantine and antipsychotics for the long-term treatment of function and neuropsychiatric symptoms in people with Alzheimer's disease (MAIN-AD).

PubMed

Ballard, Clive; Thomas, Alan; Gerry, Stephen; Yu, Ly-Mee; Aarsland, Dag; Merritt, Claire; Corbett, Anne; Davison, Christopher; Sharma, Narenda; Khan, Zunera; Creese, Byron; Loughlin, Paul; Bannister, Carol; Burns, Alistair; Win, Soe Nyunt; Walker, Zuzana

2015-04-01

Neuropsychiatric symptoms in Alzheimer disease (AD) cause significant distress and present a complex clinical challenge for treatment. Pharmacological treatment options are limited to antipsychotics, which carry extensive safety issues. There is emerging evidence to support the potential benefits of memantine, currently licensed for moderate to severe AD, in the prophylaxis of neuropsychiatric symptoms. The MAIN-AD study is a double-blind randomized placebo-controlled withdrawal trial comparing memantine with antipsychotics for the treatment of neuropsychiatric symptoms over 24 weeks. A total of 199 people with probable AD living in care homes already receiving an antipsychotic were randomized to receive either memantine or to continue an antipsychotic. The primary outcomes were function (Bristol Activities of Daily Living Scale [BADLS]) and agitation (Cohen-Mansfield Agitation Inventory [CMAI]). Secondary outcomes were Neuropsychiatric Inventory (NPI), Mini-Mental State Examination (MMSE), and mortality. There was no significant difference between groups on the BADLS or CMAI. At 24 weeks, there was a nonsignificant adjusted difference in favor of memantine on the BADLS of 0.23 (95% CI -1.80-2.27; P = .82) and in favor of antipsychotic on the CMAI of 0.09 (95% CI -0.35-8.53; P = .07). Although there were no significant differences in total NPI, there were 5.01 (95% CI -1.68-11.70; P = .05) and 3.63 (95% CI -1.40-8.67; P = .16) point advantages favoring antipsychotics at weeks 12 and 24, respectively. In addition, in an exploratory analysis, individuals allocated to antipsychotics were significantly less likely to experience relapse of neuropsychiatric symptoms at all time points. The group receiving memantine had a nonsignificant 1.3-point advantage on the MMSE at 24 weeks. This study indicates no benefits for memantine in the long-term treatment and prophylaxis of clinically significant neuropsychiatric symptoms. The results did indicate some benefits for antipsychotic medications in reducing the relapse of neuropsychiatric symptoms, but this must be balanced against increased mortality risk. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Midazolam: An Improved Anticonvulsant Treatment for Nerve Agent-Induced Seizures

DTIC Science & Technology

2002-01-01

variety of compounds that different authors had championed as being capable of stopping or moderating nerve agent seizures (e.g., memantine , clonidine...e.g., memantine , neuroactive steroids; EEG seizures were still evident) or required such a narrow dose range or specific treatment conditions that

Neuroprotective Treatment of Laser-Induced Retinal Injuries

DTIC Science & Technology

2000-10-01

to evaluate the neuroprotective effect of memantine in our rat model of laser-induced retinal-lesions. Methods: Argon laser retinal lesions were...inflicted in the eyes of 36 pigmented rats. The treated group received memantine 10 mg/kg dissolved in saline, immediately after exposure to laser and then

Memantine add-on to antipsychotic treatment for residual negative and cognitive symptoms of schizophrenia: a meta-analysis.

PubMed

Kishi, Taro; Matsuda, Yuki; Iwata, Nakao

2017-07-01

We examined whether memantine add-on to antipsychotic treatment is beneficial in schizophrenia treatment. This systematic review and meta-analysis aimed to achieve stronger evidence on the efficacy and safety of memantine add-on for treating schizophrenia. We analyzed double-blind, randomized, placebo-controlled trials of memantine add-on treatment in schizophrenia patients receiving antipsychotics. The primary outcomes were amelioration of negative symptoms and all-cause discontinuation. Dichotomous outcomes are presented as risk ratios (RRs), and continuous outcomes are presented as mean differences (MDs) or standardized mean differences (SMDs). Eight studies (n = 448) were included. Although memantine add-on treatment was superior to placebo for ameliorating negative symptoms (SMD = -0.96, p = 0.006, I 2  = 88%; N = 7, n = 367) in the Positive and Negative Syndrome Scale general subscale (MD = -1.62, p = 0.002, I 2  = 0%; N = 4, n = 151) and Mini-Mental Status Examination score (MD = -3.07, p < 0.0001, I 2  = 21%; N = 3, n = 83), there were no statistically significant differences in the amelioration of overall (SMD = -0.75, p = 0.06, I 2  = 86%; N = 5, n = 271), positive (SMD = -0.46, p = 0.07, I 2  = 80%; N = 7, n = 367), and depressive symptoms (SMD = -0.127, p = 0.326, I 2  = 0%; N = 4, n = 201); all-cause discontinuation (RR = 1.34, p = 0.31, I 2  = 0%; N = 8, n = 448); and individual adverse events (fatigue, dizziness, headache, nausea, constipation) between the groups. For negative symptoms, the significant heterogeneity disappeared when risperidone studies alone were considered (I 2  = 0%). However, memantine add-on treatment remained superior to placebo (SMD = -1.29, p = 0.00001). Meta-regression analysis showed that patient age was associated with memantine-associated amelioration of negative symptoms (slope = 0.171, p = 0.0206). Memantine add-on treatment may be beneficial for treating psychopathological symptoms (especially negative symptoms) in schizophrenia patients. The negative-symptom effect size may be associated with younger adult schizophrenia patients.

Effect of memantine on the levels of glial cells, neuropeptides, and peptide-degrading enzymes in rat brain regions of ibotenic acid-treated alzheimer's disease model.

PubMed

Ahmed, M M; Hoshino, H; Chikuma, T; Yamada, M; Kato, T

2004-01-01

It has been implicated that glia activation plays a critical role in the progression of Alzheimer's disease (AD). However, the precise mechanism of glia activation is not clearly understood yet. In our present studies, we confirmed our previous results where change the levels of neuropeptides and peptidases in ibotenic acid (IBO) infusion into the rat nucleus basalis magnocellularis, an animal model of AD. Furthermore, we extended our study to investigate a possible protection effect of co-administration on the changes of neuropeptides, and neuronal and glial cells in IBO-infused rat brain by memantine treatment. The levels of substance P and somatostatin were decreased in the striatum and frontal cortex 1 week after IBO infusion, and recovered to the control level by memantine treatment, indicating the involvement of neuropeptides in AD pathology. Furthermore, the immunohistochemical and enzymatic studies of GFAP and CD 11b, and peptidylarginine deiminase, markers of glia, in the striatum and frontal cortex showed the increase in IBO-treated rat brain as compared with controls, while co-administration of memantine and IBO no increase of astrocytes and microglia activation was observed. The present biochemical and immunohistochemical results suggest that glia activation might play an important role to the pathology of AD, and correlate with the changes of neuropeptide levels in AD brain that is recovered by memantine treatment.

Memantine Reduced Cell Death, Astrogliosis, and Functional Deficits in an in vitro Model of Repetitive Mild Traumatic Brain Injury.

PubMed

Effgen, Gwen B; Morrison, Barclay

2017-02-15

Clinical studies suggest that athletes with a history of concussion may be at risk for additional mild traumatic brain injury (mTBI), and repetitive exposure to mTBI acutely increases risk for more significant and persistent symptoms and increases future risk for developing neurodegenerative diseases. Currently, symptoms of mTBI are managed with rest and pain medication; there are no drugs approved by the Food and Drug Administration (FDA) that target the biochemical pathology underlying mTBI to treat or prevent acute and long-term effects of repetitive mTBI. Memantine is an FDA-approved drug for treating Alzheimer's disease, and also was shown to be neuroprotective in rodents following a single, moderate to severe TBI. Therefore, we investigated the potential for memantine to mitigate negative outcomes from repetitive mild stretch injury in organotypical hippocampal slice cultures. Samples received two injuries 24 h apart; injury resulted in significant cell death, loss of long-term potentiation (LTP), and astrogliosis compared with naïve, uninjured samples. Delivery of 1.5 μM memantine 1 h following each stretch significantly reduced the effect of injury for all outcome measures, and did not alter those outcome measures that were unaffected by the injury. Therefore, memantine warrants further pre-clinical and clinical investigation for its therapeutic efficacy to prevent cognitive deficits and neuropathology from multiple mTBIs.

Long-term oral administration of the NMDA receptor antagonist memantine extends life span in spinocerebellar ataxia type 1 knock-in mice.

PubMed

Iizuka, Akira; Nakamura, Kazuhiro; Hirai, Hirokazu

2015-04-10

Spinocerebellar ataxia type 1 (SCA1) is a progressive neurodegenerative disease caused by extension of a CAG repeat in the Sca1gene. Although the mechanisms underlying the symptoms of SCA1 have not been determined, aberrant neuronal activation potentially contributes to the neuronal cell death characteristic of the disease. Here we examined the potential involvement of extrasynaptic N-methyl-d-aspartate receptor (NMDAR) activation in the pathogenesis of SCA1 by administering memantine, a low-affinity noncompetitive NMDAR antagonist, in SCA1 knock-in (KI) mice. In KI mice, the exon in the ataxin 1 gene is replaced with abnormally expanded 154CAG repeats. Memantine was administered orally to the SCA1 KI mice from 4 weeks of age until death. The treatment significantly attenuated body-weight loss and prolonged the life span of SCA1 KI mice. Furthermore, memantine significantly suppressed the loss of Purkinje cells in the cerebellum and motor neurons in the dorsal motor nucleus of the vagus, which are critical for motor function and parasympathetic function, respectively. These findings support the contribution of aberrant activation of extrasynaptic NMDARs to neuronal cell death in SCA1 KI mice and suggest that memantine may also have therapeutic benefits in human SCA1 patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Treatment Strategies fir the NMDA Component of Organophosphorous Convulsions

DTIC Science & Technology

2005-04-01

Prophylactic and agents induce seizures and brain damage in lithium-treated rats. therapeutic efficacy of memantine against seizures produced by Science 1983;220...Gupta, R.C., Dettbarn, W.D., Wamil, A.W. (1992) Prophylactic and therapeutic efficacy of memantine against seizures produced by soman in the rat

Studies on the interaction of NMDA receptor antagonist memantine with cell membranes: A mini-review.

PubMed

Zambrano, Pablo; Suwalsky, Mario; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2018-03-01

Memantine is an NMDA receptor antagonist clinically used for the treatment of moderate to severe Alzheimer's disease. Currently, it is the only NMDA receptor antagonist drug marketed against this disease. Despite the large number of publications regarding its clinical and therapeutic use, studies related to its mechanism of action are still inconclusive. Knowledge of drug interactions with cell membranes may lead to the development of novel drugs for neurodegenerative diseases. The present mini-review aims to give an overview of the latest findings regarding the interaction of memantine with cell membranes, specifically with that of the human erythrocyte. Copyright © 2018 Elsevier B.V. All rights reserved.

[Efficacy of memantine in the treatment of Alzheimer's disease].

PubMed

Molinuevo Guix, J L; Lladó Plarrumaní, A

2005-12-01

Alzheimer's disease (AD) is a neurodegenerative disorder clinically characterized by cognitive loss with impairment of daily living activities. The benefits presently observed with the approved treatments are mainly symptomatic without clear evidence of neuroprotection. N-methyl-D-aspartate (NMDA) glutamate receptor antagonists have very extensive therapeutic potential in several central nervous system disorders and can be used in chronic neurodegenerative diseases and in other neurological diseases such as epilepsy. Memantine, a moderate-low affinity, uncompetitive NMDA receptor antagonist, is the only antiglutamatergic drug currently approved for the treatment of moderate to severe AD. Several studies have demonstrated that treatment with memantine has cognitive and functional benefits through all disease stages, while it is safe and well tolerated. Additionally, memantine generates an indirect positive effect on the caregiver, which results in some social benefits. This fact, together with a delay on the transition towards a greater dependence stage is probably associated with a decrease in the number of patients institutionalized. From a socio-economic perspective, these effects mean lower global cost of disease, therefore being a cost-effective drug.

N-Methyl-d-Aspartate (NMDA) Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection

PubMed Central

Costa, Vivian V.; Del Sarto, Juliana L.; Rocha, Rebeca F.; Silva, Flavia R.; Doria, Juliana G.; Olmo, Isabella G.; Marques, Rafael E.; Queiroz-Junior, Celso M.; Foureaux, Giselle; Araújo, Julia Maria S.; Cramer, Allysson; Real, Ana Luíza C. V.; Ribeiro, Lucas S.; Sardi, Silvia I.; Ferreira, Anderson J.; Machado, Fabiana S.; de Oliveira, Antônio C.; Teixeira, Antônio L.; Nakaya, Helder I.; Souza, Danielle G.

2017-01-01

ABSTRACT Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration. PMID:28442607

Use of antidementia drugs and risk of pneumonia in older persons with Alzheimer's disease.

PubMed

Lampela, Pasi; Tolppanen, Anna-Maija; Tanskanen, Antti; Tiihonen, Jari; Lavikainen, Piia; Hartikainen, Sirpa; Taipale, Heidi

2017-05-01

Persons with Alzheimer's disease are at an increased risk of pneumonia, but the comparative risks during specific antidementia treatments are not known. We compared the risk of pneumonia in the use of donepezil, rivastigmine (oral, transdermal), galantamine and memantine. We used data from a nationwide cohort of community-dwelling individuals diagnosed with Alzheimer's disease during 2005-2011 in Finland, who initiated monotherapy with acetylcholinesterase inhibitor or memantine (n = 65,481). The risk of hospitalization or death due to pneumonia was investigated with Cox proportional hazard models. The risk of pneumonia was higher in persons using rivastigmine patch (n = 9709) (adjusted hazard ratio (HR) 1.15, 95% confidence interval (CI) 1.04-1.27) and memantine (n = 11,024) (HR 1.59, 95% CI 1.48-1.71) compared with donepezil users (n = 26,416) whereas oral rivastigmine (n = 7384) (HR 1.08, 95% CI 0.98-1.19) and galantamine (n = 10,948) (HR 0.91, 95% CI 0.83-1.00) were not associated with an increased risk. These results did not change when adjusting for comorbid conditions, use of psychotropic drugs or with inverse probability of treatment weighting. The increased risk of pneumonia in this fragile group of aged persons should be taken into account. Memantine is associated with the highest risk in the comparison of antidementia drugs. KEY Message Pneumonia risk is increased in persons with Alzheimer's disease who use memantine or rivastigmine patches.

Comprehensive, Individualized, Person-Centered Management of Community-Residing Persons with Moderate-to-Severe Alzheimer Disease: A Randomized Controlled Trial.

PubMed

Reisberg, Barry; Shao, Yongzhao; Golomb, James; Monteiro, Isabel; Torossian, Carol; Boksay, Istvan; Shulman, Melanie; Heller, Sloane; Zhu, Zhaoyin; Atif, Ayesha; Sidhu, Jaskirat; Vedvyas, Alok; Kenowsky, Sunnie

2017-01-01

The aim was to examine added benefits of a Comprehensive, Individualized, Person-Centered Management (CI-PCM) program to memantine treatment. This was a 28-week, clinician-blinded, randomized, controlled, parallel-group study, with a similar study population, similar eligibility criteria, and a similar design to the memantine pivotal trial of Reisberg et al. [N Engl J Med 2003;348:1333-1341]. Twenty eligible community-residing Alzheimer disease (AD) subject-caregiver dyads were randomized to the CI-PCM program (n = 10) or to usual community care (n = 10). Primary outcomes were the New York University Clinician's Interview-Based Impression of Change Plus Caregiver Input (NYU-CIBIC-Plus), assessed by one clinician set, and an activities of daily living inventory, assessed by a separate clinician set at baseline and at weeks 4, 12, and 28. Primary outcomes showed significant benefits of the CI-PCM program at all post-baseline evaluations. Improvement on the NYU-CIBIC-Plus in the management group at 28 weeks was 2.9 points over the comparator group. The memantine 2003 trial showed an improvement of 0.3 points on this global measure in memantine-treated versus placebo-randomized subjects at 28 weeks. Hence, globally, the management program intervention benefits were 967% greater than memantine treatment alone. These results are approximately 10 times those usually observed with both nonpharmacological and pharmacological treatments and indicate substantial benefits with the management program for advanced AD persons. © 2017 S. Karger AG, Basel.

Memantine in Japanese patients with moderate to severe Alzheimer's disease: meta-analysis of multiple-index responder analyses.

PubMed

Okuizumi, Kaoru; Kamata, Teruyoshi; Matsui, Daiju; Saito, Kengo; Matsumoto, Takuyuki; Fukuchi, Yoshikazu

2018-04-01

Responder analyses assessing clinical worsening have attempted to clarify clinically meaningful drug efficacy enhancements in patients with Alzheimer's disease (AD). This was a meta-analysis of two multicenter, randomized, double-blind, parallel-group, 24-week studies of 633 Japanese patients with moderate to severe AD receiving memantine 20 mg/day (n = 318) or placebo (n = 315). The clinical trial registration number is UMIN000026013. Overall odds ratios (OR) for a reduced likelihood of clinical worsening (memantine versus placebo) were statistically significant on the following individual and combined rating scales: Severe Impairment Battery-Japanese version (SIB-J, OR 0.52; 95% CI: 0.37, 0.73; p = 0.0001); Behavioral Pathology in AD Rating Scale (BEHAVE-AD, OR 0.53; 95% CI: 0.37, 0.75; p = 0.0003); and SIB-J + Clinician's Interview-Based Impression of Change-plus-Japanese version (SIB-J + CIBIC-plus-J; OR 0.53; 95% CI: 0.37, 0.77; p = 0.0009). A significantly reduced risk of triple worsening was evident in the memantine versus placebo group on the combined SIB-J + CIBIC-plus-J + BEHAVE-AD rating scales (OR 0.38; 95% CI: 0.22, 0.65; p = 0.0003). Memantine is a viable treatment option for patients with AD presenting not only with cognitive impairment, but also with a broader range of symptoms, including the behavioral and psychological symptoms of dementia.

Memantine, an Antagonist of the NMDA Glutamate Receptor, Affects Cell Proliferation, Differentiation and the Intracellular Cycle and Induces Apoptosis in Trypanosoma cruzi

PubMed Central

Damasceno, Flávia Silva; Barisón, María Julia; Pral, Elisabeth Mieko Furusho; Paes, Lisvane Silva; Silber, Ariel Mariano

2014-01-01

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and affects approximately 10 million people in endemic areas of Mexico and Central and South America. Currently available chemotherapies are limited to two compounds: Nifurtimox and Benznidazole. Both drugs reduce the symptoms of the disease and mortality among infected individuals when used during the acute phase, but their efficacy during the chronic phase (during which the majority of cases are diagnosed) remains controversial. Moreover, these drugs have several side effects. The aim of this study was to evaluate the effect of Memantine, an antagonist of the glutamate receptor in the CNS of mammals, on the life cycle of T. cruzi. Memantine exhibited a trypanocidal effect, inhibiting the proliferation of epimastigotes (IC50 172.6 µM). Furthermore, this compound interfered with metacyclogenesis (approximately 30% reduction) and affected the energy metabolism of the parasite. In addition, Memantine triggered mechanisms that led to the apoptosis-like cell death of epimastigotes, with extracellular exposure of phosphatidylserine, increased production of reactive oxygen species, decreased ATP levels, increased intracellular Ca2+ and morphological changes. Moreover, Memantine interfered with the intracellular cycle of the parasite, specifically the amastigote stage (IC50 31 µM). Interestingly, the stages of the parasite life cycle that require more energy (epimastigote and amastigote) were more affected as were the processes of differentiation and cell invasion. PMID:24587468

A Role for Prefrontal Cortical NMDA Receptors in Murine Alcohol-Heightened Aggression.

PubMed

Newman, Emily L; Terunuma, Miho; Wang, Tiffany L; Hewage, Nishani; Bicakci, Matthew B; Moss, Stephen J; DeBold, Joseph F; Miczek, Klaus A

2018-05-01

Alcohol is associated with nearly half of all violent crimes committed in the United States; yet, a potential neural basis for this type of pathological aggression remains elusive. Alcohol may act on N-methyl-d-aspartate receptors (NMDARs) within cortical circuits to impede processing and to promote aggression. Here, male mice were characterized as alcohol-heightened (AHAs) or alcohol non-heightened aggressors (ANAs) during resident-intruder confrontations after self-administering 1.0 g/kg alcohol (6% w/v) or water. Alcohol produced a pathological-like pattern of aggression in AHAs; these mice shifted their bites to more vulnerable locations on the body of a submissive animal, including the anterior back and ventrum after consuming alcohol. In addition, through immunoblotting, we found that AHAs overexpressed the NMDAR GluN2D subunit in the prefrontal cortex (PFC) as compared to ANAs while the two phenotypes expressed similar levels of GluN1, GluN2A and GluN2B. After identifying several behavioral and molecular characteristics that distinguish AHAs from ANAs, we tested additional mice for their aggression following preferential antagonism of GluN2D-containing NMDARs. In these experiments, groups of AHAs and ANAs self-administered 1.0 g/kg alcohol (6% w/v) or water before receiving intraperitoneal (i.p.) doses of ketamine or memantine, or infusions of memantine directly into the prelimbic (PLmPFC) or infralimbic medial PFC (ILmPFC). Moderate doses of IP ketamine, IP memantine, or intra-PLmPFC memantine increased aggression in AHAs, but only in the absence of alcohol. Prior alcohol intake blocked the pro-aggressive effects of ketamine or memantine. In contrast, only memantine, administered systemically or intra-PLmPFC, interacted with prior alcohol intake to escalate aggression in ANAs. Intra-ILmPFC memantine had no effect on aggression in either AHAs or ANAs. In sum, this work illustrates a potential role of GluN2D-containing NMDARs in the PLmPFC in alcohol-heightened aggression. GluN2D-containing NMDARs are highly expressed on cortical parvalbumin-containing interneurons, suggesting that, in a subset of individuals, alcohol may functionally alter signal integration within cortical microcircuits to dysregulate threat reactivity and promote aggression. This work suggests that targeting GluN2D-NMDARs may be of use in reducing the impact of alcohol-related violence in the human population.

Memantine in patients with Alzheimer's disease receiving donepezil: new analyses of efficacy and safety for combination therapy.

PubMed

Atri, Alireza; Molinuevo, José L; Lemming, Ole; Wirth, Yvonne; Pulte, Irena; Wilkinson, David

2013-01-01

Memantine and cholinesterase inhibitors potentially offer additional benefits in Alzheimer's disease (AD) when used together. This study assessed the efficacy and safety of combination treatment with memantine added to stable donepezil in patients with moderate to severe AD, and in a subset with moderate AD. Post hoc meta-analyses of data combined from two 24-week, randomised, double-blind, placebo-controlled trials of memantine 20 mg/day versus placebo, added to a stable cholinesterase inhibitor, were conducted. Data were included for all patients receiving donepezil 10 mg/day with Mini-Mental State Examination (MMSE) scores < 20 (n = 510). Efficacy was assessed using measures of cognition, function, and global status. Furthermore, marked clinical worsening, defined as concurrent deterioration from baseline in the three main efficacy domains, and safety, measured by treatment-emergent adverse events, were assessed. Analyses were performed for patients with moderate to severe AD (MMSE 5-19; MOD-SEV subgroup), and also for patients with moderate AD (MMSE 10-19; MOD subgroup; n = 367). At week 24, in the MOD-SEV subgroup, patients receiving memantine added to donepezil significantly outperformed those receiving placebo added to donepezil in measures of cognition (P < 0.0001), function (P = 0.02), and global status (P = 0.010), with standardised mean differences (SMDs) of 0.36, 0.21, and 0.23, respectively (all last observation carried forward). Similarly, in the MOD subgroup, significant benefits were observed for cognition (P = 0.008), function (P = 0.04) and global status (P = 0.008), with SMDs of 0.28, 0.21, and 0.28, respectively. Significantly fewer patients receiving memantine added to donepezil showed marked clinical worsening than those receiving placebo added to donepezil, in both subgroups (MOD-SEV: 8.7% versus 20.4%, P = 0.0002; MOD: 5.9% versus 15.0%, P = 0.006). The incidence of adverse events was similar between treatment groups. These results support and extend previous evidence that combination treatment with memantine added to stable donepezil in patients with moderate AD, and in those with moderate to severe AD, is associated with significant benefits in reducing 24-week decline in cognition, function and global status. Combination treatment produces substantially reduced rates of marked clinical worsening, has good safety and tolerability, and generates effect sizes that are both statistically significant and clinically meaningful.

Lack of evidence for the efficacy of memantine in mild Alzheimer disease.

PubMed

Schneider, Lon S; Dagerman, Karen S; Higgins, Julian P T; McShane, Rupert

2011-08-01

We directly assessed the clinical trials' evidence for memantine's efficacy in mild Alzheimer disease (AD). Memantine is indicated in the United States and Europe for moderate to severe AD, which is diagnosed if a patient has a Mini-Mental State Examination (MMSE) score of less than 15 or less than 20, respectively. Yet memantine is very frequently prescribed for mild AD and mild cognitive impairment, and a manufacturer-sponsored meta-analysis claimed its efficacy in mild AD. Manufacturer-sponsored meta-analyses, registries, presentations, and publications were systematically searched for randomized placebo-controlled, parallel-group clinical trials of memantine in patients with mild to moderate AD. The trials' characteristics and outcomes were extracted by one reviewer and checked by another. Meta-analyses were performed as inverse variance-weighted averages of mean differences using fixed-effects models. Summary results for patients with mild AD were obtained by contrasting the summary results for patients with mild or moderate AD with the summary results for the subset of patients with moderate AD. Three trials were identified that included 431 patients with mild AD (ie, with MMSE scores of 20-23) and 697 patients with moderate AD (ie, with MMSE scores of 10-19). There were no significant differences between memantine and placebo on any outcome for patients with mild AD, either within any trial or when data were combined: mean differences (95% confidence intervals [CIs]) on the Alzheimer Disease Assessment Scale-cognitive subscale (ADAS-cog), the Clinician's Interview-Based Impression of Change plus caregiver's input (CIBIC-plus), the Alzheimer Disease Cooperative Study-activities of daily living (ADCS-ADL) scale, and the Neuropsychiatric Inventory (NPI) were -0.17 (95% CI, -1.60 to 1.26), -0.09 (95% CI, -0.30 to 0.12), 0.62 (95% CI, -1.64 to 2.71), and 0.09 (95% CI, -2.11 to 2.29), respectively. For patients with moderate AD, there were small differences on the ADAS-cog and the CIBIC-plus, -1.33 (95% CI, -2.28 to -0.38) and -0.16 (95% CI, -0.32 to 0.00), respectively, but no differences on the ADCS-ADL scale (-0.57 [95% CI, -1.75 to 0.60]) or the NPI (0.25 [95% CI, -1.48 to 1.99]). Despite its frequent off-label use, evidence is lacking for a benefit of memantine in mild AD, and there is meager evidence for its efficacy in moderate AD. Prospective trials are needed to further assess the potential for efficacy of memantine either alone or added to cholinesterase inhibitors in mild and moderate AD.

Simultaneous usage of dementia medications and anticholinergics among Asians and Pacific Islanders.

PubMed

Schultz, Brian R; Takeshita, Junji; Goebert, Deborah; Takeshita, Steven; Lu, Brett Y; Guilloux, Alexandre; Higa, Joy

2017-11-01

The simultaneous use of dementia medications and anticholinergic medications occurs frequently. Cholinesterase inhibitors and anticholinergic medications likely counteract one another, potentially exposing patients to medications with decreased benefit, more adverse effects, and higher cost of care. We identified the rate of concurrent prescriptions of cholinesterase inhibitors/memantine with anticholinergics in an urban hospital setting with a large Asian and Pacific Islander population. This study is a retrospective review of patients hospitalized from 1 January 2006 to 31 December 2010 at a general hospital who simultaneously received US Food and Drug Administration-approved dementia medications (galantamine, rivastigmine, donepezil, and/or memantine) and anticholinergics. Overall, 304 patients receiving cholinesterase inhibitors/memantine also received anticholinergics. Of these patients, 64.1% were given high-potency anticholinergic medications, and 35.9% received medium-potency medications. Indications for the use of anticholinergic medication were urological (17.8%), gastrointestinal excluding nausea (32.6%), nausea (10.2%), psychiatric (7.9%), and other (31.6%). Asian patients received the combination of cholinesterase inhibitors/memantine and anticholinergics less frequently than Native Hawaiian or Caucasian patients (8.4% vs 12.2% and 13.3%, respectively; χ 2  = 16.04, degrees of freedom = 2, P < 0.0003). Simultaneous prescribing of cholinesterase inhibitors, memantine, and anticholinergic medications was significantly less common than in previous studies, with some ethnic variability. The less frequent occurrence of concurrent medications in the Asian population may be because of variations in the rate of indications or in tolerability for anticholinergic medications among the population. © 2017 Japanese Psychogeriatric Society.

Optimization of o-phtaldialdehyde/2-mercaptoethanol postcolumn reaction for the hydrophilic interaction liquid chromatography determination of memantine utilizing a silica hydride stationary phase.

PubMed

Douša, Michal; Pivoňková, Veronika; Sýkora, David

2016-08-01

A rapid procedure for the determination of memantine based on hydrophilic interaction chromatography with fluorescence detection was developed. Fluorescence detection after postcolumn derivatization with o-phtaldialdehyde/2-mercaptoethanol was performed at excitation and emission wavelengths of 345 and 450 nm, respectively. The postcolumn reaction conditions such as reaction temperature, derivatization reagent flow rate, and reagents concentration were studied due to steric hindrance of amino group of memantine. The derivatization reaction was applied for the hydrophilic interaction liquid chromatography method which was based on Cogent Silica-C stationary phase with a mobile phase consisting of a mixture of 10 mmol/L citric acid and 10 mmol/L o-phosphoric acid (pH 6.0) with acetonitrile using an isocratic composition of 2:8 v/v. The benefit of the reported approach consists in a simple sample pretreatment and a quick and sensitive hydrophilic interaction chromatography method. The developed method was validated in terms of linearity, accuracy, precision, and selectivity according to the International Conference on Harmonisation guidelines. The developed method was successfully applied for the analysis of commercial memantine tablets. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Memantine in moderately-severe-to-severe Alzheimer's disease: a postmarketing surveillance study.

PubMed

Clerici, Francesca; Vanacore, Nicola; Elia, Antonietta; Spila-Alegiani, Stefania; Pomati, Simone; Da Cas, Roberto; Raschetti, Roberto; Mariani, Claudio

2009-01-01

Postmarketing surveillance studies (PMS) are an important tool for evaluating a drug's effectiveness and safety in clinical practice. To our knowledge, no PMS on memantine monotherapy for moderately-severe-to-severe Alzheimer's disease (AD) according to National Institute of Neurological and Communicative Disorders and Stroke - Alzheimer's Disease and Related Disorders Association criteria has been conducted to date. The Lombardy Health Office, Italy, promoted this PMS to evaluate the effectiveness and safety of memantine in the treatment of moderately-severe-to-severe AD in clinical practice. A total of 451 patients with moderately-severe-to-severe AD (mean age 77 +/- 7 years; 72% female), free of cholinergic medication, received memantine (standard titration to 10 mg twice daily). After 6 months of therapy, treatment effectiveness was evaluated according to two definitions of response ('no deterioration' and 'improvement'), as measured by changes in baseline scores on the Clinical Global Impression of Change, Mini-Mental State Examination, Neuropsychiatric Inventory and Activities of Daily Living scales. The safety measure was the frequency of adverse events (AEs). At 6-month assessment, 26.8% of subjects showed no deterioration and 3.8% showed improvement. In those showing no deterioration, response to treatment at the 3-month assessment was associated with a greater probability of a response at 6 months (adjusted odds ratio = 8.54; 95% CI 4.54, 16.05). Seventy patients (15.5%) experienced at least one AE and 39 (8.6%) discontinued treatment prematurely because of an AE. Of those who experienced an AE, 27 (38.6%) manifested behavioural and psychological symptoms of dementia. The proportion of responders to memantine treatment in this PMS was similar to that reported in a previous randomized clinical trial (26.8% vs 29%, respectively). The proportion of patients who discontinued treatment prematurely because of an AE (8.6%) was similar to that reported in two previous randomized clinical trials (10% and 12.4%). This PMS provides additional evidence that both the effectiveness and the tolerability of memantine may be transferred into real world medicine, where AD patients receiving treatment are not selected according to strict criteria.

Neo-adjuvant chemotherapy with cisplatin induces low expression of NMDA receptors and postoperative cognitive impairment.

PubMed

Cheng, Jing; Liu, Xiaoqing; Cao, Longhui; Zhang, Tianhua; Li, Huiting; Lin, Wenqian

2017-01-10

Whether Neo-adjuvant chemotherapy can affect patients' postoperative brain function is not clear. In this study, we investigated the effect of preoperative cisplatin treatment on postoperative cognitive function and its possible mechanism in rats. Moreover, we also tested whether the NMDAR inhibitor memantine could attenuate cisplatin-induced alterations. 12-month-oldSprague-Dawley rats randomly received an intraperitoneal injection of either cisplatin once a week at a dose of 3mg/kg for three consecutive weeks or an equivalent volume of normal saline. After the injections, the normal saline injection group was divided into 3 groups (n=5 each): a normal saline group (group S), normal saline+pentobarbital group (group SP), and normal saline+pentobarbital+operation group (group SPO).The cisplatin injection group was divided into 3 groups: a cisplatin group (group C), cisplatin+pentobarbital group (group CP), and cisplatin+pentobarbital+operation group (group CPO).Rats in the group SP, SPO,CP and CPO were anaesthetized with sodium pentobarbital and then the SPO and CPO groups underwent a simple laparotomy operation. The effects of memantine were tested through two additional groups of rats (cisplatin+memantine group (group CM) and cisplatin+pentobarbital+operation+memantine group (group CPOM)). A Morris water maze test was performed to evaluate the spatial learning and memory ability five days after anesthesia or operation. After the test, the hippocampi were removed for detection of the expression of NMDAR by western bloting. The relevant protein expression levels of PSD95 and ERK1/2 were detected by western blot analysis. Rats treated with cisplatin had a longer mean escape latency and spent a shorter amount of time in the target quadrant than did the normal saline injection rats. Furthermore, the protein expression levels of NMDA receptors, PSD95 and ERK1/2 were decreased in cisplatin group and memantine could up-regulate their expression. These results suggest that neo-adjuvant chemotherapy with cisplatin exacerbate the postoperative cognitive dysfunction in rats, and this may be caused by a lower expression of NMDA receptors in the hippocampus. Memantine could attenuate these alterations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Isoflurane-Induced Caspase-3 Activation Is Dependent on Cytosolic Calcium and Can Be Attenuated by Memantine

PubMed Central

Zhang, Guohua; Dong, Yuanlin; Zhang, Bin; Ichinose, Fumito; Wu, Xu; Culley, Deborah J.; Crosby, Gregory

2008-01-01

Increasing evidence indicates that caspase activation and apoptosis are associated with a variety of neurodegenerative disorders, including Alzheimer's disease. We reported that anesthetic isoflurane can induce apoptosis, alter processing of the amyloid precursor protein (APP), and increase amyloid-β protein (Aβ) generation. However, the mechanism by which isoflurane induces apoptosis is primarily unknown. We therefore set out to assess effects of extracellular calcium concentration on isoflurane-induced caspase-3 activation in H4 human neuroglioma cells stably transfected to express human full-length APP (H4-APP cells). In addition, we tested effects of RNA interference (RNAi) silencing of IP3 receptor, NMDA receptor, and endoplasmic reticulum (ER) calcium pump, sacro-/ER calcium ATPase (SERCA1). Finally, we examined the effects of the NMDA receptor partial antagonist, memantine, in H4-APP cells and brain tissue of naive mice. EDTA (10 mm), BAPTA (10 μm), and RNAi silencing of IP3 receptor, NMDA receptor, or SERCA1 attenuated capase-3 activation. Memantine (4 μm) inhibited isoflurane-induced elevations in cytosolic calcium levels and attenuated isoflurane-induced caspase-3 activation, apoptosis, and cell viability. Memantine (20 mg/kg, i.p.) reduced isoflurane-induced caspase-3 activation in brain tissue of naive mice. These results suggest that disruption of calcium homeostasis underlies isoflurane-induced caspase activation and apoptosis. We also show for the first time that the NMDA receptor partial antagonist, memantine, can prevent isoflurane-induced caspase-3 activation and apoptosis in vivo and in vitro. These findings, indicating that isoflurane-induced caspase activation and apoptosis are dependent on cytosolic calcium levels, should facilitate the provision of safer anesthesia care, especially for Alzheimer's disease and elderly patients. PMID:18434534

Evolution of the evidence on the effectiveness and cost-effectiveness of acetylcholinesterase inhibitors and memantine for Alzheimer's disease: systematic review and economic model.

PubMed

Hyde, Christopher; Peters, Jaime; Bond, Mary; Rogers, Gabriel; Hoyle, Martin; Anderson, Rob; Jeffreys, Mike; Davis, Sarah; Thokala, Praveen; Moxham, Tiffany

2013-01-01

in 2007 the National Institute of Health and Clinical Excellence (NICE) restricted the use of acetylcholinesterase inhibitors and memantine. we conducted a health technology assessment (HTA) of the effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine and memantine for the treatment of AD to re-consider and up-date the evidence base used to inform the 2007 NICE decision. The systematic review of effectiveness targeted randomised controlled trials. A comprehensive search, including MEDLINE, Embase and the Cochrane Library, was conducted from January 2004 to March 2010. All key review steps were done by two reviewers. Random effects meta-analysis was conducted. The cost-effectiveness was assessed using a cohort-based model with three health states: pre-institutionalised, institutionalised and dead. The perspective was NHS and Personal Social Services and the cost year 2009. confidence about the size and statistical significance of the estimates of effect of galantamine, rivastigmine and memantine improved on function and global impact in particular. Cost-effectiveness also changed. For donepezil, galantamine and rivastigmine, the incremental cost per quality-adjusted life year (QALY) in 2004 was above £50,000; in 2010 the same drugs 'dominated' best supportive care (improved clinical outcome at reduced cost). This was primarily because of changes in the modelled costs of introducing the drugs. For memantine, the cost-effectiveness also improved from a range of £37-53,000 per QALY gained to a base-case of £32,000. there has been a change in the evidence base between 2004 and 2010 consistent with the change in NICE guidance. Further evolution in cost-effectiveness estimates is possible particularly if there are changes in drug prices.

Memantine loaded PLGA PEGylated nanoparticles for Alzheimer's disease: in vitro and in vivo characterization.

PubMed

Sánchez-López, Elena; Ettcheto, Miren; Egea, Maria Antonia; Espina, Marta; Cano, Amanda; Calpena, Ana Cristina; Camins, Antoni; Carmona, Nuria; Silva, Amélia M; Souto, Eliana B; García, Maria Luisa

2018-03-27

Memantine, drug approved for moderate to severe Alzheimer's disease, has not shown to be fully effective. In order to solve this issue, polylactic-co-glycolic (PLGA) nanoparticles could be a suitable solution to increase drug's action on the target site as well as decrease adverse effects. For these reason, Memantine was loaded in biodegradable PLGA nanoparticles, produced by double emulsion method and surface-coated with polyethylene glycol. MEM-PEG-PLGA nanoparticles (NPs) were aimed to target the blood-brain barrier (BBB) upon oral administration for the treatment of Alzheimer's disease. The production parameters were optimized by design of experiments. MEM-PEG-PLGA NPs showed a mean particle size below 200 nm (152.6 ± 0.5 nm), monomodal size distribution (polydispersity index, PI < 0.1) and negative surface charge (- 22.4 mV). Physicochemical characterization of NPs confirmed that the crystalline drug was dispersed inside the PLGA matrix. MEM-PEG-PLGA NPs were found to be non-cytotoxic on brain cell lines (bEnd.3 and astrocytes). Memantine followed a slower release profile from the NPs against the free drug solution, allowing to reduce drug administration frequency in vivo. Nanoparticles were able to cross BBB both in vitro and in vivo. Behavioral tests carried out on transgenic APPswe/PS1dE9 mice demonstrated to enhance the benefit of decreasing memory impairment when using MEM-PEG-PLGA NPs in comparison to the free drug solution. Histological studies confirmed that MEM-PEG-PLGA NPs reduced β-amyloid plaques and the associated inflammation characteristic of Alzheimer's disease. Memantine NPs were suitable for Alzheimer's disease and more effective than the free drug.

Aggression and increased glutamate in the mPFC during withdrawal from intermittent alcohol in outbred mice.

PubMed

Hwa, Lara S; Nathanson, Anna J; Shimamoto, Akiko; Tayeh, Jillian K; Wilens, Allison R; Holly, Elizabeth N; Newman, Emily L; DeBold, Joseph F; Miczek, Klaus A

2015-08-01

Disrupted social behavior, including occasional aggressive outbursts, is characteristic of withdrawal from long-term alcohol (EtOH) use. Heavy EtOH use and exaggerated responses during withdrawal may be treated using glutamatergic N-methyl-D-aspartate receptor (NMDAR) antagonists. The current experiments explore aggression and medial prefrontal cortex (mPFC) glutamate as consequences of withdrawal from intermittent access to EtOH and changes in aggression and mPFC glutamate caused by NMDAR antagonists memantine and ketamine. Swiss male mice underwent withdrawal following 1-8 weeks of intermittent access to 20 % EtOH. Aggressive and nonaggressive behaviors with a conspecific were measured 6-8 h into EtOH withdrawal after memantine or ketamine (0-30 mg/kg, i.p.) administration. In separate mice, extracellular mPFC glutamate after memantine was measured during withdrawal using in vivo microdialysis. At 6-8 h withdrawal from EtOH, mice exhibited more convulsions and aggression and decreased social contact compared to age-matched water controls. Memantine, but not ketamine, increased withdrawal aggression at the 5-mg/kg dose in mice with a history of 8 weeks of EtOH but not 1 or 4 weeks of EtOH or in water drinkers. Tonic mPFC glutamate was higher during withdrawal after 8 weeks of EtOH compared to 1 week of EtOH or 8 weeks of water. Five milligrams per kilogram of memantine increased glutamate in 8-week EtOH mice, but also in 1-week EtOH and water drinkers. These studies reveal aggressive behavior as a novel symptom of EtOH withdrawal in outbred mice and confirm a role of NMDARs during withdrawal aggression and for disrupted social behavior.

Aggression and increased glutamate in the mPFC during withdrawal from intermittent alcohol in outbred mice

PubMed Central

Hwa, Lara S.; Nathanson, Anna J.; Shimamoto, Akiko; Tayeh, Jillian K.; Wilens, Allison R.; Holly, Elizabeth N.; Newman, Emily L.; DeBold, Joseph F.; Miczek, Klaus A.

2015-01-01

Rationale Disrupted social behavior, including occasional aggressive outbursts, is characteristic of withdrawal from long-term alcohol (EtOH) use. Heavy EtOH use and exaggerated responses during withdrawal may be treated using glutamatergic N-methyl-D-aspartate receptor (NMDAR) antagonists. Objectives The current experiments explore aggression and medial prefrontal cortex (mPFC) glutamate as consequences of withdrawal from intermittent access to EtOH, and changes in aggression and mPFC glutamate caused by NMDAR antagonists memantine and ketamine. Methods Swiss male mice underwent withdrawal following 1-8 weeks of intermittent access to 20% EtOH. Aggressive and non-aggressive behaviors with a conspecific were measured 6-8 h into EtOH withdrawal after memantine or ketamine (0-30 mg/kg, i.p.) administration. In separate mice, extracellular mPFC glutamate after memantine was measured during withdrawal using in vivo microdialysis. Results At 6-8 h withdrawal from EtOH, mice exhibited more convulsions and aggression, and decreased social contact compared to age-matched water controls. Memantine, but not ketamine, increased withdrawal aggression at the 5 mg/kg dose in mice with a history of 8 weeks EtOH but not 1 or 4 weeks of EtOH or in water drinkers. Tonic mPFC glutamate was higher during withdrawal after 8 weeks EtOH compared to 1 week EtOH or 8 weeks water. Five mg/kg memantine increased glutamate in 8 week EtOH mice, but also in 1 week EtOH and water drinkers. Conclusions These studies reveal aggressive behavior as a novel symptom of EtOH withdrawal in outbred mice and confirm a role of NMDARs during withdrawal aggression and for disrupted social behavior. PMID:25899790

Combined treatment with memantine/es-citalopram for older depressed patients with cognitive impairment: a pilot study.

PubMed

Pelton, Gregory H; Harper, Oliver L; Roose, Steven P; Marder, Karen; D'Antonio, Kristina; Devanand, D P

2016-06-01

The objective of the study is to assess combined antidepressant and memantine treatment in older patients presenting with depression and cognitive impairment. Thirty-five depressed patients with cognitive impairment participated in this open-label pilot study. We evaluated whether, over a 48-week period, combined antidepressant (primarily es-citalopram) and memantine treatment was effective in the treatment of cognitive impairment and depression. Neuropsychological testing was performed, and antidepressant response monitored at baseline and at the 12, 24, and 48-week time points. Treatment with escitalopram (mean daily dose 18.62 mg, SD 5.15) and memantine (mean daily dose 13.62 mg, SD 6.67) was associated with improvement in Hamilton Depression Rating Scale scores over the 48-week study period. Patients demonstrated significant improvement in the primary outcome of cognitive performance (Selective Reminding Test total immediate recall; SRT-IR) over the 48-week treatment period (p = 0.0147). Significant improvement was also observed in measures of naming and verbal fluency but not in the other cognitive domains. One of the 35 patients (2.9%) converted to Alzheimer's disease over the 48-week treatment period. In the amnestic mild cognitive impairment subsample (n = 22), the conversion rate was 4.5%, a rate lower than in other reports of patients with DEP-CI. In this open-label trial, combined antidepressant and memantine treatment in patients with DEP-CI was associated with improved cognition and a low rate of conversion to dementia compared with published studies in patients with DEP-CI. Although limited by the open-label study design that incorporates practice effects that can improve cognitive test performance, the findings suggest the need for a larger randomized placebo-controlled trial. Copyright © 2015 John Wiley & Sons, Ltd.

Indistinguishable Synaptic Pharmacodynamics of the N-Methyl-d-Aspartate Receptor Channel Blockers Memantine and Ketamine

PubMed Central

Emnett, Christine M.; Eisenman, Lawrence N.; Taylor, Amanda M.; Izumi, Yukitoshi; Zorumski, Charles F.

2013-01-01

Memantine and ketamine, voltage- and activation-dependent channel blockers of N-methyl-d-aspartate (NMDA) receptors (NMDARs), have enjoyed a recent resurgence in clinical interest. Steady-state pharmacodynamic differences between these blockers have been reported, but it is unclear whether the compounds differentially affect dynamic physiologic signaling. In this study, we explored nonequilibrium conditions relevant to synaptic transmission in hippocampal networks in dissociated culture and hippocampal slices. Equimolar memantine and ketamine had indistinguishable effects on the following measures: steady-state NMDA currents, NMDAR excitatory postsynaptic current (EPSC) decay kinetics, progressive EPSC inhibition during repetitive stimulation, and extrasynaptic NMDAR inhibition. Therapeutic drug efficacy and tolerability of memantine have been attributed to fast kinetics and strong voltage dependence. However, pulse depolarization in drug presence revealed a surprisingly slow and similar time course of equilibration for the two compounds, although memantine produced a more prominent fast component (62% versus 48%) of re-equilibration. Simulations predicted that low gating efficacy underlies the slow voltage–dependent relief from block. This prediction was empirically supported by faster voltage-dependent blocker re-equilibration with several experimental manipulations of gating efficacy. Excitatory postsynaptic potential–like voltage commands produced drug differences only with large, prolonged depolarizations unlikely to be attained physiologically. In fact, we found no difference between drugs on measures of spontaneous network activity or acute effects on plasticity in hippocampal slices. Despite indistinguishable synaptic pharmacodynamics, ketamine provided significantly greater neuroprotection from damage induced by oxygen glucose deprivation, consistent with the idea that under extreme depolarizing conditions, the biophysical difference between drugs becomes detectable. We conclude that despite subtle differences in voltage dependence, during physiologic activity, blocker pharmacodynamics are largely indistinguishable and largely voltage independent. PMID:24101301

Therapy for nystagmus.

PubMed

Thurtell, Matthew J; Leigh, R John

2010-12-01

Pathological forms of nystagmus and their visual consequences can be treated using pharmacological, optical, and surgical approaches. Acquired periodic alternating nystagmus improves following treatment with baclofen, and downbeat nystagmus may improve following treatment with aminopyridines. Gabapentin and memantine are helpful in reducing acquired pendular nystagmus due to multiple sclerosis. Ocular oscillations in oculopalatal tremor may also improve following treatment with memantine or gabapentin. The infantile nystagmus syndrome (INS) may have only a minor impact on vision if "foveation periods" are well developed, but symptomatic patients may benefit from treatment with gabapentin, memantine, or base-out prisms to induce convergence. Several surgical therapies are also reported to improve INS, but selection of the optimal treatment depends on careful evaluation of visual acuity and nystagmus intensity in various gaze positions. Electro-optical devices are a promising and novel approach for treating the visual consequences of acquired forms of nystagmus.

Effects of Memantine and Oleocanthal on Alzheimer's Disease

NASA Astrophysics Data System (ADS)

Houston, Mariyam; Bonacum, Jason; Zhang, Guoping

2014-03-01

Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by accumulation of neuritic plaques composed of amyloid- β (A β) proteins and neurofibrillary tangles composed of tau proteins. Although there is no known cure for AD, the symptoms can be treated with a drug called memantine. Memantine acts an NMDAR antagonist by inhibiting the action of the NMDA receptor. Recently, Oleocanthal, a phenolic molecule that is found in extra virgin olive oil, has been linked to reduced risk of AD. Though the mechanism by which Oleocanthal plays in reducing the risk of AD is not completely understood, recent studies have shown that Oleocanthal somehow inhibits the formation of the neurofibrillary tangles and reduces the formation of A β senile plaques. Our first-principles calculation, based on Gaussian03 program, shows that in the M2 segment, memantine binds to serine, but ketamine binds to glycine. This may explain their different effects, despite the fact that they are both NMDAR antagonists. Using the same method, we also investigate how Oleocanthal binds to the peptides by comparing the relative energies of each of the structures. Our results may help better understand the mechanism by which Oleocanthal decreases the chances of developing AD. U.S. DOE, DE-FG02-06ER46304; ISU SURE program; University of the CSRC; DEPT of Chemistry and Physics.

Utilization of antihypertensives, antidepressants, antipsychotics, and hormones in Alzheimer disease.

PubMed

Zhu, Carolyn W; Livote, Elayne E; Kahle-Wrobleski, Kristin; Scarmeas, Nikolaos; Albert, Marilyn; Brandt, Jason; Blacker, Deborah; Sano, Mary; Stern, Yaakov

2011-01-01

This study explores the longitudinal relationship between patient characteristics and use of 4 drug classes (antihypertensives, antidepressants, antipsychotics, and hormones) that showed significant changes in use rates over time in patients with Alzheimer disease. Patient/caregiver-reported prescription medication usage was categorized by drug class for 201 patients from the Predictors Study. Patient characteristics included use of cholinesterase inhibitors and/or memantine, function, cognition, living situation, baseline age, and sex. Assessment interval, year of study entry, and site were controlled for. Before adjusting for covariates, useage increased for antihypertensives (47.8% to 62.2%), antipsychotics (3.5% to 27.0%), and antidepressants (32.3% to 40.5%); use of hormones decreased (19.4% to 5.4%). After controlling for patient characteristics, effects of time on the use of antidepressants were no longer significant. Antihypertensive use was associated with poorer functioning, concurrent use of memantine, and older age. Antipsychotic use was associated with poorer functioning and poorer cognition. Antidepressant use was associated with younger age, poorer functioning, and concurrent use of cholinesterase inhibitors and memantine. Hormone use was associated with being female and younger age. Findings suggest accurate modeling of the Alzheimer disease treatment paradigm for certain subgroups of patients should include antihypertensives and antipsychotics in addition to cholinesterase inhibitors and memantine.

Pharmacological tests of hypotheses for acquired pendular nystagmus.

PubMed

Shaikh, Aasef G; Thurtell, Matthew J; Optican, Lance M; Leigh, R John

2011-09-01

Acquired pendular nystagmus (APN) occurs with multiple sclerosis (MS) and oculopalatal tremor (OPT); distinct features of the nystagmus have led to the development of separate models for their pathogenesis. APN in MS has been attributed to instability in the neural integrator, which normally ensures steady gaze. APN in OPT may result from electrotonic coupling between neurons in the hypertrophied inferior olivary nucleus, which induces maladaptive learning in cerebellar cortex. We tested these two hypotheses by analyzing the effects of gabapentin, memantine, and baclofen on both forms of nystagmus. No drug changed the dominant frequency of either form of APN, but the variability of frequency was affected with gabapentin and memantine in patients with OPT. The amplitude of APN in both MS and OPT was reduced with gabapentin and memantine, but not baclofen. Analyzing the effects of drug therapies on ocular oscillations provides a novel approach to test models of nystagmus. © 2011 New York Academy of Sciences.

Pharmacological tests of hypotheses for acquired pendular nystagmus

PubMed Central

Shaikh, Aasef G.; Thurtell, Matthew J.; Optican, Lance M.; Leigh, R. John

2011-01-01

Acquired pendular nystagmus (APN) occurs with multiple sclerosis (MS) and oculopalatal tremor (OPT); distinct features of the nystagmus have led to the development of separate models for the pathogenesis. APN in MS has been attributed to instability in the neural integrator, which normally ensures steady gaze. APN in OPT may result from electrotonic coupling between neurons in the hypertrophied inferior olivary nucleus, which induces maladaptive learning in cerebellar cortex. We tested these two hypotheses by analyzing the effects of gabapentin, memantine, and baclofen on both forms of nystagmus. No drug changed the dominant frequency of either form of APN, but the variability of frequency was affected with gabapentin and memantine in patients with OPT. The amplitude of APN in both MS and OPT was reduced with gabapentin and memantine, but not baclofen. Analyzing the effects of drug therapies on ocular oscillations provides a novel approach to test models of nystagmus. PMID:21951011

Memantine and Kynurenic Acid: Current Neuropharmacological Aspects

PubMed Central

Majláth, Zsófia; Török, Nóra; Toldi, József; Vécsei, László

2016-01-01

Glutamatergic neurotransmission, of special importance in the human brain, is implicated in key brain functions such as synaptic plasticity and memory. The excessive activation of N-methyl- D-aspartate (NMDA) receptors may result in excitotoxic neuronal damage; this process has been implicated in the pathomechanism of different neurodegenerative disorders, such as Alzheimer’s disease (AD). Memantine is an uncompetitive antagonist of NMDA receptors with a favorable pharmacokinetic profile, and is therefore clinically well tolerated. Memantine is approved for the treatment of AD, but may additionally be beneficial for other dementia forms and pain conditions. Kynurenic acid (KYNA) is an endogenous antagonist of NMDA receptors which has been demonstrated under experimental conditions to be neuroprotective. The development of a well-tolerated NMDA antagonist may offer a novel therapeutic option for the treatment of neurodegenerative disease and pain syndromes. KYNA may be a valuable candidate for future drug development. PMID:26564141

Memantine, a Low-Affinity NMDA Receptor Antagonist, Protects against Methylmercury-Induced Cytotoxicity of Rat Primary Cultured Cortical Neurons, Involvement of Ca2+ Dyshomeostasis Antagonism, and Indirect Antioxidation Effects.

PubMed

Liu, Wei; Xu, Zhaofa; Yang, Tianyao; Xu, Bin; Deng, Yu; Feng, Shu

2017-09-01

Methylmercury (MeHg) is an extremely dangerous environmental pollutant that induces severe toxic effects in the central nervous system. Neuronal damage plays critical roles mediating MeHg-induced loss of brain function and neurotoxicity. The molecular mechanisms of MeHg neurotoxicity are incompletely understood. The objective of the study is to explore mechanisms that contribute to MeHg-induced neurocyte injuries focusing on neuronal Ca 2+ dyshomeostasis and alteration of N-methyl-D-aspartate receptors (NMDARs) expression, as well as oxidative stress in primary cultured cortical neurons. In addition, the neuroprotective effects of memantine against MeHg cytotoxicity were also investigated. The cortical neurons were exposed to 0, 0.01, 0.1, 1, or 2 μM methylmercury chloride (MeHgCl) for 0.5-12 h, or pre-treated with 2.5, 5, 10, or 20 μM memantine for 0.5-6 h, respectively; cell viability and LDH release were then quantified. For further experiments, 2.5, 5, and 10 μM of memantine pre-treatment for 3 h followed by 1 μM MeHgCl for 6 h were performed for evaluation of neuronal injuries, specifically addressing apoptosis; intracellular free Ca 2+ concentrations; ATPase activities; calpain activities; expressions of NMDAR subunits (NR1, NR2A, NR2B); NPSH levels; and ROS formation. Exposure of MeHgCl resulted in toxicity of cortical neurons, which were shown as a loss of cell viability, high levels of LDH release, morphological changes, and cell apoptosis. Moreover, intracellular Ca 2+ dyshomeostasis, ATPase activities inhibition, calpain activities, and NMDARs expression alteration were observed with 1 μM MeHgCl administration. Last but not least, NPSH depletion and reactive oxygen species (ROS) overproduction showed an obvious oxidative stress in neurons. However, memantine pre-treatment dose-dependently antagonized MeHg-induced neuronal toxic effects, apoptosis, Ca 2+ dyshomeostasis, NMDARs expression alteration, and oxidative stress. In conclusion, the cytoprotective effects of memantine against MeHg appeared to be mediated not only via its NMDAR binding properties and Ca 2+ homeostasis maintenance but also by indirect antioxidation effects.

Enhancing Effects of NMDA-Receptor Blockade on Extinction Learning and Related Brain Activation Are Modulated by BMI

PubMed Central

Golisch, Anne; Heba, Stefanie; Glaubitz, Benjamin; Tegenthoff, Martin; Lissek, Silke

2017-01-01

A distributed network including prefrontal and hippocampal regions is involved in context-related extinction learning as well as in renewal. Renewal describes the recovery of an extinguished response if the context of extinction differs from the context of recall. Animal studies have demonstrated that prefrontal, but not hippocampal N-methyl-D-aspartate receptor (NMDAR) antagonism disrupted extinction learning and processing of task context. However, human studies of NMDAR in extinction learning are lacking, while NMDAR antagonism yielded contradictory results in other learning tasks. This fMRI study investigated the role of NMDAR for human behavioral and brain activation correlates of extinction and renewal. Healthy volunteers received a single dose of the NMDAR antagonist memantine prior to extinction of previously acquired stimulus-outcome associations presented in either identical or novel contexts. We observed better, and partly faster, extinction learning in participants receiving the NMDAR antagonist compared to placebo. However, memantine did not affect renewal. In both extinction and recall, the memantine group showed a deactivation in extinction-related brain regions, particularly in the prefrontal cortex, while hippocampal activity was increased. This higher hippocampal activation was in turn associated with the participants' body mass index (BMI) and extinction errors. Our results demonstrate potentially dose-related enhancing effects of memantine and highlight involvement of hippocampal NMDAR in context-related extinction learning. PMID:28326025

Intravitreal memantine retinal toxicity in rabbits.

PubMed

Moreno Páramo, D; Reyna Vielma, S; Rodríguez Reyes, A; Hernández Ayuso, I; Quiroz Mercado, H

2016-02-01

To histologically evaluate whether the intravitreal application of memantine produces retinal toxicity in rabbits. A cross-sectional design, experimental, descriptive study was performed on 16 eyes of 16 New Zealand rabbits of 3 kg, divided in 4 groups of 4 rabbits. A dose of 70 ng/ml of intravitreal memantine was administered in Group A, a dose of 150 ng/ml in Group B, a dose of 400 ng/ml in Group C, and Group D received 1 ml of balanced salt solution. The injected eye of half of each group was enucleated 15 days after the injection, and the rest within 30 days after injection. Following enucleation, each eye was placed in 10% formaldehyde. Histopathological analysis was performed on all enucleated eyes. The animals were treated according to the guidelines of the Association for Research on Vision and Ophthalmology (ARVO). Groups A, B and D did not show any histopathological changes after their enucleation at 15 and 30 days. Group C showed changes in the photoreceptor layer after enucleation at 15 and 30 days. In our study, it was observed that memantine concentrations at 70 ng/ml and 150 ng/ml are safe when administered intravitreally; however, doses of 400 ng/ml produced retinal structural changes. This research should continue to assess its clinical usefulness. Copyright © 2015 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Transdermal therapeutic systems for memantine delivery. Comparison of passive and iontophoretic transport.

PubMed

Del Río-Sancho, S; Serna-Jiménez, C E; Sebastián-Morelló, M; Calatayud-Pascual, M A; Balaguer-Fernández, C; Femenía-Font, A; Kalia, Y N; Merino, V; López-Castellano, A

2017-01-30

Memantine is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist used in the treatment of moderate to severe dementia including the symptoms of Alzheimer's disease (AD). It is administered orally but compliance, swallowing problems and the routine use of multiple medications in elderly AD patients means that an alternative route of administration would be of interest. The aim of the present study was to develop memantine hydrochloride occlusive transdermal therapeutic systems (TTS) for passive and iontophoretic delivery across the skin. Polyvinyl pyrrolidone (PVP) and a mixture with polyvinyl alcohol (PVA) were employed as polymeric matrices. The study involved the TTS characterization in addition to quantification of the memantine transport across porcine skin in vitro. The evaluation of the TTS physical properties suggested that systems were made more mechanically resistant by including PVA (6%) or high concentrations of PVP (24%). Moreover, a linear correlation was observed between the concentration of PVP and the bioadhesion of the systems. Drug delivery experiments showed that the highest transdermal flux provided by a passive TTS (PVP 24% w/w limonene) was 8.89±0.81μgcm -2 h -1 whereas the highest iontophoretic transport was 46.4±3.6μgcm -2 h -1 . These innovative TTS would enable two dosage regimens that could lead to therapeutic plasma concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

Memantine Can Reduce Ethanol-Induced Caspase-3 Activity and Apoptosis in H4 Cells by Decreasing Intracellular Calcium.

PubMed

Wang, Xiaolong; Chen, Jiajun; Wang, Hongbo; Yu, Hao; Wang, Changliang; You, Jiabin; Wang, Pengfei; Feng, Chunmei; Xu, Guohui; Wu, Xu; Zhao, Rui; Zhang, Guohua

2017-08-01

Caspase-3 activation and apoptosis are associated with various neurodegenerative disorders. Calcium activation is an important factor in promoting apoptosis. We, therefore, assessed the role of intracellular calcium in ethanol-induced activation of caspase-3 in H4 human neuroglioma cells and the protective effect of the NMDA receptor antagonist, memantine, on ethanol-induced apoptosis in H4 cells. H4 cells were treated with 100 mM EtOH (in culture medium) for 2 days. For interaction studies, cells were treated with memantine (4 μM), EDTA (1 mM), or BAPTA-AM (10 μM) before treatment with EtOH. Knockdown of the gene encoding the NR1 subunit of the NMDA receptor was performed using RNAi. Apoptosis was detected by Annexin V-FITC/PI staining and flow cytometry. Cell viability was detected using an MTS cell proliferation kit. Fluorescence dual wavelength spectrophotometry was used to determine the intracellular calcium concentration. The levels of NR1, caspase-3, IP3R1, and SERCA1 proteins were detected by western blotting. NR1, IP3R1, and SERCA1 mRNA levels were detected by qPCR. We observed increased expression of NR1, IP3R1, SERCA1, and increased intracellular levels of calcium ions in H4 cells exposed to ethanol. In addition, the calcium chelators, EDTA and BAPTA, and RNAi disruption of the NMDA receptor reduced ethanol-induced caspase-3 activation in H4 cells. Memantine treatment reduced the ethanol-induced increase of intracellular calcium, caspase-3 activation, apoptosis, and the ethanol-induced decrease in cell viability. Our results indicate that ethanol-induced caspase-3 activation and apoptosis are likely to be dependent on cytosolic calcium levels and that they can be reduced by memantine treatment.

Toxicological Differences Between NMDA Receptor Antagonists and Cholinesterase Inhibitors.

PubMed

Shi, Xiaodong; Lin, Xiaotian; Hu, Rui; Sun, Nan; Hao, Jingru; Gao, Can

2016-08-01

Cholinesterase inhibitors (ChEIs), represented by donepezil, rivastigmine, and galantamine, used to be the only approved class of drugs for the treatment of Alzheimer's disease. After the approval of memantine by the Food and Drug Administration (FDA), N-methyl-d-aspartic acid (NMDA) receptor antagonists have been recognized by authorities and broadly used in the treatment of Alzheimer's disease. Along with complementary mechanisms of action, NMDA antagonists and ChEIs differ not only in therapeutic effects but also in adverse reactions, which is an important consideration in clinical drug use. And the number of patients using NMDA antagonists and ChEIs concomitantly has increased, making the matter more complicated. Here we used the FDA Adverse Event Reporting System for statistical analysis , in order to compare the adverse events of memantine and ChEIs. In general, the clinical evidence confirmed the safety advantages of memantine over ChEIs, reiterating the precautions of clinical drug use and the future direction of antidementia drug development. © The Author(s) 2016.

An Open-Label Exploratory Study with Memantine: Correlation between Proton Magnetic Resonance Spectroscopy and Cognition in Patients with Mild to Moderate Alzheimer's Disease

PubMed Central

Gordon, Marc L.; Kingsley, Peter B.; Goldberg, Terry E.; Koppel, Jeremy; Christen, Erica; Keehlisen, Lynda; Kohn, Nina; Davies, Peter

2012-01-01

Aim To characterize progression of Alzheimer's disease (AD) using proton magnetic resonance spectroscopy (1H MRS). Methods Eleven subjects with mild to moderate AD underwent neurocognitive testing and single-voxel 1H MRS from the precuneus and posterior cingulate region at baseline, after 24 weeks of monotherapy with a cholinesterase inhibitor, and after another 24 weeks of combination therapy with open-label memantine and a cholinesterase inhibitor. Baseline metabolites [N-acetylaspartate (NAA), myo-inositol (mI), choline (Cho), and creatine (Cr)] and their ratios in AD subjects were compared with those of an age-matched control group of 28 cognitively normal subjects. Results AD subjects had significantly higher mI/Cr and lower NAA, NAA/Cr, NAA/Cho, and NAA/mI. Baseline Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) scores significantly correlated with NAA/Cr, mI/Cr, and NAA/mI. There was an increase in mI and a decrease in NAA/mI, but no significant change in other metabolites or ratios, or neurocognitive measures, when memantine was added to a cholinesterase inhibitor. Conclusion Metabolite ratios significantly differed between AD and control subjects. Baseline metabolite ratios correlated with function (ADCS-ADL). There was an increase in mI and a decrease in NAA/mI, but no changes in other metabolites, ratios, or cognitive measures, when memantine was added to a cholinesterase inhibitor. PMID:22962555

N-Methyl-d-Aspartate (NMDA) Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection.

PubMed

Costa, Vivian V; Del Sarto, Juliana L; Rocha, Rebeca F; Silva, Flavia R; Doria, Juliana G; Olmo, Isabella G; Marques, Rafael E; Queiroz-Junior, Celso M; Foureaux, Giselle; Araújo, Julia Maria S; Cramer, Allysson; Real, Ana Luíza C V; Ribeiro, Lucas S; Sardi, Silvia I; Ferreira, Anderson J; Machado, Fabiana S; de Oliveira, Antônio C; Teixeira, Antônio L; Nakaya, Helder I; Souza, Danielle G; Ribeiro, Fabiola M; Teixeira, Mauro M

2017-04-25

Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N -methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration. IMPORTANCE Zika virus (ZIKV) infection is a global health emergency associated with serious neurological complications, including microcephaly and Guillain-Barré syndrome. Infection of experimental animals with ZIKV causes significant neuronal damage and microgliosis. Treatment with drugs that block NMDARs prevented neuronal damage both in vitro and in vivo These results suggest that overactivation of NMDARs contributes significantly to the neuronal damage induced by ZIKV infection, and this is amenable to inhibition by drug treatment. Copyright © 2017 Costa et al.

Double-blind, randomized comparison of memantine and escitalopram for the treatment of major depressive disorder comorbid with alcohol dependence.

PubMed

Muhonen, Leea H; Lönnqvist, Jouko; Juva, Kati; Alho, Hannu

2008-03-01

The aim of the study was to evaluate possible new treatments for major depressive disorder in patients with comorbid alcohol dependence in a municipal alcohol treatment unit. The efficacy of memantine, a noncompetitive glutamate N-methyl-D-aspartate (NMDA)-receptor blocker used for the treatment of moderate to severe Alzheimer's disease, was compared with that of escitalopram, a selective serotonin reuptake inhibitor antidepressant. Eighty alcohol-dependent outpatients with major depressive disorder (DSM-IV criteria) seeking treatment from municipal alcohol treatment clinics in Helsinki, Finland, were randomly assigned 1:1 to receive memantine 20 mg/day or escitalopram 20 mg/day. During the study period, patients continued their routine treatment at the clinics. Abstinence was not required. Concomitant interventions or imposed treatment goals were not offered by the study physician. The patients returned to the treatment clinics at weeks 1, 2, 4, 12, and 26 for data collection and for medication checking and dispensing. Outcome measures were the Montgomery-Asberg Depression Rating Scale (MADRS) and Beck Depression Inventory-II for depression, Hamilton Rating Scale for Anxiety (HAM-A) and Beck Anxiety Inventory for anxiety, Consortium to Establish a Registry for Alzheimer's Disease test battery for cognitive functions, and Social and Occupational Functioning Assessment Scale for social and occupational functions and quality-of-life measures. Twenty-nine patients in each group completed the study. All primary and secondary outcome statistical analyses were performed by an independent source for intent-to-treat populations, which included all patients randomly assigned to treatment. The study was conducted from December 2004 to May 2006. Both treatments significantly reduced the baseline level of depression and anxiety according to MADRS and HAM-A, which were the primary measures (p < .0001). There was no significant difference between the memantine and escitalopram groups. Assessed cognitive functioning scores were primarily within the normative range and were unchanged in both groups. Quality-of-life outcomes equally improved in both treatment groups. These data provide new evidence for the safety and potential efficacy of memantine and escitalopram for major depressive disorder in patients with comorbid alcohol dependence. ClinicalTrials.gov identifier NCT00368862.

Drug Product Life-Cycle Management as Anticompetitive Behavior: The Case of Memantine.

PubMed

Capati, Vincent C; Kesselheim, Aaron S

2016-04-01

A "product hop" involves the substitution of a new formulation of a prescription drug by a pharmaceutical manufacturer for an old version to forestall generic competition. In 2015, for example, Forest Laboratories, the brand-name drug manufacturer of memantine, an Alzheimer's disease treatment, introduced an extended-release version and tried to restrict patient access to the previous version. Product hops can lead to useful incremental innovation but can also have major public health implications by disrupting patients on stable treatment regimens and increasing costs for patients and payers. This commentary reviews alleged anticompetitive product hopping in the case of memantine, which involved proposed conduct that would have left Alzheimer's disease patients with no effective choice but to transition to memantine XR. Policy solutions that can limit anticompetitive product hops include raising the bar for obtaining patents on new drug product formulations and changing automatic generic substitution laws. No outside funding supported this research. To support his work at PORTAL in the summer of 2015, Capati was the recipient of the University of New Hampshire School of Law Rudman Center Public Service Fellowship. Kesselheim's research was supported by Greenwall Faculty Scholars program, the Laura and John Arnold Foundation, and the Harvard Program in Therapeutic Science. In 2013, Kesselheim served as an expert on behalf of a class of individual plaintiffs against Warner Chilcott regarding potential antitrust violations Kesselheim was responsible for concept and design of this commentary. Capati took the lead in data collection and analysis, along with Kesselheim. Capati wrote the manuscript, which was revised by primarily by Kesselheim, along with Capati.

Add-On Memantine Treatment for Bipolar II Disorder Comorbid with Alcohol Dependence: A 12-Week Follow-Up Study.

PubMed

Lee, Sheng-Yu; Wang, Tzu-Yun; Chen, Shiou-Lan; Chang, Yun-Hsuan; Chen, Po-See; Huang, San-Yuan; Tzeng, Nian-Sheng; Wang, Liang-Jen; Lee, I Hui; Chen, Kao Ching; Yang, Yen Kuang; Hong, Jau-Shyong; Lu, Ru-Band

2018-06-01

Bipolar disorder (BD), especially BD-II, is frequently comorbid with alcohol dependence. Because BD-II and alcohol dependence are neurodegenerative disorders, agents with anti-inflammatory and neurotrophic effects might provide effective therapy. We investigated whether add-on memantine to regular valproic acid treatment ameliorated clinical symptoms, reduced alcohol use, and cytokine levels, and increased plasma brain-derived neurotrophic factor (BDNF) in BD-II patients with comorbid alcohol dependence. In a single-arm 12-week clinical trial, BD-II patients with comorbid alcohol dependence (n = 45) undergoing regular valproic acid treatments were given add-on memantine (5 mg/d). Symptom severity, alcohol use, cytokine (plasma tumor necrosis factor-α and C-reactive protein [CRP], transforming growth factor-β1 [TGF-β1], interleukin-8 [IL-8], IL-10), and plasma BDNF levels were regularly assessed. Mean within-group decreases in Hamilton Depression Rating Scale (HDRS) and Young Mania Rating Scale (YMRS) scores, alcohol use, CRP, BDNF, and IL-8 levels were significantly different from baseline after 12 weeks of treatment. We found no significant correlation between alcohol use levels and changes in HDRS or YMRS scores. The correlation between reduced alcohol use and reduced TGF-β1 level was significant (B = 0.003, p = 0.019). BD-II comorbid with alcohol dependence might benefit from add-on memantine treatment, which significantly reduced clinical severity, alcohol use, and plasma cytokine levels, and increased BDNF levels. Copyright © 2018 by the Research Society on Alcoholism.

Effects of memantine on soluble Alphabeta(25-35)-induced changes in peptidergic and glial cells in Alzheimer's disease model rat brain regions.

PubMed

Arif, M; Chikuma, T; Ahmed, Md M; Nakazato, M; Smith, M A; Kato, T

2009-12-15

Soluble forms of amyloid-beta (Abeta) have been considered responsible for cognitive dysfunction prior to senile plaque formation in Alzheimer's disease (AD). As its mechanism is not well understood, we examined the effects of repeated i.c.v. infusion of soluble Alphabeta(25-35) on peptidergic system and glial cells in the pathogenesis of AD. The present study aims to investigate the protective effects of memantine on Abeta(25-35)-induced changes in peptidergic and glial systems. Infusion of Alphabeta(25-35) decreased the level of immunoreactive somatostatin (SS) and substance P (SP) in the hippocampus prior to neuronal loss or caspase activation, which is correlated with the loss of spine density and activation of inducible nitric-oxide synthase (iNOS). Biochemical experiment with peptide-degrading enzymes, prolyl oligopeptidase (POP) and endopeptidase 24.15 (EP 24.15) activities demonstrated a concomitant increase with the activation of glial marker proteins, glial fibrillary acidic protein (GFAP) and CD11b in the Abeta-treated hippocampus. Double immunostaining experiments of EP 24.15 and GFAP/CD11b antibodies clearly demonstrated the co-localization of neuro peptidases with astrocytes and microglia. Treatment with memantine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist significantly attenuated Abeta(25-35)-induced changes of neuropeptides, their metabolizing enzymes, glial marker proteins, and activation of iNOS. Taken together, the data implies that memantine exerts its protective effects by modulating the neuropeptide system as a consequence of suppressing the glial cells and oxidative stress in AD model rat brain regions.

Prevalence of Drug-Induced Xerostomia in Older Adults with Cognitive Impairment or Dementia: An Observational Study.

PubMed

Gil-Montoya, José Antonio; Barrios, Rocío; Sánchez-Lara, Inés; Carnero-Pardo, Cristobal; Fornieles-Rubio, Francisco; Montes, Juan; Gonzalez-Moles, Miguel Angel; Bravo, Manuel

2016-08-01

Older adults, especially those with cognitive impairment or dementia, frequently consume drugs with potential xerostomic effects that impair their quality of life and oral health. The objective of this study was to determine the prevalence and analyze the possible pharmacological etiology of xerostomia in older people with or without cognitive impairment. Individuals with cognitive impairment were recruited from patients diagnosed using standardized criteria in two neurology departments in Southern Spain. A comparison group was recruited from healthcare centers in the same city after ruling out cognitive impairment. Data on oral health, xerostomia, and drug consumption were recorded in both groups. Dry mouth was evaluated using a 1-item questionnaire and recording clinical signs of oral dryness. All drugs consumed by the participants were recorded, including memantine, anticholinesterases, antipsychotics, antidepressants, and anxiolytics. The final sample comprised 200 individuals with mild cognitive impairment or dementia and 156 without. Xerostomia was present in 70.5 % of participants with cognitive impairment versus 36.5 % of those without, regardless of the drug consumed. Memantine consumption was the only variable significantly related to xerostomia in the multivariate model (OR 3.1; 95 % CI 1.1-8.7), and this relationship persisted after adjusting for possible confounders and forcing the inclusion of drugs with xerostomic potential. More than 70 % of participants diagnosed with cognitive impairment or dementia had xerostomia. Anticholinesterases and memantine were both associated with the presence of xerostomia. In the case of memantine, this association was independent of the consumption of the other drugs considered.

Inflammatory mediators leading to protein misfolding and uncompetitive/fast off-rate drug therapy for neurodegenerative disorders.

PubMed

Lipton, Stuart A; Gu, Zezong; Nakamura, Tomohiro

2007-01-01

Inflammatory mediators, including free radicals such as nitric oxide (NO) and reactive oxygen species (ROS), can contribute to neurodegenerative diseases in part by triggering protein misfolding. In this chapter, we will discuss a newly discovered pathway for this phenomenon and possible novel treatments. Excitotoxicity, defined as overstimulation of glutamate receptors, has been implicated in a final common pathway contributing to neuronal injury and death in a wide range of acute and chronic neurological disorders, ranging from Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis, and Alzheimer's disease (AD) to stroke and trauma. Excitotoxic cell death is due, at least in part, to excessive activation of N-methyl-d-aspartate (NMDA)-type glutamate receptors, leading to excessive Ca(2+) influx through the receptor's associated ion channel and subsequent free radical production, including NO and ROS. These free radicals can trigger a variety of injurious pathways, but newly discovered evidence suggests that some proteins are S-nitrosylated (transfer of NO to a critical thiol group), and this reaction can mimic the effect of rare genetic mutations. This posttranslational modification can contribute to protein misfolding, triggering neurodegenerative diseases. One such molecule affected is protein disulfide isomerase (PDI), an enzyme responsible for normal protein folding in the endoplasmic reticulum (ER). We found that when PDI is S-nitrosylation (forming SNO-PDI), the function of the enzyme is compromised, leading to misfolded proteins and contributing to neuronal cell injury and loss. Moreover, SNO-PDI occurs at pathological levels in several human diseases, including AD and PD. This discovery thus links protein misfolding to excitotoxicity and free radical formation in a number of neurodegenerative disorders. Another molecule whose S-nitrosylation can lead to abnormal protein accumulation is the E3 ubiquitin ligase, parkin, which contributes to the pathogenesis of PD. One way to ameliorate excessive NO production and hence abnormal S-nitrosylations would be to inhibit NMDA receptors. In fact, blockade of excessive NMDA receptor activity can in large measure protect neurons from this type of injury and death. However, inhibition of the NMDA receptor by high-affinity antagonists also blocks the receptor's normal function in synaptic transmission and leads to unacceptable side effects. For this reason, many NMDA receptor antagonists have disappointingly failed in advanced clinical trials. Our group was the first to demonstrate that gentle blockade of NMDA receptors by memantine, via a mechanism of uncompetitive open-channel block with a rapid "off-rate," can prevent this type of damage in a clinically efficacious manner without substantial side effects. For these Uncompetitive/Fast Off-rate therapeutics, we use the term "UFO drugs" because like Unidentified Flying Objects, they leave very quickly as soon as their job is finished. As a result, memantine blocks excessive NMDA receptor activity without disrupting normal activity. Memantine does this by preferentially entering the receptor-associated ion channel when it is excessively open, and, most importantly, when its off-rate from the channel is relatively fast so that it does not accumulate to interfere with normal synaptic transmission. Hence, memantine is clinically well tolerated, has been used in Europe for PD for many years, and recently passed multiple phase III trials for dementia, leading to its approval by the FDA and European Union for moderate-to-severe AD. Clinical studies of memantine for additional neurological disorders, including other dementias, neuropathic pain, and glaucoma, are underway. We have also developed a series of second-generation drugs that display greater neuroprotective properties than memantine. These second-generation drugs take advantage of the fact that the NMDA receptor has other modulatory sites, including critical thiol groups that are S-nitrosylated. In this case, in contrast to PDI or parkin, S-nitrosylation proves to be neuroprotective by decreasing excessive NMDA receptor activity. Targeted S-nitrosylation of the NMDA receptor can be achieved by coupling NO to memantine, yielding second-generation "UFO drugs" known as NitroMemantines.

[Memantine as add-on medication to acetylcholinesterase inhibitor therapy for Alzheimer dementia].

PubMed

Haussmann, R; Donix, M

2017-01-01

Currently available data indicate superior therapeutic effects of combination treatment for Alzheimer dementia with memantine and acetylcholine esterase inhibitors in certain clinical contexts. Out of five randomized, placebo-controlled, double-blind trials two showed superior therapeutic effects in comparison to monotherapy with acetylcholinesterase inhibitors regarding various domains. Recently published meta-analyses and cost-benefit analyses also showed positive results. Recently published German guidelines for dementia treatment also take these new data into account and recommend combination treatment in patients with severe dementia on stable donepezil medication. This article gives an overview of current evidence for combination therapy.

Abeta oligomers induce neuronal oxidative stress through an N-methyl-D-aspartate receptor-dependent mechanism that is blocked by the Alzheimer drug memantine.

PubMed

De Felice, Fernanda G; Velasco, Pauline T; Lambert, Mary P; Viola, Kirsten; Fernandez, Sara J; Ferreira, Sergio T; Klein, William L

2007-04-13

Oxidative stress is a major aspect of Alzheimer disease (AD) pathology. We have investigated the relationship between oxidative stress and neuronal binding of Abeta oligomers (also known as ADDLs). ADDLs are known to accumulate in brain tissue of AD patients and are considered centrally related to pathogenesis. Using hippocampal neuronal cultures, we found that ADDLs stimulated excessive formation of reactive oxygen species (ROS) through a mechanism requiring N-methyl-d-aspartate receptor (NMDA-R) activation. ADDL binding to neurons was reduced and ROS formation was completely blocked by an antibody to the extracellular domain of the NR1 subunit of NMDA-Rs. In harmony with a steric inhibition of ADDL binding by NR1 antibodies, ADDLs that were bound to detergent-extracted synaptosomal membranes co-immunoprecipitated with NMDA-R subunits. The NR1 antibody did not affect ROS formation induced by NMDA, showing that NMDA-Rs themselves remained functional. Memantine, an open channel NMDA-R antagonist prescribed as a memory-preserving drug for AD patients, completely protected against ADDL-induced ROS formation, as did other NMDA-R antagonists. Memantine and the anti-NR1 antibody also attenuated a rapid ADDL-induced increase in intraneuronal calcium, which was essential for stimulated ROS formation. These results show that ADDLs bind to or in close proximity to NMDA-Rs, triggering neuronal damage through NMDA-R-dependent calcium flux. This response provides a pathologically specific mechanism for the therapeutic action of memantine, indicates a role for ROS dysregulation in ADDL-induced cognitive impairment, and supports the unifying hypothesis that ADDLs play a central role in AD pathogenesis.

Low doses of dextromethorphan have a beneficial effect in the treatment of neuropathic pain.

PubMed

Morel, Véronique; Pickering, Gisèle; Etienne, Monique; Dupuis, Amandine; Privat, Anne-Marie; Chalus, Maryse; Eschalier, Alain; Daulhac, Laurence

2014-12-01

N-methyl-D-aspartate receptor (NMDAR) antagonists may be given in persistent neuropathic pain, but adverse events especially with ketamine may limit their clinical use. Less central and cognitive adverse events are described with dextromethorphan and memantine. These molecules have been explored in many preclinical and clinical studies, but data are conflicting as regards neuropathic pain alleviation. Dextromethorphan and memantine have been administered to animals after spinal nerve ligation (SNL) to evaluate their antinociceptive/cognitive effects and associated molecular events, including the phosphorylation of several tyrosine (pTyr(1336), pTyr(1472)) residues in the NR2B NMDAR subunit. Spinal nerve ligation and sham animals received dextromethorphan (10 mg/kg, i.p.), memantine (20 mg/kg, i.p.) or saline (1 mL/kg, i.p.). These drugs were administered once symptoms of allodynia and hyperalgesia had developed. Tests were carried out before and after surgery. Tactile allodynia, mechanical hyperalgesia and spatial memory were, respectively, evaluated by von Frey, Randall & Selitto and Y-maze tests and molecular events by Western blot analysis. Spinal nerve-ligated animals displayed nociception and impaired spatial memory. Dextromethorphan, but not memantine, reversed neuropathic pain (NP) symptoms, restored spatial memory integrity and decreased the expression of pTyr(1336)NR2B. Following postoperative administration of dextromethorphan, this study has demonstrated for the first time a concordance between behaviour, cognitive function and molecular events via pTyr(1336)NR2B for neuropathic pain alleviation. Confirmation of these findings in patients would constitute a major step forward in the treatment of neuropathic pain and in the improvement of cognitive function and quality of life. © 2014 Société Française de Pharmacologie et de Thérapeutique.

Alterations in expression of Cat-315 epitope of perineuronal nets during normal ageing, and its modulation by an open-channel NMDA receptor blocker, memantine.

PubMed

Yamada, Jun; Ohgomori, Tomohiro; Jinno, Shozo

2017-06-15

The perineuronal net (PNN), a specialized aggregate of the extracellular matrix, is involved in neuroprotection against oxidative stress, which is now recognized as a major contributor to age-related decline in brain functions. In this study, we investigated the age-related molecular changes of PNNs using monoclonal antibody Cat-315, which recognizes human natural killer-1 (HNK-1) glycan on aggrecan-based PNNs. Western blot analysis showed that the expression levels of Cat-315 epitope in the hippocampus were higher in middle-aged (MA, 12-month-old) mice than in young adult (YA, 2-month-old) mice. Although there were no differences in the expression levels of Cat-315 epitope between old age (OA, 20-month-old) and MA mice, Cat-315 immunoreactivity was also detected in astrocytes of OA mice. To focus on Cat-315 epitope in PNNs, we used YA and MA mice in the following experiments. Optical disector analysis showed that there were no differences in the numbers of Cat-315-positive (Cat-315 + ) PNNs between YA and MA mice. Fluorescence intensity analysis indicated that Cat-315 immunoreactivity in PNNs increased with age in the dorsal hippocampus, which is mainly involved in cognitive functions. Administration of an open-channel blocker of NMDA receptor, memantine, reduced the expression levels of Cat-315 epitope in the hippocampus. Furthermore, the numbers of glutamatergic and GABAergic terminals colocalized with Cat-315 epitope around parvalbumin-positive neurons were decreased by memantine. These findings provide novel insight into the involvement of PNNs in normal brain ageing, and suggest that memantine may counteract the age-related alterations in expression levels of Cat-315 epitope via regulation of its subcellular localization. © 2017 Wiley Periodicals, Inc.

[Role of hippocampal neuronal intracellular calcium overload in modulating cognitive dysfunction and the neuronprotective effect of mematine in a mouse model of chronic intermittent hypoxia].

PubMed

Ming, Hong; Chen, Rui; Wang, Jing; Ju, Jingmei; Sun, Li; Zhang, Guoxing

2014-12-01

To investigate the role of hippocampal intracellular calcium overload in modulating cognitive dysfunction and the neuronprotective effect of mematine in a mouse model of chronic intermittent hypoxia. 45 ICR male mice were randomly divided into 3 groups: the unhandled control group (UC group, n = 15), the chronic intermittent hypoxia (CIH group, n = 15) and the pretreatment memantine group (MEM group, n = 15). CIH and MEM mice were subjected to intermittent hypoxia while UC mice to room air for 8 h per day during 4 weeks. Mice in the MEM group were pretreated with memantine (5 mg/kg) by intraperitoneal injection before the cycle started, and those in the UC group and the CIH group were treated with same volume of physiological saline. Neurobehavioral assessments were performed by Open filed and Morris water maze, [Ca²⁺]i in hippocampal neurons was evaluate by flow cytometry, and the expression of cleaved caspase-3, phospho-ERK1/2 in hippocampus were detected by Western blotting. Compared with the UC group, CIH mice displayed markedly more locomotor activity (P < 0.05) in Open filed test, longer mean escape latency (P < 0.05), less number of times of crossing the platform (P < 0.01) and less percentage of time in target quadrant (P < 0.01). Furthermore, exposure to CIH enhanced [Ca²⁺]i (vs. UC mice, 155 ± 12 vs. 92 ± 8, P < 0.01), and up-regulated the expression of cleaved caspase-3 (P < 0.01), but down-regulated the level of phospho-ERK1/2 (P < 0.05) in the hippocampus. Pre-treatment with memantine significantly decreased hyperlocomotion (P < 0.05), attenuated memory deficit (P < 0.05), mitigated [Ca²⁺]i (vs. CIH mice, 90 ± 8 vs. 155 ± 12, P < 0.01), decrease the expression of cleaved caspase-3 (P < 0.01), but increased the level of phospho-ERK1/2(P < 0.05) comparing to the CIH group. The neurobehavioral impairments induced by CIH are mediated, at least in part, by intracellular calcium concentration overload, neuron apoptosis, dephosphorylation of ERK1/2, which can be attenuated by memantine. Memantine may have a therapeutic effect in the neurocognitive impairment associated with OSAHS.

A population-based study of dosing and persistence with anti-dementia medications.

PubMed

Brewer, Linda; Bennett, Kathleen; McGreevy, Cora; Williams, David

2013-07-01

Cholinesterase inhibitors and memantine are the mainstay of pharmacological intervention for the cognitive symptoms of Alzheimer's disease (AD). This study assessed the adequacy of dosing and persistence with AD medications and the predictors of these variables in the 'real world' (outside the clinical trial setting). The Health Service Executive-Primary Care Reimbursement Services prescription claims database in the Republic of Ireland contains prescription information for 1.6 million people. Patients aged >70 years who received at least two prescriptions for donepezil, rivastigmine, galantamine and memantine between January 2006 and December 2010 were included in the study. Rates of dose-maximisation were recorded by examining the initiation dose of each AD drug commenced during the study period and any subsequent dose titrations. Non-persistence was defined by a gap in prescribing of more than 63 consecutive days. Predictors of dose-maximisation and non-persistence were also analysed. Between January 2006 and December 2010, 20,729 patients aged >70 years received a prescription for an AD medication. Despite most patients on donepezil and memantine receiving a prescription for the maximum drug dose, this dose was maintained for 2 consecutive months in only two-thirds of patients. Patients were significantly more likely to have their doses of donepezil and memantine maximised if prescribed in more recent years (2010 vs. 2007). Rates of non-persistence were 30.1 % at 6 months and 43.8 % at 12 months. Older age [75+ vs. <75 years; hazards ratio (HR) 1.16, 95 % confidence interval (CI) 1.06-1.27] and drug type (rivastigmine vs. donepezil; HR 1.15, 95 % CI 1.03-1.27) increased the risk of non-persistence. Non-persistence was lower for those commencing therapy in more recent years (2010 vs. 2007; HR 0.81, 95 % CI 0.73-0.89, p < 0.001) and for those on multiple anti-dementia medications (HR 0.59, 95 % CI 0.54-0.65, p < 0.001). Persistence was significantly higher when memantine was co-prescribed with donepezil (p < 0.0001). Future studies should explore the reasons underlying non-persistence and failure to maintain dose-maximisation in patients on AD medications. There may be scope to improve the dosing and persistence with these medications in the community.

Influence of Memantine on Continuous Treatment with Rivastigmine Patches-Retrospective Study Using the Logistic Regression Analysis.

PubMed

Yasutaka, Yuki; Fujioka, Shinsuke; Terasawa, Mariko; Shibaguchi, Hirotomo; Futagami, Koujiro; Ouma, Shinji; Tsuboi, Yoshio; Kamimura, Hidetoshi

2017-01-01

Rivastigmine patches exhibit stable effects when attached once a day, and may reduce Alzheimer's disease (AD) patient's or caregiver's burden. On the other hand, it was reported that adverse events, such as dermal disorder, frequently appeared after the start of rivastigmine administration. We retrospectively investigated medical records in 120 patients with moderate or mild AD in whom rivastigmine administration was started in the Department of Neurology, Fukuoka University Hospital between July 2011 and June 2014 (43 males, 77 females, mean age: 76.9±8.0 years). In 72 patients (60.0%), rivastigmine administration was discontinued within 52 weeks after its start. In 45 of these, it was discontinued before reaching a dose of 18 mg/d which was proven to be effective for AD patients. A primary reason for discontinuation was the appearance or deterioration of adverse events in 64 patients. Of these, 43 complained of dermal disorder, accounting for the highest percentage. To clarify factors influencing the continuous administration of rivastigmine, multivariate analysis was performed in 114 patients meeting criteria. Combination therapy with memantine was extracted as a factor (p=0.008). The results of this study suggest that adherence to combination therapy with rivastigmine and memantine is more favorable than that to monotherapy with rivastigmine.

Pharmacologic dissociation between impulsivity and alcohol drinking in High Alcohol Preferring mice

PubMed Central

Oberlin, Brandon G.; Bristow, R. Evan; Heighton, Meredith E.; Grahame, Nicholas J.

2014-01-01

Background Impulsivity is genetically correlated with, and precedes addictive behaviors and alcoholism. If impulsivity or attention is causally related to addiction, certain pharmacological manipulations of impulsivity and/or attention may affect alcohol drinking, and vice versa. The current studies were designed to explore the relationship among impulsivity, drinking, and vigilance in selectively bred High Alcohol Preferring (HAP) mice, a line that has previously demonstrated both high impulsivity and high alcohol consumption. Amphetamine, naltrexone and memantine were tested in a delay discounting (DD) task for their effects on impulsivity and vigilance. The same drugs and doses were also assessed for effects on alcohol drinking in a two-bottle choice test. Methods HAP mice were subjected to a modified version of adjusting amount DD using 0.5 sec and 10 sec delays to detect decreases and increases, respectively, in impulsive responding. In 2 experiments, mice were given amphetamine (0.4, 0.8 or 1.2 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) before DD testing. Another pair of studies used scheduled access, two-bottle choice drinking to assess effects of amphetamine (0.4, 1.2, or 3.0 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) on alcohol consumption. Results Amphetamine dose-dependently reduced impulsivity and vigilance decrement in DD, but similar doses left alcohol drinking unaffected. Naltrexone and memantine decreased alcohol intake at doses that did not affect water drinking, but had no effects on impulsivity or vigilance decrement in the DD task. Conclusions Contrary to our hypothesis, none of the drugs tested here, while effective either on alcohol drinking or impulsivity, decreased both behaviors. These findings suggest that the genetic association between drinking and impulsivity observed in this population is mediated by mechanisms other than those targeted by the drugs tested in these studies. PMID:20491739

Cost-utility analysis of memantine extended release added to cholinesterase inhibitors compared to cholinesterase inhibitor monotherapy for the treatment of moderate-to-severe dementia of the Alzheimer's type in the US.

PubMed

Saint-Laurent Thibault, Catherine; Özer Stillman, Ipek; Chen, Stephanie; Getsios, Denis; Proskorovsky, Irina; Hernandez, Luis; Dixit, Shailja

2015-01-01

This study evaluates the cost-effectiveness of memantine extended release (ER) as an add-on therapy to acetylcholinesterase inhibitor (AChEI) [combination therapy] for treatment of patients with moderate-to-severe Alzheimer's disease (AD) from both a healthcare payer and a societal perspective over 3 years when compared to AChEI monotherapy in the US. A phase III trial evaluated the efficacy and safety of memantine ER for treatment of AD patients taking an AChEI. The analysis assessed the long-term costs and health outcomes using an individual patient simulation in which AD progression is modeled in terms of cognition, behavior, and functioning changes. Input parameters are based on patient-level trial data, published literature, and publicly available data sources. Changes in anti-psychotic medication use are incorporated based on a published retrospective cohort study. Costs include drug acquisition and monitoring, total AD-related medical care, and informal care associated with caregiver time. Incremental cost-utility ratio (ICUR), life years, care time for caregiver, time in community and institution, time on anti-psychotics, time by disease severity, and time without severe symptoms are reported. Costs and health outcomes are discounted at 3% per annum. Considering a societal perspective over 3 years, this analysis shows that memantine ER combined with an AChEI provides better clinical outcomes and lower costs than AChEI monotherapy. Discounted average savings were estimated at $18,355 and $20,947 per patient and quality-adjusted life-years (QALYs) increased by an average of 0.12 and 0.13 from a societal and healthcare payer perspective, respectively. Patients on combination therapy spent an average of 4 months longer living at home and spend less time in moderate-severe and severe stages of the disease. Combination therapy for patients with moderate-to-severe AD is a cost-effective treatment compared to AChEI monotherapy in the US.

MK-801 and memantine act differently on short-term memory tested with different time-intervals in the Morris water maze test.

PubMed

Duda, Weronika; Wesierska, Malgorzata; Ostaszewski, Pawel; Vales, Karel; Nekovarova, Tereza; Stuchlik, Ales

2016-09-15

N-methyl-d-aspartate receptors (NMDARs) play a crucial role in spatial memory formation. In neuropharmacological studies their functioning strongly depends on testing conditions and the dosage of NMDAR antagonists. The aim of this study was to assess the immediate effects of NMDAR block by (+)MK-801 or memantine on short-term allothetic memory. Memory was tested in a working memory version of the Morris water maze test. In our version of the test, rats underwent one day of training with 8 trials, and then three experimental days when rats were injected intraperitoneally with low- 5 (MeL), high - 20 (MeH) mg/kg memantine, 0.1mg/kg MK-801 or 1ml/kg saline (SAL) 30min before testing, for three consecutive days. On each experimental day there was just one acquisition and one test trial, with an inter-trial interval of 5 or 15min. During training the hidden platform was relocated after each trial and during the experiment after each day. The follow-up effect was assessed on day 9. Intact rats improved their spatial memory across the one training day. With a 5min interval MeH rats had longer latency then all rats during retrieval. With a 15min interval the MeH rats presented worse working memory measured as retrieval minus acquisition trial for path than SAL and MeL and for latency than MeL rats. MK-801 rats had longer latency than SAL during retrieval. Thus, the high dose of memantine, contrary to low dose of MK-801 disrupts short-term memory independent on the time interval between acquisition and retrieval. This shows that short-term memory tested in a working memory version of water maze is sensitive to several parameters: i.e., NMDA receptor antagonist type, dosage and the time interval between learning and testing. Copyright © 2016. Published by Elsevier B.V.

Memantine can improve chronic ethanol exposure-induced spatial memory impairment in male C57BL/6 mice by reducing hippocampal apoptosis.

PubMed

Wang, Xiaolong; Yu, Hao; You, Jiabin; Wang, Changliang; Feng, Chunmei; Liu, Zhaodi; Li, Ya; Wei, Rucheng; Xu, Siqi; Zhao, Rui; Wu, Xu; Zhang, Guohua

2018-05-22

Chronic ethanol intake can induce neuronal apoptosis, leading to dementia. We investigated the protective effects of memantine on spatial memory impairment induced by chronic ethanol exposure in mice. Male C57BL/6 mice were administered 10% (m/V) or 20% (m/V) ethanol as the only choice of drinking water. Mice were treated for 60 d, 90 d, or 180 d. Mice were treated with memantine for the same duration (daily 10 mg/kg oral). The Morris water maze and radial arm maze test were used to measure spatial memory. Mice were sacrificed after the behavioral tests. Brains were removed to prepare for paraffin sections, and hippocampi were isolated for protein and RNA extraction. 4',6-diamidino-2-phenylindole (DAPI) staining and immunohistochemical staining of cleaved caspase-3 were performed. Western blot analysis was used to detect the expression of cleaved caspase-3 and calcium-related proteins, including N-methyl-d-aspartic acid receptor 1 (NR1), 1,4,5-trisphosphate receptor 1 (IP3R1), and sarco/endoplasmic reticulum calcium adenosine triphosphatase 1 (SERCA1). The changes of NR1, IP3R1 and SERCA1 mRNA were detected using quantitative polymerase chain reaction (qPCR). The results revealed that chronic ethanol exposure induced spatial memory impairment in mice, as well as increasing the expression of NR1, IP3R1 and SERCA1, the activation of caspase-3 and apoptosis in hippocampus. The effect was particularly prominent in the 20% ethanol group after 180 d exposure. Memantine decreased ethanol-induced spatial memory impairment, caspase-3 activation and apoptosis in the mouse hippocampus. These results suggest that disruption of intracellular calcium balance by ethanol can induce caspase-3 activation and apoptosis, which underlies subsequent spatial memory impairment in mice. Copyright © 2018 Elsevier B.V. All rights reserved.

Low-dose memantine-induced working memory improvement in the allothetic place avoidance alternation task (APAAT) in young adult male rats

PubMed Central

Wesierska, Malgorzata J.; Duda, Weronika; Dockery, Colleen A.

2013-01-01

N-methyl-D-aspartate receptors (NMDAR) are involved in neuronal plasticity. To assess their role simultaneously in spatial working memory and non-cognitive learning, we used NMDAR antagonists and the Allothetic Place Avoidance Alternation Task (APAAT). In this test rats should avoid entering a place where shocks were presented on a rotating arena which requires cognitive coordination for the segregation of stimuli. The experiment took place 30 min after intraperitoneal injection of memantine (5, 10, 20 mg/kg b.w.: MemL, MemM, MemH, respectively) and (+)MK-801 (0.1, 0.2, 0.3 mg/kg b.w.: MK-801L, MK-801M, MK-801H, respectively). Rats from the control group were intact or injected with saline (0.2 ml/kg). Over three consecutive days the rats underwent habituation, two avoidance training intervals with shocks, and a retrieval test. The shock sector was alternated daily. The after-effects of the agents were tested on Day 21. Rats treated with low dose memantine presented a longer maximum time avoided and fewer entrances than the MemH, MK-801M, MK-801H and Control rats. The shocks per entrances ratio, used as an index of cognitive skill learning, showed skill improvement after D1, except for rats treated by high doses of the agents. The activity levels, indicated by the distance walked, were higher for the groups treated with high doses of the agents. On D21 the MK801H rats performed the memory task better than the MemH rats, whereas the rats' activity depended on condition, not on the group factor. These results suggest that in naïve rats mild NMDAR blockade by low-dose memantine improves working memory related to a highly challenging task. PMID:24385956

Protein Dynamics Associated with Failed and Rescued Learning in the Ts65Dn Mouse Model of Down Syndrome

PubMed Central

Ahmed, Md. Mahiuddin; Dhanasekaran, A. Ranjitha; Block, Aaron; Tong, Suhong; Costa, Alberto C. S.; Stasko, Melissa; Gardiner, Katheleen J.

2015-01-01

Down syndrome (DS) is caused by an extra copy of human chromosome 21 (Hsa21). Although it is the most common genetic cause of intellectual disability (ID), there are, as yet, no effective pharmacotherapies. The Ts65Dn mouse model of DS is trisomic for orthologs of ∼55% of Hsa21 classical protein coding genes. These mice display many features relevant to those seen in DS, including deficits in learning and memory (L/M) tasks requiring a functional hippocampus. Recently, the N-methyl-D-aspartate (NMDA) receptor antagonist, memantine, was shown to rescue performance of the Ts65Dn in several L/M tasks. These studies, however, have not been accompanied by molecular analyses. In previous work, we described changes in protein expression induced in hippocampus and cortex in control mice after exposure to context fear conditioning (CFC), with and without memantine treatment. Here, we extend this analysis to Ts65Dn mice, measuring levels of 85 proteins/protein modifications, including components of MAP kinase and MTOR pathways, and subunits of NMDA receptors, in cortex and hippocampus of Ts65Dn mice after failed learning in CFC and after learning was rescued by memantine. We show that, compared with wild type littermate controls, (i) of the dynamic responses seen in control mice in normal learning, >40% also occur in Ts65Dn in failed learning or are compensated by baseline abnormalities, and thus are considered necessary but not sufficient for successful learning, and (ii) treatment with memantine does not in general normalize the initial protein levels but instead induces direct and indirect responses in approximately half the proteins measured and results in normalization of the endpoint protein levels. Together, these datasets provide a first view of the complexities associated with pharmacological rescue of learning in the Ts65Dn. Extending such studies to additional drugs and mouse models of DS will aid in identifying pharmacotherapies for effective clinical trials. PMID:25793384

Effect of rivastigmine or memantine add-on therapy is affected by butyrylcholinesterase genotype in patients with probable Alzheimer's disease.

PubMed

Han, Hyun Jeong; Kwon, Jay C; Kim, Jung Eun; Kim, Shin Gyeom; Park, Jong-Moo; Park, Kyung Won; Park, Key Chung; Park, Kee Hyung; Moon, So Young; Seo, Sang Won; Choi, Seong Hye; Cho, Soo-Jin

2015-01-01

The K variant of butyrylcholinesterase (BCHE-K) exhibits a reduced acetylcholine-hydrolyzing capacity; so the clinical response to rivastigmine may differ in Alzheimer's disease (AD) patients with the BCHE-K gene. To investigate the clinical response to rivastigmine transdermal patch monotherapy or memantine plus rivastigmine transdermal patch therapy in AD patients based on the BCHE-K gene. A total of 146 probable AD patients consented to genetic testing for butyrylcholinesterase and underwent the final efficacy evaluations. Responders were defined as patients with an equal or better score on the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) at 16 weeks compared to their baseline score. BCHE-K carriers showed a lower responder rate on the ADAS-cog than non-carriers (38.2 vs. 61.7%, p = 0.02), and this trend was evident in AD patients with apolipoprotein E ε 4 (35 vs. 60.7%, p = 0.001). The presence of the BCHE-K allele predicted a worse response on the ADAS-cog (odds ratio 0.35, 95% confidence interval 0.14-0.87), after adjusting for demographic and baseline cognitive and functional variables. The BCHE-K genotype may be related to a poor cognitive response to rivastigmine patch or memantine add-on therapy, especially in the presence of apolipoprotein E ε 4.

AChE Inhibitors and NMDA Receptor Antagonists in Advanced Alzheimer's Disease.

PubMed

Glynn-Servedio, Brianna E; Ranola, Trisha Seys

2017-09-01

The objective of this article is to review the available evidence for duration of treatment with, and considerations for discontinuation of, acetylcholinesterase inhibitors and N-methyl-d-aspartate receptor antagonists in Alzheimer's disease. Literature searches of clinical trials and meta-analyses were conducted using PubMed with the search terms Alzheimer's, dementia, donepezil, galantamine, memantine, and rivastigmine. References from included trials were also used to find additional citations. 2,925 articles were initially identified. Twenty-one studies were included that looked at the use of acetylcholinesterase inhibitors and/or memantine in the treatment of moderate-to-severe Alzheimer's dementia. Several clinical trials have demonstrated small improvements in measures of cognition and activities of daily living with medications used to treat dementia. However, not all patients will benefit from treatment, and the impact of treatment on long-term outcomes, including institutionalization, remains unclear. This paper reviews the available data to support the use of acetylcholinesterase inhibitors and/or memantine in patients with advanced Alzheimer's disease, including those in nursing facilities, and reviews recommendations for consideration of therapy discontinuation. The evidence to support a specific time frame for discontinuation of Alzheimer's disease treatment is limited. It is reasonable to stop a medication if there is no noticeable benefit after the first three months of treatment or once a patient's dementia progresses to a point where there would be no meaningful benefit from continued therapy.

Memantine Attenuates Alzheimer’s Disease-Like Pathology and Cognitive Impairment

PubMed Central

Wang, Xiaochuan; Blanchard, Julie; Iqbal, Khalid

2015-01-01

Deficiency of protein phosphatase-2A is a key event in Alzheimer’s disease. An endogenous inhibitor of protein phosphatase-2A, inhibitor-1, I1 PP2A, which inhibits the phosphatase activity by interacting with its catalytic subunit protein phosphatase-2Ac, is known to be upregulated in Alzheimer’s disease brain. In the present study, we overexpressed I1 PP2A by intracerebroventricular injection with adeno-associated virus vector-1-I1 PP2A in Wistar rats. The I1 PP2A rats showed a decrease in brain protein phosphatase-2A activity, abnormal hyperphosphorylation of tau, neurodegeneration, an increase in the level of activated glycogen synthase kinase-3beta, enhanced expression of intraneuronal amyloid-beta and spatial reference memory deficit; littermates treated identically but with vector only, i.e., adeno-associated virus vector-1-enhanced GFP, served as a control. Treatment with memantine, a noncompetitive NMDA receptor antagonist which is an approved drug for treatment of Alzheimer’s disease, rescued protein phosphatase-2A activity by decreasing its demethylation at Leu309 selectively and attenuated Alzheimer’s disease-like pathology and cognitive impairment in adeno-associated virus vector-1-I1 PP2A rats. These findings provide new clues into the possible mechanism of the beneficial therapeutic effect of memantine in Alzheimer’s disease patients. PMID:26697860

Memantine-derived drugs as potential antitumor agents for the treatment of glioblastoma.

PubMed

Cacciatore, Ivana; Fornasari, Erika; Marinelli, Lisa; Eusepi, Piera; Ciulla, Michele; Ozdemir, Ozlem; Tatar, Abdulgani; Turkez, Hasan; Di Stefano, Antonio

2017-11-15

Glioblastoma is one of the most aggressive malignant primary brain cancer in adults. To date, surgery, radiotherapy and current pharmacological treatments are not sufficient to manage this pathology that has a high mortality rate (median survival 12-15months). Recently, anticancer multi-targeted compounds have attracted much attention with the aim to obtain new drugs able to hit different biological targets that are involved in the onset and progression of the disease. Here, we report the synthesis of novel memantine-derived drugs (MP1-10) and their potential antitumor activities in human U87MG glioblastoma cell line. MP1-10 were synthetized joining memantine, which is a NMDA antagonist, to different histone deacetylase inhibitors to obtain one molecule with improved therapeutic efficacy. Biological results indicated that MP1 and MP2 possessed more potent anti-proliferative effects on U87MG cells than MP3-10 in a dose-dependent manner. MP1 and MP2 induced significant cell death by apoptosis characterized by apoptotic morphological changes in Hoechst staining. Both drugs also exhibited non-genotoxic and only mild cytotoxic effects in human whole blood cells. However, only MP1, showing good chemico-physical properties (solubility, LogP) and enzymatic stabilities in gastric and intestinal fluids, can be considered a suitable candidate for in vivo pharmacokinetic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Memantine

MedlinePlus

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Alzheimer Disease: Pharmacologic and Nonpharmacologic Therapies for Cognitive and Functional Symptoms.

PubMed

Epperly, Ted; Dunay, Megan A; Boice, Jack L

2017-06-15

Alzheimer disease comprises a syndrome of progressive cognitive and functional decline. Treatments should target cognitive and functional symptoms. Cholinesterase inhibitors, memantine, and a combination of a cholinesterase inhibitor and memantine have produced statistically significant but clinically small delays in various domains of cognitive and functional decline in select patients with Alzheimer disease. Vitamin E has been shown to delay functional decline in patients with mild to moderate Alzheimer disease, especially when taken in combination with a cholinesterase inhibitor. Structured programs of physical exercise improve physical function and reduce rates of neuropsychiatric symptoms in patients with mild to severe Alzheimer disease. Cognitive stimulation programs show benefit in maintenance of cognitive function and improved self-reported quality of life in patients with mild to moderate Alzheimer disease.

Lithium, phenserine, memantine and pioglitazone reverse memory deficit and restore phospho-GSK3β decreased in hippocampus in intracerebroventricular streptozotocin induced memory deficit model.

PubMed

Ponce-Lopez, Teresa; Liy-Salmeron, Gustavo; Hong, Enrique; Meneses, Alfredo

2011-12-02

Intracerebroventricular (ICV) streptozotocin (STZ) treated rat has been described as a suitable model for sporadic Alzheimer's disease (AD). Central application of STZ has demonstrated behavioral and neurochemical features that resembled those found in human AD. Chronic treatments with antioxidants, acetylcholinesterase (AChE) inhibitors, or improving glucose utilization drugs have reported a beneficial effect in ICV STZ-treated rats. In the present study the post-training administration of a glycogen synthase kinase (GSK3) inhibitor, lithium; antidementia drugs: phenserine and memantine, and insulin sensitizer, pioglitazone on memory function of ICV STZ-rats was assessed. In these same animals the phosphorylated GSK3β (p-GSK3β) and total GSK3β levels were determined, and importantly GSK3β regulates the tau phosphorylation responsible for neurofibrillary tangle formation in AD. Wistar rats received ICV STZ application (3mg/kg twice) and 2 weeks later short- (STM) and long-term memories (LTM) were assessed in an autoshaping learning task. Animals were sacrificed immediately following the last autoshaping session, their brains removed and dissected. The enzymes were measured in the hippocampus and prefrontal cortex (PFC) by western blot. ICV STZ-treated rats showed a memory deficit and significantly decreased p-GSK3β levels, while total GSK3β did not change, in both the hippocampus and PFC. Memory impairment was reversed by lithium (100mg/kg), phenserine (1mg/kg), memantine (5mg/kg) and pioglitazone (30 mg/kg). The p-GSK3β levels were restored by lithium, phenserine and pioglitazone in the hippocampus, and restored by lithium in the PFC. Memantine produced no changes in p-GSK3β levels in neither the hippocampus nor PFC. Total GSK3β levels did not change with either drug. Altogether these results show the beneficial effects of drugs with different mechanisms of actions on memory impairment induced by ICV STZ, and restored p-GSK3β levels, a kinase key of signaling cascade of insulin receptor. 2011 Elsevier B.V. All rights reserved.

Effect of donepezil in patients with Alzheimer's disease previously untreated or treated with memantine or nootropic agents in Germany: an observational study.

PubMed

Klinger, Tatjana; Ibach, Bernd; Schoenknecht, Peter; Kamleiter, Martin; Silver, Gabrielle; Schroeder, Johannes; Mielke, Ruediger

2005-05-01

This open-label, prospective, observational, Post-Marketing Surveillance (PMS) study assessed the efficacy and safety of donepezil in patients who had been switched from therapies currently used in Germany to treat Alzheimer's disease (AD), such as memantine and nootropics, due to insufficient efficacy or poor tolerability. A treatment-naive population was included as a comparator. Patients with AD were treated with donepezil and observed for a period of approximately 3 months. A cognitive assessment was made using the Mini-Mental State Examination (MMSE). Quality of life (QoL) was assessed by the investigators who answered the question 'How did therapy with donepezil influence the QoL of the patient and/or his family over the observation period?' and was graded using three ratings: improved/unchanged/worsened. Adverse events (AEs) were also monitored. A total of 913 patients entered the study (mean +/- SD MMSE score 18.03 +/- 5.34). Efficacy assessments were analyzed for three groups: an overall group of patients who had received any form of prior AD drug therapy (N+ group; n = 709); a subgroup of patients from the N+ group who had received prior memantine therapy only (M+ group; n = 111) and patients who were drug treatment naive (N- group; n = 204). In the evaluable population donepezil improved MMSE scores by 2.21 +/- 3.47 points on average, with similar improvements observed in all three groups. QoL was judged to be improved in at least 70% of patients, again with similar results obtained for all three groups. Donepezil was well tolerated, with 85 of 913 (9.3%) patients reporting AEs. The most common AEs were those typically seen with cholinergic therapies (i.e., diarrhoea, vomiting and nausea). In this observational PMS study, donepezil was shown to be efficacious and well tolerated in patients who were being insufficiently treated with memantine or nootropic therapy. The magnitude of response was similar to that observed in patients who were previously treatment naive, suggesting prior medication does not effect donepezil's efficacy.

The Relationship Between the Renin-Angiotensin-Aldosterone System and NMDA Receptor-Mediated Signal and the Prevention of Retinal Ganglion Cell Death.

PubMed

Kobayashi, Mamoru; Hirooka, Kazuyuki; Ono, Aoi; Nakano, Yuki; Nishiyama, Akira; Tsujikawa, Akitaka

2017-03-01

Excitotoxicity, which is due to glutamate-induced toxic effects on the retinal ganglion cell (RGC), is one of several mechanisms of RGC loss. The renin-angiotensin-aldosterone system (RAAS) has also been implicated in RGC death. Therefore, it is important to determine the exact relationship between the RAAS and N-methyl-d-aspartate (NMDA) receptor-mediated signal in order to prevent RGC death. N-methyl-d-aspartate or aldosterone was injected into the vitreous body. After intravitreal injection of NMDA or aldosterone, animals were treated with spironolactone or memantine. Retinal damage was evaluated by measuring the number of RGCs at 4 weeks after local administration of aldosterone or at 2 weeks after local administration of NMDA. Vitreous humor levels of aldosterone were measured using enzyme immunoassay kits. A significantly decreased number of RGCs were observed after intravitreal injection of NMDA. Although spironolactone did not show any neuroprotective effects, memantine significantly reduced NMDA-induced degeneration in the retina. Furthermore, a significant decrease in the number of RGCs was observed after an intravitreal injection of aldosterone. While memantine did not exhibit any neuroprotective effects, spironolactone caused a significant reduction in the aldosterone-induced degeneration in the retina. There was no change in the aldosterone concentration in the vitreous humor after an NMDA injection. Our findings indirectly show that there is no relationship between the RAAS and NMDA receptor-mediated signal with regard to RGC death.

NMDA Receptors as Potential Therapeutic Targets in Diabetic Nephropathy: Increased Renal NMDA Receptor Subunit Expression in Akita Mice and Reduced Nephropathy Following Sustained Treatment With Memantine or MK-801.

PubMed

Roshanravan, Hila; Kim, Eun Young; Dryer, Stuart E

2016-10-01

N-methyl-d-aspartate (NMDA) receptors are expressed throughout the kidney, and the abundance of these receptors and some of their endogenous agonists are increased in diabetes. Moreover, sustained activation of podocyte NMDA receptors induces Ca(2+) influx, oxidative stress, loss of slit diaphragm proteins, and apoptosis. We observed that NMDA receptor subunits and their transcripts are increased in podocytes and mesangial cells cultured in elevated glucose compared with controls. A similar increase in NMDA subunits, especially NR1, NR2A, and NR2C, was observed in glomeruli and tubules of Akita mice. Sustained continuous treatment with the strong NMDA receptor antagonist dizocilpine (MK-801) for 28 days starting at 8 weeks of age reduced 24-h albumin excretion and mesangial matrix expansion and improved glomerular ultrastructure in Akita mice. MK-801 did not alleviate reduced Akita mouse body weight and had no effect on kidney histology or ultrastructure in DBA/2J controls. The structurally dissimilar NMDA antagonist memantine also reduced diabetic nephropathy, although it was less effective than MK-801. Inhibition of NMDA receptors may represent a valid therapeutic approach to reduce renal complications of diabetes, and it is possible to develop well-tolerated agents with minimal central nervous system effects. Two such agents, memantine and dextromethorphan, are already in widespread clinical use. © 2016 by the American Diabetes Association.

Novel Treatment with Neuroprotective and Antiviral Properties against a Neuroinvasive Human Respiratory Virus

PubMed Central

Brison, Elodie; Jacomy, Hélène

2014-01-01

ABSTRACT Human coronaviruses (HCoVs) are recognized respiratory pathogens with neuroinvasive and neurotropic properties in mice and humans. HCoV strain OC43 (HCoV-OC43) can infect and persist in human neural cells and activate neuroinflammatory and neurodegenerative mechanisms, suggesting that it could be involved in neurological disease of unknown etiology in humans. Moreover, we have shown that HCoV-OC43 is neurovirulent in susceptible mice, causing encephalitis, and that a viral mutant with a single point mutation in the viral surface spike (S) protein induces a paralytic disease that involves glutamate excitotoxicity in susceptible mice. Herein, we show that glutamate recycling via the glial transporter 1 protein transporter and glutamine synthetase are central to the dysregulation of glutamate homeostasis and development of motor dysfunctions and paralytic disease in HCoV-OC43-infected mice. Moreover, memantine, an N-methyl-d-aspartate receptor antagonist widely used in the treatment of neurological diseases in humans, improved clinical scores related to paralytic disease and motor disabilities by partially restoring the physiological neurofilament phosphorylation state in virus-infected mice. Interestingly, memantine attenuated mortality rates and body weight loss and reduced HCoV-OC43 replication in the central nervous system in a dose-dependent manner. This novel action of memantine on viral replication strongly suggests that it could be used as an antiviral agent to directly limit viral replication while improving neurological symptoms in various neurological diseases with a viral involvement. IMPORTANCE PMID:24227863

The effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine and memantine for the treatment of Alzheimer's disease (review of Technology Appraisal No. 111): a systematic review and economic model.

PubMed

Bond, M; Rogers, G; Peters, J; Anderson, R; Hoyle, M; Miners, A; Moxham, T; Davis, S; Thokala, P; Wailoo, A; Jeffreys, M; Hyde, C

2012-01-01

Alzheimer’s disease (AD) is the most commonly occurring form of dementia. It is predominantly a disease of later life, affecting 5% of those over 65 in the UK. Review and update guidance to the NHS in England and Wales on the clinical effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine [acetylcholinesterase inhibitors (AChEIs)] and memantine within their licensed indications for the treatment of AD, which was issued in November 2006 (amended September 2007 and August 2009). Electronic databases were searched for systematic reviews and/or metaanalyses, randomised controlled trials (RCTs) and ongoing research in November 2009 and updated in March 2010; this updated search revealed no new includable studies. The databases searched included The Cochrane Library (2009 Issue 4, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials), MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, PsycINFO, EconLit, ISI Web of Science Databases--Science Citation Index, Conference Proceedings Citation Index, and BIOSIS; the Centre for Reviews and Dissemination (CRD) databases--NHS Economic Evaluation Database, Health Technology Assessment, and Database of Abstracts of Reviews of Effects. The clinical effectiveness systematic review was undertaken following the principles published by the NHS CRD. We included RCTs whose population was people with AD. The intervention and comparators depended on disease severity, measured by the Mini Mental State Examination (MMSE). mild AD (MMSE 21-26)--donepezil, galantamine and rivastigmine; moderate AD (MMSE 10-20)--donepezil, galantamine, rivastigmine and memantine; severe AD (MMSE < 10)--memantine. Comparators: mild AD (MMSE 21-26)--placebo or best supportive care (BSC); moderate AD (MMSE 10-20)--donepezil, galantamine, rivastigmine, memantine, placebo or BSC; severe AD (MMSE < 10)--placebo or BSC. The outcomes were clinical, global, functional, behavioural, quality of life, adverse events, costs and cost-effectiveness. Where appropriate, data were pooled using pair-wise meta-analysis, multiple outcome measures, metaregression and mixedtreatment comparisons. The decision model was based broadly on the structure of the three-state Markov model described in the previous technology assessment report, based upon time to institutionalisation, parameterised with updated estimates of effectiveness, costs and utilities. Notwithstanding the uncertainty of our results, we found in the base case that the AChEIs are probably cost saving at a willingness-to-pay (WTP) of £’30,000 per qualityadjusted life-year (QALY) for people with mild-to-moderate AD. For this class of drugs, there is a > 99% probability that the AChEIs are more cost-effective than BSC. These analyses assume that the AChEIs have no effect on survival. For the AChEIs, in people with mild to moderate AD, the probabilistic sensitivity analyses suggested that donepezil is the most cost-effective, with a 28% probability of being the most cost-effective option at a WTP of £’30,000 per QALY (27% at a WTP of £’20,000 per QALY). In the deterministic results, donepezil dominates the other drugs and BSC, which, along with rivastigmine patches, are associated with greater costs and fewer QALYs. Thus, although galantamine has a slightly cheaper total cost than donepezil (£’69,592 vs £’69,624), the slightly greater QALY gains from donepezil (1.616 vs 1.617) are enough for donepezil to dominate galantamine.The probability that memantine is cost-effective in a moderate to severe cohort compared with BSC at a WTP of £’30,000 per QALY is 38% (and 28% at a WTP of £’20,000 per QALY). The deterministic ICER for memantine is £’32,100 per/QALY and the probabilistic ICER is £’36,700 per/QALY. Trials were of 6 months maximum follow-up, lacked reporting of key outcomes, provided no subgroup analyses and used insensitive measures. Searches were limited to English language, The model does not include behavioural symptoms and there is uncertainty about the model structure and parameters. The additional clinical effectiveness evidence identified continues to suggest clinical benefit from the AChEIs in alleviating AD symptoms, although there is debate about the magnitude of the effect. Although there is also new evidence on the effectiveness of memantine, it remains less supportive of this drug’s use than the evidence for AChEIs. The conclusions concerning cost-effectiveness are quite different from the previous assessment. This is because both the changes in effectiveness and costs between drug use and non-drug use underlying the ICERs are very small. This leads to highly uncertain results, which are very sensitive to change. RESEARCH PRIORITIES: RCTs to include mortality, time to institutionalisation and quality of life, powered for subgroup analysis. The National Institute for Health Research Health Technology Assessment programme.

Identification of Splice Variants as Molecular Markers in Parkinson’s Disease

DTIC Science & Technology

2006-09-01

cyclosporine, cisapride, astemizole; b. NMDA antagonists: e.g. amantadine, budipine, memantine, remacemide, dextromethorphan ; c. Any investigational...f. Drugs known to improve dyskinesias: amantadine, dextromethorphan , beta-blockers, fluoxitene, clozapine, quetiapine, olanzapine, buspirone, other

Pharmacologic treatments for the behavioral symptoms associated with autism spectrum disorders across the lifespan

PubMed Central

Doyle, Carolyn A.; McDougle, Christopher J.

2012-01-01

This review outlines pharmacologic treatments for the behavioral symptoms associated with autism spectrum disorders (ASDs) in children, adolescents, and adults. Symptom domains include repetitive and stereotyped behaviors, irritability and aggression, hyperactivity and inattention, and social impairment. Medications covered include serotonin reuptake inhibitors (SRIs), mirtazapine, antipsychotics, psychostimulants, atomoxetine, α-2 agonists, D-cycloserine, and memantine. Overall, SRIs are less efficacious and more poorly tolerated in children with ASDs than in adults. Antipsychotics are the most efficacious drugs for the treatment of irritability in ASDs, and may be useful in the treatment of other symptoms. Psychostimulants demonstrate some benefit for the treatment of hyperactivity and inattention in individuals with ASDs, but are less efficacious and associated with more adverse effects compared with individuals with ADHD. D-cycloserine and memantine appear helpful in the treatment of social impairment, although further research is needed. PMID:23226952

Use of antidementia drugs in frontotemporal lobar degeneration.

PubMed

López-Pousa, Secundino; Calvó-Perxas, Laia; Lejarreta, Saioa; Cullell, Marta; Meléndez, Rosa; Hernández, Erélido; Bisbe, Josep; Perkal, Héctor; Manzano, Anna; Roig, Anna Maria; Turró-Garriga, Oriol; Vilalta-Franch, Joan; Garre-Olmo, Josep

2012-06-01

Clinical evidence indicates that acetylcholinesterase inhibitors (AChEIs) are not efficacious to treat frontotemporal lobar degeneration (FTLD). The British Association for Psychopharmacology recommends avoiding the use of AChEI and memantine in patients with FTLD. Cross-sectional design using 1092 cases with Alzheimer's disease (AD) and 64 cases with FTLD registered by the Registry of Dementias of Girona. Bivariate analyses were performed, and binary logistic regressions were used to detect variables associated with antidementia drugs consumption. The AChEIs were consumed by 57.6% and 42.2% of the patients with AD and FTLD, respectively. Memantine was used by 17.2% and 10.9% of patients with AD and FTLD, respectively. Binary logistic regressions yielded no associations with antidementia drugs consumption. There is a discrepancy regarding clinical practice and the recommendations based upon clinical evidence. The increased central nervous system drug use detected in FTLD requires multicentric studies aiming at finding the best means to treat these patients.

Treatment of Alzheimer disease.

PubMed

Winslow, Bradford T; Onysko, Mary K; Stob, Christian M; Hazlewood, Kathleen A

2011-06-15

Alzheimer disease is the most common form of dementia, affecting nearly one-half [corrected] of Americans older than 85 years. It is characterized by progressive memory loss and cognitive decline. Amyloid plaque accumulation, neurofibrillary tau tangles, and depletion of acetylcholine are among the pathologic manifestations of Alzheimer disease. Although there are no proven modalities for preventing Alzheimer disease, hypertension treatment, omega-3 fatty acid supplementation, physical activity, and cognitive engagement demonstrate modest potential. Acetylcholinesterase inhibitors are first-line medications for the treatment of Alzheimer disease, and are associated with mild improvements in cognitive function, behavior, and activities of daily living; however, the clinical relevance of these effects is unclear. The most common adverse effects of acetylcholinesterase inhibitors are nausea, vomiting, diarrhea, dizziness, confusion, and cardiac arrhythmias. Short-term use of the N-methyl-D-aspartate receptor antagonist memantine can modestly improve measures of cognition, behavior, and activities of daily living in patients with moderate to severe Alzheimer disease. Memantine can also be used in combination with acetylcholinesterase inhibitors. Memantine is generally well tolerated, but whether its benefits produce clinically meaningful improvement is controversial. Although N-methyl-D-aspartate receptor antagonists and acetylcholinesterase inhibitors can slow the progression of Alzheimer disease, no pharmacologic agents can reverse the progression. Atypical antipsychotics can improve some behavioral symptoms, but have been associated with increased mortality rates in older patients with dementia. There is conflicting evidence about the benefit of selegiline, testosterone, and ginkgo for the treatment of Alzheimer disease. There is no evidence supporting the beneficial effects of vitamin E, estrogen, or nonsteroidal anti-inflammatory drug therapy.

Antidepressant, anxiolytic and procognitive effects of rivastigmine and donepezil in the chronic mild stress model in rats.

PubMed

Papp, Mariusz; Gruca, Piotr; Lason-Tyburkiewicz, Magdalena; Willner, Paul

2016-04-01

The treatment of depression in old age is complicated by frequent co-morbidity with cognitive impairment. Anti-dementia drugs have some efficacy to improve cognitive performance and there is an inconsistent literature regarding the effect of such drugs on depressive symptoms. Here, we have investigated whether anti-dementia drugs would have antidepressant-like and pro-cognitive effects in a well-validated animal model of depression and cognitive impairment, chronic mild stress (CMS). Rats were subjected to CMS for a total of 8 weeks. After 2 weeks, subgroups of stressed and non-stressed animals were treated daily, for 5 weeks followed by 1 week of drug withdrawal, with vehicle, imipramine (10 mg/kg), rivastigmine (2 mg/kg), donepezil (0.3 mg/kg) or memantine (5 mg/kg). Sucrose intake was tested weekly, and animals were also tested in the elevated plus maze (at week 7) and in an object recognition task (at weeks 7 and 8). CMS decreased sucrose intake, had an anxiogenic effect in the elevated plus maze, and impaired performance in the object recognition test. Imipramine, rivastigmine and donepezil normalized performance in all three tests. Memantine had anxiolytic and pro-cognitive effects, but did not reverse CMS-induced anhedonia. The fact that all three anti-dementia drugs reversed CMS-induced cognitive impairment and that cholinesterase inhibitors, but not memantine, have antidepressant-like effects in this model suggest that different mechanisms may underlie CMS-induced anhedonia and cognitive impairment. We discuss the clinical implications of these findings.

Central inhibition of initiation of swallowing by systemic administration of diazepam and baclofen in anaesthetized rats.

PubMed

Tsujimura, Takanori; Sakai, Shogo; Suzuki, Taku; Ujihara, Izumi; Tsuji, Kojun; Magara, Jin; Canning, Brendan J; Inoue, Makoto

2017-05-01

Dysphagia is caused not only by neurological and/or structural damage but also by medication. We hypothesized memantine, dextromethorphan, diazepam, and baclofen, all commonly used drugs with central sites of action, may regulate swallowing function. Swallows were evoked by upper airway (UA)/pharyngeal distension, punctate mechanical stimulation using a von Frey filament, capsaicin or distilled water (DW) applied topically to the vocal folds, and electrical stimulation of a superior laryngeal nerve (SLN) in anesthetized rats and were documented by recording electromyographic activation of the suprahyoid and thyrohyoid muscles and by visualizing laryngeal elevation. The effects of intraperitoneal or topical administration of each drug on swallowing function were studied. Systemic administration of diazepam and baclofen, but not memantine or dextromethorphan, inhibited swallowing evoked by mechanical, chemical, and electrical stimulation. Both benzodiazepines and GABA A receptor antagonists diminished the inhibitory effects of diazepam, whereas a GABA B receptor antagonist diminished the effects of baclofen. Topically applied diazepam or baclofen had no effect on swallowing. These data indicate that diazepam and baclofen act centrally to inhibit swallowing in anesthetized rats. NEW & NOTEWORTHY Systemic administration of diazepam and baclofen, but not memantine or dextromethorphan, inhibited swallowing evoked by mechanical, chemical, and electrical stimulation. Both benzodiazepines and GABA A receptor antagonists diminished the inhibitory effects of diazepam, whereas a GABA B receptor antagonist diminished the effects of baclofen. Topical applied diazepam or baclofen was without effect on swallowing. Diazepam and baclofen act centrally to inhibit swallowing in anesthetized rats. Copyright © 2017 the American Physiological Society.

Effects of FDA approved medications for Alzheimer’s disease on clinical progression

PubMed Central

Mielke, Michelle M.; Leoutsakos, Jeannie-Marie; Corcoran, Chris D.; Green, Robert C.; Norton, Maria C.; Welsh-Bohmer, Kathleen A.; Tschanz, JoAnn T.; Lyketsos, Constantine G.

2011-01-01

Background Observational studies suggest cholinesterase inhibitors and/or memantine may delay clinical progression of Alzheimer’s disease (AD) in 40% of individuals taking the medications. Given this response and existence of side effects, we sought to quantify medication use and benefits in a population-based study of incident AD cases. Methods The Cache County Dementia Progression study (DPS) enrolled and followed a cohort of 327 incident AD cases up to 9 years. Drug exposure was expressed using a persistency index (PI), calculated as total years of drug use divided by total years of observation. Linear mixed effects models examined PI, and interactions with sex and APOE ε4, as predictors of clinical progression on the Mini-Mental State Exam (MMSE) and Clinical Dementia Rating-Sum of Boxes (CDR-Sum). Results Sixty-nine participants (21.1%) ever used cholinesterase inhibitors or memantine. There was a strong three-way interaction between PI, sex, and time. Among women, a higher PI (i.e. greater duration of use) of cholinesterase inhibitors was associated with slower progression on the MMSE and CDR-Sum, particularly among those with an APOE ε4 allele. In contrast, higher PI was associated with faster progression in males. Conclusion A low percentage of individuals with AD in the community are taking cholinesterase inhibitors or memantine. This study suggests that women, particularly those with an APOE ε4 allele, may receive the most benefit from these medications. With the newly approved increased dose of donepezil, it will be imperative to determine whether a higher dose is needed in men or whether other factors warrant consideration. PMID:22301194

A Systematic Review of NMDA Receptor Antagonists for Treatment of Neuropathic Pain in Clinical Practice.

PubMed

Aiyer, Rohit; Mehta, Neel; Gungor, Semih; Gulati, Amitabh

2018-05-01

To investigate the efficacy of N-methyl-D-aspartate receptor (NMDAR) antagonists for neuropathic pain (NeuP) and review literature to determine if specific pharmacologic agents provide adequate NeuP relief. Literature was reviewed on PubMed using a variety of key words for 8 NMDAR antagonists. These key words include: "Ketamine and Neuropathy," "Ketamine and Neuropathic Pain," "Methadone and Neuropathy," "Methadone and Neuropathic Pain," "Memantine and Neuropathic pain," "Memantine and Neuropathy," "Amantadine and Neuropathic Pain," "Amantadine and Neuropathy," "Dextromethorphan and Neuropathic Pain," "Dextromethorphan and Neuropathy," "Carbamazepine and Neuropathic Pain," "Carbamazepine and Neuropathy," "Valproic Acid and Neuropathy," "Valproic Acid and Neuropathic Pain," "Phenytoin and Neuropathy," and "Phenytoin and Neuropathic Pain." With the results, the papers were reviewed using the PRISMA (Preferred Reporting in Systematic and Meta-Analyses) guideline. A total of 58 randomized controlled trials were reviewed among 8 pharmacologic agents, which are organized by date and alphabetical order. Of the trials for ketamine, 15 showed some benefit for analgesia. Methadone had 3 positive trials, while amantadine and memantine each only had 2 trials showing NeuP analgesic properties. Dextromethorphan and valproic acid both had 4 randomized controlled trials that showed some NeuP treatment benefit while carbamazepine had over 8 trials showing efficacy. Finally, phenytoin only had 1 trial that showed clinical response in treatment. There are a variety of NMDAR antagonist agents that should be considered for treatment of NeuP. Nevertheless, continued and further investigation of the 8 pharmacologic agents is needed to continue to evaluate their efficacy for treatment of NeuP.

Concomitant manipulation of murine NMDA- and AMPA-receptors to produce pro-cognitive drug effects in mice.

PubMed

Vignisse, Julie; Steinbusch, Harry W M; Grigoriev, Vladimir; Bolkunov, Alexei; Proshin, Alexey; Bettendorff, Lucien; Bachurin, Sergey; Strekalova, Tatyana

2014-02-01

Bifunctional drug therapy targeting distinct receptor signalling systems can generate increased efficacy at lower concentrations compared to monofunctional therapy. Non-competitive blockade of the NMDA receptors or the potentiation of AMPA receptors is well documented to result in memory enhancement. Here, we compared the efficacy of the low-affinity NMDA receptor blocker memantine or the positive modulator of AMPA receptor QXX (in C57BL/6J at 1 or 5mg/kg, ip) with new derivatives of isothiourea (0.5-1 mg/kg, ip) that have bifunctional efficacy. Low-affinity NMDA blockade by these derivatives was achieved by introducing greater flexibility into the molecule, and AMPA receptor stimulation was produced by a sulfamide-containing derivative of isothiourea. Contextual learning was examined in a step-down avoidance task and extinction of contextual memory was studied in a fear-conditioning paradigm. Memantine enhanced contextual learning while QXX facilitated memory extinction; both drugs were effective at 5 mg/kg. The new derivative IPAC-5 elevated memory scores in both tasks at the dose 0.5 mg/kg and exhibited the lowest IC₅₀ values of NMDA receptor blockade and highest potency of AMPA receptor stimulation. Thus, among the new drugs tested, IPAC-5 replicated the properties of memantine and QXX in one administration with increased potency. Our data suggest that a concomitant manipulation of NMDA- and AMPA-receptors results in pro-cognitive effects and supports the concept bifunctional drug therapy as a promising strategy to replace monofunctional therapies with greater efficacy and improved compliance. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

Pharmacological Modulation of Three Modalities of CA1 Hippocampal Long-Term Potentiation in the Ts65Dn Mouse Model of Down Syndrome

PubMed Central

Scott-McKean, Jonah J.; Roque, Adriano L.; Surewicz, Krystyna; Johnson, Mark W.; Surewicz, Witold K.

2018-01-01

The Ts65Dn mouse is the most studied animal model of Down syndrome. Past research has shown a significant reduction in CA1 hippocampal long-term potentiation (LTP) induced by theta-burst stimulation (TBS), but not in LTP induced by high-frequency stimulation (HFS), in slices from Ts65Dn mice compared with euploid mouse-derived slices. Additionally, therapeutically relevant doses of the drug memantine were shown to rescue learning and memory deficits in Ts65Dn mice. Here, we observed that 1 μM memantine had no detectable effect on HFS-induced LTP in either Ts65Dn- or control-derived slices, but it rescued TBS-induced LTP in Ts65Dn-derived slices to control euploid levels. Then, we assessed LTP induced by four HFS (4xHFS) and found that this form of LTP was significantly depressed in Ts65Dn slices when compared with LTP in euploid control slices. Memantine, however, did not rescue this phenotype. Because 4xHFS-induced LTP had not yet been characterized in Ts65Dn mice, we also investigated the effects of picrotoxin, amyloid beta oligomers, and soluble recombinant human prion protein (rPrP) on this form of LTP. Whereas ≥10 μM picrotoxin increased LTP to control levels, it also caused seizure-like oscillations. Neither amyloid beta oligomers nor rPrP had any effect on 4xHFS-induced LTP in Ts65Dn-derived slices. PMID:29849573

Clinical practice with anti-dementia drugs: A revised (third) consensus statement from the British Association for Psychopharmacology.

PubMed

O'Brien, John T; Holmes, Clive; Jones, Matthew; Jones, Roy; Livingston, Gill; McKeith, Ian; Mittler, Peter; Passmore, Peter; Ritchie, Craig; Robinson, Louise; Sampson, Elizabeth L; Taylor, John-Paul; Thomas, Alan; Burns, Alistair

2017-02-01

The British Association for Psychopharmacology coordinated a meeting of experts to review and revise its previous 2011 guidelines for clinical practice with anti-dementia drugs. As before, levels of evidence were rated using accepted standards which were then translated into grades of recommendation A-D, with A having the strongest evidence base (from randomised controlled trials) and D the weakest (case studies or expert opinion). Current clinical diagnostic criteria for dementia have sufficient accuracy to be applied in clinical practice (B) and both structural (computed tomography and magnetic resonance imaging) and functional (positron emission tomography and single photon emission computerised tomography) brain imaging can improve diagnostic accuracy in particular situations (B). Cholinesterase inhibitors (donepezil, rivastigmine, and galantamine) are effective for cognition in mild to moderate Alzheimer's disease (A), memantine for moderate to severe Alzheimer's disease (A) and combination therapy (cholinesterase inhibitors and memantine) may be beneficial (B). Drugs should not be stopped just because dementia severity increases (A). Until further evidence is available other drugs, including statins, anti-inflammatory drugs, vitamin E, nutritional supplements and Ginkgo biloba, cannot be recommended either for the treatment or prevention of Alzheimer's disease (A). Neither cholinesterase inhibitors nor memantine are effective in those with mild cognitive impairment (A). Cholinesterase inhibitors are not effective in frontotemporal dementia and may cause agitation (A), though selective serotonin reuptake inhibitors may help behavioural (but not cognitive) features (B). Cholinesterase inhibitors should be used for the treatment of people with Lewy body dementias (both Parkinson's disease dementia and dementia with Lewy bodies), and memantine may be helpful (A). No drugs are clearly effective in vascular dementia, though cholinesterase inhibitors are beneficial in mixed dementia (B). Early evidence suggests multifactorial interventions may have potential to prevent or delay the onset of dementia (B). Though the consensus statement focuses on medication, psychological interventions can be effective in addition to pharmacotherapy, both for cognitive and non-cognitive symptoms. Many novel pharmacological approaches involving strategies to reduce amyloid and/or tau deposition in those with or at high risk of Alzheimer's disease are in progress. Though results of pivotal studies in early (prodromal/mild) Alzheimer's disease are awaited, results to date in more established (mild to moderate) Alzheimer's disease have been equivocal and no disease modifying agents are either licensed or can be currently recommended for clinical use.

Estimated prevalence of dementia based on analysis of drug databases in the Region of Madrid (Spain).

PubMed

de Hoyos-Alonso, M C; Bonis, J; Tapias-Merino, E; Castell, M V; Otero, A

2016-01-01

The progressive rise in dementia prevalence increases the need for rapid methods that complement population-based prevalence studies. To estimate the prevalence of dementia in the population aged 65 and older based on use of cholinesterase inhibitors and memantine. Descriptive study of use and prescription of cholinesterase inhibitors and/or memantine in 2011 according to 2 databases: Farm@drid (pharmacy billing records for the Region of Madrid) and BIFAP (database for pharmacoepidemiology research in primary care, with diagnosis and prescription records). We tested the comparability of drug use results from each database using the chi-square test and prevalence ratios. The prevalence of dementia in Madrid was estimated based on the dose per 100 inhabitants/day, adjusting the result for data obtained from BIFAP on combination treatment in the general population (0.37%) and the percentage of dementia patients undergoing treatment (41.13%). Cholinesterase inhibitors and memantine were taken by 2.08% and 0.72% of Madrid residents aged 65 and older was respectively. Both databases displayed similar results for use of these drugs. The estimated prevalence of dementia in individuals aged 65 and older is 5.91% (95% CI%, 5.85-5.95) (52 287 people), and it is higher in women (7.16%) than in men (4.00%). The estimated prevalence of dementia is similar to that found in population-based studies. Analysing consumption of specific dementia drugs can be a reliable and inexpensive means of updating prevalence data periodically and helping rationalise healthcare resources. Copyright © 2014 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

Combined treatment of methylprednisolone pulse and memantine hydrochloride prompts recovery from neurological dysfunction and cerebral hypoperfusion in carbon monoxide poisoning: a case report.

PubMed

Iwamoto, Konosuke; Ikeda, Ken; Mizumura, Sunao; Tachiki, Kazuhiro; Yanagihashi, Masaru; Iwasaki, Yasuo

2014-03-01

A 49-year-old healthy man developed sudden unconsciousness under inadequate ventilation. Blood gas analysis showed carboxyhemoglobin of 7.3%. After normobaric oxygen therapy, he recovered completely 7 days later. At 3 weeks after carbon monoxide (CO) exposures, memory and gait disturbances appeared. Neurological examination revealed Mini-Mental State Examination (MMSE) score of 5 of 30 points, leg hyper-reflexia with Babinski signs, and Parkinsonism. Brain fluid-attenuated inversion recovery imaging disclosed symmetric hypointense lesions in the thalamus and the globus pallidus, and hyperintense lesions in the cerebral white matter. Brain single-photon emission tomography (SPECT) scanning with (99m)Technesium-ethyl cysteinate dimer displayed marked hypoperfusion in the cerebellum, the thalamus, the basal ganglia, and the entire cerebral cortex. He was diagnosed as CO poisoning and treated with hyperbaric oxygen therapy. The neurological deficits were not ameliorated. At 9 weeks after neurological onset, methylprednisolone (1000 mg/day, intravenous, 3 days) and memantine hydrochloride (20 mg/day, per os) were administered. Three days later, MMSE score was increased from 3 to 20 points. Neurological examination was normal 3 weeks later. Brain SPECT exhibited 20% increase of regional cerebral blood flows in the cerebellum, the thalamus, the basal ganglia, and the entire cerebral cortex. These clinicoradiological changes supported that the treatment with steroid pulse and memantine hydrochloride could prompt recovery from neurological dysfunction and cerebral hypoperfusion. Further clinical trials are warranted whether such combined therapy can attenuate neurological deficits and cerebral hypoperfusion in patients with CO poisoning. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Common influences of non-competitive NMDA receptor antagonists on the consolidation and reconsolidation of cocaine-cue memory.

PubMed

Alaghband, Yasaman; Marshall, John F

2013-04-01

Environmental stimuli or contexts previously associated with rewarding drugs contribute importantly to relapse among addicts, and research has focused on neurobiological processes maintaining those memories. Much research shows contributions of cell surface receptors and intracellular signaling pathways in maintaining associations between rewarding drugs (e.g., cocaine) and concurrent cues/contexts; these memories can be degraded at the time of their retrieval through reconsolidation interference. Much less studied is the consolidation of drug-cue memories during their acquisition. The present experiments use the cocaine-conditioned place preference (CPP) paradigm in rats to directly compare, in a consistent setting, the effects of N-methyl-D-aspartate (NMDA) glutamate receptor antagonists MK-801 and memantine on the consolidation and reconsolidation of cocaine-cue memories. For the consolidation studies, animals were systemically administered MK-801 or memantine immediately following training sessions. To investigate the effects of these NMDA receptor antagonists on the retention of previously established cocaine-cue memories, animals were systemically administered MK-801 or memantine immediately after memory retrieval. Animals given either NMDA receptor antagonist immediately following training sessions did not establish a preference for the cocaine-paired compartment. Post-retrieval administration of either NMDA receptor antagonist attenuated the animals' preference for the cocaine-paired compartment. Furthermore, animals given NMDA receptor antagonists post-retrieval showed a blunted response to cocaine-primed reinstatement. Using two distinct NMDA receptor antagonists in a common setting, these findings demonstrate that NMDA receptor-dependent processes contribute both to the consolidation and reconsolidation of cocaine-cue memories, and they point to the potential utility of treatments that interfere with drug-cue memory reconsolidation.

Effectiveness of Anti-Dementia Drugs in Extremely Severe Alzheimer's Disease: A 12-Week, Multicenter, Randomized, Single-Blind Study.

PubMed

Hong, Yun Jeong; Choi, Seong Hye; Jeong, Jee Hyang; Park, Kyung Won; Na, Hae Ri

2018-01-01

There is insufficient evidence to guide decisions concerning how long anti-dementia drug (ADD) regimens should be maintained in severe Alzheimer's disease (AD). We investigated whether patients with extremely severe AD who were already receiving donepezil or memantine benefited from continuing treatment. In this randomized and rater-blinded trial, 65 AD patients with a Mini-Mental State Examination score from 0 to 5 and a score of 6c or worse on Functional Assessment Staging were randomly assigned to an ADD-continuation group (N = 30) or an ADD-discontinuation group (N = 35). The current use of donepezil or memantine was maintained for 12 weeks in the ADD-continuation group and was discontinued after baseline in the ADD-discontinuation group. Efficacy measures were obtained at baseline and 12 weeks. The primary efficacy variable was the change from baseline to the end of the study in Baylor Profound Mental State Examination (BPMSE) scores. The change in the BPMSE from baseline to the end of the study in the ADD-continuation group (a 0.4-point improvement) was not equivalent to that in the ADD-discontinuation group (a 0.5-point decline), as determined by two one-sided tests of equivalence. Study withdrawals due to adverse events (11.4% versus 6.7%) were more frequent in the ADD-discontinuation group than in the ADD-continuation group. Continued treatment with donepezil or memantine seems unequal and might be superior to withdrawal of the drugs in terms of the effects on global cognition in patients with extremely severe AD. Current Controlled Trials number: KCT0000874 (CRIS).

False recognition in a mouse model of Alzheimer’s disease: rescue with sensory restriction and memantine

PubMed Central

McTighe, Stephanie M.; Heath, Christopher J.; Whitcomb, Daniel J.; Cho, Kwangwook; Bussey, Timothy J.; Saksida, Lisa M.

2012-01-01

Alzheimer’s disease is commonly regarded as a loss of memory for past events. However, patients with Alzheimer’s disease seem not only to forget events but also to express false confidence in remembering events that have never happened. How and why false recognition occurs in such patients is currently unknown, and treatments targeting this specific mnemonic abnormality have not been attempted. Here, we used a modified object recognition paradigm to show that the tgCRND8 mouse—which overexpresses amyloid β and develops amyloid plaques similar to those in the brains of patients with Alzheimer’s disease—exhibits false recognition. Furthermore, we found that false recognition did not occur when tgCRND8 mice were kept in a dark, quiet chamber during the delay, paralleling previous findings in patients with mild cognitive impairment, which is often considered to be prodromal Alzheimer’s disease. Additionally, false recognition did not occur when mice were treated with the partial N-methyl-d-aspartic acid receptor antagonist memantine. In a subsequent experiment, we found abnormally enhanced N-methyl-d-aspartic acid receptor-dependent long-term depression in these mice, which could be normalized by treatment with memantine. We suggest that Alzheimer’s disease typical amyloid β pathology leads to aberrant synaptic plasticity, thereby making memory representations more susceptible to interfering sensory input, thus increasing the likelihood of false recognition. Parallels between these findings and those from the literature on Alzheimer’s disease and mild cognitive impairment suggest a mechanism underlying false recognition in these patients. The false recognition phenomenon may provide a novel paradigm for the discovery of potential therapies to treat the mnemonic dysfunction characteristic of this disease. PMID:22466291

Combining galantamine and memantine in multitargeted, new chemical entities potentially useful in Alzheimer's disease.

PubMed

Simoni, Elena; Daniele, Simona; Bottegoni, Giovanni; Pizzirani, Daniela; Trincavelli, Maria L; Goldoni, Luca; Tarozzo, Glauco; Reggiani, Angelo; Martini, Claudia; Piomelli, Daniele; Melchiorre, Carlo; Rosini, Michela; Cavalli, Andrea

2012-11-26

Herein we report on a novel series of multitargeted compounds obtained by linking together galantamine and memantine. The compounds were designed by taking advantage of the crystal structures of acetylcholinesterase (AChE) in complex with galantamine derivatives. Sixteen novel derivatives were synthesized, using spacers of different lengths and chemical composition. The molecules were then tested as inhibitors of AChE and as binders of the N-methyl-d-aspartate (NMDA) receptor (NMDAR). Some of the new compounds were nanomolar inhibitors of AChE and showed micromolar affinities for NMDAR. All compounds were also tested for selectivity toward NMDAR containing the 2B subunit (NR2B). Some of the new derivatives showed a micromolar affinity for NR2B. Finally, selected compounds were tested using a cell-based assay to measure their neuroprotective activity. Three of them showed a remarkable neuroprotective profile, inhibiting the NMDA-induced neurotoxicity at subnanomolar concentrations (e.g., 5, named memagal, IC(50) = 0.28 nM).

Anticonvulsant Effects of Memantine and MK-801 in Guinea Pig Hippocampal Neurons.

DTIC Science & Technology

investigation we compared the anticonvulsant properties of Mem to those of MK-801 in guinea pig hippocampal slices. Extracellular recordings were...obtained from area CA1 of guinea pig hippocampal slices in a total submersion chamber at 32 deg C in normal oxygenated artificial cerebrospinal fluid (ACSF

Combination Therapy with Cholinesterase Inhibitors and Memantine for Alzheimer’s Disease: A Systematic Review and Meta-Analysis

PubMed Central

Kishi, Taro; Iwata, Nakao

2015-01-01

Background: We performed an updated meta-analysis of randomized controlled trials of combination therapy with cholinesterase inhibitors and memantine in patients with Alzheimer’s disease. Methods: We reviewed cognitive function, activities of daily living, behavioral disturbance, global assessment, discontinuation rate, and individual side effects. Results: Seven studies (total n=2182) were identified. Combination therapy significantly affected behavioral disturbance scores (standardized mean difference=−0.13), activity of daily living scores (standardized mean difference=−0.10), and global assessment scores (standardized mean difference=−0.15). In addition, cognitive function scores (standardized mean difference=−0.13, P=.06) exhibited favorable trends with combination therapy. The effects of combination therapy were more significant in the moderate-to-severe Alzheimer’s disease subgroup in terms of all efficacy outcome scores. The discontinuation rate was similar in both groups, and there were no significant differences in individual side effects. Conclusions: Combination therapy was beneficial for the treatment of moderate-to-severe Alzheimer’s disease in terms of cognition, behavioral disturbances, activities of daily living, and global assessment was well tolerated. PMID:25548104

Combination therapy with cholinesterase inhibitors and memantine for Alzheimer's disease: a systematic review and meta-analysis.

PubMed

Matsunaga, Shinji; Kishi, Taro; Iwata, Nakao

2014-12-28

We performed an updated meta-analysis of randomized controlled trials of combination therapy with cholinesterase inhibitors and memantine in patients with Alzheimer's disease. We reviewed cognitive function, activities of daily living, behavioral disturbance, global assessment, discontinuation rate, and individual side effects. Seven studies (total n=2182) were identified. Combination therapy significantly affected behavioral disturbance scores (standardized mean difference=-0.13), activity of daily living scores (standardized mean difference=-0.10), and global assessment scores (standardized mean difference=-0.15). In addition, cognitive function scores (standardized mean difference=-0.13, P=.06) exhibited favorable trends with combination therapy. The effects of combination therapy were more significant in the moderate-to-severe Alzheimer's disease subgroup in terms of all efficacy outcome scores. The discontinuation rate was similar in both groups, and there were no significant differences in individual side effects. Combination therapy was beneficial for the treatment of moderate-to-severe Alzheimer's disease in terms of cognition, behavioral disturbances, activities of daily living, and global assessment was well tolerated. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Combined use of Pregabalin and Memantine in Fibromyalgia Syndrome Treatment: A Novel Analgesic and Neuroprotective Strategy?

PubMed Central

Recla, Jill M.; Sarantopoulos, Constantine D.

2009-01-01

Fibromyalgia syndrome (FMS) is a chronic widespread pain syndrome that is estimated to affect 4 to 8 million U.S. adults. The exact molecular mechanisms underlying this illness remain unclear, rendering most clinical treatment and management techniques relatively ineffective. It is now known that abnormalities in both nociceptive and central pain processing systems are necessary (but perhaps not sufficient) to condition the onset and maintenance of FMS. These same systemic abnormalities are thought to be responsible for the loss of cephalic gray matter density observed in all FMS patients groups studied to date. The current scope of FMS treatment focuses largely on analgesia and does not clearly address potential neuroprotective strategies. This article proposes a combined treatment of pregabalin and memantine to decrease the pain and rate of gray matter atrophy associated with FMS. This dual-drug therapy targets the voltage-gated calcium ion channel (VGCC) and the N-methyl D-aspartate receptor (NMDAR) (respectively), two primary components of the human nociceptive and pain processing systems. PMID:19362430

Alzheimer's disease, β-amyloid, glutamate, NMDA receptors and memantine – searching for the connections

PubMed Central

Danysz, Wojciech; Parsons, Chris G

2012-01-01

β-amyloid (Aβ) is widely accepted to be one of the major pathomechanisms underlying Alzheimer's disease (AD), although there is presently lively debate regarding the relative roles of particular species/forms of this peptide. Most recent evidence indicates that soluble oligomers rather than plaques are the major cause of synaptic dysfunction and ultimately neurodegeneration. Soluble oligomeric Aβ has been shown to interact with several proteins, for example glutamatergic receptors of the NMDA type and proteins responsible for maintaining glutamate homeostasis such as uptake and release. As NMDA receptors are critically involved in neuronal plasticity including learning and memory, we felt that it would be valuable to provide an up to date review of the evidence connecting Aβ to these receptors and related neuronal plasticity. Strong support for the clinical relevance of such interactions is provided by the NMDA receptor antagonist memantine. This substance is the only NMDA receptor antagonist used clinically in the treatment of AD and therefore offers an excellent tool to facilitate translational extrapolations from in vitro studies through in vivo animal experiments to its ultimate clinical utility. PMID:22646481

Neuronal oxidative injury and dendritic damage induced by carbofuran: Protection by memantine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Ramesh C.; Milatovic, Snjezana; Dettbarn, Wolf-D.

Carbamate insecticides mediate their neurotoxicity by acetylcholinesterase (AChE) inactivation. Male Sprague-Dawley rats acutely intoxicated with the carbamate insecticide carbofuran (1.5 mg/kg, sc) developed hypercholinergic signs within 5-7 min of exposure, with maximal severity characterized by seizures within 30-60 min, lasting for about 2 h. At the time of peak severity, compared with controls, AChE was maximally inhibited (by 82-90%), radical oxygen species (ROS) markers (F{sub 2}-isoprostanes, F{sub 2}-IsoPs; and F{sub 4}-neuroprostanes, F{sub 4}-NeuroPs) were elevated 2- to 3-fold, and the radical nitrogen species (RNS) marker citrulline was elevated 4- to 8-fold in discrete brain regions (cortex, amygdala, and hippocampus). Inmore » addition, levels of high-energy phosphates (HEPs) were significantly reduced (ATP, by 43-56%; and phosphocreatine, by 37-48%). Values of total adenine nucleotides and total creatine compounds declined markedly (by 41-56% and 35-45%, respectively), while energy charge potential remained unchanged. Quantitative morphometric analysis of pyramidal neurons of the hippocampal CA1 region revealed significant decreases in dendritic lengths (by 64%) and spine density (by 60%). Pretreatment with the N-methyl-D-aspartate (NMDA) receptor antagonist memantine (18 mg/kg, sc), in combination with atropine sulfate (16 mg/kg, sc), significantly attenuated carbofuran-induced changes in AChE activity and levels of F{sub 2}-IsoPs and F{sub 4}-NeuroPs, declines in HEPs, as well as the alterations in morphology of hippocampal neurons. MEM and ATS pretreatment also protected rats from carbofuran-induced hypercholinergic behavioral activity, including seizures. These findings support the involvement of ROS and RNS in seizure-induced neuronal injury and suggest that memantine by preventing carbofuran-induced neuronal hyperactivity blocks pathways associated with oxidative damage in neurons.« less

Delayed preconditioning with NMDA receptor antagonists in a rat model of perinatal asphyxia.

PubMed

Makarewicz, Dorota; Sulejczak, Dorota; Duszczyk, Małgorzata; Małek, Michał; Słomka, Marta; Lazarewicz, Jerzy W

2014-01-01

In vitro experiments have demonstrated that preconditioning primary neuronal cultures by temporary application of NMDA receptor antagonists induces long-term tolerance against lethal insults. In the present study we tested whether similar effects also occur in brain submitted to ischemia in vivo and whether the potential benefit outweighs the danger of enhancing the constitutive apoptosis in the developing brain. Memantine in pharmacologically relevant doses of 5 mg/kg or (+)MK-801 (3 mg/kg) was administered i.p. 24, 48, 72 and 96 h before 3-min global forebrain ischemia in adult Mongolian gerbils or prior to hypoxia/ischemia in 7-day-old rats. Neuronal loss in the hippocampal CA1 in gerbils or weight deficit of the ischemic hemispheres in the rat pups was evaluated after 14 days. Also, the number of apoptotic neurons in the immature rat brain was evaluated. In gerbils only the application of (+)MK-801 24 h before ischemia resulted in significant prevention of the loss of pyramidal neurons. In rat pups administration of (+)MK-801 at all studied times before hypoxia-ischemia, or pretreatment with memantine or with hypoxia taken as a positive control 48 to 92 h before the insult, significantly reduced brain damage. Both NMDA receptor antagonists equally reduced the number of apoptotic neurons after hypoxia-ischemia, while (+)MK-801-evoked potentiation of constitutive apoptosis greatly exceeded the effect of memantine. We ascribe neuroprotection induced in the immature rats by the pretreatment with both NMDA receptor antagonists 48 to 92 h before hypoxia-ischemia to tolerance evoked by preconditioning, while the neuroprotective effect of (+)MK-801 applied 24 h before the insults may be attributed to direct consequences of the inhibition of NMDA receptors. This is the first report demonstrating the phenomenon of inducing tolerance against hypoxia-ischemia in vivo in developing rat brain by preconditioning with NMDA receptor antagonists.

Simultaneous determination of antidementia drugs in human plasma: procedure transfer from HPLC-MS to UPLC-MS/MS.

PubMed

Noetzli, Muriel; Ansermot, Nicolas; Dobrinas, Maria; Eap, Chin B

2012-05-01

A previously developed high performance liquid chromatography mass spectrometry (HPLC-MS) procedure for the simultaneous determination of antidementia drugs, including donepezil, galantamine, memantine, rivastigmine and its metabolite NAP 226-90, was transferred to an ultra performance liquid chromatography system coupled to a tandem mass spectrometer (UPLC-MS/MS). The drugs and their internal standards ([(2)H(7)]-donepezil, [(13)C,(2)H(3)]-galantamine, [(13)C(2),(2)H(6)]-memantine, [(2)H(6)]-rivastigmine) were extracted from 250 μL human plasma by protein precipitation with acetonitrile. Chromatographic separation was achieved on a reverse phase column (BEH C18 2.1 mm × 50 mm; 1.7 μm) with a gradient elution of an ammonium acetate buffer at pH 9.3 and acetonitrile at a flow rate of 0.4 mL/min and an overall run time of 4.5 min. The analytes were detected on a tandem quadrupole mass spectrometer operated in positive electrospray ionization mode, and quantification was performed using multiple reaction monitoring. The method was validated according to the recommendations of international guidelines over a calibration range of 1-300 ng/mL for donepezil, galantamine and memantine, and 0.2-50 ng/mL for rivastimgine and NAP 226-90. The trueness (86-108%), repeatability (0.8-8.3%), intermediate precision (2.3-10.9%) and selectivity of the method were found to be satisfactory. Matrix effects variability was inferior to 15% for the analytes and inferior to 5% after correction by internal standards. A method comparison was performed with patients' samples showing similar results between the HPLC-MS and UPLC-MS/MS procedures. Thus, this validated UPLC-MS/MS method allows to reduce the required amount of plasma, to use a simplified sample preparation, and to obtain a higher sensitivity and specificity with a much shortened run-time. Copyright © 2012 Elsevier B.V. All rights reserved.

[Treatment pattern of Alzheimer's disease with cholinesterase inhibitors (TRAIN study)].

PubMed

Gil-Néciga, E; Gobartt, A L

To describe the relation between the level of cognitive impairment in Alzheimer's disease and the use of cholinesterase inhibitors (ChEIs) in neurology, geriatric and psychiatric units, and to establish the clinical profile of these patients. An epidemiological, multi-centre, cross-sectional study was conducted. Subjects included in the study were consecutive outpatients diagnosed with Alzheimer's disease, in accordance with the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, and who had been treated with rivastigmine, donepezil or galantamine, either on its own or in association with memantine in the last six months. The recruitment period lasted three months. In a single visit, researchers determined the medication that was used, the dose, the mini-mental test, the overall clinical impression-overall improvement and the overall clinical impression-severity of the disease. A total of 1940 patients were selected from neurology, psychiatric and geriatric services all over the country. Possible differences in the habits of different specialists as regards prescribing were analysed, together with the relation between cognitive impairment and the type of medication employed. The mean age of the patients was 77 +/- 6.6 years, 62% of whom were females; the mean score on the mini-mental test was 17.4 +/- 5.5. The mini-mental score was similar in patients treated with rivastigmine (18.02 +/- 5.23), donepezil (17.08 +/- 5.54) or galantamine (17.34 +/- 5.38). In patients who were treated with memantine in association with a ChEI, the mini-mental score was significantly lower (11.44 +/- 5.68) (p < 0.0001). The doses of the different ChEIs used by the specialists were similar. A higher percentage of patients had maximum doses of donepezil (81%) than in the cases of rivastigmine (43%) and galantamine (67%). The different specialists involved (neurologists, geriatricians and psychiatrists) displayed similar habits regarding the utilisation of ChEIs to treat Alzheimer's disease. There was no relation between the degree of impairment and the drug chosen, except in the case of memantine.

[The role of dosed walking in the combination with elements of cognitive training in the comprehensive treatment of the patients presenting with Alzheimer's disease].

PubMed

Zimushkina, N A; Kosareva, P V; Cherkasova, V G

The objective of the present study was to evaluate the effectiveness of dosed physical exercises for the combined treatment of the patients presenting with mild to moderate dementia associated with Alzheimer's disease (AD). The comprehensive examination involved 41 patients (32 women and 9 men) with the confirmed diagnosis of 'probable' AD with stages 1 and 2 of dementia and 17 healthy volunteers comprising the group of comparison. In all the patients, the neurological examination was supplemented by neuropsychological testing. Two treatment modalities were applied, one being conventional therapy with the use of memantine at the average effective dose, the other with the combination of memantine and dosed physical exercises including elements of cognitive training. In the group of patients treated with memantine alone, changes in cognitive performances among the men did not suggest any statistically significant positive trendency whereas the results of estimation in the women based on the clock drawing test (CDT) and the Mini-Mental State Examination (MMSE) scores revealed the significant improvement of cognitive performances. The most pronounced effects were documented in the women who had received combined therapy with the inclusion of dosed physical exercises in the form of walking. The comparison of the results of the treatment with observations of the patients included in the comparison group demonstrated the improvement of frontal cognitive functioning in the patients of both sexes under the influence of the combined treatment which manifested itself as the absence of the statistically significant differences between the results of the evaluation based on the Frontal Assessment Battery (FAB) scale. The prescription of dosed physical exercises with elements of cognitive training to be applied for the treatment of the patients presenting with dementia of different severity associated with Alzheimer's disease makes it possible to optimize the outcome of the conventional medical treatment and thereby to improve the results of scoring assessments of cognitive performances based on the MMSE, FAB, and CDT scales.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaja-Milatovic, Snjezana; Gupta, Ramesh C.; Aschner, Michael

Prophylactic agents acutely administered in response to anticholinesterases intoxication can prevent toxic symptoms, including fasciculations, seizures, convulsions and death. However, anticholinesterases also have long-term unknown pathophysiological effects, making rational prophylaxis/treatment problematic. Increasing evidence suggests that in addition to excessive cholinergic stimulation, organophosphate compounds such as diisopropylphosphorofluoridate (DFP) induce activation of glutamatergic neurons, generation of reactive oxygen (ROS) and nitrogen species (RNS), leading to neurodegeneration. The present study investigated multiple affectors of DFP exposure critical to cerebral oxidative damage and whether antioxidants and NMDA receptor antagonist memantine provide neuroprotection by preventing DFP-induced biochemical and morphometric changes in rat brain. Rats treatedmore » acutely with DFP (1.25 mg/kg, s.c.) developed onset of toxicity signs within 7-15 min that progressed to maximal severity of seizures and fasciculations within 60 min. At this time point, DFP caused significant (p < 0.01) increases in biomarkers of ROS (F{sub 2}-isoprostanes, F{sub 2}-IsoPs; and F{sub 4}-neuroprostanes, F{sub 4}-NeuroPs), RNS (citrulline), and declines in high-energy phosphates (HEP) in rat cerebrum. At the same time, quantitative morphometric analysis of pyramidal neurons of the hippocampal CA1 region revealed significant (p < 0.01) reductions in dendritic lengths and spine density. When rats were pretreated with the antioxidants N-tert-butyl-{alpha}-phenylnitrone (PBN, 200 mg/kg, i.p.), or vitamin E (100 mg/kg, i.p./day for 3 days), or memantine (18 mg/kg, i.p.), significant attenuations in DFP-induced increases in F{sub 2}-IsoPs, F{sub 4}-NeuroPs, citrulline, and depletion of HEP were noted. Furthermore, attenuation in oxidative damage following antioxidants or memantine pretreatment was accompanied by rescue from dendritic degeneration of pyramidal neurons in the CA1 hippocampal area. These findings closely associated DFP-induced lipid peroxidation with dendritic degeneration of pyramidal neurons in the CA1 hippocampal area and point to possible interventions to limit oxidative injury and dendritic degeneration induced by anticholinesterase neurotoxicity.« less

The Development and Validation of Novel, Simple High-Performance Liquid Chromatographic Method with Refractive Index Detector for Quantification of Memantine Hydrochloride in Dissolution Samples.

PubMed

Sawant, Tukaram B; Wakchaure, Vikas S; Rakibe, Udyakumar K; Musmade, Prashant B; Chaudhari, Bhata R; Mane, Dhananjay V

2017-07-01

The present study was aimed to develop an analytical method for quantification of memantine (MEM) hydrochloride in dissolution samples using high-performance liquid chromatography with refractive index (RI) detector. The chromatographic separation was achieved on C18 (250 × 4.5 mm, 5 μm) column using isocratic mobile phase comprises of buffer (pH 5.2):methanol (40:60 v/v) pumped at a flow rate of 1.0 mL/min. The column effluents were monitored using RI detector. The retention time of MEM was found to be ~6.5 ± 0.3 min. The developed chromatographic method was validated and found to be linear over the concentration range of 5.0-45.0 μg/mL for MEM. Mean recovery of MEM was found to be 99.2 ± 0.5% (w/w). The method was found to be simple, fast, precise and accurate, which can be utilized for the quantification of MEM in dissolution samples. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Repositioning of Memantine as a Potential Novel Therapeutic Agent against Meningitic E. coli–Induced Pathogenicities through Disease-Associated Alpha7 Cholinergic Pathway and RNA Sequencing-Based Transcriptome Analysis of Host Inflammatory Responses

PubMed Central

Peng, Liang; Wu, Chun-Hua; Cao, Hong; Zhong, John F.; Hoffman, Jill; Huang, Sheng-He

2015-01-01

Neonatal sepsis and meningitis (NSM) remains a leading cause worldwide of mortality and morbidity in newborn infants despite the availability of antibiotics over the last several decades. E. coli is the most common gram-negative pathogen causing NSM. Our previous studies show that α7 nicotinic receptor (α7 nAChR), an essential regulator of inflammation, plays a detrimental role in the host defense against NSM. Despite notable successes, there still exists an unmet need for new effective therapeutic approaches to treat this disease. Using the in vitro/in vivo models of the blood-brain barrier (BBB) and RNA-seq, we undertook a drug repositioning study to identify unknown antimicrobial activities for known drugs. We have demonstrated for the first time that memantine (MEM), a FDA-approved drug for treatment of Alzheimer’s disease, could very efficiently block E. coli-caused bacteremia and meningitis in a mouse model of NSM in a manner dependent on α7 nAChR. MEM was able to synergistically enhance the antibacterial activity of ampicillin in HBMEC infected with E. coli K1 (E44) and in neonatal mice with E44-caused bacteremia and meningitis. Differential gene expression analysis of RNA-Seq data from mouse BMEC infected with E. coli K1 showed that several E44-increased inflammatory factors, including IL33, IL18rap, MMP10 and Irs1, were significantly reduced by MEM compared to the infected cells without drug treatment. MEM could also significantly up-regulate anti-inflammatory factors, including Tnfaip3, CISH, Ptgds and Zfp36. Most interestingly, these factors may positively and negatively contribute to regulation of NF-κB, which is a hallmark feature of bacterial meningitis. Furthermore, we have demonstrated that circulating BMEC (cBMEC) are the potential novel biomarkers for NSM. MEM could significantly reduce E44-increased blood level of cBMEC in mice. Taken together, our data suggest that memantine can efficiently block host inflammatory responses to bacterial infection through modulation of both inflammatory and anti-inflammatory pathways. PMID:25993608

Repositioning of Memantine as a Potential Novel Therapeutic Agent against Meningitic E. coli-Induced Pathogenicities through Disease-Associated Alpha7 Cholinergic Pathway and RNA Sequencing-Based Transcriptome Analysis of Host Inflammatory Responses.

PubMed

Yu, Jing-Yi; Zhang, Bao; Peng, Liang; Wu, Chun-Hua; Cao, Hong; Zhong, John F; Hoffman, Jill; Huang, Sheng-He

2015-01-01

Neonatal sepsis and meningitis (NSM) remains a leading cause worldwide of mortality and morbidity in newborn infants despite the availability of antibiotics over the last several decades. E. coli is the most common gram-negative pathogen causing NSM. Our previous studies show that α7 nicotinic receptor (α7 nAChR), an essential regulator of inflammation, plays a detrimental role in the host defense against NSM. Despite notable successes, there still exists an unmet need for new effective therapeutic approaches to treat this disease. Using the in vitro/in vivo models of the blood-brain barrier (BBB) and RNA-seq, we undertook a drug repositioning study to identify unknown antimicrobial activities for known drugs. We have demonstrated for the first time that memantine (MEM), a FDA-approved drug for treatment of Alzheimer's disease, could very efficiently block E. coli-caused bacteremia and meningitis in a mouse model of NSM in a manner dependent on α7 nAChR. MEM was able to synergistically enhance the antibacterial activity of ampicillin in HBMEC infected with E. coli K1 (E44) and in neonatal mice with E44-caused bacteremia and meningitis. Differential gene expression analysis of RNA-Seq data from mouse BMEC infected with E. coli K1 showed that several E44-increased inflammatory factors, including IL33, IL18rap, MMP10 and Irs1, were significantly reduced by MEM compared to the infected cells without drug treatment. MEM could also significantly up-regulate anti-inflammatory factors, including Tnfaip3, CISH, Ptgds and Zfp36. Most interestingly, these factors may positively and negatively contribute to regulation of NF-κB, which is a hallmark feature of bacterial meningitis. Furthermore, we have demonstrated that circulating BMEC (cBMEC) are the potential novel biomarkers for NSM. MEM could significantly reduce E44-increased blood level of cBMEC in mice. Taken together, our data suggest that memantine can efficiently block host inflammatory responses to bacterial infection through modulation of both inflammatory and anti-inflammatory pathways.

Inhibition of NMDA Receptors Prevents the Loss of BDNF Function Induced by Amyloid β.

PubMed

Tanqueiro, Sara R; Ramalho, Rita M; Rodrigues, Tiago M; Lopes, Luísa V; Sebastião, Ana M; Diógenes, Maria J

2018-01-01

Brain-derived neurotrophic factor (BDNF) plays important functions in cell survival and differentiation, neuronal outgrowth and plasticity. In Alzheimer's disease (AD), BDNF signaling is known to be impaired, partially because amyloid β (Aβ) induces truncation of BDNF main receptor, TrkB-full length (TrkB-FL). We have previously shown that such truncation is mediated by calpains, results in the formation of an intracellular domain (ICD) fragment and causes BDNF loss of function. Since calpains are Ca 2+ -dependent proteases, we hypothesized that excessive intracellular Ca 2+ build-up could be due to dysfunctional N-methyl-d-aspartate receptors (NMDARs) activation. To experimentally address this hypothesis, we investigated whether TrkB-FL truncation by calpains and consequent BDNF loss of function could be prevented by NMDAR blockade. We herein demonstrate that a NMDAR antagonist, memantine, prevented excessive calpain activation and TrkB-FL truncation induced by Aβ 25-35 . When calpains were inhibited by calpastatin, BDNF was able to increase the dendritic spine density of neurons exposed to Aβ 25135 . Moreover, NMDAR inhibition by memantine also prevented Aβ-driven deleterious impact of BDNF loss of function on structural (spine density) and functional outcomes (synaptic potentiation). Collectively, these findings support NMDAR/Ca 2+ /calpains mechanistic involvement in Aβ-triggered BDNF signaling disruption.

Dementia drug consumption in the Basque Country between 2006 and 2011.

PubMed

Villanueva, G; López de Argumedo, M; Elizondo, I

We evaluated the consumption of specific medications for treating cognitive symptoms associated with AD and other types of dementia in individuals over 60 years of age between 2006 and 2011 in the Basque Country. A retrospective descriptive study was conducted. The pharmacy division of the Basque Government Department of Health provided the prescribing data for the following drugs: donepezil, rivastigmine, galantamine, and memantine. The number of defined daily doses (DDDs) and the number of DDDs per 1000 inhabitants/day (DHD) were calculated. Consumption increased by 49.72% between 2006 and 2011. There were marked differences between drugs (13.02% donepezil; 93.18% rivastigmine; 37.79% galantamine; 70.40% memantine) and Basque provinces (16.34% in Áraba; 50.49% in Bizkaia; 57.37% in Gipuzkoa). Likewise, expenditure increased from €11.5 million in 2006 to € 18.1 million in 2011. This study shows increased consumption of these drugs, although there are also marked differences by province which may be due to differences in prescribing habits. Spending for these drugs rose parallel to this increase in consumption; drug prices remained stable throughout the study period. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

GRIN2B encephalopathy: novel findings on phenotype, variant clustering, functional consequences and treatment aspects

PubMed Central

Platzer, Konrad; Yuan, Hongjie; Schütz, Hannah; Winschel, Alexander; Chen, Wenjuan; Hu, Chun; Kusumoto, Hirofumi; Heyne, Henrike O; Helbig, Katherine L; Tang, Sha; Willing, Marcia C; Tinkle, Brad T; Adams, Darius J; Depienne, Christel; Keren, Boris; Mignot, Cyril; Frengen, Eirik; Strømme, Petter; Biskup, Saskia; Döcker, Dennis; Strom, Tim M; Mefford, Heather C; Myers, Candace T; Muir, Alison M; LaCroix, Amy; Sadleir, Lynette; Scheffer, Ingrid E; Brilstra, Eva; van Haelst, Mieke M; van der Smagt, Jasper J; Bok, Levinus A; Møller, Rikke S; Jensen, Uffe B; Millichap, John J; Berg, Anne T; Goldberg, Ethan M; De Bie, Isabelle; Fox, Stephanie; Major, Philippe; Jones, Julie R; Zackai, Elaine H; Jamra, Rami Abou; Rolfs, Arndt; Leventer, Richard J; Lawson, John A; Roscioli, Tony; Jansen, Floor E; Ranza, Emmanuelle; Korff, Christian M; Lehesjoki, Anna-Elina; Courage, Carolina; Linnankivi, Tarja; Smith, Douglas R; Stanley, Christine; Mintz, Mark; McKnight, Dianalee; Decker, Amy; Tan, Wen-Hann; Tarnopolsky, Mark A; Brady, Lauren I; Wolff, Markus; Dondit, Lutz; Pedro, Helio F; Parisotto, Sarah E; Jones, Kelly L; Patel, Anup D; Franz, David N; Vanzo, Rena; Marco, Elysa; Ranells, Judith D; Di Donato, Nataliya; Dobyns, William B; Laube, Bodo; Traynelis, Stephen F; Lemke, Johannes R

2017-01-01

Background We aimed for a comprehensive delineation of genetic, functional and phenotypic aspects of GRIN2B encephalopathy and explored potential prospects of personalised medicine. Methods Data of 48 individuals with de novo GRIN2B variants were collected from several diagnostic and research cohorts, as well as from 43 patients from the literature. Functional consequences and response to memantine treatment were investigated in vitro and eventually translated into patient care. Results Overall, de novo variants in 86 patients were classified as pathogenic/likely pathogenic. Patients presented with neurodevelopmental disorders and a spectrum of hypotonia, movement disorder, cortical visual impairment, cerebral volume loss and epilepsy. Six patients presented with a consistent malformation of cortical development (MCD) intermediate between tubulinopathies and polymicrogyria. Missense variants cluster in transmembrane segments and ligand-binding sites. Functional consequences of variants were diverse, revealing various potential gain-of-function and loss-of-function mechanisms and a retained sensitivity to the use-dependent blocker memantine. However, an objectifiable beneficial treatment response in the respective patients still remains to be demonstrated. Conclusions In addition to previously known features of intellectual disability, epilepsy and autism, we found evidence that GRIN2B encephalopathy is also frequently associated with movement disorder, cortical visual impairment and MCD revealing novel phenotypic consequences of channelopathies. PMID:28377535

Beyond Thiamine: Treatment for Cognitive Impairment in Korsakoff's Syndrome.

PubMed

Johnson, Justin M; Fox, Valerie

2018-03-27

Wernicke's encephalopathy is a condition whose treatment many consultation-liaison psychiatrists know quite well. Less clear, however, is the treatment of its dementia disorder descendent, the Korsakoff's syndrome (KS). This article seeks to review treatment options and provide recommendations for consultation-liaison psychiatrists treating cognitive impairment in KS. In this nonsystematic review, we reviewed PubMed, CINAHL Plus, and Google Scholar for published reports and studies regarding treatment of KS. The literature revealed case reports and placebo-controlled trials of various medications for treatment of KS, though the samples sizes were small and were mostly case reports. There is more attention devoted toward medications used in other dementia disorders, such as donepezil and memantine. The literature revealed more studies around behavioral interventions recommended for treatment of memory impairment in KS and they focused on cognitive remediation and environmental adaptation, such as the use of PDAs or alarms. There is no single, well-studied intervention proven effective as a primary treatment for cognitive impairment in KS. An approach of using environmental modifications in a well-structured living environment, combined with various cognitive interventions, such as pictorial associations, and perhaps a trial of donepezil or memantine, likely represents the best strategy for treating long-term cognitive impairment in KS. Published by Elsevier Inc.

Decrement in operant performance produced by NMDA receptor antagonists in the rat: tolerance and cross-tolerance.

PubMed

Dravolina, O A; Zvartau, E E; Bespalov, A Y

2000-04-01

Current perspectives on the clinical use of NMDA receptor antagonists infer repeated administration schedules for the management of different pathological states. The development of tolerance and cross-tolerance between different NMDA receptor antagonists may be an important factor contributing to the clinical efficacy of these drugs. The present study aimed to characterize the development of tolerance and cross-tolerance to the ability of various site-selective NMDA receptor antagonists to produce a decrement of operant responding (multiple extinction 9 s fixed-interval 1-s schedule of water reinforcement). Acute administration of D-CPPen (SDZ EAA 494; 1-5.6 mg/kg), dizocilpine (MK-801; 0.03-0.3 mg/kg), memantine (0.3-17 mg/kg), ACEA-1021 (10-56 mg/kg), and eliprodil (1-30 mg/kg) differentially affected operant responding. Both increases and decreases in response rates and accuracy of responding were observed. Repeated preexposure to D-CPPen (5.6 mg/kg, once a day for 7 days) attenuated a behavioral disruption produced by an acute challenge with D-CPPen or ACEA-1021, but potentiated the effects of dizocilpine, memantine, and eliprodil. Based on the present results, one can suggest that the repeated administration of a competitive NMDA receptor antagonist differentially affects the functional activity of various sites on NMDA receptor complex.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deshpande, S.S.; Smith, C.D.; Filbert, M.G.

An in vitro mammalian model neuronal system to evaluate the intrinsic toxicity of soman and other neurotoxicants as well as the efficacy of potential countermeasures was investigated. The link between soman toxicity glutamate hyperactivity and neuronal death in the central nervous system was investigated in primary dissociated cell cultures from rat hippocampus and cerebral neocortex. Exposure of cortical or hippocampal neurons to glutamate for 30 min produced neuronal death in almost 80% of the cells examined at 24 h. Hippocampal neurons exposed to soman for 15-12Omin at 0.1 %M concentration caused almost complete inhibition ( > 90%) of acetylcholinesterase butmore » failed to show any evidence of effects on cell viability, indicating a lack of direct cytotoxicity by this agent. Acetylcholine (ACh, 0.1 mM), alone or in combination with soman, did not potentiate glutamate toxicity in hippocampal neurons. Memantine, a drug used for the therapy of Parkinson`s disease, spasticity and other brain disorders, significantly protected hippocampal and cortical neurons in culture against glutamate and N-methyl-D- aspartate (NN4DA) excitotoxicity. In rats a single dose of memantine (18 mg/kg) administered 1 h prior to a s.c. injection of a 0.9 LD50 dose of soman reduced the severity of convulsions and increased survival. Survival. however, was accompanied by neuronal loss in the frontal cortex, piriform cortex and hippocampus.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deshpande, S.S.; Smith, C.D.; Filbert, M.G.

An in vitro mammalian model neuronal system to evaluate the intrinsic toxicity of soman and other neurotoxicants as well as the efficacy of potential countermeasures was investigated. The link between soman toxicity, glutamate hyperactivity and neuronal death in the central nervous system was investigated in primary dissociated cell cultures from rat hippocampus and cerebral neocortex. Exposure of cortical or hippocampal neurons to glutamate for 30 min produced neuronal death in almost 800/0 of the cells examined at 24 h. Hippocampal neurons exposed to soman for 15-120 min at 0.1 ptN,concentration caused almost complete inhibition > 90% of acetylcholinesterase but failedmore » to show any evidence of effects on cell viability, indicating a lack of direct cytotoxicity by this agent. Acetylcholine (ACh, 0.1 mNI). alone or in combination with soman. did not potentiate glutamate toxicity in hippocampal neurons. Memantine, a drug used for the therapy of Parkinson`s disease, spasticity and other brain disorders. significantly protected hippocampal and cortical neurons in culture against glutamate and N-methyl-D- aspartate (NNIDA) excitotoxicity. In rats a single dose of memantine (18 mg kg) administered 1 h prior to a s.c. injection of a 0.9 LD50 dose of soman reduced the severity of convulsions and increased survival. Survival. however, was accompanied by neuronal loss in the frontal cortex, piriform cortex and hippocampus.« less

Spatial recognition test: A novel cognition task for assessing topographical memory in mice.

PubMed

Havolli, Enes; Hill, Mark Dw; Godley, Annie; Goetghebeur, Pascal Jd

2017-06-01

Dysfunction in topographical memory is a core feature of several neurological disorders. There is a large unmet medical need to address learning and memory deficits as a whole in central nervous system disease. There are considerable efforts to identify pro-cognitive compounds but current methods are either lengthy or labour intensive. Our test used a two chamber apparatus and is based on the preference of rodents to explore novel environments. It was used firstly to assess topographical memory in mice at different retention intervals (RI) and secondly to investigate the effect of three drugs reported to be beneficial for cognitive decline associated with Alzheimer's disease, namely: donepezil, memantine and levetiracetam. Animals show good memory performance at all RIs tested under four hours. At the four-hour RI, animals show a significantly poorer memory performance which can be rescued using donepezil, memantine and levetiracetam. Using this test we established and validated a spatial recognition paradigm to address topographical memory in mice by showing a decremental time-induced forgetting response and reversing this decrease in performance using pharmacological tools. The spatial recognition test differs from more commonly used visuospatial laboratory tests in both throughput capability and potentially neuroanatomical substrate. This test has the potential to be used to assess cognitive performance in transgenic animals, disease models and to screen putative cognitive enhancers or depressors.

Ketamine Protects Gamma Oscillations by Inhibiting Hippocampal LTD

PubMed Central

Huang, Lanting; Yang, Xiu-Juan; Huang, Ying; Sun, Eve Y.

2016-01-01

NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer’s disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs’ therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations. PMID:27467732

Simultaneous determination of antidementia drugs in human plasma for therapeutic drug monitoring.

PubMed

Noetzli, Muriel; Choong, Eva; Ansermot, Nicolas; Eap, Chin B

2011-04-01

A simple liquid chromatography mass spectrometry method was developed and validated for the simultaneous determination of antidementia drugs, including donepezil, galantamine, rivastigmine and its major metabolite, NAP 226-90, and memantine. A solid phase extraction procedure with a mixed-mode sorbent was used to isolate the drugs from 0.5 mL human plasma. Reverse phase chromatographic separation of the compounds was obtained with a gradient elution of an ammonium acetate buffer at pH 9.3 and acetonitrile and the analytes were detected by mass spectrometry in the single ion monitoring mode. The method was validated according to the recommendations of the Food and Drug Administration, including assessment of trueness (-8.0% to +10.7%), imprecision (repeatability: 1.1-4.9%, intermediate imprecision: 2.1-8.5%), selectivity and matrix effects variability (less than 6%) as well as short- and long-term stability in plasma. The calibration ranges were from 1 ng/mL to 300 ng/mL (rivastigmine and memantine) and 2 ng/mL to 300 ng/mL (donepezil, galantamine, and NAP 226-90). The method was successfully applied to patients' samples and might contribute to evaluate whether a therapeutic drug monitoring-guided dose adjustment of antidementia drugs could contribute to minimize the risk of adverse reactions and to increase the probability of efficient therapeutic response.

Exaggerated NMDA Mediated LTD in a Mouse Model of Down Syndrome and Pharmacological Rescuing by Memantine

ERIC Educational Resources Information Center

Scott-McKean, Jonah J.; Costa, Alberto C. S.

2011-01-01

The Ts65Dn mouse is the best-studied animal model for Down syndrome. In the experiments described here, NMDA-mediated or mGluR-mediated LTD was induced in the CA1 region of hippocampal slices from Ts65Dn and euploid control mice by bath application of 20 [mu]M NMDA for 3 min and 50 [mu]M DHPG for 5 min, respectively. We found that Ts65Dn mice…

Vascular dementia: Pharmacological treatment approaches and perspectives

PubMed Central

Baskys, Andrius; Hou, Anthony C

2007-01-01

Vascular dementia is a common condition for which there are no effective approved pharmacological treatments available. Absence of effective treatments creates a difficult situation for those suffering from the disease, their caregivers, and healthcare providers. This review will address our current understanding of the mechanisms of nerve cell damage due to ischemia and summarize available clinical trial data on several commonly used compounds including memantine, donepezil, galantamine, rivastigmine, nimodipine, hydergine, nicergoline, CDP-choline, folic acid, as well as such nonpharmacological approaches as validation therapy. PMID:18044183

Memantine for the Treatment of Dementia: A Review on its Current and Future Applications

PubMed Central

Folch, Jaume; Busquets, Oriol; Ettcheto, Miren; Sánchez-López, Elena; Castro-Torres, Ruben Dario; Verdaguer, Ester; Garcia, Maria Luisa; Olloquequi, Jordi; Casadesús, Gemma; Beas-Zarate, Carlos; Pelegri, Carme; Vilaplana, Jordi; Auladell, Carme; Camins, Antoni

2017-01-01

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the presence in the brain of extracellular amyloid-β protein (Aβ) and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. The N-Methyl-D-aspartate receptors (NMDAR), ionotropic glutamate receptor, are essential for processes like learning and memory. An excessive activation of NMDARs has been associated with neuronal loss. The discovery of extrasynaptic NMDARs provided a rational and physiological explanation between physiological and excitotoxic actions of glutamate. Memantine (MEM), an antagonist of extrasynaptic NMDAR, is currently used for the treatment of AD jointly with acetylcholinesterase inhibitors. It has been demonstrated that MEM preferentially prevents the excessive continuous extrasynaptic NMDAR disease activation and therefore prevents neuronal cell death induced by excitotoxicity without disrupting physiological synaptic activity. The problem is that MEM has shown no clear positive effects in clinical applications while, in preclinical stages, had very promising results. The data in preclinical studies suggests that MEM has a positive impact on improving AD brain neuropathology, as well as in preventing Aβ production, aggregation, or downstream neurotoxic consequences, in part through the blockade of extrasynaptic NMDAR. Thus, the focus of this review is primarily to discuss the efficacy of MEM in preclinical models of AD, consider possible combinations of this drug with others, and then evaluate possible reasons for its lack of efficacy in clinical trials. Finally, applications in other pathologies are also considered. PMID:29254093

Protection of Radial Glial-Like Cells in the Hippocampus of APP/PS1 Mice: a Novel Mechanism of Memantine in the Treatment of Alzheimer's Disease.

PubMed

Sun, Dayu; Chen, Junhua; Bao, Xiaohang; Cai, Yulong; Zhao, Jinghui; Huang, Jing; Huang, Wei; Fan, Xiaotang; Xu, Haiwei

2015-08-01

The failure of adult neurogenesis in the hippocampal dentate gyrus (DG) is closely correlated with memory decline in Alzheimer's disease (AD). Radial glial-like cells (RGLs) localized to the adult DG generate intermediate progenitor cells and immature neurons and thus contribute to adult hippocampus neurogenesis. Memantine (MEM) has been indicated to dramatically increase hippocampal neurogenesis by promoting the proliferation of RGLs. In this study, we examined the effect of MEM on the capacity for hippocampal cell proliferation and the amount of RGLs in APPswe/PS1∆E9 transgenic (APP/PS1) mice between 9 and 13 months of age. MEM could enhance hippocampal neurogenesis and increase the number of RGLs in the DG subgranular zone (DG-SGZ) of APP/PS1 mice of both ages. Moreover, MEM decreased amyloidogenesis in 13-month-old APP/PS1 mice and protected cultured radial glia cells (RGCs, L2.3 cells) from apoptosis induced by the β amyloid peptide (Aβ). Additionally, MEM inhibited microglial activation in a vertical process in DG-SGZ of APP/PS1 mice and decreased interacting with RGL processes. Reelin is involved in the proliferation of RGLs in the hippocampus, which was typically upregulated in the hippocampus of APP/PS1 mice by MEM and thought to be an active signaling pathway associated with the MEM-induced increase in RGLs. Our data suggest a previously uncharacterized role for MEM in treating AD.

Self-Organizing Feature Maps Identify Proteins Critical to Learning in a Mouse Model of Down Syndrome.

PubMed

Higuera, Clara; Gardiner, Katheleen J; Cios, Krzysztof J

2015-01-01

Down syndrome (DS) is a chromosomal abnormality (trisomy of human chromosome 21) associated with intellectual disability and affecting approximately one in 1000 live births worldwide. The overexpression of genes encoded by the extra copy of a normal chromosome in DS is believed to be sufficient to perturb normal pathways and normal responses to stimulation, causing learning and memory deficits. In this work, we have designed a strategy based on the unsupervised clustering method, Self Organizing Maps (SOM), to identify biologically important differences in protein levels in mice exposed to context fear conditioning (CFC). We analyzed expression levels of 77 proteins obtained from normal genotype control mice and from their trisomic littermates (Ts65Dn) both with and without treatment with the drug memantine. Control mice learn successfully while the trisomic mice fail, unless they are first treated with the drug, which rescues their learning ability. The SOM approach identified reduced subsets of proteins predicted to make the most critical contributions to normal learning, to failed learning and rescued learning, and provides a visual representation of the data that allows the user to extract patterns that may underlie novel biological responses to the different kinds of learning and the response to memantine. Results suggest that the application of SOM to new experimental data sets of complex protein profiles can be used to identify common critical protein responses, which in turn may aid in identifying potentially more effective drug targets.

Self-Organizing Feature Maps Identify Proteins Critical to Learning in a Mouse Model of Down Syndrome

PubMed Central

Higuera, Clara; Gardiner, Katheleen J.; Cios, Krzysztof J.

2015-01-01

Down syndrome (DS) is a chromosomal abnormality (trisomy of human chromosome 21) associated with intellectual disability and affecting approximately one in 1000 live births worldwide. The overexpression of genes encoded by the extra copy of a normal chromosome in DS is believed to be sufficient to perturb normal pathways and normal responses to stimulation, causing learning and memory deficits. In this work, we have designed a strategy based on the unsupervised clustering method, Self Organizing Maps (SOM), to identify biologically important differences in protein levels in mice exposed to context fear conditioning (CFC). We analyzed expression levels of 77 proteins obtained from normal genotype control mice and from their trisomic littermates (Ts65Dn) both with and without treatment with the drug memantine. Control mice learn successfully while the trisomic mice fail, unless they are first treated with the drug, which rescues their learning ability. The SOM approach identified reduced subsets of proteins predicted to make the most critical contributions to normal learning, to failed learning and rescued learning, and provides a visual representation of the data that allows the user to extract patterns that may underlie novel biological responses to the different kinds of learning and the response to memantine. Results suggest that the application of SOM to new experimental data sets of complex protein profiles can be used to identify common critical protein responses, which in turn may aid in identifying potentially more effective drug targets. PMID:26111164

GRIN2B encephalopathy: novel findings on phenotype, variant clustering, functional consequences and treatment aspects.

PubMed

Platzer, Konrad; Yuan, Hongjie; Schütz, Hannah; Winschel, Alexander; Chen, Wenjuan; Hu, Chun; Kusumoto, Hirofumi; Heyne, Henrike O; Helbig, Katherine L; Tang, Sha; Willing, Marcia C; Tinkle, Brad T; Adams, Darius J; Depienne, Christel; Keren, Boris; Mignot, Cyril; Frengen, Eirik; Strømme, Petter; Biskup, Saskia; Döcker, Dennis; Strom, Tim M; Mefford, Heather C; Myers, Candace T; Muir, Alison M; LaCroix, Amy; Sadleir, Lynette; Scheffer, Ingrid E; Brilstra, Eva; van Haelst, Mieke M; van der Smagt, Jasper J; Bok, Levinus A; Møller, Rikke S; Jensen, Uffe B; Millichap, John J; Berg, Anne T; Goldberg, Ethan M; De Bie, Isabelle; Fox, Stephanie; Major, Philippe; Jones, Julie R; Zackai, Elaine H; Abou Jamra, Rami; Rolfs, Arndt; Leventer, Richard J; Lawson, John A; Roscioli, Tony; Jansen, Floor E; Ranza, Emmanuelle; Korff, Christian M; Lehesjoki, Anna-Elina; Courage, Carolina; Linnankivi, Tarja; Smith, Douglas R; Stanley, Christine; Mintz, Mark; McKnight, Dianalee; Decker, Amy; Tan, Wen-Hann; Tarnopolsky, Mark A; Brady, Lauren I; Wolff, Markus; Dondit, Lutz; Pedro, Helio F; Parisotto, Sarah E; Jones, Kelly L; Patel, Anup D; Franz, David N; Vanzo, Rena; Marco, Elysa; Ranells, Judith D; Di Donato, Nataliya; Dobyns, William B; Laube, Bodo; Traynelis, Stephen F; Lemke, Johannes R

2017-07-01

We aimed for a comprehensive delineation of genetic, functional and phenotypic aspects of GRIN2B encephalopathy and explored potential prospects of personalised medicine. Data of 48 individuals with de novo GRIN2B variants were collected from several diagnostic and research cohorts, as well as from 43 patients from the literature. Functional consequences and response to memantine treatment were investigated in vitro and eventually translated into patient care. Overall, de novo variants in 86 patients were classified as pathogenic/likely pathogenic. Patients presented with neurodevelopmental disorders and a spectrum of hypotonia, movement disorder, cortical visual impairment, cerebral volume loss and epilepsy. Six patients presented with a consistent malformation of cortical development (MCD) intermediate between tubulinopathies and polymicrogyria. Missense variants cluster in transmembrane segments and ligand-binding sites. Functional consequences of variants were diverse, revealing various potential gain-of-function and loss-of-function mechanisms and a retained sensitivity to the use-dependent blocker memantine. However, an objectifiable beneficial treatment response in the respective patients still remains to be demonstrated. In addition to previously known features of intellectual disability, epilepsy and autism, we found evidence that GRIN2B encephalopathy is also frequently associated with movement disorder, cortical visual impairment and MCD revealing novel phenotypic consequences of channelopathies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Zebrafish is a predictive model for identifying compounds that protect against brain toxicity in severe acute organophosphorus intoxication.

PubMed

Faria, Melissa; Prats, Eva; Padrós, Francesc; Soares, Amadeu M V M; Raldúa, Demetrio

2017-04-01

Acute organophosphorus (OP) intoxication is a worldwide clinical and public health problem. In addition to cholinergic crisis, neurodegeneration and brain damage are hallmarks of the severe form of this toxidrome. Recently, we generated a chemical model of severe acute OP intoxication in zebrafish that is characterized by altered head morphology and brain degeneration. The pathophysiological pathways resulting in brain toxicity in this model are similar to those described in humans. The aim of this study was to assess the predictive power of this zebrafish model by testing the effect of a panel of drugs that provide protection in mammalian models. The selected drugs included "standard therapy" drugs (atropine and pralidoxime), reversible acetylcholinesterase inhibitors (huperzine A, galantamine, physostigmine and pyridostigmine), N-methyl-D-aspartate (NMDA) receptor antagonists (MK-801 and memantine), dual-function NMDA receptor and acetylcholine receptor antagonists (caramiphen and benactyzine) and anti-inflammatory drugs (dexamethasone and ibuprofen). The effects of these drugs on zebrafish survival and the prevalence of abnormal head morphology in the larvae exposed to 4 µM chlorpyrifos oxon [1 × median lethal concentration (LC 50 )] were determined. Moreover, the neuroprotective effects of pralidoxime, memantine, caramiphen and dexamethasone at the gross morphological level were confirmed by histopathological and transcriptional analyses. Our results demonstrated that the zebrafish model for severe acute OP intoxication has a high predictive value and can be used to identify new compounds that provide neuroprotection against severe acute OP intoxication.

Protective effects of melatonin and memantine in human retinal pigment epithelium (ARPE-19) cells against 2-ethylpyridine-induced oxidative stress: implications for age-related macular degeneration.

PubMed

Bardak, Handan; Uğuz, Abdülhadi Cihangir; Bardak, Yavuz

2018-06-01

To investigate the possible protective effects of melatonin and memantine (MMT) against 2-ethylpyridine (2-EP)-induced oxidative stress and mitochondrial dysfunction in human RPE (ARPE-19) cells in vitro. The ARPE-19 cells were divided into seven groups. Oxidative stress was triggered by incubating the ARPE-19 cells with 30 μM of 2-EP for 24 h. Then, 200 μM of melatonin was administered over three days and 20 μM of MMT over six hours prior to the experiment. The effects of melatonin and MMT on the intracellular calcium release mechanism, reactive oxygen species production, caspase-3 and caspase-9 activities, as well as vascular endothelial growth factor levels were measured. Melatonin and MMT were found to significantly decrease apoptosis levels. The intracellular calcium release was regulated by both melatonin and MMT. Further, melatonin and MMT significantly decreased both caspase-3 and caspase-9 activities, as well as pro-caspase and poly(ADP-ribose) polymerase expression, in ARPE-19 cells. Moreover, melatonin significantly increased the protective effect of MMT. The combination of melatonin and MMT significantly decreased 2-EP-induced oxidative toxicity and apoptosis by inhibiting the intracellular reactive oxygen species production and mitochondrial depolarization levels. These notable findings are the first to demonstrate the synergistic protective effects of melatonin and MMT against 2-EP-induced oxidative stress in ARPE-19 cells.

Validity, Significance, Strengths, Limitations, and Evidentiary Value of Real-World Clinical Data for Combination Therapy in Alzheimer's Disease: Comparison of Efficacy and Effectiveness Studies

PubMed Central

Atri, Alireza; Rountree, Susan D.; Lopez, Oscar L.; Doody, Rachelle S.

2012-01-01

Background Randomized controlled efficacy trials (RCTs), the scientific gold standard, are required for regulatory approval of Alzheimer's disease (AD) interventions, yet provide limited information regarding real-world therapeutic effectiveness. Objective: To compare the nature of evidence regarding the combination of approved AD treatments from RCTs versus long-term observational controlled studies (LTOCs). Methods Comparisons of strengths, limitations, and evidence level for monotherapy [cholinesterase inhibitor (ChEI) or memantine] and combination therapy (ChEI + memantine) in RCTs versus LTOCs. Results RCTs examined highly selected populations over months. LTOCs collected data across multiple AD stages in large populations over many years. RCTs and LTOCs show similar patterns favoring combination over monotherapy over placebo/no treatment. Long-term combination therapy compared to monotherapy reduced cognitive and functional decline and delayed time to nursing home admission. Persistent treatment was associated with slower decline. While LTOCs used control groups, adjusted for multiple covariates, had higher external validity, and favorable ethical, practical and cost considerations, their limitations included potential selection bias due to lack of placebo comparisons and randomization. Conclusions Naturalistic LTOCs provide complementary long-term level II evidence to complement level I evidence from short-term RCTs regarding therapeutic effectiveness in AD that may otherwise be unobtainable. A coordinated strategy/consortium to pool LTOC data from multiple centers to estimate long-term comparative effectiveness, risks/benefits, and costs of AD treatments is needed. PMID:22327239

In Vitro Effects of Cognitives and Nootropics on Mitochondrial Respiration and Monoamine Oxidase Activity.

PubMed

Singh, Namrata; Hroudová, Jana; Fišar, Zdeněk

2017-10-01

Impairment of mitochondrial metabolism, particularly the electron transport chain (ETC), as well as increased oxidative stress might play a significant role in pathogenesis of Alzheimer's disease (AD). Some effects of drugs used for symptomatic AD treatment may be related to their direct action on mitochondrial function. In vitro effects of pharmacologically different cognitives (galantamine, donepezil, rivastigmine, 7-MEOTA, memantine) and nootropic drugs (latrepirdine, piracetam) were investigated on selected mitochondrial parameters: activities of ETC complexes I, II + III, and IV, citrate synthase, monoamine oxidase (MAO), oxygen consumption rate, and hydrogen peroxide production of pig brain mitochondria. Complex I activity was decreased by galantamine, donepezil, and memantine; complex II + III activity was increased by galantamine. None of the tested drugs caused significant changes in the rate of mitochondrial oxygen consumption, even at high concentrations. Except galantamine, all tested drugs were selective MAO-A inhibitors. Latrepirdine, donepezil, and 7-MEOTA were found to be the most potent MAO-A inhibitors. Succinate-induced mitochondrial hydrogen peroxide production was not significantly affected by the drugs tested. The direct effect of cognitives and nootropics used in the treatment of AD on mitochondrial respiration is relatively small. The safest drugs in terms of disturbing mitochondrial function appear to be piracetam and rivastigmine. The MAO-A inhibition by cognitives and nootropics may also participate in mitochondrial neuroprotection. The results support the future research aimed at measuring the effects of currently used drugs or newly synthesized drugs on mitochondrial functioning in order to understand their mechanism of action.

Postoperative pain impairs subsequent performance on a spatial memory task via effects on N-methyl-D-aspartate receptor in aged rats.

PubMed

Chi, Haidong; Kawano, Takashi; Tamura, Takahiko; Iwata, Hideki; Takahashi, Yasuhiro; Eguchi, Satoru; Yamazaki, Fumimoto; Kumagai, Naoko; Yokoyama, Masataka

2013-12-18

Pain may be associated with postoperative cognitive dysfunction (POCD); however, this relationship remains under investigated. Therefore, we examined the impact of postoperative pain on cognitive functions in aged animals. Rats were allocated to the following groups: control (C), 1.2 % isoflurane for 2 hours alone (I), I with laparotomy (IL), IL with analgesia using local ropivacaine (IL+R), and IL with analgesia using systemic morphine (IL+M). Pain was assessed by rat grimace scale (RGS). Spatial memory was evaluated using a radial maze from postoperative days (POD) 3 to 14. NMDA receptor (NR) 2 subunits in hippocampus were measured by ELISA. Finally, effects of memantine, a low-affinity uncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, on postoperative cognitive performance were tested. Postoperative RGS was increased in Group IL, but not in other groups. The number of memory errors in Group I were comparable to that in Group C, whereas errors in Group IL were increased. Importantly, in Group IL+R and IL+M, cognitive impairment was not found. The memory errors were positively correlated with the levels of NMDA receptor 2 subunits in hippocampus. Prophylactic treatment with memantine could prevent the development of memory deficits observed in Group IL without an analgesic effect. Postoperative pain contributes to the development of memory deficits after anesthesia and surgery via up-regulation of hippocampal NMDA receptors. Our findings suggest that postoperative pain management may be important for the prevention of POCD in elderly patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Pharmacological interventions for cognitive decline in people with Down syndrome.

PubMed

Livingstone, Nuala; Hanratty, Jennifer; McShane, Rupert; Macdonald, Geraldine

2015-10-29

People with Down syndrome are vulnerable to developing dementia at an earlier age than the general population. Alzheimer's disease and cognitive decline in people with Down syndrome can place a significant burden on both the person with Down syndrome and their family and carers. Various pharmacological interventions, including donepezil, galantamine, memantine and rivastigmine, appear to have some effect in treating cognitive decline in people without Down syndrome, but their effectiveness for those with Down syndrome remains unclear. To assess the effectiveness of anti-dementia pharmacological interventions and nutritional supplements for treating cognitive decline in people with Down syndrome. In January 2015, we searched CENTRAL, ALOIS (the Specialised Register of the Cochrane Dementia and Cognitive Improvement Group), Ovid MEDLINE, Embase, PsycINFO, seven other databases, and two trials registers. In addition, we checked the references of relevant reviews and studies and contacted study authors, other researchers and relevant drug manufacturers to identify additional studies. Randomised controlled trials (RCTs) of anti-dementia pharmacological interventions or nutritional supplements for adults (aged 18 years and older) with Down syndrome, in which treatment was administered and compared with either placebo or no treatment. Two review authors independently assessed the risk of bias of included trials and extracted the relevant data. Review authors contacted study authors to obtain missing information where necessary. Only nine studies (427 participants) met the inclusion criteria for this review. Four of these (192 participants) assessed the effectiveness of donepezil, two (139 participants) assessed memantine, one (21 participants) assessed simvastatin, one study (35 participants) assessed antioxidants, and one study (40 participants) assessed acetyl-L-carnitine.Five studies focused on adults aged 45 to 55 years, while the remaining four studies focused on adults aged 20 to 29 years. Seven studies were conducted in either the USA or UK, one between Norway and the UK, and one in Japan. Follow-up periods in studies ranged from four weeks to two years. The reviewers judged all included studies to be at low or unclear risk of bias.Analyses indicate that for participants who received donepezil, scores in measures of cognitive functioning (standardised mean difference (SMD) 0.52, 95% confidence interval (CI) -0.27 to 1.13) and measures of behaviour (SMD 0.42, 95% CI -0.06 to 0.89) were similar to those who received placebo. However, participants who received donepezil were significantly more likely to experience an adverse event (odds ratio (OR) 0.32, 95% CI 0.16 to 0.62). The quality of this body of evidence was low. None of the included donepezil studies reported data for carer stress, institutional/home care, or death.For participants who received memantine, scores in measures of cognitive functioning (SMD 0.05, 95% CI -0.43 to 0.52), behaviour (SMD -0.17, 95% CI -0.46 to 0.11), and occurrence of adverse events (OR 0.45, 95% CI 0.18 to 1.17) were similar to those who received placebo. The quality of this body of evidence was low. None of the included memantine studies reported data for carer stress, institutional/home care, or death.Due to insufficient data, it was possible to provide a narrative account only of the outcomes for simvastatin, antioxidants, and acetyl-L-carnitine. Results from one pilot study suggest that participants who received simvastatin may have shown a slight improvement in cognitive measures. Due to the low quality of the body of evidence in this review, it is difficult to draw conclusions about the effectiveness of any pharmacological intervention for cognitive decline in people with Down syndrome.

Antidepressant-induced Dopamine Receptor Dysregulation: A Valid Animal Model of Manic-Depressive Illness

PubMed Central

Demontis, Francesca; Serra, Francesca; Serra, Gino

2017-01-01

Background: Mania seems to be associated with an increased dopamine (DA) transmission. Antidepressant treatments can induce mania in humans and potentiated DA transmission in animals, by sensitizing DA D2 receptors in the mesolimbic system. We have suggested that the sensitization of D2 receptors may be responsible of antidepressant-induced mania. This review aims to report the experimental evidence that led to the hypothesis that antidepressant-induced DA receptors dysregulation can be considered an animal model of bipolar disorder. Methods: We reviewed papers reporting preclinical and clinical studies on the role of DA in the mechanism of action of antidepressant treatments and in the patho-physiology of mood disorders. Results: A number of preclinical and clinical evidence suggests that mania could be associated with an increased DA activity, while a reduced function of this neurotransmission might underlie depression. Chronic treatment with imipramine induces a sensitization of DA D2 receptors in the mesolimbic system, followed, after drug discontinuation, by a reduced sensitivity associated with an increased immobility time in forced swimming test of depression (FST). Blockade of glutamate NMDA receptors by memantine administration prevents the imipramine effect on DA receptors sensitivity and on the FST. Conclusion: We suggest that chronic treatment with antidepressants induces a behavioural syndrome that mimics mania (the sensitization of DA receptors), followed by depression (desensitization of DA receptors and increased immobility time in the FST), i.e. an animal model of bipolar disorder. Moreover the observation that memantine prevents the “bipolar-like” behavior, suggests that the drug may have an antimanic and mood stabilizing effect. Preliminary clinical observations support this hypothesis. PMID:28503114

Memantine transport across the mouse blood-brain barrier is mediated by a cationic influx H+ antiporter.

PubMed

Mehta, Dharmini C; Short, Jennifer L; Nicolazzo, Joseph A

2013-12-02

Memantine (MEM) is prescribed in mono and combination therapies for treating the symptoms of moderate to severe Alzheimer's disease (AD). Despite MEM being widely prescribed with other AD and non-AD medicines, very little is known about its mechanism of transport across the blood-brain barrier (BBB), and whether the nature of this transport lends MEM to a potential for drug-drug interactions at the BBB. Therefore, the purpose of this study was to characterize the mechanisms facilitating MEM brain uptake in Swiss Outbred mice using an in situ transcardiac perfusion technique, and identify the putative transporter involved in MEM disposition into the brain. Following transcardiac perfusion of MEM with increasing concentrations, the brain uptake of MEM was observed to be saturable. Furthermore, MEM brain uptake was reduced (up to 55%) by various cationic transporter inhibitors (amantadine, quinine, tetraethylammonium, choline and carnitine) and was dependent on extracellular pH, while being independent of membrane depolarization and the presence of Na(+) in the perfusate. In addition, MEM brain uptake was observed to be sensitive to changes in intracellular pH, hence, likely to be driven by H(+)/MEM antiport mechanisms. Taken together, these findings implicate the involvement of an organic cation transporter regulated by proton antiport mechanisms in the transport of MEM across the mouse BBB, possibly the organic cation/carnitine transporter, OCTN1. These studies also clearly demonstrate the brain uptake of MEM is significantly reduced by other cationic compounds, highlighting the need to consider the possibility of drug interactions with MEM at the BBB, potentially leading to reduced brain uptake and, therefore, altered efficacy of MEM when used in patients on multidrug regimens.

A practical algorithm for managing Alzheimer's disease: what, when, and why?

PubMed Central

Cummings, Jeffrey L; Isaacson, Richard S; Schmitt, Frederick A; Velting, Drew M

2015-01-01

Alzheimer's disease (AD) is the most common form of dementia and its prevalence is increasing. Recent developments in AD management provide improved ways of supporting patients and their caregivers throughout the disease continuum. Managing cardiovascular risk factors, maintaining an active lifestyle (with regular physical, mental and social activity) and following a Mediterranean diet appear to reduce AD risk and may slow cognitive decline. Pharmacologic therapy for AD should be initiated upon diagnosis. All of the currently available cholinesterase inhibitors (ChEIs; donepezil, galantamine, and rivastigmine) are indicated for mild-to-moderate AD. Donepezil (10 and 23 mg/day) and rivastigmine transdermal patch (13.3 mg/24 h) are indicated for moderate-to-severe AD. Memantine, an N-methyl-d-aspartate receptor antagonist, is approved for moderate-to-severe AD. ChEIs have been shown to improve cognitive function, global clinical status and patients' ability to perform activities of daily living. There is also evidence for reduction in emergence of behavioral symptoms with ChEI therapy. Treatment choice (e.g., oral vs. transdermal) should be based on patient or caregiver preference, ease of use, tolerability, and cost. Treatment should be individualized; patients can be switched from one ChEI to another if the initial agent is poorly tolerated or ineffective. Memantine may be introduced in moderate-to-severe disease stages. Clinicians will regularly monitor symptoms and behaviors, manage comorbidities, assess function, educate and help caregivers access information and support, evaluate patients' fitness to drive or own firearms, and provide advice about the need for legal and financial planning. Review of caregiver well-being and prompt referral for support is vital. PMID:25815358

Future directions in treatment of brain metastases

PubMed Central

Barani, Igor J.; Larson, David A.; Berger, Mitchel S.

2013-01-01

Background: Brain metastases affect up to 30% of patients with cancer. Management of brain metastases continues to evolve with ever increasing focus on cognitive preservation and quality of life. This manuscript reviews current state of brain metastases management and discusses various treatment controversies with focus on future clinical trials. Stereotactic radiosurgery (SRS) and whole-brain radiotherapy (WBRT) are discussed in context of multiple (4+ brain metastases) as well as new approaches combining radiation and targeted agents. A brief discussion of modified WBRT approaches, including hippocampal-avoidance WBRT (HA-WBRT) is included as well as a section on recently presented results of Radiation Therapy Oncology Group (RTOG) 0614, a randomized, double-blind, placebo-controlled trial of menantine for prevention of neurocognitive injury after WBRT. Methods: A search of selected studies relevant to management of brain metastases was performed in PubMed as well as in various published meeting abstracts. This data was collated and analyzed in context of contemporary management and future clinical trial plans. This data is presented in tabular form and discussed extensively in the text. Results: The published data demonstrate continued evolution of clinical trials and management strategies designed to minimize and/or prevent cognitive decline following radiation therapy management of brain metastases. Hippocampal avoidance whole-brain radiation therapy (HA-WBRT) and radiosurgery treatments for multiple brain metastases are discussed along with preliminary results of RTOG 0614, a trial of memantine therapy to prevent cognitive decline following WBRT. Trial results appear to support the use of memantine for prevention of cognitive decline. Conclusions: Different management strategies for multiple brain metastases (>4 brain metastases) are currently being evaluated in prospective clinical trials to minimize the likelihood of cognitive decline following WBRT. PMID:23717793

Future directions in treatment of brain metastases.

PubMed

Barani, Igor J; Larson, David A; Berger, Mitchel S

2013-01-01

Brain metastases affect up to 30% of patients with cancer. Management of brain metastases continues to evolve with ever increasing focus on cognitive preservation and quality of life. This manuscript reviews current state of brain metastases management and discusses various treatment controversies with focus on future clinical trials. Stereotactic radiosurgery (SRS) and whole-brain radiotherapy (WBRT) are discussed in context of multiple (4+ brain metastases) as well as new approaches combining radiation and targeted agents. A brief discussion of modified WBRT approaches, including hippocampal-avoidance WBRT (HA-WBRT) is included as well as a section on recently presented results of Radiation Therapy Oncology Group (RTOG) 0614, a randomized, double-blind, placebo-controlled trial of menantine for prevention of neurocognitive injury after WBRT. A search of selected studies relevant to management of brain metastases was performed in PubMed as well as in various published meeting abstracts. This data was collated and analyzed in context of contemporary management and future clinical trial plans. This data is presented in tabular form and discussed extensively in the text. The published data demonstrate continued evolution of clinical trials and management strategies designed to minimize and/or prevent cognitive decline following radiation therapy management of brain metastases. Hippocampal avoidance whole-brain radiation therapy (HA-WBRT) and radiosurgery treatments for multiple brain metastases are discussed along with preliminary results of RTOG 0614, a trial of memantine therapy to prevent cognitive decline following WBRT. Trial results appear to support the use of memantine for prevention of cognitive decline. Different management strategies for multiple brain metastases (>4 brain metastases) are currently being evaluated in prospective clinical trials to minimize the likelihood of cognitive decline following WBRT.

The Use of Medications Approved for Alzheimer’s Disease in Autism Spectrum Disorder: A Systematic Review

PubMed Central

Rossignol, Daniel A.; Frye, Richard E.

2014-01-01

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects 1 in 68 children in the United States. Even though it is a common disorder, only two medications (risperidone and aripiprazole) are approved by the U.S. Food and Drug Administration (FDA) to treat symptoms associated with ASD. However, these medications are approved to treat irritability, which is not a core symptom of ASD. A number of novel medications, which have not been approved by the FDA to treat ASD have been used off-label in some studies to treat ASD symptoms, including medications approved for Alzheimer’s disease. Interestingly, some of these studies are high-quality, double-blind, placebo-controlled (DBPC) studies. This article systematically reviews studies published through April, 2014, which examined the use of Alzheimer’s medications in ASD, including donepezil (seven studies, two were DBPC, five out of seven reported improvements), galantamine (four studies, two were DBPC, all reported improvements), rivastigmine (one study reporting improvements), tacrine (one study reporting improvements), and memantine (nine studies, one was DBPC, eight reported improvements). An evidence-based scale was used to rank each medication. Collectively, these studies reported improvements in expressive language and communication, receptive language, social interaction, irritability, hyperactivity, attention, eye contact, emotional lability, repetitive or self-stimulatory behaviors, motor planning, disruptive behaviors, obsessive–compulsive symptoms, lethargy, overall ASD behaviors, and increased REM sleep. Reported side effects are reviewed and include irritability, gastrointestinal problems, verbal or behavioral regression, headaches, irritability, rash, tremor, sedation, vomiting, and speech problems. Both galantamine and memantine had sufficient evidence ranking for improving both core and associated symptoms of ASD. Given the lack of medications approved to treat ASD, further studies on novel medications, including Alzheimer’s disease medications, are needed. PMID:25202686

Investigation of salt formation between memantine and pamoic acid: Its exploitation in nanocrystalline form as long acting injection.

PubMed

Mittapelly, Naresh; Rachumallu, Ramakrishna; Pandey, Gitu; Sharma, Shweta; Arya, Abhishek; Bhatta, Rabi Shankar; Mishra, Prabhat Ranjan

2016-04-01

In the present work, we prepared memantine-pamoic acid (MEM-PAM) salt by counter ion exchange in the aqueous phase to reduce the water solubility of MEM hydrochloride (native form) to make it suitable for long acting injection. The ratio of MEM to PAM in salt formation was optimized to maximize the loading efficiency and complexation efficiency. The 2:1 molar ratio of MEM to PAM salt form displayed nearly 95% complexation efficiency and 50% drug loading. The solubility was decreased by a ∼1250 folds. Thermo Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Powder X-ray Diffraction Analysis (PXRD) studies revealed the formation of new solid phase. Additionally, Nuclear Magnetic Resonance (NMR) spectroscopy confirmed the anhydrous nature of the salt form. Through Fourier transformation infrared spectroscopy (FT-IR) we identified the molecular interactions. Further, the microcrystals of the salt were transformed into nanocrystals (NCs) using high pressure homogenization. The particle size distribution and atomic force microscopy confirmed the monodispersed and spherical shape of the NCs. The in vitro dissolution studies were performed under sink condition in phosphate buffer saline pH 6.8. The results of MTT assay in murine fibroblast 3T3 cell line show that the NCs were less cytotoxic and more tolerable than plain MEM HCl. The in vivo performance of NCs administered as i.m. injection at three different doses in female Sprague-Dawley rats showed that the plasma levels lasted till the 24th day of the study. The pharmacokinetic parameters AUC0-∞ and Cmax increased linearly with increasing dose. Therefore, the results suggest that injectable NCs could represent a therapeutic alternative for the treatment of AD. Copyright © 2016 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ribeiro, Mariana P.C.; Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra; Nunes-Correia, Isabel

Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. Inmore » contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma.« less

Pharmacological Approaches for Treatment-resistant Bipolar Disorder

PubMed Central

Poon, Shi Hui; Sim, Kang; Baldessarini, Ross J.

2015-01-01

Bipolar disorder is prevalent, with high risks of disability, substance abuse and premature mortality. Treatment responses typically are incomplete, especially for depressive components, so that many cases can be considered “treatment resistant.” We reviewed reports on experimental treatments for such patients: there is a striking paucity of such research, mainly involving small incompletely controlled trials of add-on treatment, and findings remain preliminary. Encouraging results have been reported by adding aripiprazole, bupropion, clozapine, ketamine, memantine, pramipexole, pregabalin, and perhaps tri-iodothyronine in resistant manic or depressive phases. The urgency of incomplete responses in such a severe illness underscores the need for more systematic, simpler, and better controlled studies in more homogeneous samples of patients. PMID:26467409

Peripheral and Central Effects of Memantine in a Mixed Preclinical Mice Model of Obesity and Familial Alzheimer's Disease.

PubMed

Ettcheto, Miren; Sánchez-López, Elena; Gómez-Mínguez, Yaiza; Cabrera, Henrry; Busquets, Oriol; Beas-Zarate, Carlos; García, Maria Luisa; Carro, Eva; Casadesus, Gemma; Auladell, Carme; Vázquez Carrera, Manuel; Folch, Jaume; Camins, Antoni

2018-02-05

There is growing evidence that obesity associated with type 2 diabetes mellitus (T2DM) and aging are risk factors for the development of Alzheimer's disease (AD). However, the molecular mechanisms through which obesity interacts with β-amyloid (Aβ) to promote cognitive decline remains poorly understood. Memantine (MEM), a N-methyl-D-aspartate receptor antagonist, is currently used for the treatment of AD. Nonetheless, few studies have reported its effects on genetic preclinical models of this neurodegenerative disease exacerbated with high-fat diet (HFD)-induced obesity. Therefore, the present research aims to elucidate the effects of MEM on familial AD HFD-induced insulin resistance and learning and memory impairment. Furthermore, it aspires to determine the possible underlying mechanisms that connect AD to T2DM. Wild type and APPswe/PS1dE9 mice were used in this study. The animals were fed with either chow or HFD until 6 months of age, and they were treated with MEM-supplemented water (30 mg/kg) during the last 12 weeks. Our study demonstrates that MEM improves the metabolic consequences produced by HFD in this model of familial AD. Behavioural assessments confirmed that the treatment also improves animals learning abilities and decreases memory loss. Moreover, MEM treatment improves brain insulin signalling upregulating AKT, as well as cyclic adenosine monophosphate response element binding (CREB) expression, and modulates the amyloidogenic pathway, which, in turn, reduced the accumulation of Aβ. Moreover, this drug increases the activation of molecules involved with insulin signalling in the liver, such as insulin receptor substrate 2 (IRS2), which is a key protein regulating hepatic resistance to insulin. These results provide new insight into the role of MEM not only in the occurrence of AD treatment, but also in its potential application on peripheral metabolic disorders where Aβ plays a key role, as is the case of T2DM.

Effects of N-methyl-D-aspartate receptor ligands on sensitivity to reinforcer magnitude and delayed reinforcement in a delay-discounting procedure

PubMed Central

Yates, Justin R; Gunkel, Benjamin T; Rogers, Katherine K; Hughes, Mallory N; Prior, Nicholas A

2016-01-01

Rationale The N-methyl-D-aspartate (NMDA) receptor has been recently identified as an important mediator of impulsive choice, as assessed in delay discounting. Although discounting is independently influenced by sensitivity to reinforcer magnitude and delayed reinforcement, few studies have examined how NMDA receptor ligands differentially affect these parameters. Objectives The current study examined the effects of various NMDA receptor ligands on sensitivity to reinforcer magnitude and delayed reinforcement in a delay-discounting procedure. Methods Following behavioral training, rats received treatments of the following NMDA receptor ligands: the uncompetitive antagonists ketamine (0, 1.0, 5.0, or 10.0 mg/kg; i.p.), MK-801 (0, 0.003, 0.01, or 0.03 mg/kg; s.c.), and memantine (0, 2.5, 5.0, or 10.0 mg/kg; i.p.), the competitive antagonist CGS 19755 (0, 5.0, 10.0, or 20.0 mg/kg; s.c.), the non-competitive NR2B subunit-selective antagonist ifenprodil (0, 1.0, 3.0, or 10.0 mg/kg; i.p), and the partial agonist D-cycloserine (0, 3.25, 15.0, or 30.0 mg/kg; s.c.). Results When an exponential model was used to describe discounting, CGS 19755 (5.0 mg/kg) increased impulsive choice without altering sensitivity to reinforcer magnitude. Conversely, ketamine (10.0 mg/kg), memantine (5.0 mg/kg), and ifenprodil (10.0 mg/kg) decreased sensitivity to reinforcer magnitude without altering impulsive choice. MK-801 and D-cycloserine did not alter delay-discounting performance, although two-way ANOVA analyses indicated D-cycloserine (15.0 mg/kg) decreased impulsive choice. Conclusions The behavioral changes observed in delay discounting following administration of NMDA receptor antagonists do not always reflect an alteration in impulsive choice. These results emphasize the utility in employing quantitative methods to assess drug effects in delay discounting. PMID:27837332

In vitro mitochondrial failure and oxidative stress mimic biochemical features of Alzheimer disease.

PubMed

Selvatici, Rita; Marani, Luca; Marino, Silvia; Siniscalchi, Anna

2013-08-01

Primary cortical neurons exposed to the mitochondrial toxin NaN3 (0.1-3 mM) were submitted to oxidative stress with H2O2 (30-150 μM), to mimic conditions observed in neurodegenerative disorders. The effects of such treatment on a series of parameters useful in characterizing neuronal damage were investigated: (i) the basal release of glutamate, evaluated as (3)H-d-Aspartate efflux, was sharply, concentration-dependently, increased; (ii) the phosphorylation status of intracellular markers known to be involved in the neurodegenerative processes, in particular in Alzheimer disease: tau and GSK3β were increased, as well as the protein level of β-secretase (BACE1) and p35/25 evaluated by Western blotting, while (iii) the cell metabolic activity, measured with the MTT method, was reduced, in a concentration- and time-dependent manner. The latter effect, as well as tau hyperphosphorylation, was prevented both by a mixture of antioxidant drugs (100 μM ascorbic acid, 10 μM trolox, 100 μM glutathione) and by the anti-Alzheimer drug, memantine, 20 μM. Since it is well known that hippocampal cholinergic neurons are particularly affected in Alzheimer disease, the effects of NaN3 and H2O2 were also studied in electrically stimulated rat hippocampal slices, evaluating the (3)H-Choline efflux, as an index of acetylcholine release. The neurotoxic treatment depressed the neurosecretory function and the mixture of antioxidant drugs, as well as memantine, were able to restore it. The neuronal damage induced by the in vitro protocol adopted in the present work displays peculiarities of neurodegenerative disorders, e.g. Alzheimer disease, underlining the role of mitochondrial failure and oxidative stress, which appear to occur upstream the neurodegenerative process; such protocol could be utilized to test the efficacy of neuroprotective treatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigating Glutamatergic Mechanism in Attention and Impulse Control Using Rats in a Modified 5-Choice Serial Reaction Time Task

PubMed Central

Benn, Abigail; Robinson, Emma S. J.

2014-01-01

The 5-choice serial reaction time task (5CSRTT) has been widely used to study attention and impulse control in rodents. In order to mimic cognitive impairments in psychiatry, one approach has been to use acute administration of NMDA antagonists. This disruption in glutamatergic transmission leads to impairments in accuracy, omissions, and premature responses although findings have been inconsistent. In this study, we further investigated glutamatergic mechanisms using a novel version of the 5CSRTT, which we have previously shown to be more sensitive to cognitive enhancers. We first investigated the effects of systemic treatment with NMDA antagonists. We also carried out a preliminary investigation using targeted medial prefrontal cortex infusions of a NMDA antagonist (MK801), mGluR2/3 antagonist (LY341495), and mGluR7 negative allosteric modulator (MMPIP). Acute systemic administration of the different NMDA antagonists had no specific effects on accuracy. At higher doses PCP, ketamine, and memantine, increased omissions and affected other measures suggesting a general disruption in task performance. Only MK801 increased premature responses, and reduced omissions at lower doses suggesting stimulant like effects. None of the NMDA antagonists affected accuracy or any other measures when tested using a short stimulus challenge. Infusions of MK801 had no effect on accuracy but increased premature responses following infralimbic, but not prelimbic infusion. LY341495 had no effects in either brain region but a decrease in accuracy was observed following prelimbic infusion of MMPIP. Contrary to our hypothesis, disruptions to glutamate transmission using NMDA antagonists did not induce any clear deficits in accuracy in this modified version of the 5CSRTT. We also found that the profile of effects for MK801 differed from those observed with PCP, ketamine, and memantine. The effects of MK801 in the infralimbic cortex add to the literature indicating this brain region and glutamate play an important role in impulse control. PMID:25526617

Dose-dependent folic acid and memantine treatments promote synergistic or additive protection against Aβ(25-35) peptide-induced apoptosis in SH-SY5Y cells mediated by mitochondria stress-associated death signals.

PubMed

Chen, Ta-Fu; Tang, Ming-Chi; Chou, Chia-Hui; Chiu, Ming-Jang; Huang, R-F S

2013-12-01

Increased dietary folic acid (FA) is associated with reduced risks of Alzheimer's disease (AD). The AD drug memantine (Mn) has had limited therapeutic effects for the treatment of patients with moderate to severe AD. This study investigated whether and the underlying mechanisms by which the combination of Mn and FA may have synergistic or additive effects in protecting against amyloid-β(25-35) peptide (Aβ)-induced neurocytotoxicity. Aβ treatment of human neuroblastoma SH-SY5Y cells significantly induced a 6-fold increase of apoptotic cells compared with the Aβ-untreated group. Preincubation of Aβ-exposed cells with FA (500 μM) or Mn (20 μM) caused a 22% and 10% reduction of apoptotic cells, respectively, whereas the combo-treatments at such doses synergistically alleviated Aβ-induced apoptosis by 60% (P<0.05). The apoptotic protection by the combo-treatments coincided with attenuating Aβ-elicited mitochondrial (mt) membrane depolarization and abolishing Aβ-induced mt cytochrome c release to the cytosol. Increased levels of FA at 1000 μM in combination with 20 μM Mn exerted an additive protection against Aβ(25-35)-induced-apoptosis as compared to the isolate Mn group (P<0.05). The combo-treatments reversed Aβ-elicited mt membrane depolarization, attenuated Aβ-elicited mt cytochrome c release to the cytosol, and diminished Aβ-promoted superoxide generation. The apoptotic-protection by such combo-treatments was partially abolished by carbonyl cyanide 3-chlorophenylhydrazone (mt membrane potential uncoupler) and sodium azide (mt cytochrome c oxidase inhibitor). Taken together, the data demonstrated that dose-dependent FA and Mn synergistically or additively protected SH-SY5Y cells against Aβ-induced apoptosis, which was partially, if not completely, mediated by mt stress-associated death signals. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dynorphin up-regulation in the dentate granule cell mossy fiber pathway following chronic inhibition of GluN2B-containing NMDAR is associated with increased CREB (Ser 133) phosphorylation, but is independent of BDNF/TrkB signaling pathways.

PubMed

Rittase, W Bradley; Dong, Yu; Barksdale, DaRel; Galdzicki, Zygmunt; Bausch, Suzanne B

2014-05-01

Emerging evidence suggests that neuronal responses to N-methyl-d-aspartate (NMDAR) activation/inactivation are influenced by subunit composition. For example, activation of synaptic NMDAR (comprised of GluN2A>GluN2B) phosphorylates cAMP-response-element-binding protein (CREB) at Ser 133, induces BDNF expression and promotes neuronal survival. Activation of extrasynaptic NMDAR (comprised of GluN2B>GluN2) dephosphorylates CREB (Ser 133), reduces BDNF expression and triggers neuronal death. These results led us to hypothesize that chronic inhibition of GluN2B-containing NMDAR would increase CREB (Ser 133) phosphorylation, increase BDNF levels and subsequently alter downstream dynorphin (DYN) and neuropeptide Y (NPY) expression. We focused on DYN and NPY because these neuropeptides can decrease excitatory neurotransmission and seizure occurrence and we reported previously that seizure-like events are reduced following chronic treatment with GluN2B antagonists. Consistent with our hypothesis, chronic treatment (17-21days) of hippocampal slice cultures with the GluN2B-selective antagonists ifenprodil or Ro25,6981 increased both CREB (Ser 133) phosphorylation and granule cell mossy fiber pathway DYN expression. Similar treatment with the non-subtype-selective NMDAR antagonists d-APV or memantine had no significant effect on either CREB (Ser 133) phosphorylation or DYN expression. In contrast to our hypothesis, BDNF levels were decreased following chronic treatment with Ro25,6981, but not ifenprodil, d-APV or memantine. Blockade of BDNF actions and TrkB activation did not significantly augment hilar DYN expression in vehicle-treated cultures and had no effect in Ro25,6981 treated cultures. These findings suggest that chronic exposure to GluN2B-selective NMDAR antagonists increased DYN expression through a putatively pCREB-dependent, but BDNF/TrkB-independent mechanism. Published by Elsevier Inc.

Recovery of NMDA receptor currents from MK-801 blockade is accelerated by Mg2+ and memantine under conditions of agonist exposure

PubMed Central

McKay, Sean; Bengtson, C. Peter; Bading, Hilmar; Wyllie, David J.A.; Hardingham, Giles E.

2013-01-01

MK-801 is a use-dependent NMDA receptor open channel blocker with a very slow off-rate. These properties can be exploited to ‘pre-block’ a population of NMDARs, such as synaptic ones, enabling the selective activation of a different population, such as extrasynaptic NMDARs. However, the usefulness of this approach is dependent on the stability of MK-801 blockade after washout. We have revisited this issue, and confirm that recovery of NMDAR currents from MK-801 blockade is enhanced by channel opening by NMDA, and find that it is further increased when Mg2+ is also present. In the presence of Mg2+, 50% recovery from MK-801 blockade is achieved after 10′ of 100 μM NMDA, or 30′ of 15 μM NMDA exposure. In Mg2+-free medium, NMDA-induced MK-801 dissociation was found to be much slower. Memantine, another PCP-site antagonist, could substitute for Mg2+ in accelerating the unblock of MK-801 in the presence of NMDA. This suggests a model whereby, upon dissociation from its binding site in the pore, MK-801 is able to re-bind in a process antagonized by Mg2+ or another PCP-site antagonist. Finally we show that even when all NMDARs are pre-blocked by MK-801, incubation of neurons with 100 μM NMDA in the presence of Mg2+ for 2.5 h triggers sufficient unblocking to kill >80% of neurons. We conclude that while synaptic MK-801 ‘pre-block’ protocols are useful for pharmacologically assessing synaptic vs. extrasynaptic contributions to NMDAR currents, or studying short-term effects, it is problematic to use this technique to attempt to study the effects of long-term selective extrasynaptic NMDAR activation. This article is part of the Special Issue entitled ‘Glutamate Receptor-Dependent Synaptic Plasticity’. PMID:23402996

[Quality of registration of dementia diagnosis in primary care: The situation in Spain in 2002-2011].

PubMed

de Hoyos-Alonso, María del Canto; Bonis, Julio; Bryant, Verónica; Castell Alcalá, María Victoria; Otero Puime, Ángel

2016-01-01

To ascertain the diagnosis associated with specific treatment for dementia in the Primary Care Electronic Clinical Record (PC-ECR) and to analyse the factors associated with the quality of registration. Descriptive study of patients taking cholinesterase inhibitors or memantine registered in Database for pharmacoepidemiological research in PC (BIFAP) 2011: 24,575 patients between 2002 and 2011. Diagnoses associated with first prescription of these drugs were grouped into 5 categories: "dementia", "memory impairment", "dementia-related diseases", "intercurrent processes" and "convenience codes". We calculated the prevalence of each category by age and sex for each study year (95%CI) and analysed the associations and trend for 2002-2011 using difference in proportions in independent samples and binary logistic regression. A code of "dementia" was associated with first prescription in 56.5% (95%CI: 55.8-57.1) of patients. It was higher in women [OR1.09 (95%CI: 1.03-1.15)] and with increasing follow-up time [OR1.07 (95%CI: 1.06-1.08) for each year of follow-up]. "Convenience codes" [16.3% (95%CI: 15.8-16.7)] were coded more frequently in women and in those ≥80 years; "Memory impairment" [12.4% (95%CI: 12.0-12.8)], "related diseases" [4.6% (95%CI: 4.4-4.8)] and "intercurrent processes" [10.3% (95%CI: 9.9-10.6)] were used more in men and in persons <80 years. Between 2002 and 2011 improved the use of "convenience codes". Almost half of the patients taking cholinesterase inhibitors or memantine do not have a diagnosis of dementia registered in their PC-ECR. Registration improves with increasing time of follow-up. Improvements are needed in the PC-ECR, adequate care coordination, and proactive approach to increase the quality of dementia registration. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Recovery of NMDA receptor currents from MK-801 blockade is accelerated by Mg2+ and memantine under conditions of agonist exposure.

PubMed

McKay, Sean; Bengtson, C Peter; Bading, Hilmar; Wyllie, David J A; Hardingham, Giles E

2013-11-01

MK-801 is a use-dependent NMDA receptor open channel blocker with a very slow off-rate. These properties can be exploited to 'pre-block' a population of NMDARs, such as synaptic ones, enabling the selective activation of a different population, such as extrasynaptic NMDARs. However, the usefulness of this approach is dependent on the stability of MK-801 blockade after washout. We have revisited this issue, and confirm that recovery of NMDAR currents from MK-801 blockade is enhanced by channel opening by NMDA, and find that it is further increased when Mg(2+) is also present. In the presence of Mg(2+), 50% recovery from MK-801 blockade is achieved after 10' of 100 μM NMDA, or 30' of 15 μM NMDA exposure. In Mg(2+)-free medium, NMDA-induced MK-801 dissociation was found to be much slower. Memantine, another PCP-site antagonist, could substitute for Mg(2+) in accelerating the unblock of MK-801 in the presence of NMDA. This suggests a model whereby, upon dissociation from its binding site in the pore, MK-801 is able to re-bind in a process antagonized by Mg(2+) or another PCP-site antagonist. Finally we show that even when all NMDARs are pre-blocked by MK-801, incubation of neurons with 100 μM NMDA in the presence of Mg(2+) for 2.5 h triggers sufficient unblocking to kill >80% of neurons. We conclude that while synaptic MK-801 'pre-block' protocols are useful for pharmacologically assessing synaptic vs. extrasynaptic contributions to NMDAR currents, or studying short-term effects, it is problematic to use this technique to attempt to study the effects of long-term selective extrasynaptic NMDAR activation. This article is part of the Special Issue entitled 'Glutamate Receptor-Dependent Synaptic Plasticity'. Copyright © 2013 Elsevier Ltd. All rights reserved.

Suppression of NMDA receptor function in mice prenatally exposed to valproic acid improves social deficits and repetitive behaviors.

PubMed

Kang, Jaeseung; Kim, Eunjoon

2015-01-01

Animals prenatally exposed to valproic acid (VPA), an antiepileptic agent, have been used as a model for autism spectrum disorders (ASDs). Previous studies have identified enhanced NMDA receptor (NMDAR) function in the brain of VPA rats, and demonstrated that pharmacological suppression of NMDAR function normalizes social deficits in these animals. However, whether repetitive behavior, another key feature of ASDs, can be rescued by NMDAR inhibition remains unknown. We report here that memantine, an NMDAR antagonist, administered to VPA mice rescues both social deficits and repetitive behaviors such as self-grooming and jumping. These results suggest that suppression of elevated NMDAR function in VPA animals normalizes repetitive behaviors in addition to social deficits.

Neuro-ophthalmologic aspects of multiple sclerosis: Using eye movements as a clinical and experimental tool

PubMed Central

Niestroy, Annette; Rucker, Janet C; Leigh, R John

2007-01-01

Ocular motor disorders are a well recognized feature of multiple sclerosis (MS). Clinical abnormalities of eye movements, early in the disease course, are associated with generalized disability, probably because the burden of disease in affected patients falls on the brainstem and cerebellar pathways, which are important for gait and balance. Measurement of eye movements, especially when used to detect internuclear ophthalmoplegia (INO), may aid diagnosis of MS. Measurement of the ocular following response to moving sinusoidal gratings of specified spatial frequency and contrast can be used as an experimental tool to better understand persistent visual complaints in patients who have suffered optic neuritis. Patients with MS who develop acquired pendular nystagmus often benefit from treatment with gabapentin or memantine. PMID:19668480

A rational approach to the management of chronic migraine.

PubMed

Evans, Randolph W

2013-01-01

About 2% of the adult population has chronic migraine with only 20% diagnosed with this disorder. Those with medication overuse may improve with withdrawal of overuse medications. The intravenous dihydroergotamine regimen usually produces short-term benefit for those with medically refractory chronic migraine. OnabotulinumtoxinA and topiramate have shown efficacy in large placebo-controlled randomized trials. Sodium valproate, gabapentin, tizanidine, amitriptyline, fluoxetine, zonisamide, and possibly memantine may be alternative or possibly combined treatment options but with lesser levels of evidence supporting their use. Preliminary evidence suggests that nerve blocks might be beneficial. Acupuncture, biofeedback, relaxation therapy, and cognitive behavioral therapy might be of benefit. Surgical treatments including bariatric and deactivation of trigger points are of growing interest but not appropriate for most sufferers. Occipital nerve stimulation is a promising treatment with ongoing studies defining its use. © 2013 American Headache Society.

Recent strategies for drug development in fibromyalgia syndrome.

PubMed

Blumenthal, David E; Malemud, Charles J

2016-12-01

The US Federal Drug Administration (FDA) approved 3 medications for treating fibromyalgia syndrome (FMS). There have been no additional FDA approvals since January 2009 and the efficacy of the FDA-approved medications for FMS has been questioned. Areas covered: The "search for studies" tool using clinicaltrials.gov and PubMed were employed. The term, "fibromyalgia" was used for clinicaltrials.gov. The terms employed for PubMed were "Name-of-Drug Fibromyalgia", "Fibromyalgia Treatment" or "Fibromyalgia Drug Treatment." Clinical trials were reviewed if they were prospective and blinded, and if they employed a comparator, either placebo or another pharmaceutical. Expert commentary: Progress toward standardizing the outcome measures for FMS clinical trials have been made but challenges remain. Several pharmaceutical candidates for FMS have been tested since 2009. The results of these studies with potential novel targets for drug development for FMS were reviewed including the results of trials with sodium oxybate, quetiapine, esreboxetine, nabilone, memantine, naltrexone, and melatonin.

Prophylactic cranial irradiation: recent outcomes and innovations.

PubMed

Snider, James W; Gondi, Vinai; Brown, Paul D; Tome, Wolfgang; Mehta, Minesh P

2014-05-01

Brain metastases represent a frequent problem in several malignancies. They can shorten survival while causing significant morbidity and impairment in the patient's quality of life. Prophylactic cranial irradiation (PCI) has become an integral part of the standard of care in small cell lung cancer (SCLC), yet its role in other malignancies remains the subject of significant discussion. Its role has been extensively investigated in non-small cell lung cancer and less so for breast cancer and other malignancies. Improvements in medical care as well as in whole brain radiotherapy (WBRT) techniques may improve the risk-benefit ratio of this therapy so as to expand its role in cancer care. The use of memantine in WBRT patients as well as the use of hippocampal avoidance techniques are of particular interest in this effort. Herein, we review the history of PCI, its current use, and areas of investigation in the application of PCI.

Emerging pharmacotherapy for cancer patients with cognitive dysfunction

PubMed Central

2013-01-01

Advances in the diagnosis and multi-modality treatment of cancer have increased survival rates for many cancer types leading to an increasing load of long-term sequelae of therapy, including that of cognitive dysfunction. The cytotoxic nature of chemotherapeutic agents may also reduce neurogenesis, a key component of the physiology of memory and cognition, with ramifications for the patient’s mood and other cognition disorders. Similarly radiotherapy employed as a therapeutic or prophylactic tool in the treatment of primary or metastatic disease may significantly affect cognition. A number of emerging pharmacotherapies are under investigation for the treatment of cognitive dysfunction experienced by cancer patients. Recent data from clinical trials is reviewed involving the stimulants modafinil and methylphenidate, mood stabiliser lithium, anti-Alzheimer’s drugs memantine and donepezil, as well as other agents which are currently being explored within dementia, animal, and cell culture models to evaluate their use in treating cognitive dysfunction. PMID:24156319

Possible Alzheimer’s Disease in an Apolipoprotein E2 Homozygote

PubMed Central

Ignatov, Ignat; Belden, Christine; Jacobson, Sandra; Connor, Donald; Sabbagh, Marwan N.

2010-01-01

The objective of this study was to describe a case of Alzheimer’s disease in an ApoE ε2/ε2 homozygote. ApoE ε2/ε2 is the rarest of the apolipoprotein E genotypes, representing only 1.4% of the population. There is only one case reported in the literature of a nonagenarian with minimal cognitive changes whose brain showed AD pathology on postmortem study. Here we report an 87-year-old ApoE ε2/ε2 female who meets clinical criteria for Alzheimer’s disease, with confirmation from neuropsychological testing and PET scan. Clinical course is typical for Alzheimer’s disease with decline on the Mini-Mental Status Examination from a score of 25 to 19 over 3.5 years. The patient is currently treated with donepezil and memantine. In conclusion, a clinically confirmed case of Alzheimer’s disease is rare in Apo E2 homozygotes but can occur. PMID:19158419

Effects of topiramate and other anti-glutamatergic drugs on the acute intoxicating actions of ethanol in mice: modulation by genetic strain and stress

PubMed Central

Chen, Yi-Chyan; Holmes, Andrew

2008-01-01

Compounds with anti-glutamatergic properties currently in clinical use for various indications (e.g., Alzheimer's disease, epilepsy, psychosis, mood disorders) have potential utility as novel treatments for alcoholism. Enhanced sensitivity to certain acute intoxicating effects (ataxia, sedative) of alcohol may be one mechanism by which anti-glutamatergic drugs modulate alcohol use. We examined the effects of six compounds (memantine, dextromethorphan, haloperidol, lamotrigine, oxcarbazepine, topiramate) on sensitivity to acute intoxicating effects of ethanol (ataxia, hypothermia, sedation/hypnosis) in C57BL/6J mice. Analysis of topiramate was extended to determine the influence of genetic background (via comparison of the 129S1, BALB/cJ, C57BL/6J, DBA/2J inbred strains) and prior stress history (via chronic exposure of C57BL/6J to swim stress) on topiramate's effects on ethanol-induced sedation/hypnosis. Results showed that one N-methyl-D-aspartate receptor (NMDAR) antagonist, memantine, but not another, dextromethorphan, potentiated the ataxic but not hypothermic or sedative/hypnotic effects of ethanol. Haloperidol increased ethanol-induced ataxia and sedation/hypnosis to a similar extent as the prototypical NMDAR antagonist MK-801. Of the anticonvulsants tested, lamotrigine accentuated ethanol-induced sedation/hypnosis, while oxcarbazepine was without effect. Topiramate was without effect per se under baseline conditions in C57BL/6J, but had a synergistic effect with MK-801 on ethanol-induced sedation/hypnosis. Comparing inbred strains, topiramate was found to significantly potentiated ethanol's sedative/hypnotic effects in BALB/cJ, but not 129S1, C57BL/6J or DBA/2J strains. Topiramate also increased ethanol-induced sedation/hypnosis in C57BL/6J after exposure to chronic stress exposure. Current data demonstrate that, with the exception of MK-801 and haloperidol, the compounds tested had either no significant or assay-selective effects on sensitivity to acute ethanol under baseline conditions in C57BL/6J. However, significant effects of topiramate were revealed as a function of co-treatment with a NMDAR blocker, genetic background or prior stress history. These findings raise the possibility that topiramate and possibly other anti-glutamatergic drugs could promote the acute intoxicating effects of ethanol in specific subpopulations defined by genetics or life history. PMID:18843265

Pharmacodynamic, pharmacokinetic and pharmacogenetic aspects of drugs used in the treatment of Alzheimer's disease.

PubMed

Noetzli, Muriel; Eap, Chin B

2013-04-01

With the aging population and its rapidly increasing prevalence, dementia has become an important public health concern in developed and developing countries. To date, the pharmacological treatment is symptomatic and based on the observed neurotransmitter disturbances. The four most commonly used drugs are donepezil, galantamine, rivastigmine and memantine. Donepezil, galantamine and rivastigmine are acetylcholinesterase inhibitors with different pharmacodynamic and pharmacokinetic profiles. Donepezil inhibits selectively the acetylcholinesterase and has a long elimination half-life (t(1/2)) of 70 h. Galantamine is also a selective acetylcholinesterase inhibitor, but also modulates presynaptic nicotinic receptors. It has a t(1/2) of 6-8 h. Donepezil and galantamine are mainly metabolised by cytochrome P450 (CYP) 2D6 and CYP3A4 in the liver. Rivastigmine is a so-called 'pseudo-irreversible' inhibitor of acetylcholinesterase and butyrylcholinesterase. The t(1/2) of the drug is very short (1-2 h), but the duration of action is longer as the enzymes are blocked for around 8.5 and 3.5 h, respectively. Rivastigmine is metabolised by esterases in liver and intestine. Memantine is a non-competitive low-affinity antagonist of the NMDA receptor with a t(1/2) of 70 h. Its major route of elimination is unchanged via the kidneys. Addressing the issue of inter-patient variability in treatment response might be of special importance for the vulnerable population taking anti-dementia drugs. Pharmacogenetic considerations might help to avoid multiple medication changes due to non-response and/or adverse events. Some pharmacogenetic studies conducted on donepezil and galantamine reported an influence of the CYP2D6 genotype on the pharmacokinetics of the drugs and/or on the response to treatment. Moreover, polymorphisms in genes of the cholinergic markers acetylcholinesterase, butyrylcholinesterase, choline acetyltransferase and paraoxonase were found to be associated with better clinical response to acetylcholinesterase inhibitors. However, confirmation studies in larger populations are necessary to establish evidence of which subgroups of patients will most likely benefit from anti-dementia drugs. The aim of this review is to summarize the pharmacodynamics and pharmacokinetics of the four commonly used anti-dementia drugs and to give an overview on the current knowledge of pharmacogenetics in this field.

Time to Treatment Initiation in People With Alzheimer Disease: A Meta-Analysis of Randomized Controlled Trials.

PubMed

Tsoi, Kelvin K F; Hirai, Hoyee W; Chan, Joyce Y C; Kwok, Timothy C Y

2016-01-01

Alzheimer disease (AD) is a global health problem which afflicts millions of old age population worldwide. Acetylcholinesterase inhibitors and memantine are recognized drug treatments with limited clinical efficacy. It is uncertain if earlier initiation of these drugs will result in better outcomes in the longer term. To evaluate the benefit of early treatment among people with AD. Prospective randomized controlled trials were systematically searched from the OVID databases. The trials were eligible if study participants diagnosed with AD and were randomized to have early or late treatment. Any clinical assessment scales on cognitive function, physical function, behavioral problems, and the overall clinical status were the primary outcomes, and any reported adverse events were the secondary outcomes. Ten randomized trials were identified between 2000 and 2010. A total of 3092 participants with AD with mean age 75.8 years were randomly assigned to receive early treatment or treatment delayed by placebo intervention for around 6 months. Compared with late treatment, early AD drug treatment showed no significant benefit on cognitive function [mean difference (MD) of Alzheimer's Disease Assessment Scale- Cognitive Subscale = -0.49, 95% CI = -1.67 to 0.69], physical function (MD of Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory = 0.47, 95% CI = -1.44 to 2.39), behavioral problems (MD of Neuropsychiatric Inventory = -0.26, 95% CI = -2.70 to 2.18), and clinical status (MD of Clinician's Interview-Based Impression of Change plus Caregiver Input = 0.02, 95% CI = -0.23 to 0.27). Nausea was the most common adverse events in acetylcholinesterase inhibitor users, while memantine did not result in more side effects than the placebo group. For both drugs, early treatment had comparable adverse events when compared with late treatment. Earlier AD drug treatment by around 6 months did not result in significant difference in cognitive function, physical function, behavioral problems, and clinical status. This study included relative high proportion of early AD with the follow-up less than 2 years. Future studies can be conducted to further investigate the long-term findings. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Glutamate system, amyloid β peptides and tau protein: functional interrelationships and relevance to Alzheimer disease pathology

PubMed Central

Revett, Timothy J.; Baker, Glen B.; Jhamandas, Jack; Kar, Satyabrata

2013-01-01

Alzheimer disease is the most prevalent form of dementia globally and is characterized premortem by a gradual memory loss and deterioration of higher cognitive functions and postmortem by neuritic plaques containing amyloid β peptide and neurofibrillary tangles containing phospho-tau protein. Glutamate is the most abundant neurotransmitter in the brain and is essential to memory formation through processes such as long-term potentiation and so might be pivotal to Alzheimer disease progression. This review discusses how the glutamatergic system is impaired in Alzheimer disease and how interactions of amyloid β and glutamate influence synaptic function, tau phosphorylation and neurodegeneration. Interestingly, glutamate not only influences amyloid β production, but also amyloid β can alter the levels of glutamate at the synapse, indicating that small changes in the concentrations of both molecules could influence Alzheimer disease progression. Finally, we describe how the glutamate receptor antagonist, memantine, has been used in the treatment of individuals with Alzheimer disease and discuss its effectiveness. PMID:22894822

Whole-brain radiotherapy and stereotactic radiosurgery in brain metastases: what is the evidence?

PubMed

Mehta, Minesh P; Ahluwalia, Manmeet S

2015-01-01

The overall local treatment paradigm of brain metastases, which includes whole-brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS), continues to evolve. Local therapies play an important role in the management of brain metastases. The choice of local therapy depends on factors that involve the patient (performance status, expected survival, and age), the prior treatment history, and the tumor (type and subtype, number, size, location of metastases, and extracranial disease status). Multidisciplinary collaboration is required to facilitate an individualized plan to improve the outcome of disease in patients with this life-limiting complication. There has been concern about the neurocognitive effects of WBRT. A number of approaches that mitigate cognitive dysfunction, such as pharmacologic intervention (memantine) or a hippocampal-sparing strategy, have been studied in a prospective manner with WBRT. Although there has been an increase in the use of SRS in the management of brain metastases in recent years, WBRT retains an important therapeutic role.

Mechanical stress activates NMDA receptors in the absence of agonists.

PubMed

Maneshi, Mohammad Mehdi; Maki, Bruce; Gnanasambandam, Radhakrishnan; Belin, Sophie; Popescu, Gabriela K; Sachs, Frederick; Hua, Susan Z

2017-01-03

While studying the physiological response of primary rat astrocytes to fluid shear stress in a model of traumatic brain injury (TBI), we found that shear stress induced Ca 2+ entry. The influx was inhibited by MK-801, a specific pore blocker of N-Methyl-D-aspartic acid receptor (NMDAR) channels, and this occurred in the absence of agonists. Other NMDA open channel blockers ketamine and memantine showed a similar effect. The competitive glutamate antagonists AP5 and GluN2B-selective inhibitor ifenprodil reduced NMDA-activated currents, but had no effect on the mechanically induced Ca 2+ influx. Extracellular Mg 2+ at 2 mM did not significantly affect the shear induced Ca 2+ influx, but at 10 mM it produced significant inhibition. Patch clamp experiments showed mechanical activation of NMDAR and inhibition by MK-801. The mechanical sensitivity of NMDARs may play a role in the normal physiology of fluid flow in the glymphatic system and it has obvious relevance to TBI.

Mechanical stress activates NMDA receptors in the absence of agonists

PubMed Central

Maneshi, Mohammad Mehdi; Maki, Bruce; Gnanasambandam, Radhakrishnan; Belin, Sophie; Popescu, Gabriela K.; Sachs, Frederick; Hua, Susan Z.

2017-01-01

While studying the physiological response of primary rat astrocytes to fluid shear stress in a model of traumatic brain injury (TBI), we found that shear stress induced Ca2+ entry. The influx was inhibited by MK-801, a specific pore blocker of N-Methyl-D-aspartic acid receptor (NMDAR) channels, and this occurred in the absence of agonists. Other NMDA open channel blockers ketamine and memantine showed a similar effect. The competitive glutamate antagonists AP5 and GluN2B-selective inhibitor ifenprodil reduced NMDA-activated currents, but had no effect on the mechanically induced Ca2+ influx. Extracellular Mg2+ at 2 mM did not significantly affect the shear induced Ca2+ influx, but at 10 mM it produced significant inhibition. Patch clamp experiments showed mechanical activation of NMDAR and inhibition by MK-801. The mechanical sensitivity of NMDARs may play a role in the normal physiology of fluid flow in the glymphatic system and it has obvious relevance to TBI. PMID:28045032

Dementia

PubMed Central

McGuinness, B; Herron, B; Passmore, AP

2015-01-01

Dementia is a clinical diagnosis requiring new functional dependence on the basis of progressive cognitive decline. It is estimated that 1.3% of the entire UK population, or 7.1% of those aged 65 or over, have dementia. Applying these to 2013 population estimates gives an estimated number of 19,765 people living with dementia in Northern Ireland. The clinical syndrome of dementia can be due to a variety of underlying pathophysiological processes. The most common of these is Alzheimer's disease (50-75%) followed by vascular dementia (20%), dementia with Lewy bodies (5%) and frontotemporal lobar dementia (5%). The clinical symptoms and pathophysiological processes of these diseases overlap significantly. Biomarkers to aid diagnosis and prognosis are emerging. Acetylcholinesterase inhibitors and memantine are the only medications currently licensed for the treatment of dementia. The nature of symptoms mean people with dementia are more dependent and vulnerable, both socially and in terms of physical and mental health, presenting evolving challenges to society and to our healthcare systems. PMID:26170481

Hippocampal neurogenesis enhancers promote forgetting of remote fear memory after hippocampal reactivation by retrieval

PubMed Central

Ishikawa, Rie; Fukushima, Hotaka; Frankland, Paul W; Kida, Satoshi

2016-01-01

Forgetting of recent fear memory is promoted by treatment with memantine (MEM), which increases hippocampal neurogenesis. The approaches for treatment of post-traumatic stress disorder (PTSD) using rodent models have focused on the extinction and reconsolidation of recent, but not remote, memories. Here we show that, following prolonged re-exposure to the conditioning context, enhancers of hippocampal neurogenesis, including MEM, promote forgetting of remote contextual fear memory. However, these interventions are ineffective following shorter re-exposures. Importantly, we find that long, but not short re-exposures activate gene expression in the hippocampus and induce hippocampus-dependent reconsolidation of remote contextual fear memory. Furthermore, remote memory retrieval becomes hippocampus-dependent after the long-time recall, suggesting that remote fear memory returns to a hippocampus dependent state after the long-time recall, thereby allowing enhanced forgetting by increased hippocampal neurogenesis. Forgetting of traumatic memory may contribute to the development of PTSD treatment. DOI: http://dx.doi.org/10.7554/eLife.17464.001 PMID:27669409

NMDA Receptor Modulators in the Treatment of Drug Addiction.

PubMed

Tomek, Seven E; Lacrosse, Amber L; Nemirovsky, Natali E; Olive, M Foster

2013-02-06

Glutamate plays a pivotal role in drug addiction, and the N-methyl-D-aspartate (NMDA) glutamate receptor subtype serves as a molecular target for several drugs of abuse. In this review, we will provide an overview of NMDA receptor structure and function, followed by a review of the mechanism of action, clinical efficacy, and side effect profile of NMDA receptor ligands that are currently in use or being explored for the treatment of drug addiction. These ligands include the NMDA receptor modulators memantine and acamprosate, as well as the partial NMDA agonist D-cycloserine. Data collected to date suggest that direct NMDA receptor modulators have relatively limited efficacy in the treatment of drug addiction, and that partial agonism of NMDA receptors may have some efficacy with regards to extinction learning during cue exposure therapy. However, the lack of consistency in results to date clearly indicates that additional studies are needed, as are studies examining novel ligands with indirect mechanisms for altering NMDA receptor function.

Overexpression of Telomerase Reverse Transcriptase Induces Autism-like Excitatory Phenotypes in Mice.

PubMed

Kim, Ki Chan; Rhee, Jeehae; Park, Jong-Eun; Lee, Dong-Keun; Choi, Chang Soon; Kim, Ji-Woon; Lee, Han-Woong; Song, Mi-Ryoung; Yoo, Hee Jeong; Chung, ChiHye; Shin, Chan Young

2016-12-01

In addition to its classical role as a regulator of telomere length, recent reports suggest that telomerase reverse transcriptase (TERT) plays a role in the transcriptional regulation of gene expression such as β-catenin-responsive pathways. Silencing or over-expression of TERT in cultured NPCs demonstrated that TERT induced glutamatergic neuronal differentiation. During embryonic brain development, expression of transcription factors involved in glutamatergic neuronal differentiation was increased in mice over-expressing TERT (TERT-tg mice). We observed increased expression of NMDA receptor subunits and phosphorylation of α-CaMKII in TERT-tg mice. TERT-tg mice showed autism spectrum disorder (ASD)-like behavioral phenotypes as well as lowered threshold against electrically induced seizure. Interestingly, the NMDA receptor antagonist memantine restored behavioral abnormalities in TERT-tg mice. Consistent with the alteration in excitatory/inhibitory (E/I) ratio, TERT-tg mice showed autism-like behaviors, abnormal synaptic organization, and function in mPFC suggesting the role of altered TERT activity in the manifestation of ASD, which is further supported by the significant association of certain SNPs in Korean ASD patients.

Current and Emerging Therapies for the Management of Bipolar Disorders

PubMed Central

El-Mallakh, Rif S.; Elmaadawi, Ahmed Z.; Gao, Yonglin; Lohano, Kavita; Roberts, R. Jeannie

2011-01-01

Bipolar disorder is a complex condition to treat because agents that may be effective for a specific phase may not be effective for other phases, or may even worsen the overall course of the illness. Over the last decade there has been an increase in research activity in the treatment of bipolar illness. There are now several agents that are well established for the treatment of acute mania (lithium, divalproex, carbamazepine, nearly all antipsychotics), acute bipolar depression (lamotrigine, quetiapine, olanzapine/fluoxetine combination), and relapse prevention (lithium, lamotrigine, divalproex, most second generation antipsychotics). There are also novel treatments that are being studied for all three phases. These include eslicarbazepine, cariprazine, MEM-1003, memantine, tamoxifen and pentazocine for acute mania; pramipexole, modafinil, armodafinil, divalproex, lurasidone, agomelatine, cariprazine, lisedexamfetamine, riluzole, RG-2417, bifeprunox, ropinirole, GSK1014802, and magnetic stimulation for bipolar depression; and asenapine, lurasidone, and cariprazine for relapse prevention. Additionally, there are accumulating data that antidepressants, particularly serotoninergic ones, are not particularly effective in acute bipolar depression and may worsen the course of the illness. PMID:23861648

[Pharmacological treatment of dementia: when, how and for how long. Recommendations of the Working Group on Dementia of the Catalan Society of Geriatrics and Gerontology].

PubMed

Rodríguez, Daniel; Formiga, Francesc; Fort, Isabel; Robles, María José; Barranco, Elena; Cubí, Dolors

2012-01-01

Dementia in general--and Alzheimer's disease (AD) in particular--are bound to loom large among the most acute healthcare, social, and public health problems of the 21st century. AD shows a degenerative progression that can be slowed down--yet not halted--by today's most widely accepted specific treatments (those based on cholinesterase inhibitors as well as those using memantine). There is enough evidence to consider these treatments advisable for the mild, moderate and severe phases of the illness. However, in the final stage of the disease, a decision has to be made on whether to withdraw such treatment or not. In this paper, the Working Group on Dementia for the Catalan Society of Geriatrics and Gerontology reviews the use of these specific pharmacological treatments for AD, and, drawing on the scientific evidence thus gathered, makes a series of recommendations on when, how, and for how long, the currently existing specific pharmacological treatments should be used. Copyright © 2011 SEGG. Published by Elsevier Espana. All rights reserved.

NMDA receptor antagonists interventions in schizophrenia: Meta-analysis of randomized, placebo-controlled trials.

PubMed

Kishi, Taro; Iwata, Nakao

2013-09-01

We examined whether N-methyl d-aspartate (NMDA) receptor antagonists as adjunctive therapy have therapeutic potential for schizophrenia treatment. Systematic review of PubMed, Cochrane Library, PsycINFO and Google Scholar up until October 2012 and meta-analysis of randomized placebo-controlled trials were performed. Risk ratio (RR), 95% confidence intervals (CI), numbers-needed-to-harm (NNH), and standardized mean difference (SMD) were calculated. Results were across 8 studies and 406 patients (85.5% schizophrenia related disorder and 14.5% bipolar disorder) were included (amantadine: 5 trials and 220 patients, memantine: 3 trials and 186 patients). NMDA receptor antagonists (NMDAR-ANTs) as adjunctive therapy were not superior to placebo in overall (SMD = -0.25, CI = -0.72, 0.23, p = 0.31, N = 6, n = 347), positive symptoms (SMD = -0.20, CI = -0.70, 0.31, p = 0.44, N = 4, n = 205), and negative symptoms (SMD = -0.69, CI = -1.65, 0.27, p = 0.16, N = 4, n = 205), and Clinical Global Impression Severity scale (SMD = -0.27, CI = -1.20, 0.65, p = 0.56, N = 3, n = 177). There was also no significant difference in discontinuation rate between NMDAR-ANTs and placebo treatments (all cause: RR = 1.23, CI = 0.89-1.70, p = 0.20, N = 8, n = 396, side effects: RR = 1.86, CI = 0.84-4.13, p = 0.13, N = 6, n = 359, inefficacy/worsening psychosis: RR = 0.70, CI = 0.20-2.38, p = 0.56, N = 7, n = 380). However, memantine was favorable compared with placebo in Mini-Mental State Examination in schizophrenia (SMD = -0.77, CI = -1.27, -0.28, p = 0.002, N = 3, n = 71). While NMDAR-ANTs caused weight loss compared with placebo (SMD = -0.42, CI = -0.73, -0.11, p = 0.008, N = 3, n = 165), amantadine caused more frequent insomnia than placebo (RR = 3.83, CI = 1.41-10.38, p = 0.008, NNH = 9, p = 0.002, N = 2, n = 147). Our results indicate that NMDAR-ANTs as adjunctive therapy may improve cognitive function in patients with schizophrenia. Because the included studies were small, a replication study using larger samples is needed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Treating OCD: what to do when first-line therapies fail.

PubMed

Castle, David; Bosanac, Peter; Rossell, Susan

2015-08-01

To provide a clinically-focused review of the biological treatment of treatment-resistant obsessive compulsive disorder (OCD). There is a paucity of research on how to manage OCD patients who fail to respond adequately to first line therapies. High-dose selective serotonin reuptake inhibitors (SSRIs) and clomipramine have good evidence-based data. Combinations of SSRIs have little support in clinical trials, but the combination of SSRIs and clomipramine can be helpful: careful clinical and cardiac monitoring is required. Certain adjunctive antipsychotics have a reasonable evidence base in OCD, but their use also needs to be weighed against the potential side effect burden. In patients with substantial generalised anxiety symptoms, clonazepam is worth considering. Of the other augmenting strategies, memantine and ondansetron appear useful in some cases, and are well tolerated. Topiramate might ameliorate compulsions to some degree, but it is less well tolerated. If all these strategies, along with expert psychological therapy, fail, careful consideration should be given to deep brain stimulation (DBS), which has an emerging evidence base and which can result in dramatic benefits for some individuals. For some patients, gamma radiosurgery might also still have a place. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Advancements in the treatment of agitation in Alzheimer's disease.

PubMed

Antonsdottir, Inga M; Smith, Jessica; Keltz, Melanie; Porsteinsson, Anton P

2015-01-01

Neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) are associated with significant negative outcomes for patients and their caregivers. Agitation, one of the most distressing NPS, lacks well-established long-term interventions that are both effective and safe. While non-pharmacological interventions are the suggested first-line treatment, it isn't effective in managing symptoms for every patient. In such cases, clinicians turn to the use of pharmacological interventions. Traditionally, these interventions consist of off-label use of antipsychotics, sedative/hypnotics, anxiolytics, acetylcholinesterase inhibitors, memantine and antidepressants, where the efficacy doesn't necessarily outweigh the associated risks. Gains made in understanding the neurobiological mechanisms underlying agitation have fueled several recent clinical trials. A comprehensive literature search for published articles evaluating pharmacologic interventions for agitation in AD was done. A review of some of these clinical trials was completed: dextromethorphan/quinidine, scyllo-inositol, brexpiprazole, prazosin, cannabinoids, dronabinol and citalopram show promise in treating agitation. Neurobiological findings and enhanced trial designs have re-ignited the area of pharmacological treatment of NPS. Although further research is needed to fully determine the safety, tolerability and efficacy of these treatments, the mission to finding effective treatments for NPS such as agitation in patients with dementia is well underway.

Glutamate and Its Receptors as Therapeutic Targets for Migraine.

PubMed

Hoffmann, Jan; Charles, Andrew

2018-04-01

There is substantial evidence indicating a role for glutamate in migraine. Levels of glutamate are higher in the brain and possibly also in the peripheral circulation in migraine patients, particularly during attacks. Altered blood levels of kynurenines, endogenous modulators of glutamate receptors, have been reported in migraine patients. Population genetic studies implicate genes that are involved with glutamate signaling in migraine, and gene mutations responsible for familial hemiplegic migraine and other familial migraine syndromes may influence glutamate signaling. Animal studies indicate that glutamate plays a key role in pain transmission, central sensitization, and cortical spreading depression. Multiple therapies that target glutamate receptors including magnesium, topiramate, memantine, and ketamine have been reported to have efficacy in the treatment of migraine, although with the exception of topiramate, the evidence for the efficacy of these therapies is not strong. Also, because all of these therapies have other mechanisms of action, it is not possible to conclude that the efficacy of these drugs is entirely due to their effects on glutamate receptors. Further studies are needed to more clearly delineate the possible roles of glutamate and its specific receptor subtypes in migraine and to identify new ways of targeting glutamate for migraine therapy.

Old and new acetylcholinesterase inhibitors for Alzheimer's disease.

PubMed

Galimberti, Daniela; Scarpini, Elio

2016-10-01

To date, pharmacological treatment of Alzheimer's disease (AD) includes Acetylcholinesterase Inhibitors (AChEIs) for mild-to-moderate AD, and memantine for moderate-to-severe AD. AChEIs reversibly inhibit acetylcholinesterase (AChE), thus increasing the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission. These drugs provide symptomatic short-term benefits, without clearly counteracting the progression of the disease. On the wake of successful clinical trials which lead to the marketing of AChEIs donepezil, rivastigmine and galantamine, many compounds with AChEI properties have been developed and tested mainly in Phase I-II clinical trials in the last twenty years. Here, we review clinical trials initiated and interrupted, and those ongoing so far. Despite many clinical trials with novel AChEIs have been carried out after the registration of those currently used to treat mild to moderate AD, none so far has been successful in a Phase III trial and marketed. Alzheimer's disease is a complex multifactorial disorder, therefore therapy should likely address not only the cholinergic system but also additional neurotransmitters. Moreover, such treatments should be started in very mild phases of the disease, and preventive strategies addressed in elderly people.

New drugs of 2003.

PubMed

Hussar, Daniel A

2004-01-01

To provide information regarding the most important properties of the new therapeutic agents marketed in 2003. Product labeling supplemented selectively with published studies and drug information reference sources. By the author. By the author. The 28 new therapeutic agents marketed in the United States during 2003 are reviewed in this article: adalimumab, agalsidase beta, alefacept, alfuzosin hydrochloride, aprepitant, atazanavir sulfate, atomoxetine hydrochloride, bortezomib, daptomycin, efalizumab, eletriptan hydrobromide, emtricitabine, enfuvirtide, eplerenone, gefitinib, icodextrin, laronidase, memantine hydrochloride, mequinol/tretinoin, miglustat, nitazoxanide, omalizumab, palonosetron hydrochloride, pegvisomant, rosuvastatin calcium, tadalafil, tositumomab and iodine I 131 tositumomab, and vardenafil hydrochloride. Indications and information on dosage and administration for these agents are reviewed, as are the most important pharmacokinetic properties, adverse events, drug interactions, and other precautions. Practical considerations for the use of the new agents are also discussed. When possible, the properties of the new drugs are compared with those of older drugs marketed for the same indications. A number of the new therapeutic agents marketed in 2003 have important advantages over older medications. An understanding of the properties of these agents is important for the pharmacist to effectively counsel patients about their use and to serve as a valuable source of information for other health professionals regarding these drugs.

Treatment of Alzheimer’s disease in Brazil: I. Cognitive disorders

PubMed Central

do Vale, Francisco de Assis Carvalho; Corrêa Neto, Ylmar; Bertolucci, Paulo Henrique Ferreira; Machado, João Carlos Barbosa; da Silva, Delson José; Allam, Nasser; Balthazar, Márcio Luiz Figueredo

2011-01-01

This article reports the recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology for the treatment of Alzheimer’s disease (AD) in Brazil, with special focus on cognitive disorders. It constitutes a revision and broadening of the 2005 guidelines based on a consensus involving researchers (physicians and non-physicians) in the field. The authors carried out a search of articles published since 2005 on the MEDLINE, LILACS and Cochrane Library databases. The search criteria were pharmacological and non-pharmacological treatment of cognitive disorders in AD. Studies retrieved were categorized into four classes, and evidence into four levels, based on the 2008 recommendations of the American Academy of Neurology. The recommendations on therapy are pertinent to the dementia phase of AD. Recommendations are proposed for the treatment of cognitive disorders encompassing both pharmacological (including acetyl-cholinesterase inhibitors, memantine and other drugs and substances) and non-pharmacological (including cognitive rehabilitation, physical activity, occupational therapy, and music therapy) approaches. Recommendations for the treatment of behavioral and psychological symptoms of dementia due to Alzheimer’s disease are included in a separate article of this edition. PMID:29213742

Glutamate-Modulating Drugs as a Potential Therapeutic Strategy in Obsessive-Compulsive Disorder

PubMed Central

Marinova, Zoya; Chuang, De-Maw; Fineberg, Naomi

2017-01-01

Objective: Abstract: Obsessive-compulsive disorder (OCD) is a mental disease commonly associated with severe distress and impairment of social functioning. Serotonin reuptake inhibitors and/or cognitive behavioural therapy are the therapy of choice, however up to 40% of patients do not respond to treatment. Glutamatergic signalling has also been implicated in OCD. The aim of the current study was to review the clinical evidence for therapeutic utility of glutamate-modulating drugs as an augmentation or monotherapy in OCD patients. Methods: We conducted a search of the MEDLINE database for clinical studies evaluating the effect of glutamate-modulating drugs in OCD. Results: Memantine is the compound most consistently showing a positive effect as an augmentation therapy in OCD. Anti-convulsant drugs (lamotrigine, topiramate) and riluzole may also provide therapeutic benefit to some OCD patients. Finally, ketamine may be of interest due to its potential for a rapid onset of action. Conclusion: Further randomized placebo-controlled trials in larger study populations are necessary in order to draw definitive conclusions on the utility of glutamate-modulating drugs in OCD. Furthermore, genetic and epigenetic factors, clinical symptoms and subtypes predicting treatment response to glutamate-modulating drugs need to be investigated systematically. PMID:28322166

Starch functionalized biodegradable semi-IPN as a pH-tunable controlled release platform for memantine.

PubMed

Ganguly, Sayan; Maity, Tushar; Mondal, Subhadip; Das, Poushali; Das, Narayan C

2017-02-01

Sequentially prepared semi-interpenetrating polymer network (semi-IPN) has been developed here via Michael type addition of acrylic acid (AA) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) on to starch. The semi-IPN hydrogel have proficiency in fast water imbibition towards gel network and swelling tunable character with pH alteration in ambient condition. The synthesized gel has been characterized by Fourier transformed infrared spectroscopy (FTIR) to confirm Michael type grafting of monomers on to starch. The surface morphology, observed from Scanning Electron Microscopy (SEM) exhibited corrugated rough surface on hydrogel which enhances the fast water uptake feature by anomalous Fickian case II diffusion mechanism. Grafting reaction also improves its thermal stability which has been confirmed by thermogravimetric analysis (TGA). Biodegradation study with hen egg lysozyme medium reveals the accelerated enzymatic scission of the starch backbone and progressive mass loss. Degradation of the hydrogel around 60% of its primary mass has been observed within 7days. The physicochemical characterizations of this hydrogel suggest this as a promising pH-tunable, biodegradable candidate for control drug delivery vehicle. Copyright © 2016 Elsevier B.V. All rights reserved.

Alzheimer disease-like clinical phenotype in a family with FTDP-17 caused by a MAPT R406W mutation.

PubMed

Lindquist, S G; Holm, I E; Schwartz, M; Law, I; Stokholm, J; Batbayli, M; Waldemar, G; Nielsen, J E

2008-04-01

We report clinical, molecular, neuroimaging and neuropathological features of a Danish family with autosomal dominant inherited dementia, a clinical phenotype resembling Alzheimer's disease and a pathogenic mutation (R406W) in the microtubule associated protein tau (MAPT) gene. Pre-symptomatic and affected family members underwent multidisciplinary (clinical, molecular, neuroimaging and neuropathological) examinations. Treatment with memantine in a family member with early symptoms, based on the clinical phenotype and the lack of specific treatment, appears to stabilize the disease course and increase the glucose metabolism in cortical and subcortical areas, as determined by serial [F(18)]FDG-PET scanning before and after initiation of treatment. Neuropathological examination of a second affected and mutation-positive family member showed moderate atrophy of the temporal lobes including the hippocampi. Microscopy revealed abundant numbers of tau-positive neurofibrillary tangles in all cortical areas and in some brainstem nuclei corresponding to a diagnosis of frontotemporal lobe degeneration on the basis of a MAPT mutation. The clinical and genetic heterogeneity of autosomal dominant inherited dementia must be taken into account in the genetic counselling and genetic testing of families with autosomal dominantly inherited dementia in general.

Selective cortical VGLUT1 increase as a marker for antidepressant activity.

PubMed

Moutsimilli, Larissa; Farley, Severine; Dumas, Sylvie; El Mestikawy, Salah; Giros, Bruno; Tzavara, Eleni T

2005-11-01

The two recently characterized vesicular glutamate transporters (VGLUT) presynaptically mark and differentiate two distinct excitatory neuronal populations and thus define a cortical and a subcortical glutamatergic system (VGLUT1 and VGLUT2 positive, respectively). These two systems might be differentially implicated in brain neuropathology. Still, little is known on the modalities of VGLUT1 and VGLUT2 regulations in response to pharmacological or physiological stimuli. Given the importance of cortical neuronal activity in psychosis we investigated VGLUT1 mRNA and protein expression in response to chronic treatment with commonly prescribed psychotropic medications. We show that agents with antidepressant activity, namely the antidepressants fluoxetine and desipramine, the atypical antipsychotic clozapine, and the mood stabilizer lithium increased VGLUT1 mRNA expression in neurons of the cerebral cortex and the hippocampus and in concert enhanced VGLUT1 protein expression in their projection fields. In contrast the typical antipsychotic haloperidol, the cognitive enhancers memantine and tacrine, and the anxiolytic diazepam were without effect. We suggest that VGLUT1 could be a useful marker for antidepressant activity. Furthermore, adaptive changes in VGLUT1 positive neurons could constitute a common functional endpoint for structurally unrelated antidepressants, representing promising antidepressant targets in tracking specificity, mechanism, and onset at action.

Enduring amnesia induced by ICV scopolamine is reversed by sesame oil in male rats.

PubMed

Tabari, Shabnam-Sadat Seyedi; Babri, Shirin; Mirzaie, Fariba; Farajdokht, Fereshteh; Mohaddes, Gisou

2016-08-01

To evaluated the long-term effect of scopolamine and sesame oil on spatial memory. Memory impairment induced by Intracerebroventricular (ICV) injection of scopolamine hydrochloride (10 μg/ rat). Animals were gavaged for 4 weeks with saline, sesame oil (0.5, 1, or 2 mL/kg/day), or 3 weeks with memantine (30 mg/kg/day) in advance to induction of amnesia. Morris water maze (MWM) test was conducted 6 days after microinjection of scopolamine. Then, blood and brain samples were collected and evaluated for the malondialdehyde (MDA) levels, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, and total antioxidant status (TAS) and ferric reducing ability of plasma (FRAP). Scopolamine significantly decreased traveled distance and time spent in target quadrant in probe test. Pretreatment of rats with sesame oil (0.5 mg/kg) mitigated scopolamine-induced behavioral alterations. Measurement of MDA, SOD, and GPX in brain tissue, and FRAP and TAS in blood showed little changes in animals which had received scopolamine or sesame oil. Intracerebroventricular injection of scopolamine has a residual effect on memory after six days. Sesame oil has an improving effect on spatial memory; however this effect is possibly mediated by mechanisms other than antioxidant effect of sesame oil.

Pharmacological treatment of comorbid PTSD and substance use disorder: recent progress.

PubMed

Sofuoglu, Mehmet; Rosenheck, Robert; Petrakis, Ismene

2014-02-01

Previous research has identified a strong association between posttraumatic stress disorder (PTSD) and substance use disorder (SUD), necessitating the development of treatments that address both conditions. Some pharmacotherapies are effective for the treatment of PTSD and SUD alone, however; no medications have been proven to be effective for the combination of these conditions. We review the recent advances in pharmacological treatment of comorbid PTSD and SUD. A randomized clinical trial of sertraline, a serotonin reuptake inhibitor (SSRI), did not show overall efficacy for comorbid PTSD and alcohol dependence (AD), although it may have efficacy among light drinkers. Another clinical trial demonstrated the efficacy of both disulfiram and naltrexone for the treatment of AD in individuals with PTSD. A more recent clinical trial suggested that norepinephrine uptake inhibitors may also have efficacy for the treatment of comorbid PTSD and AD. In animal and preliminary human studies, brain norepinephrine and glutamate/GABA have emerged as potential treatment targets for comorbid PTSD and SUD. Noradrenergic medications that are promising for comorbid PTSD and SUD include prazosin, guanfacine, and atomoxetine. Promising glutamate/GABA medications include topiramate, memantine, acamprosate, N-acetylcysteine (NAC), and ketamine. The safety and efficacy of these medications for the treatment of PTSD and SUD need to be tested in controlled clinical trials. Published by Elsevier Ltd.

Drug delivery strategies for Alzheimer's disease treatment.

PubMed

Di Stefano, Antonio; Iannitelli, Antonio; Laserra, Sara; Sozio, Piera

2011-05-01

Current Alzheimer's disease (AD) therapy is based on the administration of the drugs donepezil, galantamine, rivastigmine and memantine. Until disease-modifying therapies become available, further research is needed to develop new drug delivery strategies to ensure ease of administration and treatment persistence. In addition to the conventional oral formulations, a variety of drug delivery strategies applied to the treatment of AD are reviewed in this paper, with a focus on strategies leading to simplified dosage regimens and to providing new pharmacological tools. Alternatives include extended release, orally disintegrating or sublingual formulations, intranasal or short- and long-acting intramuscular or transdermal forms, and nanotechnology-based delivery systems. The advent of new research on molecular mechanisms of AD pathogenesis has outlined new strategies for therapeutic intervention; these include the stimulation of α-secretase cleavage, the inhibition of γ-secretase activity, the use of non-steroidal anti-inflammatory drugs, neuroprotection based on antioxidant therapy, the use of estrogens, NO synthetase inhibitors, and natural agents such as polyphenols. Unfortunately, these compounds might not help patients with end stage AD, but might hopefully slow or stop the disease process in its early stage. Nanotechnologies may prove to be a promising contribution in future AD drug delivery strategies, in particular drug carrier nano- or microsystems, which can limit the side effects of anti-Alzheimer drugs.

Management of Depression in Patients with Dementia: Is Pharmacological Treatment Justified?

PubMed

Ford, Andrew H; Almeida, Osvaldo P

2017-02-01

Depression in the context of dementia is common and contributes to poorer outcomes in individuals and those who care for them. Non-pharmacological treatments are the preferred initial approach to managing these symptoms but data in support of these are scarce. There are a number of pharmacological treatment options available to clinicians but efficacy is uncertain and concern about potential side effects in an aging and vulnerable population needs to be taken into consideration. This review aims to provide a concise overview of pharmacological treatments for depression in dementia. Antidepressants are the mainstay of pharmacological treatment for clinically significant depression in the general population but evidence to support their use in dementia is mixed. Trials of antidepressants should generally be reserved for individuals with depression where the symptoms are distressing and surpass the threshold for major depression. Acetylcholinesterase inhibitors and memantine are effective in the symptomatic treatment of Alzheimer's disease but current evidence does not support their use to treat depressive symptoms in dementia. Similarly, antipsychotics and mood stabilizers have no proven efficacy for depression and the risk of adverse effects seems to outweigh any potential benefit. Pain can be a frequent problem in dementia and may have significant effects on behavior and mood. Preliminary evidence supports a role of adequate analgesia in improving mood in people with dementia.

Host-Guest Complexes of Carboxylated Pillar[n]arenes With Drugs.

PubMed

Wheate, Nial J; Dickson, Kristie-Ann; Kim, Ryung Rae; Nematollahi, Alireza; Macquart, René B; Kayser, Veysel; Yu, Guocan; Church, W Bret; Marsh, Deborah J

2016-12-01

Pillar[n]arenes are a new family of nanocapsules that have shown application in a number of areas, but because of their poor water solubility their biomedical applications are limited. Recently, a method of synthesizing water-soluble pillar[n]arenes was developed. In this study, carboxylated pillar[n]arenes (WP[n], n = 6 or 7) have been examined for their ability to form host-guest complexes with compounds relevant to drug delivery and biodiagnostic applications. Both pillar[n]arenes form host-guest complexes with memantine, chlorhexidine hydrochloride, and proflavine by 1 H nuclear magnetic resonance and modeling. Binding is stabilized by hydrophobic effects within the cavities, and hydrogen bonding and electrostatic interactions at the portals. Encapsulation within WP[6] results in the complete and efficient quenching of proflavine fluorescence, giving rise to "on" and "off" states that have potential in biodiagnostics. The toxicity of the pillar[n]arenes was examined using in vitro growth assays with the OVCAR-3 and HEK293 cell lines. The pillar[n]arenes are relatively nontoxic to cells except at high doses and after prolonged continuous exposure. Overall, the results show that there could be a potentially large range of medical applications for carboxylated pillar[n]arene nanocapsules. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Treatment of Alzheimer’s disease in Brazil: II. Behavioral and psychological symptoms of dementia

PubMed Central

do Vale, Francisco de Assis Carvalho; Corrêa Neto, Ylmar; Bertolucci, Paulo Henrique Ferreira; Machado, João Carlos Barbosa; da Silva, Delson José; Allam, Nasser; Balthazar, Márcio Luiz Figueredo

2011-01-01

This article reports the recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology for the treatment of Alzheimer’s disease (AD) in Brazil, with special focus on behavioral and psychological symptoms of dementia (BPSD). It constitutes a revision and broadening of the 2005 guidelines based on a consensus involving researchers (physicians and non-physicians) in the field. The authors carried out a search of articles published since 2005 on the MEDLINE, LILACS and Cochrane Library databases. The search criteria were pharmacological and non-pharmacological treatment of the behavioral and psychological symptoms of AD. Studies retrieved were categorized into four classes, and evidence into four levels, based on the 2008 recommendations of the American Academy of Neurology. The recommendations on therapy are pertinent to the dementia phase of AD. Recommendations are proposed for the treatment of BPSD encompassing both pharmacological (including acetyl-cholinesterase inhibitors, memantine, neuroleptics, anti-depressives, benzodiazepines, anti-convulsants plus other drugs and substances) and non-pharmacological (including education-based interventions, physiotherapy, occupational therapy, music therapy, therapy using light, massage and art therapy) approaches. Recommendations for the treatment of cognitive disorders of AD symptoms are included in a separate article of this edition. PMID:29213743

A Review of Pharmacologic Treatment for Compulsive Buying Disorder.

PubMed

Soares, Célia; Fernandes, Natália; Morgado, Pedro

2016-04-01

At present, no treatment recommendations can be made for compulsive buying disorder. Recent studies have found evidence for the efficacy of psychotherapeutic options, but less is known regarding the best pharmacologic treatment. The purpose of this review is to present and analyze the available published evidence on the pharmacological treatment of compulsive buying disorder. To achieve this, we conducted a review of studies focusing on the pharmacological treatment of compulsive buying by searching the PubMed/MEDLINE database. Selection criteria were applied, and 21 studies were identified. Pharmacological classes reported included antidepressants, mood stabilizers, opioid antagonists, second-generation antipsychotics, and N-methyl-D-aspartate receptor antagonists. We found only placebo-controlled trials for fluvoxamine; none showed effectiveness against placebo. Three open-label trials reported clinical improvement with citalopram; one was followed by a double-blind discontinuation. Escitalopram was effective in an open-label trial but did not show efficacy in the double-blind phase. Memantine was identified as effective in a pilot open-label study. Fluoxetine, bupropion, nortriptyline, clomipramine, topiramate and naltrexone were only reported to be effective in clinical cases. According to the available literature, there is no evidence to propose a specific pharmacologic agent for compulsive buying disorder. Future research is required for a better understanding of both pathogenesis and treatment of this disorder.

Catatonia in the medically ill: Etiology, diagnosis, and treatment. The Academy of Consultation-Liaison Psychiatry Evidence-Based Medicine Subcommittee Monograph.

PubMed

Denysenko, Lex; Sica, Nicole; Penders, Thomas M; Philbrick, Kemuel L; Walker, Audrey; Shaffer, Scott; Zimbrean, Paula; Freudenreich, Oliver; Rex, Nicole; Carroll, Brendan T; Francis, Andrew

2018-05-01

Catatonia in medically ill patients is rare but often unrecognized. This monograph summarizes current knowledge on the diagnosis, epidemiology, etiology, and management of catatonia occurring in the medical setting. PubMed searches were used to identify relevant articles from 1962 to present. More than 3,000 articles were obtained and reviewed for relevance, including references of articles identified by the initial search. Several areas were identified as important, including: (1) catatonia and delirium; (2) malignant catatonia; (3) pediatric catatonia; (4) catatonia associated with another medical condition (CAMC); (5) drug exposure and withdrawal syndromes associated with catatonia; and (6) treatment of catatonia in the medical setting. Catatonia in the medically ill appears to have numerous etiologies, although etiology does not seem to modify the general treatment approach of prompt administration of lorazepam. Delirium and catatonia are commonly comorbid in the medical setting and should not be viewed as mutually exclusive. Electroconvulsive therapy should be offered to patients who do not respond to benzodiazepines or have malignant features. Removing offending agents and treating the underlying medical condition is paramount when treating CAMC. Memantine or amantadine may be helpful adjunctive agents. There is not enough evidence to support the use of antipsychotics or stimulants in treating CAMC.

Mitochondria and NMDA Receptor-Dependent Toxicity of Berberine Sensitizes Neurons to Glutamate and Rotenone Injury

PubMed Central

Kysenius, Kai; Brunello, Cecilia A.; Huttunen, Henri J.

2014-01-01

The global incidence of metabolic and age-related diseases, including type 2 diabetes and Alzheimer's disease, is on the rise. In addition to traditional pharmacotherapy, drug candidates from complementary and alternative medicine are actively being pursued for further drug development. Berberine, a nutraceutical traditionally used as an antibiotic, has recently been proposed to act as a multi-target protective agent against type 2 diabetes, dyslipidemias, ischemic brain injury and neurodegenerative diseases, such as Parkinson's and Alzheimer's disease. However, the safety profile of berberine remains controversial, as isolated reports suggest risks with acute toxicity, bradycardia and exacerbation of neurodegeneration. We report that low micromolar berberine causes rapid mitochondria-dependent toxicity in primary neurons characterized by mitochondrial swelling, increased oxidative stress, decreased mitochondrial membrane potential and depletion of ATP content. Berberine does not induce caspase-3 activation and the resulting neurotoxicity remains unaffected by pan-caspase inhibitor treatment. Interestingly, inhibition of NMDA receptors by memantine and MK-801 completely blocked berberine-induced neurotoxicity. Additionally, subtoxic nanomolar concentrations of berberine were sufficient to sensitize neurons to glutamate excitotoxicity and rotenone injury. Our study highlights the need for further safety assessment of berberine, especially due to its tendency to accumulate in the CNS and the risk of potential neurotoxicity as a consequence of increasing bioavailability of berberine. PMID:25192195

The role of 5 HT6-receptor antagonists in Alzheimer's disease: an update.

PubMed

Khoury, Rita; Grysman, Noam; Gold, Jake; Patel, Kush; Grossberg, George T

2018-06-01

Despite recent advances in Alzheimer's disease (AD) research, no breakthrough treatments have been discovered. Cholinesterase inhibitors and the NMDA-receptor antagonist memantine are currently the two approved symptomatic treatments for AD. 5-HT6 receptor antagonism has recently emerged as a promising treatment strategy to improve cognition in AD, with a modest side-effect profile. Areas covered: 5-HT6 receptors, exclusively found in the central nervous system, modulate primarily GABA and glutamate levels, facilitating the secondary release of other neurotransmitters including dopamine, noradrenaline, and acetylcholine, all of which are compromised in AD. This review discusses findings of preclinical and phase I-III clinical trials conducted with three major 5-HT6 receptor antagonists: idalopirdine, intepirdine, and SUVN-502, in the field of AD. Expert opinion: Despite early positive findings, larger phase-III trials have failed to demonstrate any statistically significant impact on cognition for both idalopirdine and intepirdine, as adjunct to cholinesterase inhibitors. Paradoxically, 5-HT6 receptor agonists have also been shown to have cognitive enhancing properties. Thus, a better understanding of the mechanism of action of the 5-HT6 receptor and its ligands is warranted. Investigating 5-HT6 receptor partial or inverse agonists may be promising in future AD trials.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, L.W.; Talbot, B.G.; Lennox, W.J.

A pretreatment for organophosphorus (OP) anticholinesterase (e. g. , soman) intoxication should prevent lethality and convulsions (CNV) at 2 LD50s and be behavioral-decrement-free when given alone. Behavioral-deficit-free pretreatment regimens (PRGs) for guinea pigs consisted of Physostigmine (0.15 mg/kg, im) and adjunct. Adjuncts MG/KG, IM tested were akineton 0.25, aprophen 8, trihexyphenidyl 2, atropine 16, azaprophen 51, BENACTYZINE 1.25, cogentin 4, dextromethorphan 7.5, ethopropazine 12, kemadrin 11, MEMANTINE 5, promethazine 5, scopolamine 0.081 AND CONTROL 2. PRGs were given 30 min before soman (60 ug/kg, sc; 2 LD50S) or other OP agents. Animals were then observed and graded for signs ofmore » intoxication, including CNV at 7 time points and at 24 hr. Physostigmine alone reduced the incidence of CNV and lethality induced by 2 LD50s of soman by 42 and 60%, respectively. All of the PRGs tested abolished lethality and 12 shortened recovery time to 2 hr or less. Also, PRGs including azaprophen or atropine prevented CNV. When selected PRGs were tested against intoxication by sarin, tabun or VX, the efficacy was generally superior to that for soman. The data show that several PRGs are effective against soman intoxication in guinea pigs. Pretreatment, physostigmine, anticholinesterases, soman (GD).« less

Diagnosis and treatment of dementia: 6. Management of severe Alzheimer disease

PubMed Central

Herrmann, Nathan; Gauthier, Serge

2008-01-01

Background The management of severe Alzheimer disease often presents difficult choices for clinicians and families. The disease is characterized by a need for full-time care and assistance with basic activities of daily living. We outline an evidence-based approach for these choices based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia. Methods We developed evidence-based guidelines using systematic literature searches, with specific criteria for the selection and quality assessment of articles, and a clear and transparent decision-making process. We selected articles published from January 1996 to December 2005 that dealt with the management of severe Alzheimer disease. Subsequent to the conference, we searched for additional articles published from January 2006 to March 2008 using the same search terms. We graded the strength of the evidence using the criteria of the Canadian Task Force on Preventive Health Care. Results We identified 940 articles, of which 838 were selected for further study. Thirty-four articles were judged to be of at least good or fair quality and were used to generate 17 recommendations. Assessment of severe Alzheimer disease should include the measurement of cognitive function and the assessment of behaviour, function, medical status, nutrition, safety and caregiver status. Management could include treatment with a cholinesterase inhibitor or memantine, or both. Treatment of neuropsychiatric symptoms begins with nonpharmacologic approaches to addressing behavioural problems. Severe agitation, aggression and psychosis, which are potentially dangerous to the patient, the caregiver and others in the environment, can be treated with atypical antipsychotics, with consideration of their increased risk of cerebrovascular events and death. All pharmacologic approaches require careful monitoring and periodic reassessment to determine whether continued treatment is necessary. Caregiver support and use of community resources are essential. Interpretation Severe Alzheimer disease requires frequent monitoring by health professionals. Simple nonpharmacologic approaches may address problems with mood and agitation. Antipsychotic drug therapy is occasionally necessary despite the inherent risks. Therapy with a cholinesterase inhibitor and memantine may be useful for selected patients. Articles to date in this series Chertkow H. Diagnosis and treatment of dementia: Introduction. Introducing a series based on the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia. CMAJ 2008;178:316-21. Patterson C, Feightner JW, Garcia A, et al. Diagnosis and treatment of dementia: 1. Risk assessment and primary prevention of Alzheimer disease. CMAJ 2008;178:548-56. Feldman HH, Jacova C, Robillard A, et al. Diagnosis and treatment of dementia: 2. Diagnosis. CMAJ 2008;178:825-36. Chertkow H, Massoud F, Nasreddine Z, et al. Diagnosis and treatment of dementia: 3. Mild cognitive impairment and cognitive impairment without dementia. CMAJ 2008;178: 1273-85. Hogan DB, Bailey P, Black S, et al. Diagnosis and treatment of dementia: 4. Approach to management of mild to moderate dementia. CMAJ 2008;179:787-93. Hogan DB, Bailey P, Black S, et al. Diagnosis and treatment of dementia: 5. Nonpharmacologic and pharmacologic therapy for mild to moderate dementia. CMAJ 2008;179:1019-26. PMID:19047609

Ameliorating effect of anti-Alzheimer's drugs on the bidirectional association between type 2 diabetes mellitus and Alzheimer's disease.

PubMed

Ahmed, Amira S; Elgharabawy, Rehab M; Al-Najjar, Amal H

2017-07-01

Mild to severe forms of nervous system damage were exhibited by approximately 60-70% of diabetics. It is important to understand the association between type 2 diabetes mellitus and Alzheimer's disease. The aim of the present work is to understand the bidirectional association between type 2 diabetes and Alzheimer's disease pathogenesis, that was monitored by glycaemic status, lipid profile, amyloid beta 40 and 42 (Aβ40 and Aβ42), C-reactive protein, total creatine kinase, total lactate dehydrogenase, D-dimer and magnesium measurements, to assess the association between theses biochemical markers and each other, to estimate the possibility of utilizing the amyloid beta as biochemical marker of T2D in Alzheimer's patients, and to evaluate the effect of piracetam and memantine drugs on diabetes mellitus. This study involved 120 subjects divided into 20 healthy control (group I), 20 diabetic patients (group II), 20 Alzheimer's patients (group III), 20 diabetic Alzheimer's patients with symptomatic treatment (group IV), 20 diabetic Alzheimer's patients treated with memantine (group V), and 20 diabetic Alzheimer's patients treated with piracetam (group VI). The demographic characteristics, diabetic index, and lipid profile were monitored. Plasma amyloid beta 40 and amyloid beta 42, C-reactive protein, total creatine kinase, total lactate dehydrogenase, D-dimer, and magnesium were assayed. The levels of amyloid beta 40 and amyloid beta 42 were significantly elevated in diabetic Alzheimer's patients with symptomatic treatment (group IV) compared to group II (by 50.5 and 7.5 fold, respectively) and group III (by 25.4 and 2.8 fold, respectively). In groups II, III, IV, V and VI, significant and positive associations were monitored between insulin and amyloid beta 40, amyloid beta 42, C-reactive protein, total creatine kinase, and D-dimer. Diabetic markers were significantly decreased in diabetic Alzheimer's patients treated with anti-Alzheimer's drugs (especially piracetam) compared to group IV. This study reveals the role of amyloid beta 40, amyloid beta 42, insulin, HbA1c, lipid profile disturbance, C-reactive protein, D-dimer, and magnesium in the bidirectional correlation between T2D and pathogenesis of Alzheimer's disease, that is powered by their correlations, and therefore the possibility of utilizing Aβ as a biochemical marker of T2D in Alzheimer's patients is recommended. Impact statement Several aspects associated with T2D that contribute to AD and vice versa were investigated in this study. Additionally, this work reveals the role of Aβ40, Aβ42, insulin, HbA1c, lipid profile disturbance, CRP, D-dimer, and magnesium in the bidirectional association between T2D and the pathogenesis of AD, that is powered by their correlations, and therefore the possibility of utilizing Aβ as a biochemical marker of T2D in Alzheimer's patients is recommended. Furthermore, the ameloriating effect of anti-Alzheimer's drugs on diabetes mellitus confirms this association. Hereafter, a new approach for treating insulin resistance and diabetes may be developed by new therapeutic potentials such as neutralization of Aβ by anti-Aβ antibodies.

The present and future of pharmacotherapy of Alzheimer's disease: A comprehensive review.

PubMed

Anand, Abhinav; Patience, Albert Anosi; Sharma, Neha; Khurana, Navneet

2017-11-15

Alzheimer's disease (AD) is a generalized term used for the loss in memory and other intellectual abilities on levels serious enough to interfere with daily life. It accounts for 60-80% of dementia cases. The characteristic features include aggregation of Amyloid-Beta (Aβ) plaques and Tau Protein Tangles in the nervous tissue of brain. Another important aspect associated with development of AD is the decrease in levels of Acetylcholine (ACh) in brain. The conventional pharmacotherapy of AD employs the use of compounds that inhibit the enzyme acetylcholinesterase (e.g. donepezil, rivastigmine) thereby elevating the levels of Acetylcholine in nervous tissue of brain. Lately, another drug has come into picture for treatment of AD i.e.memantine. It is a Glutamatergic antagonist that protects the nervous tissue against glutamate mediated excitotoxicity. However, both these classes of drugs provide only the symptomatic relief. There has been a desperate need arising since the past few decades for evolution of a drug that could treat the underlying causes of AD and thereby halt its development in susceptible individuals. There are several plants and derived products which have been employed for their benefits against the symptoms and complications of AD. Some novel drugs having the potential to moderate AD are under clinical trials. This review presents a comprehensive overview of the existing and the upcoming potential treatments for AD. Copyright © 2017 Elsevier B.V. All rights reserved.

Development and validation of a sensitive LC-MS/MS method with electrospray ionization for quantitation of pramipexole in human plasma: application to a clinical pharmacokinetic study.

PubMed

Bharathi, D Vijaya; Hotha, Kishore Kumar; Sagar, P V Vidya; Kumar, S Sirish; Naidu, A; Mullangi, Ramesh

2009-02-01

A highly sensitive and specific LC-MS/MS method has been developed and validated for the estimation of pramipexole (PPX) with 500 microL human plasma using memantine as an internal standard (IS). The API-4000 was operated under multiple-reaction monitoring mode (MRM) using the electrospray ionization technique. Solid-phase extraction was used to extract PPX and IS from human plasma. The resolution of peaks was achieved with 0.01 m ammonium acetate buffer (pH 4.4):acetonitrile (30:70, v/v) on a Discovery CN column. The total chromatographic run time was 3.0 min and the elution of PPX and IS occurred at approximately 2.32 and 2.52, respectively. The MS/MS ion transitions monitored were 212.10 --> 153.10 for PPX and 180.20 --> 107.30 for IS. The method was proved to be accurate and precise at linearity range of 20-3540 pg/mL with a correlation coefficient (r) of > or =0.999. The intra- and inter-day precision and accuracy values found to be within the assay variability limits as per the FDA guidelines. The developed assay method was applied to a pharmacokinetic study in human volunteers following oral administration of 0.25 mg PPX tablet. Copyright (c) 2008 John Wiley & Sons, Ltd.

Copper chelator induced efficient episodic memory recovery in a non-transgenic Alzheimer's mouse model.

PubMed

Ceccom, Johnatan; Coslédan, Frédéric; Halley, Hélène; Francès, Bernard; Lassalle, Jean Michel; Meunier, Bernard

2012-01-01

Alzheimer's disease (AD) is a neurodegenerative syndrom involving many different biological parameters, including the accumulation of copper metal ions in Aβ amyloid peptides due to a perturbation of copper circulation and homeostasis within the brain. Copper-containing amyloids activated by endogenous reductants are able to generate an oxidative stress that is involved in the toxicity of abnormal amyloids and contribute to the progressive loss of neurons in AD. Since only few drugs are currently available for the treatment of AD, we decided to design small molecules able to interact with copper and we evaluated these drug-candidates with non-transgenic mice, since AD is mainly an aging disease, not related to genetic disorders. We created a memory deficit mouse model by a single icv injection of Aβ(1-42) peptide, in order to mimic the early stage of the disease and the key role of amyloid oligomers in AD. No memory deficit was observed in the control mice with the antisense Aβ(42-1) peptide. Here we report the capacity of a new copper-specific chelating agent, a bis-8-aminoquinoline PA1637, to fully reverse the deficit of episodic memory after three weeks of treatment by oral route on non-transgenic amyloid-impaired mice. Clioquinol and memantine have been used as comparators to validate this fast and efficient mouse model.

Cognitive intervention therapy as treatment for behaviour disorders in Alzheimer disease: evidence on efficacy and neurobiological correlations.

PubMed

García-Alberca, J M

2015-01-01

The prevalence of behavioural and psychological symptoms (BPS) is very high among patients with Alzheimer disease (AD); more than 90% of AD patients will present such symptoms during the course of the disease. These symptoms result in poorer quality of life for both patients and caregivers and increased healthcare costs. BPS are the main factors involved in increases to the caregiver burden, and they often precipitate the admission of patients to residential care centres. Current consensus holds that intervention models combining pharmacological and non-pharmacological treatments are the most effective for AD patients. Several studies have shown cholinesterase inhibitors and memantine combined with cognitive intervention therapy (CIT) to be effective for improving patients' cognitive function and functional capacity for undertaking daily life activities. However, the efficacy of CIT as a treatment for BPS has not yet been clearly established, which limits its use for this purpose in clinical practice. The objective of this review is to gather available evidence on the efficacy of cognitive intervention therapy (CIT) on BPS in patients with AD. The results of this review suggest that CIT may have a beneficial effect on BPS in patients with AD and should therefore be considered a treatment option for patients with AD and BPS. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Efficacy of Stereotactic Radiosurgery in Patients with Multiple Metastases: Importance of Volume Rather Than Number of Lesions.

PubMed

Dahshan, Basem A; Mattes, Malcolm D; Bhatia, Sanjay; Palek, Mary Susan; Cifarelli, Christopher P; Hack, Joshua D; Vargo, John A

2017-12-19

The role of stereotactic radiosurgery (SRS) in the treatment of multiple brain metastases is controversial. While whole brain radiation therapy (WBRT) has historically been the mainstay of treatment, its value is increasingly being questioned as emerging data supports that SRS alone can provide comparable therapeutic outcomes for limited (one to three) intracranial metastases with fewer adverse effects, including neurocognitive decline. Multiple recent studies have also demonstrated that patients with multiple (> 3) intracranial metastases with a low overall tumor volume have a favorable therapeutic response to SRS, with no significant difference compared to patients with limited metastases. Herein, we present a patient with previously controlled breast cancer who presented with multiple recurrences of intracranial metastases but low total intracranial tumor volume each time. This patient underwent SRS alone for a total of 40 metastatic lesions over three separate procedures with good local control and without any significant cognitive toxicity. The patient eventually opted for enrollment in the NRG-CC001 clinical trial after multiple cranial recurrences. She received conventional WBRT with six months of memantine and developed significant neurocognitive side effects. This case highlights the growing body of literature supporting the role of SRS alone in the management of multiple brain metastases and the importance of maximizing neurocognition as advances in systemic therapies prolong survival in Stage IV cancer.

Efficacy of Stereotactic Radiosurgery in Patients with Multiple Metastases: Importance of Volume Rather Than Number of Lesions

PubMed Central

Mattes, Malcolm D; Bhatia, Sanjay; Palek, Mary Susan; Cifarelli, Christopher P; Hack, Joshua D; Vargo, John A

2017-01-01

The role of stereotactic radiosurgery (SRS) in the treatment of multiple brain metastases is controversial. While whole brain radiation therapy (WBRT) has historically been the mainstay of treatment, its value is increasingly being questioned as emerging data supports that SRS alone can provide comparable therapeutic outcomes for limited (one to three) intracranial metastases with fewer adverse effects, including neurocognitive decline. Multiple recent studies have also demonstrated that patients with multiple (> 3) intracranial metastases with a low overall tumor volume have a favorable therapeutic response to SRS, with no significant difference compared to patients with limited metastases. Herein, we present a patient with previously controlled breast cancer who presented with multiple recurrences of intracranial metastases but low total intracranial tumor volume each time. This patient underwent SRS alone for a total of 40 metastatic lesions over three separate procedures with good local control and without any significant cognitive toxicity. The patient eventually opted for enrollment in the NRG-CC001 clinical trial after multiple cranial recurrences. She received conventional WBRT with six months of memantine and developed significant neurocognitive side effects. This case highlights the growing body of literature supporting the role of SRS alone in the management of multiple brain metastases and the importance of maximizing neurocognition as advances in systemic therapies prolong survival in Stage IV cancer. PMID:29492355

Effectiveness of nootropic drugs with cholinergic activity in treatment of cognitive deficit: a review

PubMed Central

Colucci, Luisa; Bosco, Massimiliano; Ziello, Antonio Rosario; Rea, Raffaele; Amenta, Francesco; Fasanaro, Angiola Maria

2012-01-01

Nootropics represent probably the first “smart drugs” used for the treatment of cognitive deficits. The aim of this paper is to verify, by a systematic analysis of the literature, the effectiveness of nootropics in this indication. The analysis was limited to nootropics with cholinergic activity, in view of the role played by acetylcholine in learning and memory. Acetylcholine was the first neurotransmitter identified in the history of neuroscience and is the main neurotransmitter of the peripheral, autonomic, and enteric nervous systems. We conducted a systematic review of the literature for the 5-year period 2006–2011. From the data reported in the literature, it emerges that nootropics may be an effective alternative for strengthening and enhancing cognitive performance in patients with a range of pathologies. Although nootropics, and specifically the cholinergic precursors, already have a long history behind them, according to recent renewal of interest, they still seem to have a significant therapeutic role. Drugs with regulatory indications for symptomatic treatment of Alzheimer’s disease, such as cholinesterase inhibitors and memantine, often have transient effects in dementia disorders. Nootropics with a cholinergic profile and documented clinical effectiveness in combination with cognate drugs such as cholinesterase inhibitors or alone in patients who are not suitable for these inhibitors should be taken into account and evaluated further. PMID:27186129

Pharmacogenetic studies in Alzheimer disease.

PubMed

Zúñiga Santamaría, T; Yescas Gómez, P; Fricke Galindo, I; González González, M; Ortega Vázquez, A; López López, M

2018-06-10

Alzheimer disease (AD) is the most common cause of dementia and is considered one of the main causes of disability and dependence affecting quality of life in elderly people and their families. Current pharmacological treatment includes acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine; however, only one-third of patients respond to treatment. Genetic factors have been shown to play a role in this inter-individual variability in drug response. We review pharmacogenetic reports of AD-modifying drugs, the pharmacogenetic biomarkers included, and the phenotypes evaluated. We also discuss relevant methodological considerations for the design of pharmacogenetic studies into AD. A total of 33 pharmacogenetic reports were found; the majority of these focused on the variability in response to and metabolism of donepezil. Most of the patients included were from Caucasian populations, although some studies also include Korean, Indian, and Brazilian patients. CYP2D6 and APOE are the most frequently studied biomarkers. The associations proposed are controversial. Potential pharmacogenetic biomarkers for AD have been identified; however, it is still necessary to conduct further research into other populations and to identify new biomarkers. This information could assist in predicting patient response to these drugs and contribute to better treatment decision-making in a context as complex as aging. Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Prospective evaluation of behavioral scales in the behavioral variant of frontotemporal dementia.

PubMed

Boutoleau-Bretonnière, Claire; Lebouvier, Thibaud; Volteau, Christelle; Jaulin, Philippe; Lacomblez, Lucette; Damier, Philippe; Thomas-Anterion, Catherine; Vercelletto, Martine

2012-01-01

The Neuropsychiatric Inventory (NPI) and the Frontal Behavioral Inventory (FBI) are widely used in patients with the behavioral variant of frontotemporal dementia (bvFTD). Yet, few data are available on the long-term relevance of these scales. Based on a bvFTD population that participated in the Memantine Clinical Trial (NCT00200538), we studied the evolution and correlation between scores obtained on behavioral scales (NPI and FBI), cognitive scales [Mini-Mental State Examination (MMSE) and Mattis Dementia Rating Scale (MDRS)] and a burden scale [Zarit Burden Inventory (ZBI)]. The assessments were performed at 1 year in 41 patients and at 2 years in 23 patients who agreed to participate in this open-label study. The 2-year scores obtained on the FBI were significantly higher than the scores at inclusion while those obtained on the NPI did not change. There were significant correlations between the FBI, and the MDRS and MMSE, especially regarding the negative items. The ZBI correlated with behavioral scales at all stages for positive items. This study based on a large population shows that the FBI is a better tool than the NPI for the long-term assessment of bvFTD patients. Moreover, the FBI allows a distinction to be made between behavioral disturbances that involve cognitive functions from those which have an important impact on caregiver burden. Copyright © 2012 S. Karger AG, Basel.

Sequential drug treatment algorithm for agitation and aggression in Alzheimer's and mixed dementia.

PubMed

Davies, Simon Jc; Burhan, Amer M; Kim, Donna; Gerretsen, Philip; Graff-Guerrero, Ariel; Woo, Vincent L; Kumar, Sanjeev; Colman, Sarah; Pollock, Bruce G; Mulsant, Benoit H; Rajji, Tarek K

2018-05-01

Behavioural and psychological symptoms of dementia (BPSD) include agitation and aggression in people with dementia. BPSD is common on inpatient psychogeriatric units and may prevent individuals from living at home or in residential/nursing home settings. Several drugs and non-pharmacological treatments have been shown to be effective in reducing behavioural and psychological symptoms of dementia. Algorithmic treatment may address the challenge of synthesizing this evidence-based knowledge. A multidisciplinary team created evidence-based algorithms for the treatment of behavioural and psychological symptoms of dementia. We present drug treatment algorithms for agitation and aggression associated with Alzheimer's and mixed Alzheimer's/vascular dementia. Drugs were appraised by psychiatrists based on strength of evidence of efficacy, time to onset of clinical effect, tolerability, ease of use, and efficacy for indications other than behavioural and psychological symptoms of dementia. After baseline assessment and discontinuation of potentially exacerbating medications, sequential trials are recommended with risperidone, aripiprazole or quetiapine, carbamazepine, citalopram, gabapentin, and prazosin. Titration schedules are proposed, with adjustments for frailty. Additional guidance is given on use of electroconvulsive therapy, optimization of existing cholinesterase inhibitors/memantine, and use of pro re nata medications. This algorithm-based approach for drug treatment of agitation/aggression in Alzheimer's/mixed dementia has been implemented in several Canadian Hospital Inpatient Units. Impact should be assessed in future research.

Combining drug and music therapy in patients with moderate Alzheimer's disease: a randomized study.

PubMed

Giovagnoli, Anna Rita; Manfredi, Valentina; Schifano, Letizia; Paterlini, Chiara; Parente, Annalisa; Tagliavini, Fabrizio

2018-06-01

Alzheimer's disease (AD) can impair language, but active music therapy (AMT) and memantine (M) can improve communication. This study aimed to clarify whether adding AMT to M may improve language in comparison with drugs alone in patients with moderate AD on stable therapy with acetylcholinesterase inhibitors (AchEI). Forty-five AD patients treated with stable dose of AchEI were randomized to receive AMT plus M 20 mg/day or M 20 mg/day for 24 weeks. The Severe Impairment Battery-Language (SIB-l), SIB, Mini Mental State Examination, Neuropsychiatric Inventory (NPI), Lubben Social Network Scale, Activities of Daily Living, and Instrumental Activities of Daily Living scores at baseline and 12 and 24 weeks assessed language (primary variable) and overall cognitive, psycho-behavior, social, and functional aspects (secondary variables). The SIB-l showed a stabilization of the baseline condition in both groups, in the absence of between-group differences. The NPI depression and appetite scores significantly improved in the M-AMT group. Moreover, significantly less patients in the M-AMT group than those in the M group showed worsening of the NPI total score. Daily activities, social relationships, and overall cognitive performance did not deteriorate. In patients with moderate AD, AMT added to pharmacotherapy has no further benefits for language in comparison with pharmacotherapy alone. However, this integrated treatment can improve the psycho-behavioral profile.

The Role of Glutamate Signalling in the Pathogenesis and Treatment of Obsessive-Compulsive Disorder

PubMed Central

Wu, Ke; Hanna, Gregory L.; Rosenberg, David R.; Arnold, Paul D

2011-01-01

Obsessive-compulsive disorder (OCD) is a common and often debilitating neuropsychiatric condition characterized by persistent intrusive thoughts (obsessions), repetitive ritualistic behaviours (compulsions) and excessive anxiety. While the neurobiology and etiology of OCD has not been fully elucidated, there is growing evidence that disrupted neurotransmission of glutamate within corticalstriatal-thalamocortical (CSTC) circuitry plays a role in OCD pathogenesis. This review summarizes the findings from neuroimaging, animal model, candidate gene and treatment studies in the context of glutamate signalling dysfunction in OCD. First, studies using magnetic resonance spectroscopy are reviewed demonstrating altered glutamate concentrations in the caudate and anterior cingulate cortex of patients with OCD. Second, knockout mouse models, particularly the DLGAP3 and Slitrk5 knockout mouse models, display remarkably similar phenotypes of compulsive grooming behaviour associated with glutamate signalling dysfunction. Third, candidate gene studies have identified associations between variants in glutamate system genes and OCD, particularly for SLC1A1 which has been shown to be associated with OCD in five independent studies. This converging evidence for a role of glutamate in OCD has led to the development of novel treatment strategies involving glutamatergic compounds, particularly riluzole and memantine. We conclude the review by outlining a glutamate hypothesis for OCD, which we hope will inform further research into etiology and treatment for this severe neuropsychiatric condition. PMID:22024159

Strategies for Continued Successful Treatment in Patients with Alzheimer's Disease: An Overview of Switching Between Pharmacological Agents.

PubMed

Blesa, Rafael; Toriyama, Kazuhiro; Ueda, Kengo; Knox, Sean; Grossberg, George

2018-06-12

Alzheimer's disease (AD) is the most common cause of dementia, characterized by a progressive decline in cognition and function. Current treatment options for AD include the cholinesterase inhibitors (ChEIs) donepezil, galantamine, and rivastigmine, as well as the N-methyl-D-aspartate receptor antagonist memantine. Treatment guidelines recommend the use of ChEIs as standard of care first-line therapy. Several randomized clinical studies have demonstrated the benefits of ChEIs on cognition, global function, behavior and activities of daily living. However, patients may fail to achieve sustained clinical benefits from ChEIs due to lack/loss of efficacy and/or safety, tolerability issues, and poor adherence to the treatment. The purpose of this review is to explore the strategies for continued successful treatment in patients with AD. Literature search was performed for articles published in PubMed and MEDLINE, using pre-specified search terms. Articles were critically evaluated for inclusion based on their titles, abstracts, and full text of the publication. The findings of this review indicate that dose up-titration and switching between ChEIs may help to improve response to ChEI treatment and also address issue such as lack/loss of efficacy or safety/tolerability in patients with AD. However, well-designed studies are needed to provide robust evidences. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

International price comparisons of Alzheimer's drugs: a way to close the affordability gap.

PubMed

Suh, Guk-Hee; Wimo, Anders; Gauthier, Serge; O'Connor, Daniel; Ikeda, Manabu; Homma, Akira; Dominguez, Jacqueline; Yang, Bong-Min

2009-12-01

Alzheimer's drugs are believed to have limited availability and to be unaffordable in low- and middle-income countries compared to high-income countries. The price, availability and affordability of Alzheimer's drugs have not been reported before. During 2007 an international survey was conducted in 21 countries in six continents (Argentina, Australia, Brazil, the Dominican Republic, France, India, Japan, Macedonia, Mexico, New Zealand, Nigeria, the Philippines, Portugal, Serbia, South Korea, Switzerland, Taiwan, Thailand, Uganda, the U.K. and the U.S.A.). Prices of Alzheimer's drugs were compared using the affordability index (the total number of units purchasable with one's daily income) derived from purchasing power parity (PPP) converted prices as well as raw prices. Donepezil is available in all 21 countries, whereas the newer drugs are less available. A 5 mg tablet of branded originator donepezil costs just US$0.26 in India and US$0.31 in Mexico, whereas it costs US$6.64 in the U.S.A. Pricing conditions of rivastigmine, galantamine and memantine appear to be similar to that of donepezil. The cheapest branded originators are from India and Mexico. However, in terms of PPP, Alzheimer's drugs in other low- and middle-income countries are much more expensive than in high-income countries. Most people in low- and middle-income countries cannot afford Alzheimer's drugs. Alzheimer's drugs, albeit available, are often unaffordable for those who need them most. It is hoped that equitable differential pricing will be applied to Alzheimer's drugs.

Progressive cholinergic decline in Alzheimer's Disease: consideration for treatment with donepezil 23 mg in patients with moderate to severe symptomatology.

PubMed

Sabbagh, Marwan; Cummings, Jeffrey

2011-02-07

Of the estimated 5.3 million people with Alzheimer's disease in the United States, more than half would be classified as having moderate or severe disease. Alzheimer's disease is a progressive disorder with the moderate to severe stages generally characterized by significant cognitive, functional, and behavioral dysfunction. Unsurprisingly, these advanced stages are often the most challenging for both patients and their caregivers/families. Symptomatic treatments for moderate to severe Alzheimer's disease are approved in the United States and include the acetylcholinesterase inhibitor donepezil and the glutamate receptor antagonist memantine. Progressive symptomatic decline is nevertheless inevitable even with the available therapies, and therefore additional treatment options are urgently needed for this segment of the Alzheimer's disease population. An immediate-release formulation of donepezil has been available at an approved dose of 5-10 mg/d for the past decade. Recently, the United States Food and Drug Administration approved a higher-dose (23 mg/d) donepezil formulation, which provides more gradual systemic absorption, a longer time to maximum concentration (8 hours) versus the immediate-release formulation (3 hours), and higher daily concentrations. Herein, we review (1) the scientific data on the importance of cholinergic deficits in Alzheimer's disease treatment strategies, (2) the rationale for the use of higher-dose acetylcholinesterase inhibitors in patients with advanced disease, and (3) recent clinical evidence supporting the use of higher-dose donepezil in patients with moderate to severe Alzheimer's disease.

New experimental treatments for core social domain in autism spectrum disorders.

PubMed

Canitano, Roberto

2014-01-01

Current therapeutics in autism spectrum disorders (ASD) only treat the associated symptoms, without addressing core social dysfunctions. A paradigm shift in research of the pathogenesis of ASD, its synaptic abnormalities and altered signaling in multiple dynamic systems, have led to new experimental treatments for treating the core social abnormalities of ASD. NMDA antagonists, especially memantine, have been introduced in clinical trials addressing glutamatergic transmission in children and adolescents with ASD. GABAergic signaling has been targeted in trials using the GABAB receptor agonist arbaclofen for ASD patients with promising results. Oxytocin has been recognized as implicated in social development and affiliative behaviors. Preliminary findings from clinical trials using oxytocin in children with ASD show encouraging improvements in social cognition, but larger studies are needed. In two of the single gene disorders associated with ASD, Insulin Growth Factor (IGF-1) is a new treatment that has been tested in Rett syndrome and Phelan-McDermid syndrome (Chromosome 22 deletion syndrome). IGF-1 has been demonstrated to reverse the reduction in the number of excitatory synapses and the density of neurons that characterize these conditions in animal studies and it is being introduced as an experimental treatment. As a novel approach to verify treatment efficacy, neural processing modifications were recently evaluated by fMRI after a pivotal response training intervention. Another study of neural changes in response to treatment examined variations in EEG signaling in patients after an Early Start Denver Model (ESDM) intervention.

Amyloid-beta peptide oligomers disrupt axonal transport through an NMDA receptor-dependent mechanism that is mediated by glycogen synthase kinase 3beta in primary cultured hippocampal neurons.

PubMed

Decker, Helena; Lo, Karen Y; Unger, Sandra M; Ferreira, Sergio T; Silverman, Michael A

2010-07-07

Disruption of axonal transport is a hallmark of several neurodegenerative diseases, including Alzheimer's disease (AD). Even though defective transport is considered an early pathologic event, the mechanisms by which neurodegenerative insults impact transport are poorly understood. We show that soluble oligomers of the amyloid-beta peptide (AbetaOs), increasingly recognized as the proximal neurotoxins in AD pathology, induce disruption of organelle transport in primary hippocampal neurons in culture. Live imaging of fluorescent protein-tagged organelles revealed a marked decrease in axonal trafficking of dense-core vesicles and mitochondria in the presence of 0.5 microm AbetaOs. NMDA receptor (NMDAR) antagonists, including d-AP5, MK-801, and memantine, prevented the disruption of trafficking, thereby identifying signals for AbetaO action at the cell membrane. Significantly, both pharmacological inhibition of glycogen synthase kinase-3beta (GSK-3beta) and transfection of neurons with a kinase-dead form of GSK-3beta prevented the transport defect. Finally, we demonstrate by biochemical and immunocytochemical means that AbetaOs do not affect microtubule stability, indicating that disruption of transport involves a more subtle mechanism than microtubule destabilization, likely the dysregulation of intracellular signaling cascades. Results demonstrate that AbetaOs negatively impact axonal transport by a mechanism that is initiated by NMDARs and mediated by GSK-3beta and establish a new connection between toxic Abeta oligomers and AD pathology.

Clinical effectiveness of rivastigmine monotherapy and combination therapy in Alzheimer's patients.

PubMed

Sonali, Nirmal; Tripathi, Manjari; Sagar, Rajesh; Velpandian, Thirumurthy; Subbiah, Vivekanandhan

2013-02-01

Rivastigmine is an acetylcholinesterase inhibitor; the genotype data seen alongside the phenotype data explain the mutation or the molecular genetics involved and also help to relate the phenotype of an individual with their genotype. To determine the clinical effectiveness of CYP2D6, CYP3A4, CYP2C9/19, and UGT polymorphism on the steady-state plasma concentrations and therapeutic outcome of rivastigmine monotherapy and combination therapy in patients with Alzheimer's disease. In this study, a significant allele frequency was observed for CYP2D6*3 polymorphism in patients under rivastigmine combination therapy (A>del = 0.50 [patients] and A>del = 0.20 [controls]), UGT2B7 (T = 0.17 [patients] and 0.33 [Controls], and UGT1A9*5 A = 0.58 [patients] and 0.26 [Controls]). The drug levels and P value of responders/nonresponders were found to be 0.17 ± 0.08/0.22 ± 0.16 and 0.574 for rivastigmine and 0.18 ± 0.11/0.66 ± 0.63 and 0.009 for rivastigmine in combination therapy and 1.40 ± 0.65/0.59 ± 0.84 and 0.05 for memantine in combination therapy. Poor metabolizer subjects of UGT2B7 polymorphism in patients under rivastigmine combination therapy have higher drug levels with a poor response to the drug treatments. © 2012 Blackwell Publishing Ltd.

Recent Development of Multifunctional Agents as Potential Drug Candidates for the Treatment of Alzheimer's Disease

PubMed Central

Guzior, Natalia; ckowska,, Anna Wię; Panek, Dawid; Malawska, Barbara

2015-01-01

Alzheimer’s disease (AD) is a complex and progressive neurodegenerative disorder. The available therapy is limited to the symptomatic treatment and its efficacy remains unsatisfactory. In view of the prevalence and expected increase in the incidence of AD, the development of an effective therapy is crucial for public health. Due to the multifactorial aetiology of this disease, the multi-target-directed ligand (MTDL) approach is a promising method in search for new drugs for AD. This review updates information on the development of multifunctional potential anti-AD agents published within the last three years. The majority of the recently reported structures are acetylcholinesterase inhibitors, often endowed with some additional properties. These properties enrich the pharmacological profile of the compounds giving hope for not only symptomatic but also causal treatment of the disease. Among these advantageous properties, the most often reported are an amyloid-β anti-aggregation activity, inhibition of β-secretase and monoamine oxidase, an antioxidant and metal chelating activity, NO-releasing ability and interaction with cannabinoid, NMDA or histamine H3 receptors. The majority of novel molecules possess heterodimeric structures, able to interact with multiple targets by combining different pharmacophores, original or derived from natural products or existing therapeutics (tacrine, donepezil, galantamine, memantine). Among the described compounds, several seem to be promising drug candidates, while others may serve as a valuable inspiration in the search for new effective therapies for AD. PMID:25386820

Modulation of neurological deficits and expression of glutamate receptors during experimental autoimmune encephalomyelitis after treatment with selected antagonists of glutamate receptors.

PubMed

Sulkowski, Grzegorz; Dąbrowska-Bouta, Beata; Strużyńska, Lidia

2013-01-01

The aim of our investigation was to characterize the role of group I mGluRs and NMDA receptors in pathomechanisms of experimental autoimmune encephalomyelitis (EAE), the rodent model of MS. We tested the effects of LY 367385 (S-2-methyl-4-carboxyphenylglycine, a competitive antagonist of mGluR1), MPEP (2-methyl-6-(phenylethynyl)-pyridine, an antagonist of mGluR5), and the uncompetitive NMDA receptor antagonists amantadine and memantine on modulation of neurological deficits observed in rats with EAE. The neurological symptoms of EAE started at 10-11 days post-injection (d.p.i.) and peaked after 12-13 d.p.i. The protein levels of mGluRs and NMDA did not increase in early phases of EAE (4 d.p.i.), but starting from 8 d.p.i. to 25 d.p.i., we observed a significant elevation of mGluR1 and mGluR5 protein expression by about 20% and NMDA protein expression by about 10% over the control at 25 d.p.i. The changes in protein levels were accompanied by changes in mRNA expression of group I mGluRs and NMDARs. During the late disease phase (20-25 d.p.i.), the mRNA expression levels reached 300% of control values. In contrast, treatment with individual receptor antagonists resulted in a reduction of mRNA levels relative to untreated animals.

[Concordance in the registry of dementia among the main sources of clinical information].

PubMed

Marta-Moreno, Javier; Obón-Azuara, Blanca; Gimeno-Felíu, Luis; Achkar-Tuglaman, Nesib Nicolás; Poblador-Plou, Beatriz; Calderón-Larrañaga, Amaia; Prados-Torres, Alexandra

2016-01-01

The objective of this work was to analyse the concordance in the registry of dementia among the main sources of clinical information, with the aim of determining their usefulness for epidemiological and clinical research. Descriptive study of patients assigned to the Aragon Health Service in 2010 (n=1,344,891). (i)the pharmacy billing database (n=9,392); (ii)Primary Care electronic health records (EHR) (n=9,471), and (iii)the hospital minimum basic data set (n=3,289). When studying the concordance of the databases, the group of patients with a specific treatment for dementia (i.e., acetylcholinesterase inhibitors and/or memantine) was taken as the reference. The diagnosis in Primary Care was missing for 47.3% of patients taking anti-dementia drugs. The same occurred with 38.3% of dementia patients admitted to hospital during the study year. Among patients with a diagnosis of dementia in the EHR, only half (52.3%) was under treatment for this condition. This percentage decreased to 34.4% in patients with the diagnosis registered in the hospital database. The weak concordance in the registry of the dementia diagnosis between the main health information systems makes their use and analysis more complex, and supports the need to include all available health data sources in order to gain a global picture of the epidemiological and clinical reality of this health condition. Copyright © 2015 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

Souvenaid®: a new approach to management of early Alzheimer's disease.

PubMed

Ritchie, C W; Bajwa, J; Coleman, G; Hope, K; Jones, R W; Lawton, M; Marven, M; Passmore, P

2014-03-01

Synaptic loss correlates closely with cognitive deficits in Alzheimer's disease and represents a new target for intervention. Souvenaid® is the first medical nutrition product to be designed to support synapse formation and function in early Alzheimer's disease, and has undergone an extensive, 12-year development programme. The relatively large amount of clinical data available for Souvenaid® is unusual for a medical nutrition product. Souvenaid® contains omega-3 polyunsaturated fatty acids (docosahexaenoic acid and eicosapentaenoic acid), uridine (as uridine monophosphate) and choline which are nutritional precursors required for synaptic membrane phospholipid synthesis, together with phospholipids and other cofactors. Souvenaid® has demonstrated cognitive benefits in patients with mild Alzheimer's disease but not in patients with mild-to-moderate Alzheimer's disease. Two randomised, double-blind, controlled trials (duration 12 and 24 weeks) in patients with mild Alzheimer's disease untreated with acetylcholinesterase inhibitors and/or memantine have demonstrated that Souvenaid® is well tolerated and improves episodic memory performance. The daily intake of Souvenaid® has not been associated with any harmful effects or interactions with medications and none are anticipated. The ongoing, 24-month, European Union-funded LipiDiDiet trial in subjects with prodromal Alzheimer's disease is evaluating the potential benefits of Souvenaid® on memory and in slowing progression to Alzheimer's dementia. If Souvenaid® induces synaptogenesis and improved synaptic function, it may provide benefits in other clinical conditions characterised by neurodegeneration. A number of trials are ongoing and planned to evaluate the potential wider benefits of Souvenaid®.

The influence of ionotropic and metabotropic glutamate receptor ligands on anxiety-like effect of amphetamine withdrawal in rats.

PubMed

Koltunowska, D; Gibula-Bruzda, E; Kotlinska, J H

2013-08-01

Chronic amphetamine use results in anxiety-like states after drug cessation. The aim of the study was to determine a role of ionotropic and metabotropic glutamate receptor ligands in amphetamine-evoked withdrawal anxiety in the elevated plus-maze test in rats. In our study memantine (8 and 12 mg/kg), a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist did not reduce amphetamine withdrawal anxiety. Acamprosate (NMDA and metabotropic glutamate 5 receptor (mGluR5) antagonist) at the dose 200 and 400mg/kg showed anxiolytic-like effect, thus increasing the percent of time spent in open arms and a number of open arm entries. mGluR5 selective antagonist, MTEP (3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine hydrochloride) and mGluR2/3 agonist, LY354740 (1S,2S,5R,6S)-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid), caused effects similar to acamprosate at doses 1.25-5mg/kg and 2.5-5mg/kg, respectively. None of the glutamate ligands influenced locomotor activity of rats when given to the saline-treated group. Taking into account the positive correlation between amphetamine withdrawal-induced anxiety and relapse to amphetamine taking, our results suggest that modulation of mGluRs may prevent relapse to amphetamine and might pose a new direction in amphetamine abuse therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

Activation of extrasynaptic, but not synaptic, NMDA receptors modifies amyloid precursor protein expression pattern and increases amyloid-ß production.

PubMed

Bordji, Karim; Becerril-Ortega, Javier; Nicole, Olivier; Buisson, Alain

2010-11-24

Calcium is a key mediator controlling essential neuronal functions depending on electrical activity. Altered neuronal calcium homeostasis affects metabolism of amyloid precursor protein (APP), leading to increased production of β-amyloid (Aβ), and contributing to the initiation of Alzheimer's disease (AD). A linkage between excessive glutamate receptor activation and neuronal Aβ release was established, and recent reports suggest that synaptic and extrasynaptic NMDA receptor (NMDAR) activation may have distinct consequences in plasticity, gene regulation, and neuronal death. Here, we report for the first time that prolonged activation of extrasynaptic NMDAR, but not synaptic NMDAR, dramatically increased the neuronal production of Aβ. This effect was preceded by a shift from APP695 to Kunitz protease inhibitory domain (KPI) containing APPs (KPI-APPs), isoforms exhibiting an important amyloidogenic potential. Conversely, after synaptic NMDAR activation, we failed to detect any KPI-APP expression and neuronal Aβ production was not modified. Calcium imaging data showed that intracellular calcium concentration after extrasynaptic NMDAR stimulation was lower than after synaptic activation. This suggests distinct signaling pathways for each pool of receptors. We found that modification of neuronal APP expression pattern triggered by extrasynaptic NMDAR activation was regulated at an alternative splicing level involving calcium-/calmodulin-dependent protein kinase IV, but overall APP expression remained identical. Finally, memantine dose-dependently inhibited extrasynaptic NMDAR-induced KPI-APPs expression as well as neuronal Aβ release. Altogether, these data suggest that a chronic activation of extrasynaptic NMDAR promotes amyloidogenic KPI-APP expression leading to neuronal Aβ release, representing a causal risk factor for developing AD.

[Pharmacological hypotheses and therapeutic strategies for gait disorders in Parkinson's disease].

PubMed

Devos, D; Bordet, R; Defebvre, L

2010-02-01

Gait disorders form part of the axial symptoms observed in Parkinson's disease (PD) and also represent a major source of therapeutic failure in the later stages of PD, with the appearance of freezing of gait (FOG) and falls. Double-blind clinical trials and, above all, clinical experience have demonstrated that l-DOPA is effective in reducing FOG. Dopaminergic agonists appear to be less effective than l-DOPA and lack formal proof of their efficacy. The enzyme inhibitors provide modest benefits, which need to be confirmed. Hence, these symptoms appear to be partially doparesistant and justify investigation of other major neurotransmission systems. Of the various drugs with partial noradrenergic activity, methylphenidate may improve FOG and attention disorders. Memantine has shown some value in improving motor symptoms and gait in fluctuating parkinsonian patients - possibly by reducing the effect of glutamatergic hyperactivation of the subthalamic nucleus on the pedunculopontine nucleus (PPN). The PPN's dense cholinergic innervation also suggests that cholinesterase inhibitors may be of use, although any benefits must be set against a potential aggravation of rest tremor. The many interactions between the serotoninergic and dopaminergic systems require the implementation of clinical studies on the complex motor impact of serotoninergic treatments, which may aggravate the parkinsonian syndrome while improving gait (as is the case with paroxetine and ritanserin). This review seeks to develop the various pathophysiological hypotheses prompted by the results of fundamental studies and pilot clinical trials, with a view to justifying the implementation of confirmatory, double-blind, placebo-controlled therapeutic trials. Copyright 2009 Elsevier Masson SAS. All rights reserved.

Exploring dementia management attitudes in primary care: a key informant survey to primary care physicians in 25 European countries.

PubMed

Petrazzuoli, Ferdinando; Vinker, Shlomo; Koskela, Tuomas H; Frese, Thomas; Buono, Nicola; Soler, Jean Karl; Ahrensberg, Jette; Asenova, Radost; Foguet Boreu, Quintí; Ceyhun Peker, Gülsen; Collins, Claire; Hanževački, Miro; Hoffmann, Kathryn; Iftode, Claudia; Kurpas, Donata; Le Reste, Jean Yves; Lichtwarck, Bjørn; Petek, Davorina; Pinto, Daniel; Schrans, Diego; Streit, Sven; Tang, Eugene Yee Hing; Tatsioni, Athina; Torzsa, Péter; Unalan, Pemra C; van Marwijk, Harm; Thulesius, Hans

2017-09-01

Strategies for the involvement of primary care in the management of patients with presumed or diagnosed dementia are heterogeneous across Europe. We wanted to explore attitudes of primary care physicians (PCPs) when managing dementia: (i) the most popular cognitive tests, (ii) who had the right to initiate or continue cholinesterase inhibitor or memantine treatment, and (iii) the relationship between the permissiveness of these rules/guidelines and PCP's approach in the dementia investigations and assessment. Key informant survey. Primary care practices across 25 European countries. Four hundred forty-five PCPs responded to a self-administered questionnaire. Two-step cluster analysis was performed using characteristics of the informants and the responses to the survey. Two by two contingency tables with odds ratios and 95% confidence intervals were used to assess the association between categorical variables. A multinomial logistic regression model was used to assess the association of multiple variables (age class, gender, and perceived prescription rules) with the PCPs' attitude of "trying to establish a diagnosis of dementia on their own." Discrepancies between rules/guidelines and attitudes to dementia management was found in many countries. There was a strong association between the authorization to prescribe dementia drugs and pursuing dementia diagnostic work-up (odds ratio, 3.45; 95% CI 2.28-5.23). Differing regulations about who does what in dementia management seemed to affect PCP's engagement in dementia investigations and assessment. PCPs who were allowed to prescribe dementia drugs also claimed higher engagement in dementia work-up than PCPs who were not allowed to prescribe.

Brain regions associated with anosognosia for memory disturbance in Alzheimer's disease: a magnetic resonance imaging study.

PubMed

Fujimoto, Hiroshi; Matsuoka, Teruyuki; Kato, Yuka; Shibata, Keisuke; Nakamura, Kaeko; Yamada, Kei; Narumoto, Jin

2017-01-01

Patients with Alzheimer's disease (AD) are frequently unaware of their cognitive symptoms and medical diagnosis. The term "anosognosia" is used to indicate a general lack of awareness of one's disease or disorder. The neural substrate underlying anosognosia in AD is unclear. Since anosognosia for memory disturbance might be an initial sign of AD, it is important to determine the neural correlates. This study was designed to investigate the characteristics and neural correlates of anosognosia for memory disturbance in patients with mild AD. The subjects were 49 patients with mild AD who participated in a retrospective cross-sectional study. None of the patients had been treated with cholinesterase inhibitors, memantine, or psychotropic drugs. All patients underwent magnetic resonance imaging (MRI). Anosognosia for memory disturbance was assessed based on the discrepancy between questionnaire scores of patients and their caregivers. Structural MRI data were analyzed to explore the association between anosognosia and brain atrophy, using a voxel-based approach. Statistical parametric mapping software was used to explore neural correlations. In image analysis, multiple regression analysis was performed to examine the relationship between anosognosia score and regional gray matter volume. Age, years of education, and total intracranial volume were entered as covariates. The anosognosia score for memory disturbance was significantly negatively correlated with gray matter volume in the left superior frontal gyrus. The left superior frontal gyrus was involved in anosognosia for memory disturbance, while the medial temporal lobe, which is usually damaged in mild AD, was not associated with anosognosia. The left superior frontal gyrus might be an important region for anosognosia in mild AD.

Use of antipsychotics, benzodiazepine derivatives, and dementia medication among older people with intellectual disability and/or autism spectrum disorder and dementia.

PubMed

Axmon, Anna; Kristensson, Jimmie; Ahlström, Gerd; Midlöv, Patrik

2017-03-01

Although people with intellectual disability (ID) and people with dementia have high drug prescription rates, there is a lack of studies investigating drug use among those with concurrent diagnoses of ID and dementia. To investigate the use of antipsychotics, benzodiazepine derivatives, and drugs recommended for dementia treatment (anticholinesterases [AChEIs] and memantine) among people with ID and dementia. Having received support available for people with ID and/or autism spectrum disorder (ASD) was used as a proxy for ID. The ID cohort consisted of 7936 individuals, aged at least 55 years in 2012, and the referent cohort of age- and sex-matched people from the general population (gPop). People with a specialists' diagnosis of dementia during 2002-2012 were identified (ID, n=180; gPop, n=67), and data on prescription of the investigated drugs during the period 2006-2012 were collected. People with ID/ASD and dementia were more likely than people with ID/ASD but without dementia to be prescribed antipsychotics (50% vs 39% over the study period; odds ratio (OR) 1.85, 95% confidence interval 1.13-30.3) and benzodiazepine derivatives (55% vs 36%; OR 2.42, 1.48-3.98). They were also more likely than people with dementia from the general population to be prescribed antipsychotics (50% vs 25%; OR 3.18, 1.59-6.34), but less likely to be prescribed AChEIs (28% vs 45%; OR 0.32, 0.16-0.64). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Apolipoprotein E4 serum concentration for increased sensitivity and specificity of diagnosis of drug treated Alzheimer's disease patients vs. drug treated parkinson's disease patients vs. age-matched normal controls.

PubMed

Goldknopf, Ira L; Park, Helen R; Sabbagh, Marwan

2012-12-01

Inasmuch as Alzheimer's disease (AD) is difficult to diagnose, patients with suspected dementias are often given FDA approved medications, including donepezil, rivastigmine, memantine HCl, or a combination, prior to diagnosis, and some respond with improved cognition. The present study demonstrates how concentrations of a select group of serum protein biomarkers can provide the basis for sensitive and specific differential diagnosis of AD in drug treated patients. Optimization is addressed by taking into account whether the patients and controls have or do not have increased risk of AD die to the presence or absence of Apolipoprotein E4. For differential diagnosis of AD, prospectively collected newly drawn blood serum samples were obtained from drug treated Alzheimer's disease and Parkinson's disease patients from a first (39 drug treated DTAD, and 31 age matched normal controls) and second medical center (56 drug treated DTPD, 47 age-matched normal controls). Analytically validated quantitative 2D gel electrophoresis (%CV ≤ 20%; LOD ≥ 0.5 ng/spot, 300 μg/ml of blood serum) was employed with patient and control sera for differential diagnosis of AD. Protein quantitation was subjected to statistical analysis by single variable Dot, Box and Whiskers and Receiver Operator Characteristics (ROC) plots for individual biomarker performance, and multivariate linear discriminant analysis for joint performance of groups of biomarkers. Protein spots were identified and characterized by LC MS/MS of in-gel trypsin digests, amino acid sequence spans of the identified peptides, and the protein spot molecular weights and isoelectric points. The single variable statistical profiles of 58 individual protein biomarker concentrations of the DTAD patient group differed from those of the normal and/or the disease control groups. Multivariate linear discriminant analysis of blood serum concentrations of the 58 proteins distinguished drug treated Alzheimer's disease (DTAD) patients from drug treated Parkinson's disease (DTPD) patients and age matched normal controls (collectively not-DTAD, DTAD Sensitivity 87.2%, Not-DTAD Specificity 87.2). Moreover, when the patients and controls were stratified into carriers or non-carriers of Alzheimer's high risk Apolipoprotein E 4 allele and/or the Apolipoprotein E4 protein, the DTAD, DTPD and control Apo E4 (+) profiles were more divergent from one another than the corresponding Apo E4 (-) profiles. Multivariate stepwise linear discriminant analysis selected 17 of the 58 biomarkers as optimal and complimentary for distinguishing Apo E4 (+) DTAD patients from Apo E4 (+) DTPD and Apo E4 (+) controls (collectively Apo E4 (+) not-DTAD, DTAD Sensitivity 100%, not-DTAD Specificity 100%) and 22 of the 58 biomarkers for distinguishing Apo E4 (-) DTAD patients from Apo E4 (-) DTPD and Apo E4 (-) controls (collectively Apo E4 (-) not-DTAD, DTAD Sensitivity 94.4%, not- DTAD Specificity 94.4%). Only 6 of the selected proteins were common to both the Apo E4 (+) and the Apo E4 (-) discriminant functions. Recombining of the results of Apo E4 (+) and Apo E4 (-) discriminations provided overall sensitivity for total DTAD of 97.4% and specificity for total not-DTAD of 95.7%. These results can form the basis of a blood test for differential diagnosis of Alzheimer's disease patients already under treatment (DTAD) by anti dementia drugs, including donepezil, rivastigmine, memantine HCl, or a combination thereof. Also, the profile differences and the rise in specificity and sensitivity obtained by handling the Apo E4 (+) and Apo E4 (-) groups separately supports the concept that they are different patient and control populations in terms of the "normal" physiology, the pathophysiology of disease, and the response to drug treatment. Taking that into account enables increased sensitivity and specificity of differential diagnosis of Alzheimer's disease.

Ethanol preconditioning of rat cerebellar cultures targets NMDA receptors to the synapse and enhances peroxiredoxin 2 expression.

PubMed

Mitchell, Robert M; Tajuddin, Nuzhath; Campbell, Edward M; Neafsey, Edward J; Collins, Michael A

2016-07-01

Epidemiological studies indicate that light-moderate alcohol (ethanol) consumers tend to have reduced risks of cognitive impairment and progression to dementia during aging. Exploring possible mechanisms, we previously found that moderate ethanol preconditioning (MEP, 20-30mM) of rat brain cultures for several days instigated neuroprotection against β-amyloid peptides. Our biochemical evidence implicated the NMDA receptor (NMDAR) as a potential neuroprotective "sensor", specifically via synaptic NMDAR signaling. It remains unclear how ethanol modulates the receptor and its downstream targets to engender neuroprotection. Here we confirm with deconvolution microscopy that MEP of rat mixed cerebellar cultures robustly increases synaptic NMDAR localization. Phospho-activation of the non-receptor tyrosine kinases Src and Pyk2, known to be linked to synaptic NMDAR, is also demonstrated. Additionally, the preconditioning enhances levels of an antioxidant protein, peroxiredoxin 2 (Prx2), reported to be downstream of synaptic NMDAR signaling, and NMDAR antagonism with memantine (earlier found to abrogate MEP neuroprotection) blocks the Prx2 elevations. To further link Prx2 with antioxidant-based neuroprotection, we circumvented the ethanol preconditioning-NMDAR pathway by pharmacologically increasing Prx2 with the naturally-occurring cruciferous compound, 3H-1,2-dithiole-3-thione (D3T). Thus, D3T pretreatment elevated Prx2 expression to a similar extent as MEP, while concomitantly preventing β-amyloid neurotoxicity; D3T also protected the cultures from hydrogen peroxide toxicity. The findings support a mechanism that couples synaptic NMDAR signaling, Prx2 expression and augmented antioxidant defenses in ethanol preconditioning-induced neuroprotection. That this mechanism can be emulated by a cruciferous vegetable constituent suggests that such naturally-occurring "neutraceuticals" may be useful in therapy for oxidative stress-related dementias. Copyright © 2016 Elsevier B.V. All rights reserved.

AVN-211, Novel and Highly Selective 5-HT6 Receptor Small Molecule Antagonist, for the Treatment of Alzheimer's Disease.

PubMed

Ivachtchenko, Alexandre V; Lavrovsky, Yan; Ivanenkov, Yan A

2016-03-07

Within the past decade several novel targets have been indicated as key players in Alzheimer-type dementia and associated conditions, including a "frightening" memory loss as well as severe cognitive impairments. These proteins are deeply implicated in crucial cell processes, e.g., autophagy, growth and progression, apoptosis, and metabolic equilibrium. Since recently, 5-HT6R has been considered as one of the most prominent biological targets in AD drug therapy. Therefore, we investigated the potential procognitive and neuroprotective effects of our novel selective 5-HT6R antagonist, AVN-211. During an extensive preclinical evaluation the lead compound demonstrated a relatively high therapeutic potential and improved selectivity toward 5-HT6R as compared to reference drug candidates. It was thoroughly examined in different in vivo behavioral models directly related to AD and showed evident improvements in cognition and learning. In many cases, the observed effect was considerably greater than that determined for the reported drugs and drug candidates, including memantine, SB-742457, and Lu AE58054, evaluated under the same conditions. In addition, AVN-211 showed a similar or better anxiolytic efficacy than fenobam, rufinamide, lorazepam, and buspirone in an elevated plus-maze model, elevated platform, and open field tests. The compound demonstrated low toxicity and no side effects in vivo, an appropriate pharmacokinetic profile, and stability. In conclusion, AVN-211 significantly delayed or partially halted the progressive decline in memory function associated with AD, which makes it an interesting drug candidate for the treatment of neurodegenerative and psychiatric disorders. Advanced clinical trials are currently under active discussion and in high priority.

An update on the safety of current therapies for Alzheimer's disease: focus on rivastigmine.

PubMed

Khoury, Rita; Rajamanickam, Jayashree; Grossberg, George T

2018-03-01

Alzheimer's disease (AD) is the most common cause of major neurocognitive disorders worldwide. Despite all research efforts, therapeutic options for AD are still limited to two drug classes: cholinesterase inhibitors (ChEIs) and the NMDA-receptor antagonist memantine. Donepezil, rivastigmine and galantamine are the three ChEIs FDA-approved as first-line treatment for AD. Although they share the same mode of action, they differ in terms of their pharmacologic characteristics and route of administration, which can impact their safety and tolerability profile. Rivastigmine, available in both oral and transdermal patch formulations, is a slowly reversible dual inhibitor of acetyl and butyryl cholinesterase, selective for the G1 isoform of acetylcholinesterase, without hepatic metabolism by the CYP-450 system. Despite its unique features, it has been associated with a higher incidence of adverse events in comparison to other ChEIs. The oral form, approved for the treatment of mild to moderate AD, is associated with a higher incidence of gastrointestinal side effects. The transdermal patch formulation approved for use across all stages of AD has been shown to have a better tolerability profile in comparison to both the oral form and even other ChEIs. One important tolerability concern is adverse dermatologic reactions, which are mostly benign, and can be either preventable or manageable. One important safety concern is the risk of treatment overdose by administering multiple patches at the same time, potentially leading to fatal outcomes. This can be prevented by educating patients and caregivers about the proper use of the patch. The goal for the future would be to optimize the patch formulation to increase both efficacy and safety.

Screening approach for identifying candidate drugs and drug-drug interactions related to hip fracture risk in persons with Alzheimer disease.

PubMed

Tolppanen, Anna-Maija; Taipale, Heidi; Koponen, Marjaana; Tanskanen, Antti; Lavikainen, Piia; Paananen, Jussi; Tiihonen, Jari; Hartikainen, Sirpa

2017-08-01

To assess whether a "drugome-wide" screen with case-crossover design is a feasible approach for identifying candidate drugs and drug-drug interactions. All community-dwelling residents of Finland who received a clinically verified Alzheimer disease diagnosis in 2005 to 2011 and experienced incident hip fracture (HF) afterwards (N = 4851). Three scenarios were used to test the sensitivity of this approach (1) hazard period 0 to 30 and control period 31 to 61 days before HF, (2) hazard period 0 to 30 and control period 336 to 366 days before HF, and (3) hazard period 0 to 14 and control period 16 to 30 days before HF. Nine, 44, and 5 drugs were associated with increased HF risk and 8, 23, and 4 with decreased risk in scenarios 1, 2, and 3, respectively. Six drugs were identified with scenario 1 only and 54 and 1 with scenarios 2 and 3, respectively. Only six drugs (metoprolol, simvastatin, trimethoprim, codeine combinations, fentanyl, and paracetamol) were associated with HF in all scenarios, four with 1 and 2 (cefalexin, buprenorphine, olanzapine, and memantine), and one with 1 and 3 (enalapril) or 2 and 3 (ciprofloxacin). The direction of associations was the same in all/both scenarios. The interaction results were equally versatile, with hydroxocobalamin*oxazepam being the only interaction observed in all scenarios. Case-crossover analysis is a potential approach for identifying candidate drugs and drug-drug interactions associated with adverse events as it implicitly controls for fixed confounders. The results are highly dependent on applied hazard and control periods, but the choice of periods can help in targeting the analyses to different phases of drug use. Copyright © 2017 John Wiley & Sons, Ltd.

Medications Used for Cognitive Enhancement in Patients With Schizophrenia, Bipolar Disorder, Alzheimer's Disease, and Parkinson's Disease.

PubMed

Hsu, Wen-Yu; Lane, Hsien-Yuan; Lin, Chieh-Hsin

2018-01-01

Cognitive impairment, which frequently occurs in patients with schizophrenia, bipolar disorder, Alzheimer's disease, and Parkinson's disease, has a significant impact on the daily lives of both patients and their family. Furthermore, since the medications used for cognitive enhancement have limited efficacy, the issue of cognitive enhancement still remains a clinically unsolved challenge. We reviewed the clinical studies (published between 2007 and 2017) that focused on the efficacy of medications used for enhancing cognition in patients with schizophrenia, bipolar disorder, Alzheimer's disease, and Parkinson's disease. Acetylcholinesterase inhibitors and memantine are the standard treatments for Alzheimer's disease and Parkinson's disease. Some studies have reported selective cognitive improvement in patients with schizophrenia following galantamine treatment. Newer antipsychotics, including paliperidone, lurasidone, aripiprazole, ziprasidone, and BL-1020, have also been reported to exert cognitive benefits in patients with schizophrenia. Dopaminergic medications were found to improve language function in patients with Parkinson's disease. However, no beneficial effects on cognitive function were observed with dopamine agonists in patients with schizophrenia. The efficacies of nicotine and its receptor modulators in cognitive improvement remain controversial, with the majority of studies showing that varenicline significantly improved the cognitive function in schizophrenic patients. Several studies have reported that N -methyl-d-aspartate glutamate receptor (NMDAR) enhancers improved the cognitive function in patients with chronic schizophrenia. NMDAR enhancers might also have cognitive benefits in patients with Alzheimer's disease or Parkinson's disease. Raloxifene, a selective estrogen receptor modulator, has also been demonstrated to have beneficial effects on attention, processing speed, and memory in female patients with schizophrenia. Clinical trials with larger sample sizes evaluating comprehensive cognitive domains are warranted to examine the efficacy of medications in cognitive enhancement in patients with schizophrenia, bipolar disorder, Alzheimer's disease, and Parkinson's disease.

Excitotoxicity through NMDA receptors mediates cerebellar granule neuron apoptosis induced by prion protein 90-231 fragment.

PubMed

Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Corsaro, Alessandro; Villa, Valentina; Vassalli, Massimo; Robello, Mauro; Florio, Tullio

2013-05-01

Prion diseases recognize, as a unique molecular trait, the misfolding of CNS-enriched prion protein (PrP(C)) into an aberrant isoform (PrP(Sc)). In this work, we characterize the in vitro toxicity of amino-terminally truncated recombinant PrP fragment (amino acids 90-231, PrP90-231), on rat cerebellar granule neurons (CGN), focusing on glutamatergic receptor activation and Ca(2+) homeostasis impairment. This recombinant fragment assumes a toxic conformation (PrP90-231(TOX)) after controlled thermal denaturation (1 h at 53 °C) acquiring structural characteristics identified in PrP(Sc) (enrichment in β-structures, increased hydrophobicity, partial resistance to proteinase K, and aggregation in amyloid fibrils). By annexin-V binding assay, and evaluation of the percentage of fragmented and condensed nuclei, we show that treatment with PrP90-231(TOX), used in pre-fibrillar aggregation state, induces CGN apoptosis. This effect was associated with a delayed, but sustained elevation of [Ca(2+)]i. Both CGN apoptosis and [Ca(2+)]i increase were not observed using PrP90-231 in PrP(C)-like conformation. PrP90-231(TOX) effects were significantly reduced in the presence of ionotropic glutamate receptor antagonists. In particular, CGN apoptosis and [Ca(2+)]i increase were largely reduced, although not fully abolished, by pre-treatment with the NMDA antagonists APV and memantine, while the AMPA antagonist CNQX produced a lower, although still significant, effect. In conclusion, we report that CGN apoptosis induced by PrP90-231(TOX) correlates with a sustained elevation of [Ca(2+)]i mediated by the activation of NMDA and AMPA receptors.

Current and Emerging Pharmacotherapies for Cessation of Tobacco Smoking.

PubMed

Gómez-Coronado, Nieves; Walker, Adam J; Berk, Michael; Dodd, Seetal

2018-02-01

Tobacco use disorder is a chronic illness. With its high comorbidity rate, it is a major cause of years of life lost or years lived with disability; however, it is also considered the most preventable cause of death in developed countries. Since the development of nicotine replacement therapy (NRT) in 1978, treatment options have continued to evolve and expand. Despite this, currently available treatments remain insufficient, with less than 25% of smokers remaining abstinent 1 year after treatment. In this article, we review existing and emerging smoking cessation pharmacotherapies, with a special emphasis on the most promising agents that are currently being investigated. A search of the Cochrane Database of Systematic Reviews and the PubMed, Ovid, and ClinicalTrials.gov databases (August 2 to September 1, 2017) was undertaken for articles on smoking cessation pharmacotherapies, applying no language restrictions. More than 40 pharmacotherapies were reviewed including conventional pharmacotherapies-NRT, bupropion, and varenicline (all approved by the U.S. Food and Drug Administration as first-line treatment of smoking cessation)-and novel therapies: cytisine, N-acetylcysteine, cycloserine, memantine, baclofen, topiramate, galantamine, and bromocriptine. Studies of combination NRT and varenicline showed the greatest smoking cessation rates. Clonidine and nortriptyline are second-line treatments used when first-line treatments fail or are contraindicated, or by patient preference. Some novel therapies, especially acetylcholinesterase inhibitors, cytisine, and N-acetylcysteine, display promising results. Because the results of randomized clinical trials were reported using varied end points and outcome measures, direct comparisons between different pharmacotherapies cannot easily be evaluated. Additional high-quality randomized double-blind placebo-controlled trials with long-term follow-up, using validated sustained abstinence measures, are needed to find more effective smoking cessation aids. © 2017 Pharmacotherapy Publications, Inc.

Dynamic Changes in Cytosolic ATP Levels in Cultured Glutamatergic Neurons During NMDA-Induced Synaptic Activity Supported by Glucose or Lactate.

PubMed

Lange, Sofie C; Winkler, Ulrike; Andresen, Lars; Byhrø, Mathilde; Waagepetersen, Helle S; Hirrlinger, Johannes; Bak, Lasse K

2015-12-01

We have previously shown that synaptic transmission fails in cultured neurons in the presence of lactate as the sole substrate. Thus, to test the hypothesis that the failure of synaptic transmission is a consequence of insufficient energy supply, ATP levels were monitored employing the ATP biosensor Ateam1.03YEMK. While inducing synaptic activity by subjecting cultured neurons to two 30 s pulses of NMDA (30 µM) with a 4 min interval, changes in relative ATP levels were measured in the presence of lactate (1 mM), glucose (2.5 mM) or the combination of the two. ATP levels reversibly declined following NMDA-induced neurotransmission activity, as indicated by a reversible 10-20 % decrease in the response of the biosensor. The responses were absent when the NMDA receptor antagonist memantine was present. In the presence of lactate alone, the ATP response dropped significantly more than in the presence of glucose following the 2nd pulse of NMDA (approx. 10 vs. 20 %). Further, cytosolic Ca(2+) homeostasis during NMDA-induced synaptic transmission is partially inhibited by verapamil indicating that voltage-gated Ca(2+) channels are activated. Lastly, we showed that cytosolic Ca(2+) homeostasis is supported equally well by both glucose and lactate, and that a pulse of NMDA causes accumulation of Ca(2+) in the mitochondrial matrix. In summary, we have shown that ATP homeostasis during neurotransmission activity in cultured neurons is supported by both glucose and lactate. However, ATP homeostasis seems to be negatively affected by the presence of lactate alone, suggesting that glucose is needed to support neuronal energy metabolism during activation.

Ketamine and MAG Lipase Inhibitor-Dependent Reversal of Evolving Depressive-Like Behavior During Forced Abstinence From Alcohol Drinking.

PubMed

Holleran, Katherine M; Wilson, Hadley H; Fetterly, Tracy L; Bluett, Rebecca J; Centanni, Samuel W; Gilfarb, Rachel A; Rocco, Lauren E R; Patel, Sachin; Winder, Danny G

2016-07-01

Although alcoholism and depression are highly comorbid, treatment options that take this into account are lacking, and mouse models of alcohol (ethanol (EtOH)) intake-induced depressive-like behavior have not been well established. Recent studies utilizing contingent EtOH administration through prolonged two-bottle choice access have demonstrated depression-like behavior following EtOH abstinence in singly housed female C57BL/6J mice. In the present study, we found that depression-like behavior in the forced swim test (FST) is revealed only after a protracted (2 weeks), but not acute (24 h), abstinence period. No effect on anxiety-like behavior in the EPM was observed. Further, we found that, once established, the affective disturbance is long-lasting, as we observed significantly enhanced latencies to approach food even 35 days after ethanol withdrawal in the novelty-suppressed feeding test (NSFT). We were able to reverse affective disturbances measured in the NSFT following EtOH abstinence utilizing the N-methyl D-aspartate receptor (NMDAR) antagonist and antidepressant ketamine but not memantine, another NMDAR antagonist. Pretreatment with the monoacylglycerol (MAG) lipase inhibitor JZL-184 also reduced affective disturbances in the NSFT in ethanol withdrawn mice, and this effect was prevented by co-administration of the CB1 inverse agonist rimonabant. Endocannabinoid levels were decreased within the BLA during abstinence compared with during drinking. Finally, we demonstrate that the depressive behaviors observed do not require a sucrose fade and that this drinking paradigm may favor the development of habit-like EtOH consumption. These data could set the stage for developing novel treatment approaches for alcohol-withdrawal-induced mood and anxiety disorders.

New targets for rapid antidepressant action.

PubMed

Machado-Vieira, Rodrigo; Henter, Ioline D; Zarate, Carlos A

2017-05-01

Current therapeutic options for major depressive disorder (MDD) and bipolar disorder (BD) are associated with a lag of onset that can prolong distress and impairment for patients, and their antidepressant efficacy is often limited. All currently approved antidepressant medications for MDD act primarily through monoaminergic mechanisms. Glutamate is the major excitatory neurotransmitter in the central nervous system, and glutamate and its cognate receptors are implicated in the pathophysiology of MDD, and in the development of novel therapeutics for this disorder. The rapid and robust antidepressant effects of the N-methyl-d-aspartate (NMDA) antagonist ketamine were first observed in 2000. Since then, other NMDA receptor antagonists have been studied in MDD. Most have demonstrated relatively modest antidepressant effects compared to ketamine, but some have shown more favorable characteristics. This article reviews the clinical evidence supporting the use of novel glutamate receptor modulators with direct affinity for cognate receptors: (1) non-competitive NMDA receptor antagonists (ketamine, memantine, dextromethorphan, AZD6765); (2) subunit (GluN2B)-specific NMDA receptor antagonists (CP-101,606/traxoprodil, MK-0657); (3) NMDA receptor glycine-site partial agonists (GLYX-13); and (4) metabotropic glutamate receptor (mGluR) modulators (AZD2066, RO4917523/basimglurant). We also briefly discuss several other theoretical glutamate receptor targets with preclinical antidepressant-like efficacy that have yet to be studied clinically; these include α-amino-3-hydroxyl-5-methyl-4-isoxazoleproprionic acid (AMPA) agonists and mGluR2/3 negative allosteric modulators. The review also discusses other promising, non-glutamatergic targets for potential rapid antidepressant effects, including the cholinergic system (scopolamine), the opioid system (ALKS-5461), corticotropin releasing factor (CRF) receptor antagonists (CP-316,311), and others. Published by Elsevier Ltd.

New Targets for Rapid Antidepressant Action

PubMed Central

Machado-Vieira, Rodrigo; Henter, Ioline D; Zarate, Carlos A.

2016-01-01

Current therapeutic options for major depressive disorder (MDD) and bipolar disorder (BD) are associated with a lag of onset that can prolong distress and impairment for patients, and their antidepressant efficacy is often limited. All currently approved antidepressant medications for MDD act primarily through monoaminergic mechanisms. Glutamate is the major excitatory neurotransmitter in the central nervous system, and glutamate and its cognate receptors are implicated in the pathophysiology of MDD, and in the development of novel therapeutics for this disorder. The rapid and robust antidepressant effects of the N-methyl-D-aspartate (NMDA) antagonist ketamine were first observed in 2000. Since then, other NMDA receptor antagonists have been studied in MDD. Most have demonstrated relatively modest antidepressant effects compared to ketamine, but some have shown more favorable characteristics. This article reviews the clinical evidence supporting the use of novel glutamate receptor modulators with direct affinity for cognate receptors: 1) non-competitive NMDA receptor antagonists (ketamine, memantine, dextromethorphan, AZD6765); 2) subunit (GluN2B)-specific NMDA receptor antagonists (CP-101,606/traxoprodil, MK-0657); 3) NMDA receptor glycine-site partial agonists (GLYX-13); and 4) metabotropic glutamate receptor (mGluR) modulators (AZD2066, RO4917523/basimglurant). We also briefly discuss several other theoretical glutamate receptor targets with preclinical antidepressant-like efficacy that have yet to be studied clinically; these include α-amino-3-hydroxyl-5-methyl-4-isoxazoleproprionic acid (AMPA) agonists and mGluR2/3 negative allosteric modulators. The review also discusses other promising, non-glutamatergic targets for potential rapid antidepressant effects, including the cholinergic system (scopolamine), the opioid system (ALKS-5461), corticotropin releasing factor (CRF) receptor antagonists (CP-316,311), and others. PMID:26724279

A phase II trial of tideglusib in Alzheimer's disease.

PubMed

Lovestone, Simon; Boada, Mercè; Dubois, Bruno; Hüll, Michael; Rinne, Juha O; Huppertz, Hans-Jürgen; Calero, Miguel; Andrés, María V; Gómez-Carrillo, Belén; León, Teresa; del Ser, Teodoro

2015-01-01

The ARGO study was a phase II, double-blind, placebo controlled, four parallel arm trial of tideglusib in Alzheimer's disease (AD). To prove the clinical efficacy of an inhibitor of glycogen synthase kinase-3 (GSK-3), in AD. Mild to moderate (Mini-Mental State Examination (MMSE) score, 14-26) AD patients on cholinesterase inhibitor and/or memantine treatment were administered tideglusib or placebo for 26 weeks. The ADAS-cog15 was the primary efficacy measure; function, cognition, behavior, and quality of life were assessed as secondary measures; cerebral atrophy in MRI and the levels of tau, amyloid-β, and BACE1 in cerebrospinal fluid (CSF) were exploratory endpoints. 306 AD patients were randomized to active (1000 mg QD: n = 86, 1000 mg QOD: n = 90, and 500 mg QD: n = 50) or placebo (n = 85) in 55 sites in four European countries. There were no statistically significant differences between either active and placebo arms in the efficacy variables. However, BACE1 in CSF significantly decreased with treatment in a small subgroup of patients. Participants with mild AD in the 500 mg QD group showed significant responses on ADAS-cog15, MMSE, and word fluency. Diarrhea (14-18% in active, 11% placebo) and dose-dependent, mild to moderate, and fully reversible transaminase increase (9-16% in active, 3.5% placebo) were the most frequent adverse events. Short term (26 weeks) tideglusib was acceptably safe but produced no clinical benefit in this trial. However, given the non-linear dose response, especially in mildly affected patients, further dose finding studies in early disease stages and for longer duration are warranted to examine GSK-3 inhibition in AD patients.

Autism.

PubMed

Parr, Jeremy

2010-01-07

Evidence for the efficacy of treatments for autism has improved in recent years. In this systematic review the evidence for both drug and non-drug treatments is appraised and clinical guidance is provided for their use. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of early intensive multidisciplinary intervention programmes in children with autism? What are the effects of dietary interventions in children with autism? What are the effects of drug treatments in children with autism? What are the effects of non-drug treatments in children with autism? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2009 (Clinical evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 30 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: applied behavioural analysis; auditory integration training; Autism Preschool Programme; casein-free diet; chelation; Child's Talk programme; cognitive behavioural therapy; digestive enzymes; EarlyBird programme; facilitated communication; Floortime therapy; gluten-free diet; immunoglobulins; melatonin; memantine; methylphenidate; More Than Words programme; music therapy; olanzapine; omega-3 fish oil; picture exchange communication system; Portage scheme; probiotics; relationship development interventions; risperidone; secretin; selective serotonin reuptake inhibitors (SSRIs); sensory integration training; social stories; social skills training; Son-Rise programme; TEACCH; vitamin A; vitamin B6 (pyridoxine) plus magnesium; and vitamin C.

Nandrolone-induced aggressive behavior is associated with alterations in extracellular glutamate homeostasis in mice.

PubMed

Kalinine, Eduardo; Zimmer, Eduardo Rigon; Zenki, Kamila Cagliari; Kalinine, Iouri; Kazlauckas, Vanessa; Haas, Clarissa Branco; Hansel, Gisele; Zimmer, Aline Rigon; Souza, Diogo Onofre; Müller, Alexandre Pastoris; Portela, Luis Valmor

2014-07-01

Nandrolone decanoate (ND), an anabolic androgenic steroid (AAS), induces an aggressive phenotype by mechanisms involving glutamate-induced N-methyl-d-aspartate receptor (NMDAr) hyperexcitability. The astrocytic glutamate transporters remove excessive glutamate surrounding the synapse. However, the impact of supraphysiological doses of ND on glutamate transporters activity remains elusive. We investigated whether ND-induced aggressive behavior is interconnected with GLT-1 activity, glutamate levels and abnormal NMDAr responses. Two-month-old untreated male mice (CF1, n=20) were tested for baseline aggressive behavior in the resident-intruder test. Another group of mice (n=188) was injected with ND (15mg/kg) or vehicle for 4, 11 and 19days (short-, mid- and long-term endpoints, respectively) and was evaluated in the resident-intruder test. Each endpoint was assessed for GLT-1 expression and glutamate uptake activity in the frontoparietal cortex and hippocampal tissues. Only the long-term ND endpoint significantly decreased the latency to first attack and increased the number of attacks, which was associated with decreased GLT-1 expression and glutamate uptake activity in both brain areas. These alterations may affect extracellular glutamate levels and receptor excitability. Resident males were assessed for hippocampal glutamate levels via microdialysis both prior to, and following, the introduction of intruders. Long-term ND mice displayed significant increases in the microdialysate glutamate levels only after exposure to intruders. A single intraperitoneal dose of the NMDAr antagonists, memantine or MK-801, shortly before the intruder test decreased aggressive behavior. In summary, long-term ND-induced aggressive behavior is associated with decreased extracellular glutamate clearance and NMDAr hyperexcitability, emphasizing the role of this receptor in mediating aggression mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

Neuroprotective and cognitive enhancing effects of a multi-targeted food intervention in an animal model of neurodegeneration and depression.

PubMed

Borre, Yuliya E; Panagaki, Theodora; Koelink, Pim J; Morgan, Mary E; Hendriksen, Hendrikus; Garssen, Johan; Kraneveld, Aletta D; Olivier, Berend; Oosting, Ronald S

2014-04-01

Rising neurodegenerative and depressive disease prevalence combined with the lack of effective pharmaceutical treatments and dangerous side effects, has created an urgent need for the development of effective therapies. Considering that these disorders are multifactorial in origin, treatments designed to interfere at different mechanistic levels may be more effective than the traditional single-targeted pharmacological concepts. To that end, an experimental diet composed of zinc, melatonin, curcumin, piperine, eicosapentaenoic acid (EPA, 20:5, n-3), docosahexaenoic acid (DHA, 22:6, n-3), uridine, and choline was formulated. This diet was tested on the olfactory bulbectomized rat (OBX), an established animal model of depression and cognitive decline. The ingredients of the diet have been individually shown to attenuate glutamate excitoxicity, exert potent anti-oxidant/anti-inflammatory properties, and improve synaptogenesis; processes that all have been implicated in neurodegenerative diseases and in the cognitive deficits following OBX in rodents. Dietary treatment started 2 weeks before OBX surgery, continuing for 6 weeks in total. The diet attenuated OBX-induced cognitive and behavioral deficits, except long-term spatial memory. Ameliorating effects of the diet extended to the control animals. Furthermore, the experimental diet reduced hippocampal atrophy and decreased the peripheral immune activation in the OBX rats. The ameliorating effects of the diet on the OBX-induced changes were comparable to those of the NMDA receptor antagonist, memantine, a drug used for the management of Alzheimer's disease. This proof-of-concept study suggests that a diet, which simultaneously targets multiple disease etiologies, can prevent/impede the development of a neurodegenerative and depressive disorders and the concomitant cognitive deficits. Copyright © 2014. Published by Elsevier Ltd.

Can Salivary Acetylcholinesterase be a Diagnostic Biomarker for Alzheimer?

PubMed

Bakhtiari, Sedigheh; Moghadam, Nahid Beladi; Ehsani, Marjan; Mortazavi, Hamed; Sabour, Siamak; Bakhshi, Mahin

2017-01-01

The loss of brain cholinergic activity is a key phenomenon in the biochemistry of Alzheimer's Disease (AD). Due to the specific biosynthesis of Acetylcholinesterase (AChE) of cholinergic neurons, the enzyme has been proposed as a potential biochemical marker of cholinergic activity. AChE is expressed not only in the Central Nervous System (CNS), Peripheral Nervous System (PNS) and muscles, but also on the surface of blood cells and saliva. This study aimed to measure salivary AChE activity in AD and to determine the feasibility of creating a simple laboratory test for diagnosing such patients. In this cross-sectional study, the recorded data were obtained from 15 Alzheimer's patients on memantine therapy and 15 healthy subjects. Unstimulated whole saliva samples were collected from the participants and salivary levels of AChE activity were determined by using the Ellman colorimetric method. The Mann Whitney U test was used to compare the average (median) of AChE activity between AD and controls. In order to adjust for possible confounding factors, partial correlation coefficient and multivariate linear regressions were used. Although the average of AChE activity in the saliva of people with AD was lower compared to the control group, we found no statistically significant differences using Mann Whitney U test (138 in control group vs. 175 in Alzheimer's patients, p value=0.25). Additionally, no significant differences were observed in the activity of this enzyme in both sexes or with increased age or duration of the disease. After adjusting for age and gender, there was no association between AChE activity and AD (regression coefficient β=0.08; p value= 0.67). Saliva AChE activity was not significantly associated with AD. This study might help in introduce a new diagnostic aid for AD or monitor patients with AD.

Antinociceptive Activity of Borreria verticillata: In vivo and In silico Studies

PubMed Central

Silva, Rosa H. M.; Lima, Nathália de Fátima M.; Lopes, Alberto J. O.; Vasconcelos, Cleydlenne C.; de Mesquita, José W. C.; de Mesquita, Ludmilla S. S.; Lima, Fernando C. V. M.; Ribeiro, Maria N. de S.; Ramos, Ricardo M.; Cartágenes, Maria do Socorro de S.; Garcia, João B. S.

2017-01-01

Borreria verticillata (L.) G. Mey. known vassourinha has antibacterial, antimalarial, hepatoprotective, antioxidative, analgesic, and anti-inflammatory, however, its antinociceptive action requires further studies. Aim of the study evaluated the antinociceptive activity of B. verticillata hydroalcoholic extract (EHBv) and ethyl acetate fraction (FAc) by in vivo and in silico studies. In vivo assessment included the paw edema test, writhing test, formalin test and tail flick test. Wistar rats and Swiss mice were divided into 6 groups and given the following treatments oral: 0.9% NaCl control group (CTRL), 10 mg/kg memantine (MEM), 10 mg/kg indomethacin (INDO), 500 mg/kg EHBv (EHBv 500), 25 mg/kg FAc (FAc 25) and 50 mg/kg FAc (FAc 50). EHBv, FAc 25 and 50 treatments exhibited anti-edematous and peripheral antinociceptive effects. For in silico assessment, compounds identified in FAc were subjected to molecular docking with COX-2, GluN1a and GluN2B. Ursolic acid (UA) was the compound with best affinity parameters (binding energy and inhibition constant) for COX-2, GluN1a, GluN2B, and was selected for further analysis with molecular dynamics (MD) simulations. In MD simulations, UA exhibited highly frequent interactions with residues Arg120 and Glu524 in the COX-2 active site and NMDA, whereby it might prevent COX-2 and NMDA receptor activation. Treatment with UA 10 mg/Kg showed peripheral and central antinociceptive effect. The antinociceptive effect of B. verticillata might be predominantly attributed to peripheral actions, including the participation of anti-inflammatory components. Ursolic acid is the main active component and seems to be a promising source of COX-2 inhibitors and NMDA receptor antagonists. PMID:28588488

Aspects of communication in Alzheimer's disease: clinical features and treatment options.

PubMed

Woodward, Michael

2013-06-01

During the course of Alzheimer's disease (AD), cognitive processes, including language and communication, become increasingly impaired. The aim of this review was to highlight the impact of communication deficits in AD, and discuss the need for effective treatments. PubMed was searched for studies relating to language and communication in AD. The publications identified were used as a basis for the commentary in this paper. Studies relating to the clinical effectiveness of pharmacological treatment for language and communication issues were identified systematically. Communication deficits are common in AD. From the earliest disease stage, the patient's capacity for communication declines as problems develop with the use of language and all aspects of functional communication. There is a loss of the ability to communicate thoughts and needs, and it becomes increasingly difficult to interact socially and sustain personal relationships with caregivers, family, and friends. It is unsurprising that patients become frustrated at their loss of self-expression, and studies have demonstrated that impaired communication is strongly linked with the development of significant behavioral concerns. Overall, poor communication contributes to caregiver strain, and adds notably to the burden of disease. Clinical data and post-hoc analyses provide preliminary indications that anti-AD therapies (memantine and the cholinesterase inhibitors, ChEIs) and non-pharmacological cognitive-linguistic stimulation techniques may be helpful in addressing communication difficulties. The capacity to treat or slow the progression of communication deficits in AD would prolong patient independence, and have a profound impact on the quality of life of patients and caregivers. The use of pharmacological (anti-AD therapies) and non-pharmacological (cognitive-linguistic stimulation) treatments may be useful management methods and warrant further investigation.

The noble gas xenon provides protection and trophic stimulation to midbrain dopamine neurons.

PubMed

Lavaur, Jérémie; Le Nogue, Déborah; Lemaire, Marc; Pype, Jan; Farjot, Géraldine; Hirsch, Etienne C; Michel, Patrick P

2017-07-01

Despite its low chemical reactivity, the noble gas xenon possesses a remarkable spectrum of biological effects. In particular, xenon is a strong neuroprotectant in preclinical models of hypoxic-ischemic brain injury. In this study, we wished to determine whether xenon retained its neuroprotective potential in experimental settings that model the progressive loss of midbrain dopamine (DA) neurons in Parkinson's disease. Using rat midbrain cultures, we established that xenon was partially protective for DA neurons through either direct or indirect effects on these neurons. So, when DA neurons were exposed to l-trans-pyrrolidine-2,4-dicarboxylic acid so as to increase ambient glutamate levels and generate slow and sustained excitotoxicity, the effect of xenon on DA neurons was direct. The vitamin E analog Trolox also partially rescued DA neurons in this setting and enhanced neuroprotection by xenon. However, in the situation where DA cell death was spontaneous, the protection of DA neurons by xenon appeared indirect as it occurred through the repression of a mechanism mediated by proliferating glial cells, presumably astrocytes and their precursor cells. Xenon also exerted trophic effects for DA neurons in this paradigm. The effects of xenon were mimicked and improved by the N-methyl-d-aspartate glutamate receptor antagonist memantine and xenon itself appeared to work by antagonizing N-methyl-d-aspartate receptors. Note that another noble gas argon could not reproduce xenon effects. Overall, present data indicate that xenon can provide protection and trophic support to DA neurons that are vulnerable in Parkinson's disease. This suggests that xenon might have some therapeutic value for this disorder. © 2017 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.

Glial activation and post-synaptic neurotoxicity: the key events in Streptozotocin (ICV) induced memory impairment in rats.

PubMed

Rai, Shivika; Kamat, Pradeep K; Nath, Chandishwar; Shukla, Rakesh

2014-02-01

In the present study the role of glial activation and post synaptic toxicity in ICV Streptozotocin (STZ) induced memory impaired rats was explored. In experiment set up 1: Memory deficit was found in Morris water maze test on 14-16 days after STZ (ICV; 3mg/Kg) administration. STZ causes increased expression of GFAP, CD11b and TNF-α indicating glial activation and neuroinflammation. STZ also significantly increased the level of ROS, nitrite, Ca(2+) and reduced the mitochondrial activity in synaptosomal preparation illustrating free radical generation and excitotoxicity. Increased expression and activity of Caspase-3 was also observed in STZ treated rat which specify apoptotic cell death in hippocampus and cortex. STZ treatment showed decrease expression of post synaptic markers CaMKIIα and PSD-95, while, expression of pre synaptic markers (synaptophysin and SNAP-25) remains unaltered indicating selective post synaptic neurotoxicity. Oral treatment with Memantine (10mg/kg) and Ibuprofen (50 mg/kg) daily for 13 days attenuated STZ induced glial activation, apoptotic cell death and post synaptic neurotoxicity in rat brain. Further, in experiment set up 2: where memory function was not affected i.e. 7-9 days after STZ treatment. The level of GFAP, CD11b, TNF-α, ROS and nitrite levels were increased. On the other hand, apoptotic marker, synaptic markers, mitochondrial activity and Ca(2+) levels remained unaffected. Collective data indicates that neuroinflammatory process and oxidative stress occurs earlier to apoptosis and does not affect memory function. Present study clearly suggests that glial activation and post synaptic neurotoxicity are the key factors in STZ induced memory impairment and neuronal cell death. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of glutamate receptor antagonists and antirheumatic drugs on proliferation of synoviocytes in vitro.

PubMed

Parada-Turska, Jolanta; Rzeski, Wojciech; Majdan, Maria; Kandefer-Szerszeń, Martyna; Turski, Waldemar A

2006-03-27

One of the most striking features of inflammatory arthritis is the hyperplasia of synovial fibroblasts. It is not known whether the massive synovial hyperplasia characteristic of rheumatoid arthritis is due to the proliferation of synovial fibroblasts or to defective apoptosis. It has been found that glutamate receptor antagonists inhibit proliferation of different human tumour cells and the anticancer potential of glutamate receptor antagonists was suggested. Here, we investigated the effect of glutamate receptor antagonists and selected antirheumatic drugs on proliferation of synoviocytes in vitro. Experiments were conducted on rabbit synoviocytes cell line HIG-82 obtained from American Type Culture Collection (Menassas, VA, USA). Cell proliferation was assessed by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The IC50 value (the concentration of drug necessary to induce 50% inhibition) together with confidence limits was calculated. Glutamate receptor antagonists, 1-(4-aminophenyl)-3,5-dihydro-7,8-dimethoxy-4H-2,3-benzodiazepin-4-one (CFM-2), riluzole, memantine, 1-4-aminophenyl-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine (GYKI 52466), dizocilpine, ketamine and 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)quinoxaline (NBQX), inhibited proliferation of synoviocytes with the following IC50 values (in mM): 0.014, 0.017, 0.065, 0.102, 0.15, 0.435 and 1.16, respectively. Antirheumatic drugs, celecoxib, diclofenac, nimesulide, sulfasalazine, naproxen and methotrexate, inhibited proliferation of synoviocytes with the following IC50 values (in mM): 0.0043, 0.034, 0.044, 0.096, 0.385 and 1.123, respectively. Thus, the antiproliferative potential of glutamate receptor antagonists is comparable to that of antirheumatic drugs.

Amyloid Precursor Protein 96–110 and β-Amyloid 1–42 Elicit Developmental Anomalies in Sea Urchin Embryos and Larvae that are Alleviated by Neurotransmitter Analogs for Acetylcholine, Serotonin and Cannabinoids

PubMed Central

Buznikov, Gennady A.; Nikitina, Lyudmila A.; Seidler, Frederic J.; Slotkin, Theodore A.; Bezuglov, Vladimir V.; Milošević, Ivan; Lazarević, Lidija; Rogač, Ljubica; Ruzdijić, Sabera; Rakić, Ljubiša M.

2008-01-01

Amyloid precursor protein (APP) is overexpressed in the developing brain and portions of its extracellular domain, especially amino acid residues 96–110, play an important role in neurite outgrowth and neural cell differentiation. In the current study, we evaluated the developmental abnormalities caused by administration of exogenous APP96–110 in sea urchin embryos and larvae, which, like the developing mammalian brain, utilize acetylcholine and other neurotransmitters as morphogens; effects were compared to those of β-amyloid 1–42 (Aβ42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer’s Disease. Although both peptides elicited dysmorphogenesis, Aβ42 was far more potent; in addition, whereas Aβ42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP96–110 effects were restricted to the intermediate, mid-blastula stage. For both agents, anomalies were prevented or reduced by addition of lipid-permeable analogs of acetylcholine, serotonin or cannabinoids; physostigmine, a carbamate-derived cholinesterase inhibitor, was also effective. In contrast, agents that act on NMDA receptors (memantine) or α-adrenergic receptors (nicergoline), and that are therapeutic in Alzheimer’s Disease, were themselves embryotoxic, as was tacrine, a cholinesterase inhibitor from a different chemical class than physostigmine. Protection was also provided by agents acting downstream from receptor-mediated events: increasing cyclic AMP with caffeine or isobutylmethylxanthine, or administering the antioxidant, α-tocopherol, were all partially effective. Our findings reinforce a role for APP in development and point to specific interactions with neurotransmitter systems that act as morphogens in developing sea urchins as well as in the mammalian brain. PMID:18565728

Strategies for preservation of memory function in patients with brain metastases.

PubMed

Dye, Nicholas B; Gondi, Vinai; Mehta, Minesh P

2015-06-01

Cognitive decline, particularly in memory, is a side effect seen in patients with brain metastases and when severe, can have a significant impact on their quality of life. It is most often the result of multiple intersecting etiologic factors, including the use of whole brain radiation therapy, effects of which, in part, are mediated by damage within the hippocampus. A variety of clinical factors and comorbidities may impact the likelihood and severity of this cognitive decline, and affected patients should be considered for evaluation in a comprehensive neuro-rehabilitation or "brain fitness" program. Avoiding WBRT is warranted for some patients with brain metastases; particularly those <50 years old. However, when WBRT is clinically indicated, hippocampal avoidance WBRT (HA-WBRT) has been shown to significantly reduce memory decline compared to historical controls without compromising treatment efficacy. Additionally, the NMDA receptor antagonist memantine and renin-angiotensin-aldosterone system (RAAS) blockers have shown promise as neuroprotective agents that could be used prophylactically with radiation. After the onset of neurocognitive decline the treatment is largely symptom-driven, however simply screening for and treating depression, fatigue, anxiety, cognitive slowing, and other processes may alleviate some impairment. Stimulants such as methylphenidate may be useful in treating symptoms of fatigue and cognitive slowing. Other treatments including donepezil and cognitive rehabilitation have been extensively tested in the population at risk for dementia, although they have not been adequately studied in patients following cranial radiotherapy. An innovative hypothetical approach is the use of intranasal metabolic stimulants such as low dose insulin, which could be valuable in improving cognition and memory, by reversing impaired brain metabolic activity. Prevention of neurocognitive decline in patients with brain metastases requires a multimodal approach tailored to each patient's need, avoiding WBRT in some, altering the WBRT plan in others, and/or using neuroprotective prophylaxis in those in whom avoidance cannot be utilized. Likewise treatment will require a personalized combination of strategies optimized to address the patient's symptoms.

Low dose of L-glutamic acid attenuated the neurological dysfunctions and excitotoxicity in bilateral common carotid artery occluded mice.

PubMed

Ramanathan, Muthiah; Abdul, Khadar K; Justin, Antony

2016-10-01

Glutamate, an excitatory neurotransmitter in the brain, produces excitotoxicity through its agonistic action on postsynaptic N-methyl-D-aspartate receptor, resulting in neurodegeneration. We hypothesized that the administration of low doses of glutamate in cerebral ischemia could attenuate the excitotoxicity in neurons through its autoreceptor regulatory mechanism, and thereby control neurodegeneration. To test the hypothesis, the effect of L-glutamic acid (L-GA) 400 μmol/l/kg was evaluated in a bilateral common carotid artery occlusion-induced global ischemic mouse model. Memantine was used as a positive control. Global ischemia in mice was induced by occlusion of both the common carotid artery (bilateral common carotid artery occlusion) for 20 min, followed by reperfusion injury. L-GA was infused slowly through the tail vein 30 min before the surgery and every 24 h thereafter until the end of the experiment. The time-dependent change in cerebral blood flow was monitored using a laser Doppler image analyzer. The neurotransmitters glutamate and γ-aminobutyric acid (GABA) and the neurobiochemicals ATP, glutathione, and nitric oxide were measured in the different regions of brain at 0, 24, 48, and 72 h after reperfusion injury. L-GA increased locomotor activity, muscle coordination, and cerebral blood flow in ischemic mice at 72 h after ischemic insult. L-GA reduced glutamate levels in the cortex, striatum, and hippocampus at 72 h, whereas GABA levels were elevated in all three brain regions studied. Further, L-GA elevated glutathione levels and attenuated nitric oxide levels, but failed to restore ATP levels 72 h after ischemia-reperfusion. We conclude that the gradual reduction of glutamate along with elevation of GABA in different brain regions could have contributed toward the neuroprotective effect of L-GA. Hence, a slow infusion of a low dose of L-GA could be beneficial in controlling excitotoxicity-induced neurodegeneration following ischemia.

The effect of funding sources on donepezil randomised controlled trial outcome: a meta-analysis.

PubMed

Killin, Lewis O J; Russ, Tom C; Starr, John M; Abrahams, Sharon; Della Sala, Sergio

2014-04-07

To investigate whether there is a difference in the treatment effect of donepezil on cognition in Alzheimer disease between industry-funded and independent randomised controlled trials. Fixed effects meta-analysis of standardised effects of donepezil on cognition as measured by the Mini Mental State Examination and the Alzheimer's Disease Assessment Scale-cognitive subscale. Studies included in the meta-analyses reported in the National Institute for Health and Care Excellence (NICE) technical appraisal 217 updated with new studies through a PubMed search. Inclusion criteria were double-blind, placebo-controlled trials of any length comparing patients diagnosed with probable Alzheimer disease (according to the NINCDS-ADRDA/DSM-III/IV criteria) taking any dosage of donepezil. Studies of combination therapies (eg, donepezil and memantine) were excluded, as were studies that enrolled patients with a diagnosis of Alzheimer disease associated with other disorders (eg, Parkinson's disease and Down's syndrome). Our search strategy identified 14 relevant trials (4 independent) with suitable data. Trials sponsored by pharmaceutical companies reported a larger effect of donepezil on standardised cognitive tests than trials published by independent research groups (standardised mean difference (SMD)=0.46, 95% CI 0.37 to 0.55 vs SMD=0.33, 95% CI 0.18 to 0.48, respectively). This difference remained when only data representing change up to 12 weeks from baseline were analysed (industry SMD=0.44, 95% CI 0.34 to 0.53 vs independent SMD=0.35, 95% CI 0.18 to 0.52). Analysis revealed that the effect of funding as a moderator variable of study heterogeneity was not statistically significant at either time point. The effect size of donepezil on cognition is larger in industry-funded than independent trials and this is not explained by the longer duration of industry-funded trials. The lack of a statistically significant moderator effect may indicate that the differences are due to chance, but may also result from lack of power.

Potential impact of amyloid imaging on diagnosis and intended management in patients with progressive cognitive decline.

PubMed

Grundman, Michael; Pontecorvo, Michael J; Salloway, Stephen P; Doraiswamy, P Murali; Fleisher, Adam S; Sadowsky, Carl H; Nair, Anil K; Siderowf, Andrew; Lu, Ming; Arora, Anupa K; Agbulos, Abigail; Flitter, Matthew L; Krautkramer, Michael J; Sarsour, Khaled; Skovronsky, Daniel M; Mintun, Mark A

2013-01-01

Florbetapir F18 has been approved by the Food and Drug Administration for in vivo assessment of amyloid pathology in patients undergoing evaluation for Alzheimer disease (AD). The aim of this study was to determine the impact of amyloid imaging on the diagnoses and management of patients undergoing evaluation for cognitive decline. Patients were recruited to participate at 19 clinical sites. The site physician provided a provisional diagnosis, an estimate of their diagnostic confidence, and their plan for diagnostic evaluation and management both before and after receiving the results from amyloid imaging with florbetapir F18. Analyses compared the frequency of AD and non-AD diagnoses, plans for ancillary testing, and intended patient management before and after florbetapir imaging. A total of 229 patients participated in the trial (113 amyloid positive, 116 amyloid negative). After receiving the results of the florbetapir scan, diagnosis changed in 125/229, or 54.6% [95% confidence intervals (CI), 48.1%-60.9%], of cases, and diagnostic confidence increased by an average of 21.6% (95% CI, 18.3%-24.8%). A total of 199/229 or 86.9% (95% CI, 81.9%-90.7%) of cases had at least 1 change in their management plan. Intended cholinesterase inhibitor or memantine treatment increased by 17.7% (95% CI, 11.8%-25.8%) of all cases with positive scans and decreased by 23.3% (95% CI, 16.5%-31.8%) of all those with negative scans. Among subjects who had not yet undergone a completed work up, planned brain structural imaging (computed tomographic/magnetic resonance imaging) decreased by 24.4% (95% CI, 17.5%-32.8%) and planned neuropsychological testing decreased by 32.8% (95% CI, 25.0%-41.6%). In summary, amyloid imaging results altered physician's diagnostic thinking, intended testing, and management of patients undergoing evaluation for cognitive decline.

Retrieval-induced NMDA receptor-dependent Arc expression in two models of cocaine-cue memory.

PubMed

Alaghband, Yasaman; O'Dell, Steven J; Azarnia, Siavash; Khalaj, Anna J; Guzowski, John F; Marshall, John F

2014-12-01

The association of environmental cues with drugs of abuse results in persistent drug-cue memories. These memories contribute significantly to relapse among addicts. While conditioned place preference (CPP) is a well-established paradigm frequently used to examine the modulation of drug-cue memories, very few studies have used the non-preference-based model conditioned activity (CA) for this purpose. Here, we used both experimental approaches to investigate the neural substrates of cocaine-cue memories. First, we directly compared, in a consistent setting, the involvement of cortical and subcortical brain regions in cocaine-cue memory retrieval by quantifying activity-regulated cytoskeletal-associated (Arc) protein expression in both the CPP and CA models. Second, because NMDA receptor activation is required for Arc expression, we investigated the NMDA receptor dependency of memory persistence using the CA model. In both the CPP and CA models, drug-paired animals showed significant increases in Arc immunoreactivity in regions of the frontal cortex and amygdala compared to unpaired controls. Additionally, administration of a NMDA receptor antagonist (MK-801 or memantine) immediately after cocaine-CA memory reactivation impaired the subsequent conditioned locomotion associated with the cocaine-paired environment. The enhanced Arc expression evident in a subset of corticolimbic regions after retrieval of a cocaine-context memory, observed in both the CPP and CA paradigms, likely signifies that these regions: (i) are activated during retrieval of these memories irrespective of preference-based decisions, and (ii) undergo neuroplasticity in order to update information about cues previously associated with cocaine. This study also establishes the involvement of NMDA receptors in maintaining memories established using the CA model, a characteristic previously demonstrated using CPP. Overall, these results demonstrate the utility of the CA model for studies of cocaine-context memory and suggest the involvement of an NMDA receptor-dependent Arc induction pathway in drug-cue memory interference. Copyright © 2014 Elsevier Inc. All rights reserved.

Caregiver Preference and Treatment Compliance in Patients with Mild-to-Moderate Alzheimer's Disease in South Korea: RECAP Study Results.

PubMed

Lee, Kang Joon; Cho, Seong-Jin; Kim, Byeong Chae; Park, Minseok; Lee, Jae-Hong

2017-02-01

The aim of this study was to assess caregiver preference and treatment compliance with oral and transdermal medications in a "real-world" setting in patients with mild-to-moderate Alzheimer's disease (AD) in South Korea. Real-world evaluation of compliance and preference in Alzheimer's disease treatment (RECAP) was a 24-week, multicenter, prospective, non-interventional study in patients with AD treated with oral or transdermal therapy. Here, we report data from patients living in South Korea. Eligible patients were grouped into one of two treatment cohorts: oral (donepezil, galantamine, rivastigmine, or memantine) or transdermal (rivastigmine patch). Caregiver preference, patient compliance, and physician preference were assessed at week 24 (end of the study). Safety was assessed by reported adverse events (AEs). A total of 398 patients were enrolled (oral 51.8%; transdermal 48.2%) and 79.4% completed the study. Caregivers of patients that were exposed to either the oral or transdermal monotherapy showed a preference for the treatment to which the patients were exposed (both p < 0.0001). However, caregivers of patients that were exposed to both forms of treatments reported a higher preference for transdermal monotherapy (65.9%; p < 0.0041). Patients in both treatment cohorts showed good compliance, with an overall mean (SD) score of 8.84 (1.514) (a median of 9). Of the 15 participating physicians, eight indicated their preference for transdermal therapy and seven preferred oral therapy at week 24. A total of 133 (33.4%) patients reported at least one AE during the study period (oral: 60 patients; transdermal: 73 patients). The study showed higher caregiver preference for transdermal monotherapy over oral monotherapy when patients with AD were exposed to both forms of treatment and good patient compliance for both oral and transdermal treatments.

Sembragiline in Moderate Alzheimer’s Disease: Results of a Randomized, Double-Blind, Placebo-Controlled Phase II Trial (MAyflOwer RoAD)

PubMed Central

Nave, Stephane; Doody, Rachelle S.; Boada, Mercè; Grimmer, Timo; Savola, Juha-Matti; Delmar, Paul; Pauly-Evers, Meike; Nikolcheva, Tania; Czech, Christian; Borroni, Edilio; Ricci, Benedicte; Dukart, Juergen; Mannino, Marie; Carey, Tracie; Moran, Emma; Gilaberte, Inma; Muelhardt, Nicoletta Milani; Gerlach, Irene; Santarelli, Luca; Ostrowitzki, Susanne; Fontoura, Paulo

2017-01-01

Background: Sembragiline is a potent, selective, long-acting, and reversible MAO-B inhibitor developed as a potential treatment for Alzheimer’s disease (AD). Objective: To evaluate the safety, tolerability, and efficacy of sembragiline in patients with moderate AD. Methods: In this Phase II study (NCT01677754), 542 patients with moderate dementia (MMSE 13–20) on background acetylcholinesterase inhibitors with/without memantine were randomized (1:1:1) to sembragiline 1 mg, 5 mg, or placebo once daily orally for 52 weeks. Results: No differences between treated groups and placebo in adverse events or in study completion. The primary endpoint, change from baseline in ADAS-Cog11, was not met. At Week 52, the difference between sembragiline and placebo in ADAS-Cog11 change from baseline was – 0.15 (p = 0.865) and 0.90 (p = 0.312) for 1 and 5 mg groups, respectively. Relative to placebo at Week 52 (but not at prior assessment times), the 1 mg and 5 mg sembragiline groups showed differences in ADCS-ADL of 2.64 (p = 0.051) and 1.89 (p = 0.160), respectively. A treatment effect in neuropsychiatric symptoms (as assessed by the difference between sembragiline and placebo on BEHAVE-AD-FW) was also seen at Week 52 only: – 2.80 (p = 0.014; 1 mg) and – 2.64 (p = 0.019; 5 mg), respectively. A post hoc subgroup analysis revealed greater treatment effects on behavior and functioning in patients with more severe baseline behavioral symptoms (above the median). Conclusions: This study showed that sembragiline was well-tolerated in patients with moderate AD. The study missed its primary and secondary endpoints. Post hoc analyses suggested potential effect on neuropsychiatric symptoms and functioning in more behaviorally impaired study population at baseline. PMID:28550255

Retrieval-induced NMDA receptor-dependent Arc expression in two models of cocaine-cue memory

PubMed Central

Alaghband, Yasaman; O'Dell, Steven J.; Azarnia, Siavash; Khalaj, Anna J.; Guzowski, John F.; Marshall, John F.

2014-01-01

The association of environmental cues with drugs of abuse results in persistent drug-cue memories. These memories contribute significantly to relapse among addicts. While conditioned place preference (CPP) is a well-established paradigm frequently used to examine the modulation of drug-cue memories, very few studies have used the non-preference-based model conditioned activity (CA) for this purpose. Here, we used both experimental approaches to investigate the neural substrates of cocaine-cue memories. First, we directly compared, in a consistent setting, the involvement of cortical and subcortical brain regions in cocaine-cue memory retrieval by quantifying activity-regulated cytoskeletal associated gene (Arc) protein expression in both the CPP and CA models. Second, because NMDA receptor activation is required for Arc expression, we investigated the NMDA receptor dependency of memory persistence using the CA model. In both the CPP and CA models, drug-paired animals showed significant increases in Arc immunoreactivity in regions of the frontal cortex and amygdala compared to unpaired controls. Additionally, administration of a NMDA receptor antagonist (MK-801 or memantine) immediately after cocaine-CA memory reactivation impaired the subsequent conditioned locomotion associated with the cocaine-paired environment. The enhanced Arc expression evident in a subset of corticolimbic regions after retrieval of a cocaine-context memory, observed in both the CPP and CA paradigms, likely signifies that these regions: (i) are activated during retrieval of these memories irrespective of preference-based decisions, and (ii) undergo neuroplasticity in order to update information about cues previously associated with cocaine. This study also establishes the involvement of NMDA receptors in maintaining memories established using the CA model, a characteristic previously demonstrated using CPP. Overall, these results demonstrate the utility of the CA model for studies of cocaine-context memory and suggest the involvement of an NMDA receptor-dependent Arc induction pathway in drug-cue memory interference. PMID:25225165

Pharmacological treatment for memory disorder in multiple sclerosis.

PubMed

He, Dian; Zhang, Yun; Dong, Shuai; Wang, Dongfeng; Gao, Xiangdong; Zhou, Hongyu

2013-12-17

This is an update of the Cochrane review "Pharmacologic treatment for memory disorder in multiple sclerosis" (first published in The Cochrane Library 2011, Issue 10).Multiple sclerosis (MS) is a chronic immune-mediated, inflammatory, demyelinating, neurodegenerative disorder of the central nervous system (CNS) and can cause both neurological and neuropsychological disability. Both demyelination and axonal and neuronal loss are believed to contribute to MS-related cognitive impairment. Memory disorder is one of the most frequent cognitive dysfunctions and presents a considerable burden to people with MS and to society due to the negative impact on function. A number of pharmacological agents have been evaluated in many existing randomised controlled trials for their efficacy on memory disorder in people with MS but the results were not consistent. To assess the absolute and comparative efficacy, tolerability and safety of pharmacological treatments for memory disorder in adults with MS. We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Trials Register (24 July 2013), PsycINFO (January 1980 to 26 June 2013) and CBMdisc (1978 to 24 June 2013), and checked reference lists of identified articles, searched some relevant journals manually, registers of clinical trials and published abstracts of conference proceedings. All double-blind, randomised controlled parallel trials on pharmacological treatment versus placebo or one or more pharmacological treatments in adults with MS who had at least mild memory impairment (at 0.5 standard deviations below age- and sex-based normative data on a validated memory scale). We placed no restrictions regarding dose, route of administration and frequency; however, we only included trials with an administration duration of 12 weeks or greater. Two review authors independently assessed trial quality and extracted data. We discussed disagreements and resolved them by consensus among review authors. We contacted principal investigators of included studies for additional data or confirmation. We included seven randomised controlled trials (RCTs) involving 625 people mostly with relapsing-remitting, secondary-progressive and primary-progressive MS, evaluating the absolute efficacy of donepezil, ginkgo biloba, memantine and rivastigmine versus placebo in improving memory performance with diverse assessment scales. Overall, clinical and methodological heterogeneities existed across these studies. Moreover, most of them had methodological limitations on non-specific selections of targeted sample, non-matched variables at baseline or incomplete outcome data (high attrition bias). Only the two studies on donepezil had clinical and methodological homogeneity and relatively low risks for bias. One RCT evaluating estriol versus placebo is currently ongoing.We could not carry out a meta-analysis due to the heterogeneities across studies and the high attrition bias. A subgroup analysis for donepezil versus placebo showed no treatment effects on total recall on the Selective Reminding Test (mean difference (MD) 1.68; 95% confidence interval (CI) -2.21 to 5.58), total correct scores on the 10/36 Spatial Recall Test (MD -0.93; 95% CI -3.18 to 1.32), the Symbol Digit Modalities Test (MD -1.27; 95% CI -3.15 to 0.61) and the Paced Auditory Serial Addition Test (2+3 sec) (MD 2.23; 95% CI -1.87 to 6.33). Concerning safety, the main adverse events were: diarrhoea (risk ratio (RR) 3.88; 95% CI 1.66 to 9.05), nausea (RR 1.71; 95% CI 0.93 to 3.18) and abnormal dreams (RR 2.91; 95% CI 1.38 to 6.14). However, the results in both studies were subjected to a serious imprecision resulting from the small sample sizes and the low power of test (lower than 80%), which contributed to a moderate quality of the evidence. No serious adverse events were attributed to the treatments in all experimental groups. We found no convincing evidence to support the efficacy of pharmacological symptomatic treatment for MS-associated memory disorder because most of available RCTs had a limited quality. Whether pharmacological treatment is effective for memory disorder in patients with MS remains inconclusive. However, there is moderate-quality evidence that donepezil 10 mg daily was not effective in improving memory in MS patients with mild memory impairment, but had a good tolerability. Adverse events such as nausea, diarrhoea and abnormal dreams were not frequent but were associated with treatment. Ginkgo biloba, memantine and rivastigmine were safe and well tolerated and no serious adverse effects were reported. Future large-scale RCTs with higher methodological quality are needed.

Anti-Dementia Drugs, Gait Performance and Mental Imagery of Gait: A Non-Randomized Open-Label Trial.

PubMed

Beauchet, Olivier; Barden, John; Liu-Ambrose, Teresa; Chester, Victoria L; Annweiler, Cedric; Szturm, Tony; Grenier, Sébastien; Léonard, Guillaume; Bherer, Louis; Allali, Gilles

2016-09-01

Few studies have examined the effect of anti-dementia drugs (i.e., acetylcholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists) on gait performance. Past studies have focused on the stride time (i.e., gait cycle duration) but not on the mental imagery of gait. To compare mental imagery of gait and spatiotemporal gait parameters in patients with dementia [i.e., Alzheimer's disease (AD) and non-AD] before and after the use of anti-dementia drugs (i.e., acetylcholinesterase inhibitors and memantine) and in controls (i.e., patients with dementia who did not take anti-dementia drugs). A total of 112 patients (mean age 82.5 ± 4.2 years, 68.8 % female) with mild-to-moderate AD and non-AD dementia were included in this non-randomized open-label trial (n = 56 in the Intervention group, and n = 56 in the Control group matched for age, sex, and stage and type of dementia) nested in a cohort study (mean follow-up 238.5 ± 79.8 days). Mental imagery of gait was assessed with the actual and imagined Timed Up and Go tests (aTUG and iTUG) and the difference between aTUG and iTUG (i.e., delta-TUG). Spatiotemporal gait parameters were measured with the GAITRite(®) system during normal walking. Participants in the Intervention group had a longer iTUG time (p < 0.001) and a lower delta-TUG value (p = 0.001) at the follow-up compared with those in the Control group. There was a significant increase in iTUG (p = 0.001) and decrease in delta-TUG (p < 0.001) from baseline to the follow-up only in the Intervention group. Multiple linear regression showed that the use of anti-dementia drugs was associated with a longer iTUG time and a lower delta-TUG value (best performance, p < 0.002). Our findings showed an improvement in mental imagery of gait with the use of anti-dementia drugs, but no changes in actual gait performance. NCT01315704.

Preclinical evaluation of the antipsychotic potential of the mGlu2-positive allosteric modulator JNJ-40411813

PubMed Central

Lavreysen, Hilde; Langlois, Xavier; Donck, Luc Ver; Nuñez, José María Cid; Pype, Stefan; Lütjens, Robert; Megens, Anton

2015-01-01

JNJ-40411813/ADX71149 (1-butyl-3-chloro-4-(4-phenylpiperidin-1-yl) pyridin-2(1H)-one) is a positive allosteric modulator (PAM) of the mGlu2 receptor, which also displays 5-Hydroxytryptamine (5HT2A) antagonism after administration in rodents due to a rodent-specific metabolite. JNJ-40411813 was compared with the orthosteric mGlu2/3 agonist LY404039 (4-amino-2-thiabicyclo [3.1.0] hexane-4,6-dicarboxylic acid 2,2-dioxide), the selective mGlu2 PAM JNJ-42153605 (3-(cyclopropylmethyl)-7-(4-phenylpiperidin-1-yl)-8-(trifluoromethyl)[1,2,4]triazolo[4,3-a]pyridine) and the 5HT2A antagonist ritanserin in rodent models for antipsychotic activity and potential side effects, attempting to differentiate between the various compounds and mechanisms of action. In mice, JNJ-40411813, JNJ-42153605, and LY404039 inhibited spontaneous locomotion and phencyclidine- and scopolamine-induced but not d-amphetamine-induced hyperlocomotion; the 5HT2A antagonist ritanserin inhibited only spontaneous locomotion and phencyclidine-induced hyperlocomotion. As measured by 2-deoxyglucose uptake, all compounds reversed memantine-induced brain activation in mice. The two mGlu2 PAMs and LY404039, but not ritanserin, inhibited conditioned avoidance behavior in rats. Like ritanserin, the mGlu2 ligands antagonized 2,5-dimethoxy-4-methylamphetamine-induced head twitches in rats. LY404039 but not the mGlu2 PAMs impaired rotarod performance in rats and increased the acoustic startle response in mice. Our results show that although 5HT2A antagonism has effect in some models, mGlu2 receptor activation is sufficient for activity in several animal models of antipsychotic activity. The mGlu2 PAMs mimicked the in vivo pharmacodynamic effects observed with LY404039 except for effects on the rotarod and acoustic startle, suggesting that they produce a primary activity profile similar to that of the mGlu2/3 receptor agonist while they can be differentiated based on their secondary activity profile. The results are discussed in light of clinical data available for some of these molecules, in particular JNJ-40411813. PMID:25692027

[The ability of NMDA glutamate receptor blockers to prevent a pentylenetetrazole kindling in mice and morphological changes in the hippocampus].

PubMed

Vasil'ev, D S; Tumanova, N L; Lavrent'eva, V V; Starshinova, L A; Zhabko, E P; Lukomskaia, N Ia; Zhuravin, I A; Magazanik, L G

2013-09-01

We investigated in mice the relationship between convulsions and morphological changes of hippocampal neurons that arise in the development of pentylentetrazol (PTZ)-induced kindling. The kindling was caused by of 35 mg/kg PTZ i.p. 3 times a week for a month. By the end of this period, 70% of the mice responded to the injections of PTZ with pronounced clonic or tonic-clonic seizures. The hippocampal slices (layer stratum pyramidale, CA1, Nissl's stain) obtained from mice exhibiting seizures revealed a large number of modified cells (24.7 +/- 2.1%). These hyperchromic neurons have been characterized by a decrease of the size cell body, there was a loss of turgor, the body cells shrink, and dendritic spines curl. Part of the cells took the shape of elongated neck. Such modified the dark type of neurons contained only 2.3 +/- 2.3% in the hippocampus of intact mice, and 30% of the mice resistant to the convulsive action ofPTZ during the period of observation. The expression of protein NeuN (Fox3) in hippocamal neuron including the hyperchromic once suggests that neurons on the whole did not die and were relatively viable. Preventive administration of NMDA receptor blockers (0.5 mg/kg, memantine 0.1 mg/kg or IEM-1958 1 mg/kg, s.c.) 30 minutes prior to PTZ reduced the proportion of mice which exhibited PTZ kindling from 70% to 40%. The modified neurons were observed in which the PTZ kindling due to the blocker presence did not develop, i.e., the same as in intact mice. Contrary, 24.0 +/- 5.6% of hyperchromic neurons were found in the hippocampal slices from mice manifested seizures, despite the co-administration of NMDA blockers. The data obtained indicate that modified neurons are the result of seizures suffered by the animals in the course of PTZ kindling, and that the blockade of NMDA glutamate receptors can suppress manifestations of seizures and the accompanying morphological changes of hippocampal neurons.

The effect of an interactive cycling training on cognitive functioning in older adults with mild dementia: study protocol for a randomized controlled trial.

PubMed

Karssemeijer, E G A; Bossers, W J R; Aaronson, J A; Kessels, R P C; Olde Rikkert, M G M

2017-03-21

To date there is no cure or an effective disease-modifying drug to treat dementia. Available acetylcholine-esterase inhibiting drugs or memantine only produce small benefits on cognitive and behavioural functioning and their clinical relevance remains controversial. Combined cognitive-aerobic interventions are an appealing alternative or add-on to current pharmacological treatments. The primary aim of this study is to investigate the efficacy of a combined cognitive-aerobic training and a single aerobic training compared to an active control group in older adults with mild dementia. We expect to find a beneficial effect on executive functioning in both training regimes, compared to the control intervention, with the largest effect in the combined cognitive-aerobic group. Secondary, intervention effects on cognitive functioning in other domains, physical functioning, physical activity levels, activities of daily living, frailty and quality of life are studied. The design is a single-blind, randomized controlled trial (RCT) with three groups: a combined cognitive-aerobic bicycle training (interactive cycling), a single aerobic bicycle training and a control intervention, which consists of stretching and toning exercises. Older adults with mild dementia follow a 12-week training program consisting of three training sessions of 30-40 min per week. The primary study outcome is objective executive functioning measured with a neuropsychological assessment. Secondary measures are objective cognitive functioning in other domains, physical functioning, physical activity levels, activities of daily living, frailty, mood and quality of life. The three groups are compared at baseline, after 6 and 12 weeks of training, and at 24-week follow-up. This study will provide novel information on the effects of an interactive cycling training on executive function in older adults with mild dementia. Furthermore, since this study has both a combined cognitive-aerobic training and a single aerobic training group the effectiveness of the different components of the intervention can be identified. The results of this study may be used for physical and mental activity recommendations in older adults with dementia. The Netherlands National Trial Register NTR5581 . Registered 14 February 2016.

Add-on prolonged-release melatonin for cognitive function and sleep in mild to moderate Alzheimer's disease: a 6-month, randomized, placebo-controlled, multicenter trial.

PubMed

Wade, Alan G; Farmer, Mildred; Harari, Gil; Fund, Naama; Laudon, Moshe; Nir, Tali; Frydman-Marom, Anat; Zisapel, Nava

2014-01-01

A link between poor sleep quality and Alzheimer's disease (AD) has recently been suggested. Since endogenous melatonin levels are already reduced at preclinical AD stages, it is important to ask whether replenishing the missing hormone would be beneficial in AD and whether any such effects would be related to the presence of sleep disorder in patients. The effects of add-on prolonged-release melatonin (PRM) (2 mg) to standard therapy on cognitive functioning and sleep were investigated in 80 patients (men [50.7%], women [49.3%], average age 75.3 years [range, 52-85 years]) diagnosed with mild to moderate AD, with and without insomnia comorbidity, and receiving standard therapy (acetylcholinesterase inhibitors with or without memantine). In this randomized, double-blind, parallel-group study, patients were treated for 2 weeks with placebo and then randomized (1:1) to receive 2 mg of PRM or placebo nightly for 24 weeks, followed by 2 weeks placebo. The AD Assessment Scale-Cognition (ADAS-Cog), Instrumental Activities of Daily Living (IADL), Mini-Mental State Examination (MMSE), sleep, as assessed by the Pittsburgh Sleep Quality Index (PSQI) and a daily sleep diary, and safety parameters were measured. Patients treated with PRM (24 weeks) had significantly better cognitive performance than those treated with placebo, as measured by the IADL (P=0.004) and MMSE (P=0.044). Mean ADAS-Cog did not differ between the groups. Sleep efficiency, as measured by the PSQI, component 4, was also better with PRM (P=0.017). In the comorbid insomnia (PSQI ≥6) subgroup, PRM treatment resulted in significant and clinically meaningful effects versus the placebo, in mean IADL (P=0.032), MMSE score (+1.5 versus -3 points) (P=0.0177), and sleep efficiency (P=0.04). Median ADAS-Cog values (-3.5 versus +3 points) (P=0.045) were significantly better with PRM. Differences were more significant at longer treatment duration. PRM was well tolerated, with an adverse event profile similar to that of placebo. Add-on PRM has positive effects on cognitive functioning and sleep maintenance in AD patients compared with placebo, particularly in those with insomnia comorbidity. The results suggest a possible causal link between poor sleep and cognitive decline.

Patterns of Innovation in Alzheimer's Disease Drug Development: A Strategic Assessment Based on Technological Maturity.

PubMed

Beierlein, Jennifer M; McNamee, Laura M; Walsh, Michael J; Ledley, Fred D

2015-08-01

This article examines the current status of translational science for Alzheimer's disease (AD) drug discovery by using an analytical model of technology maturation. Previous studies using this model have demonstrated that nascent scientific insights and inventions generate few successful leads or new products until achieving a requisite level of maturity. This article assessed whether recent failures and successes in AD research follow patterns of innovation observed in other sectors. The bibliometric-based Technology Innovation Maturation Evaluation model was used to quantify the characteristic S-curve of growth for AD-related technologies, including acetylcholinesterase, N-methyl-d-aspartate (NMDA) receptors, B-amyloid, amyloid precursor protein, presenilin, amyloid precursor protein secretases, apolipoprotein E4, and transactive response DNA binding protein 43 kDa (TDP-43). This model quantifies the accumulation of knowledge as a metric for technological maturity, and it identifies the point of initiation of an exponential growth stage and the point at which growth slows as the technology is established. In contrast to the long-established acetylcholinesterase and NMDA receptor technologies, we found that amyloid-related technologies reached the established point only after 2000, and that the more recent technologies (eg, TDP-43) have not yet approached this point. The first approvals for new molecular entities targeting acetylcholinesterase and the NMDA receptor occurred an average of 22 years after the respective technologies were established, with only memantine (which was phenotypically discovered) entering clinical trials before this point. In contrast, the 6 lead compounds targeting the formation of amyloid plaques that failed in Phase III trials between 2009 and 2014 all entered clinical trials before the respective target technologies were established. This analysis suggests that AD drug discovery has followed a predictable pattern of innovation in which technological maturity is an important determinant of success in development. Quantitative analysis indicates that the lag in emergence of new products, and the much-heralded clinical failures of recent years, should be viewed in the context of the ongoing maturation of AD-related technologies. Although these technologies were not sufficiently mature to generate successful products a decade ago, they may be now. Analytical models of translational science can inform basic and clinical research results as well as strategic development of new therapeutic products. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of standard ethanolic extract from Erythrina velutina in acute cerebral ischemia in mice.

PubMed

Rodrigues, Francisca Taciana Sousa; de Sousa, Caren Nádia Soares; Ximenes, Naiara Coelho; Almeida, Anália Barbosa; Cabral, Lucas Moraes; Patrocínio, Cláudio Felipe Vasconcelos; Silva, Aline Holanda; Leal, Luzia Kalyne Almeida Moreira; Honório Júnior, José Eduardo Ribeiro; Macedo, Danielle; Vasconcelos, Silvânia Maria Mendes

2017-12-01

The objective of this study was to verify a possible neuroprotective effect of the ethanolic extract of Erythrina velutina (EEEV). Male Swiss mice were submitted to transient cerebral ischemia by occlusion of both carotid arteries for 30 min and treated for 5 days with EEEV (200 or 400 mg/kg) or Memantine (MEM) 10 mg/kg, with initiation of treatment 2 or 24 h after Ischemia. On the 6th day after the induction of ischemia, the animals were submitted to evaluation of locomotor activity and memory and then sacrificed. The brains were dissected for the removal of the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) for determination of amino acid concentrations. In the step down and Y-maze tests, ischemia caused damage to the animals and treatment with EEEV or MEM reversed this effect. The animals submitted to ischemia also showed memory deficit in the object recognition test, an effect that was reverted by EEEV400 and MEM10. Amino acid dosage showed an increase in excitatory amino acid concentrations in the PFC of the ischemic animals and this effect was reversed by the treatment with EEEV400/24H. Regarding the inhibitory amino acids, ischemia caused an increase of taurine in the PFC while treatment with MEM10/24H or EEEV400/24H reversed this effect. In HC, an increase in excitatory amino acids was also observed in ischemiated animals having treatment with EEEV200/2H or EEEV400/24H reversed this effect. Similar effect was also observed in the same area in relation to the inhibitory amino acids with treatment with MEM10/24H or EEEV400/24H. In the ST, ischemia was also able to cause an increase in excitatory amino acids that was reversed more efficiently by the treatments with MEM10/24H and EEEV200. Also in this area, an increase of taurine and GABA was observed and only the treatment with EEEV200/2H showed a reversion of this effect. In view of these findings, EEEV presents a neuroprotective effect possibly due to its action on amino acid concentrations, and is therefore a potential therapeutic tool in reducing the damage caused by ischemia. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Clinical trials and late-stage drug development for Alzheimer’s disease: an appraisal from 1984 to 2014

PubMed Central

Schneider, Lon S.; Mangialasche, Francesca; Andreasen, Niels; Feldman, Howard; Giacobini, Ezio; Jones, Roy; Mantua, Valentina; Mecocci, Patrizia; Pani, Luca; Winblad, Bengt; Kivipelto, Miia

2014-01-01

The modern era of drug development for Alzheimer’s disease began with the proposal of the cholinergic hypothesis of memory impairment and the 1984 research criteria for Alzheimer’s disease. Since then, despite the evaluation of numerous potential treatments in clinical trials, only four cholinesterase inhibitors and memantine have shown sufficient safety and efficacy to allow marketing approval at an international level. Although this is probably because the other drugs tested were ineffective, inadequate clinical development methods have also been blamed for the failures. Here we review the development of treatments for Alzheimer’s disease during the past 30 years, considering the drugs, potential targets, late-stage clinical trials, development methods, emerging use of biomarkers and evolution of regulatory considerations in order to summarize advances and anticipate future developments. We have considered late-stage Alzheimer’s disease drug development from 1984 to 2013, including individual clinical trials, systematic and qualitative reviews, meta-analyses, methods, commentaries, position papers and guidelines. We then review the evolution of drugs in late clinical development, methods, biomarkers and regulatory issues. Although a range of small molecules and biological products against many targets have been investigated in clinical trials, the predominant drug targets have been the cholinergic system and the amyloid cascade. Trial methods have evolved incrementally: inclusion criteria have largely remained focused on mild to moderate Alzheimer’s disease criteria, recently extending to early or prodromal Alzheimer disease or ‘mild cognitive impairment due to Alzheimer’s disease’, for drugs considered to be disease modifying. The duration of trials has remained at 6 to 12 months for drugs intended to improve symptoms; 18- to 24-month trials have been established for drugs expected to attenuate clinical course. Cognitive performance, activities of daily living, global change and severity ratings have persisted as the primary clinically relevant outcomes. Regulatory guidance and oversight have evolved to allow for enrichment of early-stage Alzheimer’s disease trial samples by using biomarkers and phase-specific outcomes. In conclusion, validated drug targets for Alzheimer’s disease remain to be developed. Only drugs that affect an aspect of cholinergic function have shown consistent, but modest, clinical effects in late-phase trials. There is opportunity for substantial improvements in drug discovery and clinical development methods. PMID:24605808

Glutamate Receptors within the Mesolimbic Dopamine System Mediate Alcohol Relapse Behavior.

PubMed

Eisenhardt, Manuela; Leixner, Sarah; Luján, Rafael; Spanagel, Rainer; Bilbao, Ainhoa

2015-11-25

Glutamatergic input within the mesolimbic dopamine (DA) pathway plays a critical role in the development of addictive behavior. Although this is well established for some drugs of abuse, it is not known whether glutamate receptors within the mesolimbic system are involved in mediating the addictive properties of chronic alcohol use. Here we evaluated the contribution of mesolimbic NMDARs and AMPARs in mediating alcohol-seeking responses induced by environmental stimuli and relapse behavior using four inducible mutant mouse lines lacking the glutamate receptor genes Grin1 or Gria1 in either DA transporter (DAT) or D1R-expressing neurons. We first demonstrate the lack of GluN1 or GluA1 in either DAT- or D1R-expressing neurons in our mutant mouse lines by colocalization studies. We then show that GluN1 and GluA1 receptor subunits within these neuronal subpopulations mediate the alcohol deprivation effect, while having no impact on context- plus cue-induced reinstatement of alcohol-seeking behavior. We further validated these results pharmacologically by demonstrating similar reductions in the alcohol deprivation effect after infusion of the NMDAR antagonist memantine into the nucleus accumbens and ventral tegmental area of control mice, and a rescue of the mutant phenotype via pharmacological potentiation of AMPAR activity using aniracetam. In conclusion, dopamine neurons as well as D1R-expressing medium spiny neurons and their glutamatergic inputs via NMDARs and AMPARs act in concert to influence relapse responses. These results provide a neuroanatomical and molecular substrate for relapse behavior and emphasize the importance of glutamatergic drugs in modulating relapse behavior. Here we provide genetic and pharmacological evidence that glutamate receptors within the mesolimbic dopamine system play an essential role in alcohol relapse. Using various inducible and site-specific transgenic mouse models and pharmacological validation experiments, we show that critical subunits of NMDARs and AMPARs expressed either in dopamine neurons or in dopamine receptor D1-containing neurons play an important role in the alcohol deprivation effect (the increase in alcohol intake after a period of abstinence) while having no impact on context- plus cue-induced reinstatement of alcohol-seeking responses. Medications targeting glutamatergic neurotransmission by selective inactivation of these glutamate receptors might have therapeutic efficacy. Copyright © 2015 the authors 0270-6474/15/3515523-16$15.00/0.

Effects of recirculation in a three-tank pilot-scale system for pharmaceutical removal with powdered activated carbon.

PubMed

Kårelid, Victor; Larsson, Gen; Björlenius, Berndt

2017-05-15

The removal of pharmaceutically active compounds by powdered activated carbon (PAC) in municipal wastewater is a promising solution to the problem of polluted recipient waters. Today, an efficient design strategy is however lacking with regard to high-level overall, and specific, substance removal in the large scale. The performance of PAC-based removal of pharmaceuticals was studied in pilot-scale with respect to the critical parameters; contact time and PAC dose using one PAC product selected by screening in bench-scale. The goal was a minimum of 95% removal of the pharmaceuticals present in the evaluated municipal wastewater. A set of 21 pharmaceuticals was selected from an initial 100 due to their high occurrence in the effluent water of two selected wastewater treatment plants (WWTPs) in Sweden, whereof candidates discussed for future EU regulation directives were included. By using recirculation of PAC over a treatment system using three sequential contact tanks, a combination of the benefits of powdered and granular carbon performance was achieved. The treatment system was designed so that recirculation could be introduced to any of the three tanks to investigate the effect of recirculation on the adsorption performance. This was compared to use of the setup, but without recirculation. A higher degree of pharmaceutical removal was achieved in all recirculation setups, both overall and with respect to specific substances, as compared to without recirculation. Recirculation was tested with nominal contact times of 30, 60 and 120 min and the goal of 95% removal could be achieved already at the shortest contact times at a PAC dose of 10-15 mg/L. In particular, the overall removal could be increased even to 97% and 99%, at 60 and 120 min, respectively, when the recirculation point was the first tank. Recirculation of PAC to either the first or the second contact tank proved to be comparable, while a slightly lower performance was observed with recirculation to the third tank. With regards to individual substances, clarithromycin and diclofenac were ubiquitously removed according to the set goal and in contrast, a few substances (fluconazole, irbesartan, memantine and venlafaxine) required specific settings to reach an acceptable removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanisms and Therapy for Cancer Metastasis to the Brain.

PubMed

Franchino, Federica; Rudà, Roberta; Soffietti, Riccardo

2018-01-01

Advances in chemotherapy and targeted therapies have improved survival in cancer patients with an increase of the incidence of newly diagnosed brain metastases (BMs). Intracranial metastases are symptomatic in 60-70% of patients. Magnetic resonance imaging (MRI) with gadolinium is more sensitive than computed tomography and advanced neuroimaging techniques have been increasingly used in the detection, treatment planning, and follow-up of BM. Apart from the morphological analysis, the most effective tool for characterizing BM is immunohistochemistry. Molecular alterations not always reflect those of the primary tumor. More sophisticated methods of tumor analysis detecting circulating biomarkers in fluids (liquid biopsy), including circulating DNA, circulating tumor cells, and extracellular vesicles, containing tumor DNA and macromolecules (microRNA), have shown promise regarding tumor treatment response and progression. The choice of therapeutic approaches is guided by prognostic scores (Recursive Partitioning Analysis and diagnostic-specific Graded Prognostic Assessment-DS-GPA). The survival benefit of surgical resection seems limited to the subgroup of patients with controlled systemic disease and good performance status. Leptomeningeal disease (LMD) can be a complication, especially in posterior fossa metastases undergoing a "piecemeal" resection. Radiosurgery of the resection cavity may offer comparable survival and local control as postoperative whole-brain radiotherapy (WBRT). WBRT alone is now the treatment of choice only for patients with single or multiple BMs not amenable to surgery or radiosurgery, or with poor prognostic factors. To reduce the neurocognitive sequelae of WBRT intensity modulated radiotherapy with hippocampal sparing, and pharmacological approaches (memantine and donepezil) have been investigated. In the last decade, a multitude of molecular abnormalities have been discovered. Approximately 33% of patients with non-small cell lung cancer (NSCLC) tumors and epidermal growth factor receptor mutations develop BMs, which are targetable with different generations of tyrosine kinase inhibitors (TKIs: gefitinib, erlotinib, afatinib, icotinib, and osimertinib). Other "druggable" alterations seen in up to 5% of NSCLC patients are the rearrangements of the "anaplastic lymphoma kinase" gene TKI (crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib). In human epidermal growth factor receptor 2-positive, breast cancer targeted therapies have been widely used (trastuzumab, trastuzumab-emtansine, lapatinib-capecitabine, and neratinib). Novel targeted and immunotherapeutic agents have also revolutionized the systemic management of melanoma (ipilimumab, nivolumab, pembrolizumab, and BRAF inhibitors dabrafenib and vemurafenib).

Use of medications of questionable benefit in advanced dementia.

PubMed

Tjia, Jennifer; Briesacher, Becky A; Peterson, Daniel; Liu, Qin; Andrade, Susan E; Mitchell, Susan L

2014-11-01

Advanced dementia is characterized by severe cognitive impairment and complete functional dependence. Patients' goals of care should guide the prescribing of medication during such terminal illness. Medications that do not promote the primary goal of care should be minimized. To estimate the prevalence of medications with questionable benefit used by nursing home residents with advanced dementia, identify resident- and facility-level characteristics associated with such use, and estimate associated medication expenditures. Cross-sectional study of medication use by nursing home residents with advanced dementia using a nationwide long-term care pharmacy database linked to the Minimum Data Set (460 facilities) between October 1, 2009, and September 30, 2010. Use of medication deemed of questionable benefit in advanced dementia based on previously published criteria and mean 90-day expenditures attributable to these medications per resident. Generalized estimating equations using the logit link function were used to identify resident- and facility-related factors independently associated with the likelihood of receiving medications of questionable benefit after accounting for clustering within nursing homes. Of 5406 nursing home residents with advanced dementia, 2911 (53.9%) received at least 1 medication with questionable benefit (range, 44.7% in the Mid-Atlantic census region to 65.0% in the West South Central census region). Cholinesterase inhibitors (36.4%), memantine hydrochloride (25.2%), and lipid-lowering agents (22.4%) were the most commonly prescribed. In adjusted analyses, having eating problems (adjusted odds ratio [AOR], 0.68; 95% CI, 0.59-0.78), a feeding tube (AOR, 0.58; 95% CI, 0.48-0.70), or a do-not-resuscitate order (AOR, 0.65; 95% CI, 0.57-0.75), and enrolling in hospice (AOR, 0.69; 95% CI, 0.58-0.82) lowered the likelihood of receiving these medications. High facility-level use of feeding tubes increased the likelihood of receiving these medications (AOR, 1.45; 95% CI, 1.12-1.87). The mean (SD) 90-day expenditure for medications with questionable benefit was $816 ($553), accounting for 35.2% of the total average 90-day medication expenditures for residents with advanced dementia who were prescribed these medications. Most nursing home residents with advanced dementia receive medications with questionable benefit that incur substantial associated costs.

Drug and Exercise Treatment of Alzheimer Disease and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis of Effects on Cognition in Randomized Controlled Trials.

PubMed

Ströhle, Andreas; Schmidt, Dietlinde K; Schultz, Florian; Fricke, Nina; Staden, Theresa; Hellweg, Rainer; Priller, Josef; Rapp, Michael A; Rieckmann, Nina

2015-12-01

Demographic changes are increasing the pressure to improve therapeutic strategies against cognitive decline in Alzheimer disease (AD) and mild cognitive impairment (MCI). Besides drug treatment, physical activity seems to be a promising intervention target as epidemiological and clinical studies suggest beneficial effects of exercise training on cognition. Using comparable inclusion and exclusion criteria, we analyzed the efficacy of drug therapy (cholinesterase inhibitors, memantine, and Ginkgo biloba) and exercise interventions for improving cognition in AD and MCI populations. We searched The Cochrane Library, EBSCO, OVID, Web of Science, and U.S Food and Drug Administration data from inception through October 30, 2013. Randomized controlled trials in which at least one treatment arm consisted of an exercise or a pharmacological intervention for AD or MCI patients, and which had either a non-exposed control condition or a control condition that received another intervention. Treatment discontinuation rates and Standardized Mean Change score using Raw score standardization (SMCR) of cognitive performance were calculated. Discontinuation rates varied substantially and ranged between 0% and 49% with a median of 18%. Significantly increased discontinuation rates were found for galantamine and rivastigmine as compared to placebo in AD studies. Drug treatments resulted in a small pooled effect on cognition (SMCR: 0.23, 95% CI: 0.20 to 0.25) in AD studies (N = 45, 18,434 patients) and no effect in any of the MCI studies (N = 5, 3,693 patients; SMCR: 0.03, 95% CI: 0.00 to 0.005). Exercise interventions had a moderate to strong pooled effect size (SMCR: 0.83, 95% CI: 0.59 to 1.07) in AD studies (N = 4, 119 patients), and a small effect size (SMCR: 0.20, 95% CI: 0.11 to 0.28) in MCI (N = 6, 443 patients). Drug treatments have a small but significant impact on cognitive functioning in AD and exercise has the potential to improve cognition in AD and MCI. Head-to-head trials with sufficient statistical power are necessary to directly compare efficacy, safety, and acceptability. Combining these two approaches might further increase the efficacy of each individual intervention. PROSPERO (2013:CRD42013003910). Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

[Treatment-resistant anxiety disorders: A literature review of drug therapy strategies].

PubMed

Ammar, G; Naja, W J; Pelissolo, A

2015-06-01

Anxiety disorders are widespread psychiatric conditions with significant social and professional disability, poor quality of life, an increased risk of suicide, and frequent attendance of medical services. Serotonin reuptake inhibitors (SRI) and serotonin and norepinephrine reuptake inhibitors (SNRI) have demonstrated a rather robust efficacy for the treatment of most of anxiety disorders. Nevertheless a substantial number of patients are resistant or still suffer from residual symptoms despite this first line treatment. The objective of our paper is to review relevant studies for the pharmacologic management of anxiety disorders resistant to the first line treatment. For this purpose, we conducted a pubmed/medline search for double-blind placebo-controlled trials of treatment-resistant anxiety disorders. An adequate trial for a SRI in the treatment of obsessive-compulsive disorder (OCD) should continue for at least 12 weeks. Special considerations of the comorbidities and symptom profile could help in the choice of an appropriate pharmacotherapy. Several trials have highlighted the efficacy of antipsychotics as an add-on to SRI in treatment-resistant OCD such as haloperidol more so when comorbid with a tic disorder, or risperidone that can reduce OCD as well as depressive symptoms. Aripiprazole has been shown efficacious in two placebo-controlled double-blind trials, while the efficacy of quetiapine and olanzapine remains controversial. Other trials showed some efficacy of anticonvulsants (lamotrigine, topiramate), pindolol, memantin and N-acetylcystein as an adjunctive treatment to SRI for resistant OCD. Few trials have investigated selective serotonin reuptake inhibitors (SSRI) or SNRI resistant generalized anxiety disorder showing a failure of adjunctive therapy with olanzapine, quetiapine, ziprasidone and risperidone. These studies were underpowered and very limited in number. Adjunctive risperidone for resistant post-traumatic stress disorder (PTSD) showed benefit in some but not all trials. Olanzapine was beneficial for the reduction of the CAPS score in addition to the improvement of sleep disturbances. Furthermore, prazosin was efficacious by reducing PTSD symptoms, sleep disturbances, nightmares, and psychological distress. One double-blind placebo-controlled study was conducted to investigate treatment-resistant social phobia showing no benefit of pindolol add-on paroxetine. Our results demonstrate that the pharmacological management of treatment-resistant anxiety disorders is not sufficiently investigated in double-blind placebo-controlled trials, despite a growing evidence in favor of antipsychotics and some other pharmacological agents in resistant OCD and, to a lesser extent, PTSD. Hence, there is a crucial need for larger double-blind placebo-controlled trials for resistant anxiety disorders. Finally, being out of the scope of our review, we omitted studies of non-pharmacologic therapies. Copyright © 2014. Published by Elsevier Masson SAS.

Masitinib as an adjunct therapy for mild-to-moderate Alzheimer's disease: a randomised, placebo-controlled phase 2 trial

PubMed Central

2011-01-01

Introduction Neuroinflammation is thought to be important in Alzheimer's disease pathogenesis. Mast cells are a key component of the inflammatory network and participate in the regulation of the blood-brain barrier's permeability. Masitinib, a selective oral tyrosine kinase inhibitor, effectively inhibits the survival, migration and activity of mast cells. As the brain is rich in mast cells, the therapeutic potential of masitinib as an adjunct therapy to standard care was investigated. Methods A randomised, placebo-controlled, phase 2 study was performed in patients with mild-to-moderate Alzheimer's disease, receiving masitinib as an adjunct to cholinesterase inhibitor and/or memantine. Patients were randomly assigned to receive masitinib (n = 26) (starting dose of 3 or 6 mg/kg/day) or placebo (n = 8), administered twice daily for 24 weeks. The primary endpoint was change from baseline in the Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-Cog) to assess cognitive function and the related patient response rate. Results The rate of clinically relevant cognitive decline according to the ADAS-Cog response (increase >4 points) after 12 and 24 weeks was significantly lower with masitinib adjunctive treatment compared with placebo (6% vs. 50% for both time points; P = 0.040 and P = 0.046, respectively). Moreover, whilst the placebo treatment arm showed worsening mean ADAS-Cog, Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory, and Mini-Mental State Examination scores, the masitinib treatment arm reported improvements, with statistical significance between treatment arms at week 12 and/or week 24 (respectively, P = 0.016 and 0.030; P = 0.035 and 0.128; and P = 0.047 and 0.031). The mean treatment effect according to change in ADAS-Cog score relative to baseline at weeks 12 and 24 was 6.8 and 7.6, respectively. Adverse events occurred more frequently with masitinib treatment (65% vs. 38% of patients); however, the majority of events were of mild or moderate intensity and transitory. Severe adverse events occurred at a similar frequency in the masitinib and placebo arms (15% vs. 13% of patients, respectively). Masitinib-associated events included gastrointestinal disorders, oedema, and rash. Conclusions Masitinib administered as add-on therapy to standard care during 24 weeks was associated with slower cognitive decline in Alzheimer's disease, with an acceptable tolerance profile. Masitinib may therefore represent an innovative avenue of treatment in Alzheimer's disease. This trial provides evidence that may support a larger placebo-controlled investigation. Trial registration Clinicaltrials.gov NCT00976118 PMID:21504563

Regulation of copper and iron homeostasis by metal chelators: a possible chemotherapy for Alzheimer's disease.

PubMed

Robert, Anne; Liu, Yan; Nguyen, Michel; Meunier, Bernard

2015-05-19

With the increase of life expectancy of humans in more than two-thirds of the countries in the World, aging diseases are becoming the frontline health problems. Alzheimer's disease (AD) is now one of the major challenges in drug discovery, since, with the exception of memantine in 2003, all clinical trials with drug candidates failed over the past decade. If we consider that the loss of neurons is due to a high level of oxidative stress produced by nonregulated redox active metal ions like copper linked to amyloids of different sizes, regulation of metal homeostasis is a key target. The difficulty for large copper-carrier proteins to directly extract copper ions from metalated amyloids might be considered as being at the origin of the rupture of the copper homeostasis regulation in AD brains. So, there is an urgent need for new specific metal chelators that should be able to regulate the homeostasis of metal ions, specially copper and iron, in AD brains. As a consequence of that concept, chelators promoting metal excretion from brain are not desired. One should favor ligands able to extract copper ions from sinks (amyloids being the major one) and to transfer these redox-active metal ions to copper-carrier proteins or copper-containing enzymes. Obviously, the affinity of these chelators for the metal ion should not be a sufficient criterion, but the metal specificity and the ability of the chelators to release the metal under specific biological conditions should be considered. Such an approach is still largely unexplored. The requirements for the chelators are very high (ability to cross the brain-blood barrier, lack of toxicity, etc.), few chemical series were proposed, and, among them, biochemical or biological data are scarce. As a matter of fact, the bioinorganic pharmacology of AD represents less than 1% of all articles dedicated to AD drug research. The major part of these articles deals with an old and rather toxic drug, clioquinol and related analogs, that do not efficiently extract copper from soluble amyloids. We have designed and developed new tetradendate ligands such as 21 and PA1637 based on bis(8-aminoquinolines) that are specific for copper chelation and are able to extract copper(II) from amyloids and then can release copper ion upon reduction with a biological reducing agent. These studies contribute to the understanding of the physicochemical properties of the tetradentate copper ligands compared with bidentate ligands like clioquinol. One of these copper ligands, PA1637, after selection with a nontransgenic mouse model that is able to efficiently monitor the loss of episodic memory, is currently under preclinical development.

Ketamine and other glutamate receptor modulators for depression in adults.

PubMed

Caddy, Caroline; Amit, Ben H; McCloud, Tayla L; Rendell, Jennifer M; Furukawa, Toshi A; McShane, Rupert; Hawton, Keith; Cipriani, Andrea

2015-09-23

Considering the ample evidence of involvement of the glutamate system in the pathophysiology of depression, pre-clinical and clinical studies have been conducted to assess the antidepressant efficacy of glutamate inhibition, and glutamate receptor modulators in particular. This review focuses on the use of glutamate receptor modulators in unipolar depression. To assess the effects - and review the acceptability - of ketamine and other glutamate receptor modulators in comparison to placebo (or saline placebo), other pharmacologically active agents, or electroconvulsive therapy (ECT) in alleviating the acute symptoms of depression in people with unipolar major depressive disorder. We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR, to 9 January 2015). This register includes relevant randomised controlled trials (RCTs) from: the Cochrane Library (all years), MEDLINE (1950 to date), EMBASE (1974 to date), and PsycINFO (1967 to date). We did not apply any restrictions to date, language or publication status. Double- or single-blind RCTs comparing ketamine, memantine, or other glutamate receptor modulators with placebo (or saline placebo), other active psychotropic drugs, or electroconvulsive therapy (ECT) in adults with unipolar major depression. Three review authors independently identified studies, assessed trial quality and extracted data. The primary outcomes for this review were response rate and adverse events. We included 25 studies (1242 participants) on ketamine (9 trials), memantine (3), AZD6765 (3), D-cycloserine (2), Org26576 (2), atomoxetine (1), CP-101,606 (1), MK-0657 (1), N-acetylcysteine (1), riluzole (1) and sarcosine (1). Twenty-one studies were placebo-controlled and the majority were two-arm studies (23 out of 25). Twenty-two studies defined an inclusion criteria specifying the severity of depression; 11 specified at least moderate depression; eight, severe depression; and the remaining three, mild-moderate depression. Nine studies recruited only treatment-resistant patients.We rated the risk of bias as low or unclear for most domains, though lack of detail regarding masking of treatment in the studies reduced our certainty in the effect for all outcomes. We rated three studies as having high risk for selective outcome reporting. Many trials did not provide information on all the prespecified outcomes and we found no data, or very limited data, on very important issues like suicidality, cognition, quality of life, costs to healthcare services and dropouts due to lack of efficacy.Among all glutamate receptor modulators, only ketamine (administered intravenously) proved to be more efficacious than placebo, though the quality of evidence was limited by risk of bias and small sample sizes. There was low quality evidence that treatment with ketamine increased the likelihood of response after 24 hours (odds ratio (OR) 10.77, 95% confidence interval (CI) 2.00 to 58.00; 3 RCTs, 56 participants), 72 hours (OR 12.59, 95% CI 2.38 to 66.73; 3 RCTs, 56 participants), and one week (OR 2.58, 95% CI 1.08 to 6.16; 4 RCTs, 131 participants). The effect of ketamine was even less certain at two weeks, as data were available from only one trial (OR 0.93, 95% CI 0.31 to 2.83; 51 participants, low quality evidence). This was consistent across all efficacy outcomes. Ketamine caused more confusion and emotional blunting compared to placebo. There was insufficient evidence to determine if this increased the likelihood of leaving the study early (OR 1.90, 95% CI 0.43 to 8.47; 5 RCTs, 139 participants, low quality evidence).One RCT with 72 participants reported higher numbers of responders on ketamine than midazolam at 24 hours (OR 0.36, 95% CI 0.14 to 0.58), 72 hours (OR 0.37, 95% CI 0.16 to 0.59), and one week (OR 0.29, 95% CI 0.08 to 0.49). However, midazolam was better tolerated than ketamine in terms of blurred vision, dizziness, general malaise and nausea/vomiting at 24 hours post-infusion. The evidence contributing to these outcomes was of low quality.We found better efficacy of sarcosine over citalopram at four weeks (OR 6.93, 95% CI 1.53 to 31.38; 1 study, 40 participants), but not at two weeks (OR: 8.14, 95% CI 0.88 to 75.48); fewer participants in the sarcosine group experienced adverse events (OR 0.04, 95% CI 0.00 to 0.68; P = 0.03, 1 study, 40 participants). This was based on low quality evidence. No significant results were found for the remaining glutamate receptor modulators.In one study with 18 participants, ketamine was more effective than ECT at 24 hours (OR 28.00, 95% CI 2.07 to 379.25) and 72 hours (OR 12.25, 95% CI 1.33 to 113.06), but not at one week (OR 3.35, 95% CI 0.12 to 93.83), or two weeks (OR 3.35, 95% CI 0.12 to 93.83). No differences in terms of adverse events were found between ketamine and ECT, however the only adverse events reported were blood pressure and heart rate. This study was rated as very low quality. We found limited evidence for ketamine's efficacy over placebo at time points up to one week in terms of the primary outcome, response rate. The effects were less certain at two weeks post-treatment. No significant results were found for the remaining ten glutamate receptor modulators, except for sarcosine being more effective than citalopram at four weeks. In terms of adverse events, the only significant differences in favour of placebo over ketamine were in regards to confusion and emotional blunting. Despite the promising nature of these preliminary results, our confidence in the evidence was limited by risk of bias and the small number of participants. Many trials did not provide information on all the prespecified outcomes and we found no data, or very limited data, on very important issues like suicidality, cognition, quality of life, costs to healthcare services and dropouts due to lack of efficacy.All included studies administered ketamine intravenously, which can pose practical problems in clinical practice. Very few trials were included in the meta-analyses for each comparison; the majority of comparisons contained only one study. Further RCTs (with adequate blinding) are needed to explore different modes of administration of ketamine with longer follow-up, which test the comparative efficacy of ketamine and the efficacy of repeated administrations.

[Basic and clinical studies of pressure-independent damaging factors of open angle glaucoma].

PubMed

Araie, Makoto

2011-03-01

Pathogenesis of open-angle glaucoma involves both pressure-dependent damaging factors and pressure-independent damaging factors. The high prevalence of open-angle glaucoma with normal pressure (normal-tension glaucoma) in Japan implies that treatment of pressure-independent damaging factors in Japanese open-angle glaucoma patients is of importance. In an attempt to investigate the roles of pressure-independent damaging factors in open-angle glaucoma, we carried out basic and clinical studies and obtained the following results. 1. The rate of deterioration of visual field after trabeculectomy in normal tension glaucoma patients with post-operative intraocular pressure (IOP) of 10 mmHg was found to be -0.25 dB/year of mean deviation (MD), suggesting that contribution of pressure-independent damaging factors to the deterioration of MD in open-angle glaucoma is around -0.25 dB/year of mean deviation (MD). 2. Experiments using isolated purified cultured retinal ganglion cells (RGCs) indicated that calcium-channel blockers and some of antiglaucoma drugs showed neuroprotective effects on RGCs at concentrations of 0.01 microM or higher. 3. In mice, damage to RGCs resulted in secondary degeneration of neurons and activation of glial cells in the lateral geniculate nucleous (LGN) and superior colliculus, and these secondary changes in the central nervous system (CNS) due to RGC damage was partly ameliorated by systemic administration of memantine. 4. Mice experimental high IOP glaucoma models could be established using laser irradiation of the limbal area, and the usefulness of Tonolab in IOP measurements of mice eye was confirmed. 5. Monkey experimental high IOP glaucoma models revealed that in the glaucomatous optic nerve head vaso-constrictive reactions to an alpha-1 agonist was abolished, while vasodilative reaction to a prostaglandin FP receptor agonist was retained. 6. In monkeys with experimental high IOP glaucoma, secondary damage to neurons in the LGN and the glial reaction to it were also found, similar to the mice experiments. In living monkeys the glial reaction in the LGN could be observed by means of positron emission tomography. 7. In the LGN of monkeys with experimental high IOP glaucoma, the M-cell system was preferentially damaged in the early stage, while in the later stages both the M- and P-cell systems were damaged. 8. In a single-instituted prospective double-blinded clinical trial, oral administration of nilvadipine at 4 mg/day, a DHP calcium-channel blocker, was found to significantly retard the visual field progression in normal tension glaucoma patients over 3 years, while significantly increasing the choroidal and optic nerve blood flow by about 35%. 9. A multi-instituted prospective double-blinded clinical trial in normal tension glaucoma patients revealed that the rate of MD deterioration under monotherapy with either topical nipradilol or timolol was around -0.05 dB/year, thought to be considerably slower than -0.25 dB/year, the commonly estimated rate of MD deterioration by pressure-independent damaging factors. The current results indicate the possibility of treatment of pressure-independent damaging factors of open-angle glaucoma in Japanese open-angle glaucoma patients with oral nilvadipine and topical anti-glaucoma agents.

Symptomatic treatments for amyotrophic lateral sclerosis/motor neuron disease.

PubMed

Ng, Louisa; Khan, Fary; Young, Carolyn A; Galea, Mary

2017-01-10

Motor neuron disease (MND), which is also known as amyotrophic lateral sclerosis (ALS), causes a wide range of symptoms but the evidence base for the effectiveness of the symptomatic treatment therapies is limited. To summarise the evidence from Cochrane Systematic Reviews of all symptomatic treatments for MND. We searched the Cochrane Database of Systematic Reviews (CDSR) on 15 November 2016 for systematic reviews of symptomatic treatments for MND. We assessed the methodological quality of the included reviews using the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the GRADE approach. We followed standard Cochrane study (review) selection and data extraction procedures. We reported findings narratively and in tables. We included nine Cochrane Systematic Reviews of interventions to treat symptoms in people with MND. Three were empty reviews with no included randomised controlled trials (RCTs); however, all three reported on non-RCT evidence and the remaining six included mostly one or two studies. We deemed all of the included reviews of high methodological quality. Drug therapy for painThere is no RCT evidence in a Cochrane Systematic Review exploring the efficacy of drug therapy for pain in MND. Treatment for crampsThere is evidence (13 RCTs, N = 4012) that for the treatment of cramps in MND, compared to placebo:- memantine and tetrahydrocannabinol (THC) are probably ineffective (moderate-quality evidence);- vitamin E may have little or no effect (low-quality evidence); and- the effects of L-threonine, gabapentin, xaliproden, riluzole, and baclofen are uncertain as the evidence is either very low quality or the trial specified the outcome but did not report numerical data.The review reported adverse effects of riluzole, but it is not clear whether other interventions had adverse effects. Treatment for spasticityIt is uncertain whether an endurance-based exercise programme improved spasticity or quality of life, measured at three months after the programme, as the quality of evidence is very low (1 RCT, comparison "usual activities", N = 25). The review did not evaluate other approaches, such as use of baclofen as no RCTs were available. Mechanical ventilation for supporting respiratory functionNon-invasive ventilation (NIV) probably improves median survival and quality of life in people with respiratory insufficiency and normal to moderately impaired bulbar function compared to standard care, and improves quality of life but not survival for people with poor bulbar function (1 RCT, N = 41, moderate-quality evidence; a second RCT did not provide data). The review did not evaluate other approaches such as tracheostomy-assisted ('invasive') ventilation, or assess timing of NIV initiation. Treatment for sialorrhoeaA single session of botulinum toxin type B injections to parotid and submandibular glands probably improves sialorrhoea and quality of life at up to 4 weeks compared to placebo injections, but not at 8 or 12 weeks after the injections (moderate-quality evidence from 1 placebo-controlled RCT, N = 20). The review authors found no trials of other approaches. Enteral tube feeding for supporting nutritionThere is no RCT evidence in a Cochrane Systematic Review to support benefit or harms of enteral tube feeding in supporting nutrition in MND. Repetitive transcranial magnetic stimulationIt is uncertain whether repetitive transcranial magnetic stimulation (rTMS) improves disability or limitation in activity in MND in comparison with sham rTMS (3 RCTs, very low quality evidence, N = 50). Therapeutic exerciseThere is evidence that exercise may improve disability in MND at three months after the exercise programme, but not quality of life, in comparison with "usual activities" or "usual care" including stretching (2 RCTs, low-quality evidence, N = 43). Multidisciplinary careThere is no RCT evidence in a Cochrane Systematic Review to demonstrate any benefit or harm for multidisciplinary care in MND.None of the reviews, other than the review of treatment for cramps, reported that adverse events occurred. However, the trials were too small for reliable adverse event reporting. This overview has highlighted the lack of robust evidence in Cochrane Systematic Reviews on interventions to manage symptoms resulting from MND. It is important to recognise that clinical trials may fail to demonstrate efficacy of an intervention for reasons other than a true lack of efficacy, for example because of insufficient statistical power, the wrong choice of dose, insensitive outcome measures or inappropriate participant eligibility. The trials were mostly too small to reliably assess adverse effects of the treatments. The nature of MND makes it difficult to research clinically accepted or recommended practice, regardless of the level of evidence supporting the practice. It would not be ethical, for example, to design a placebo-controlled trial for treatment of pain in MND or to withhold multidisciplinary care where such care is available. It is therefore highly unlikely that there will ever be classically designed placebo-controlled RCTs in these areas.We need more research with appropriate study designs, robust methodology, and of sufficient duration to address the changing needs-of people with MND and their caregivers-associated with MND disease progression and mortality. There is a significant gap in studies assessing the effectiveness of interventions for symptoms relating to MND, such as pseudobulbar emotional lability and cognitive and behavioural difficulties. Future studies should use appropriate outcome measures that are reliable, have internal and external validity, and are sensitive to change in what is being measured (such as quality of life).