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Sample records for repeated opioid administration

  1. Population Pharmacokinetic Modeling After Repeated Administrations of RBP-6000, a New, Subcutaneously Injectable, Long-Acting, Sustained-Release Formulation of Buprenorphine, for the Treatment of Opioid Use Disorder.

    PubMed

    Laffont, Celine M; Gomeni, Roberto; Heidbreder, Christian; Jones, J P; Nasser, Azmi F

    2016-07-01

    RBP-6000 is a novel sustained-release formulation of buprenorphine for the treatment of opioid use disorder, which has been designed for once-monthly (28 days) subcutaneous (SC) injections. A population pharmacokinetic (PK) model was developed to describe the time course of buprenorphine plasma concentrations after repeated SC injections of RBP-6000 at 50 mg, 100 mg, 200 mg, or 300 mg in treatment-seeking opioid-dependent subjects previously on sublingual buprenorphine (Subutex(®) ) treatment. The μ-opioid receptor occupancy was predicted using a previously developed PK/PD Emax model. The results of the population PK analysis jointly with the predicted level of μ-opioid receptor occupancy provided quantitative criteria for clinical dose selection for RBP-6000: the dose of 300 mg every 28 days seems appropriate for immediately achieving an effective exposure after the first SC injection and to maintain effective levels of exposure during chronic treatment. Furthermore, simulations conducted to evaluate the potential impact of a holiday in drug intake indicated that in the unexpected event of a 2-week holiday, levels of μ-opioid receptor occupancy remained consistently above 70% with no significant loss of drug efficacy. This analysis indicated that RBP-6000 has the potential for becoming an effective treatment for opioid-dependent subjects by addressing compliance issues associated with the current once-a-day treatments. PMID:26479717

  2. A history of neuraxial administration of local analgesics and opioids.

    PubMed

    Brill, S; Gurman, G M; Fisher, A

    2003-09-01

    The history of intrathecal and epidural anaesthesia is in parallel with the development of general anaesthesia. As ether anaesthesia (1846) is considered the first modern anaesthetic since its use by Morton 157 yr ago, so Bier made history by using cocaine for intrathecal anaesthesia in 1898. The first published report on opioids for intrathecal anaesthesia belongs to a Romanian surgeon, Racoviceanu-Pitesti, who presented his experience at Paris in 1901. It was almost a century before the opioids were used for epidural analgesia. Behar and his colleagues published the first report on the epidural use of morphine for the treatment of pain in The Lancet in 1979. Epidural and intrathecal opioids are today part of a routine regimen for intra- and postoperative analgesia. Over the last 30 yr, the use of epidural opioids has became a standard for analgesia in labour and delivery, and for the management of chronic pain. Finally, epidural opioids have been shown to have a pre-emptive effect, when used before major surgery. We present the evolution of neuraxial anaesthesia and the history of intrathecal and epidural administration of opioids. PMID:12974588

  3. Prolonged central mu-opioid receptor occupancy after single and repeated nalmefene dosing.

    PubMed

    Ingman, Kimmo; Hagelberg, Nora; Aalto, Sargo; Någren, Kjell; Juhakoski, Auni; Karhuvaara, Sakari; Kallio, Antero; Oikonen, Vesa; Hietala, Jarmo; Scheinin, Harry

    2005-12-01

    The opioid antagonist nalmefene offers an alternative to traditional pharmacological treatments for alcoholism. The present study was designed to investigate the relationship between nalmefene plasma concentration and central mu-opioid receptor occupancy after a clinically effective dose (20 mg, orally). Pharmacokinetics and mu-opioid receptor occupancy of nalmefene after single and repeated dosing over 7 days was studied in 12 healthy subjects. Serial blood samples were obtained after both dosings, and pharmacokinetic parameters for nalmefene and main metabolites were determined. Central mu-opioid receptor occupancy of nalmefene was measured with positron emission tomography (PET) and [(11)C]carfentanil at four time points (3, 26, 50, 74 h) after both dosings. Nalmefene was rapidly absorbed in all subjects. The mean t(1/2) of nalmefene was 13.4 h after single and repeated dosing. The accumulation of nalmefene and its main metabolites in plasma during the repeated dosing period was as expected for a drug with linear pharmacokinetics, and steady-state was reached for all analytes. Both nalmefene dosings resulted in a very high occupancy at mu-opioid receptors (87-100%), and the decline in the occupancy was similar after both dosings but clearly slower than the decline in the plasma concentration of nalmefene or metabolites. High nalmefene occupancy (83-100%) persisted at 26 h after the dosings. The prolonged mu-opioid receptor occupancy by nalmefene indicates slow dissociation of the drug from mu-opioid receptors. These results support the rational of administering nalmefene when needed before alcohol drinking, and they additionally suggest that a high mu-opioid receptor occupancy can be maintained when nalmefene is taken once daily. PMID:15956985

  4. Inflammatory Pain Promotes Increased Opioid Self-Administration: Role of Dysregulated Ventral Tegmental Area μ Opioid Receptors

    PubMed Central

    Hipólito, Lucia; Wilson-Poe, Adrianne; Campos-Jurado, Yolanda; Zhong, Elaine; Gonzalez-Romero, Jose; Virag, Laszlo; Whittington, Robert; Comer, Sandra D.; Carlton, Susan M.; Walker, Brendan M.; Bruchas, Michael R.

    2015-01-01

    Pain management in opioid abusers engenders ethical and practical difficulties for clinicians, often resulting in pain mismanagement. Although chronic opioid administration may alter pain states, the presence of pain itself may alter the propensity to self-administer opioids, and previous history of drug abuse comorbid with chronic pain promotes higher rates of opioid misuse. Here, we tested the hypothesis that inflammatory pain leads to increased heroin self-administration resulting from altered mu opioid receptor (MOR) regulation of mesolimbic dopamine (DA) transmission. To this end, the complete Freund's adjuvant (CFA) model of inflammation was used to assess the neurochemical and functional changes induced by inflammatory pain on MOR-mediated mesolimbic DA transmission and on rat intravenous heroin self-administration under fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement. In the presence of inflammatory pain, heroin intake under an FR schedule was increased for high, but attenuated for low, heroin doses with concomitant alterations in mesolimbic MOR function suggested by DA microdialysis. Consistent with the reduction in low dose FR heroin self-administration, inflammatory pain reduced motivation for a low dose of heroin, as measured by responding under a PR schedule of reinforcement, an effect dissociable from high heroin dose PR responding. Together, these results identify a connection between inflammatory pain and loss of MOR function in the mesolimbic dopaminergic pathway that increases intake of high doses of heroin. These findings suggest that pain-induced loss of MOR function in the mesolimbic pathway may promote opioid dose escalation and contribute to opioid abuse-associated phenotypes. SIGNIFICANCE STATEMENT This study provides critical new insights that show that inflammatory pain alters heroin intake through a desensitization of MORs located within the VTA. These findings expand our knowledge of the interactions between

  5. Alternate Routes of Administration among Prescription Opioid Misusers and Associations with Sexual HIV Transmission Risk Behaviors.

    PubMed

    Buttram, Mance E; Kurtz, Steven P

    2016-01-01

    Literature suggests that young adult prescription opioid misusers who are using alternate routes of administration (e.g., snorting, injecting) may be engaging in sexual and non-sexual HIV risk behaviors. This study examines demographics, substance use, sexual risk behavior, and health and social problems associated with alternate routes of administration of prescription opioids among a sample of young adult prescription opioid misusers. Data are drawn from baseline assessments from a behavioral intervention trial. Eligible participants were ages 18-39, and reported recent (past 90 days) heterosexual sex, and recent and regular substance use and attendance at large, recognized local nightclubs. The analyses include 446 racially/ethnically diverse participants. In bivariate regression models, compared to those who did not, participants reporting alternate routes of administration (n = 209) were more likely to be White (p < 0.025) and report group sex participation history (p = 0.002), sex with an injection drug user (p = 0.003), sexual victimization history (p = 0.003), and severe mental distress (p < 0.000). White race, group sex participation history, and severe mental distress remained significant in the multivariate model. Alternate routes of administration of prescription opioids are associated with sexual HIV transmission risk behaviors. Early prevention and intervention efforts that address sexual and non-sexual HIV risk behaviors are warranted. PMID:27224253

  6. Opioid and adjuvant analgesics: compared and contrasted.

    PubMed

    Khan, Mohammed Ilyas Ahmed; Walsh, Declan; Brito-Dellan, Norman

    2011-08-01

    AAs (1-2 days). Rotation among opioids is a useful therapeutic strategy to improve analgesic response or minimize toxicity. Most AAs are unsuitable for rescue dosing because of their pharmacological characteristics. The mu agonist side effect profile is similar among the different opioid agents, regardless of the route of administration. The appropriate use of AAs will reduce opioid-related side effects. No apparent tolerance to analgesia develops with AAs. Abrupt discontinuation of an opioid after chronic repeated use for more than a few days will cause a withdrawal syndrome of variable severity. Adjuvant analgesics are an essential tool in cancer pain. PMID:21622486

  7. Preprodynorphin mediates locomotion and D2 dopamine and mu-opioid receptor changes induced by chronic 'binge' cocaine administration.

    PubMed

    Bailey, A; Yoo, J H; Racz, I; Zimmer, A; Kitchen, I

    2007-09-01

    Evidence suggests that the kappa-opioid receptor (KOP-r) system plays an important role in cocaine addiction. Indeed, cocaine induces endogenous KOP activity, which is a mechanism that opposes alterations in behaviour and brain function resulting from repeated cocaine use. In this study, we have examined the influence of deletion of preprodynorphin (ppDYN) on cocaine-induced behavioural effects and on hypothalamic-pituitary-adrenal axis activity. Furthermore, we have measured mu-opioid receptor (MOP-r) agonist-stimulated [(35)S]GTPgammaS, dopamine D(1), D(2) receptor and dopamine transporter (DAT) binding. Male wild-type (WT) and ppDYN knockout (KO) mice were injected with saline or cocaine (45 mg/kg/day) in a 'binge' administration paradigm for 14 days. Chronic cocaine produced an enhancement of locomotor sensitisation in KO. No genotype effect was found on stereotypy behaviour. Cocaine-enhanced MOP-r activation in WT but not in KO. There was an overall decrease in D(2) receptor binding in cocaine-treated KO but not in WT mice. No changes were observed in D(1) and DAT binding. Cocaine increased plasma corticosterone levels in WT but not in KO. The data confirms that the endogenous KOP system inhibits dopamine neurotransmission and that ppDYN may mediate the enhancement of MOP-r activity and the activation of the hypothalamic-pituitary-adrenal axis after chronic cocaine treatment. PMID:17532787

  8. Perspectives on opioid tolerance from basic research: behavioural studies after spinal administration in rodents.

    PubMed

    Stevens, C W

    1994-01-01

    For tolerance development studies, computer modelling and statistical tests suggested that the equation which best described the decrement of analgesic effect was best served by an exponential decay function. Further analysis of the time course data led to the tentative conclusion that all groups of animals became tolerant at the same rate, regardless of drug or dose. A literature search revealed then, as it does now, that although there are many statements regarding the rate of opioid tolerance, there has been little systematic investigation of this. The Holy Grail of obtaining the rates of tolerance for a number of opioid agents in a systematic study is well within grasp. This information will be needed in clinical practice for the rational choice of opioid with regard to rate of the development of tolerance. The working hypothesis that emerges for the magnitude of opioid tolerance is that more potent agonists produce less tolerance. Further confirmation of this hypothesis has been forthcoming. This suggests that clinical use of more potent opioids, such as fentanyl, should be considered as a substitute for morphine in long term treatment regimens. The working hypothesis for cross-tolerance is that agents acting on the same receptors will show cross-tolerance. Cross-tolerance will also be observed among agents acting on different receptors, but only those that exhibit pharmacological synergy after short term administration. Asymmetry of cross-tolerance can occur, as the magnitude of this cross-tolerance is determined by the relative potency of the toleragen with regard to that of the probe agent. Given the additional factor of receptor selectivity with agents of different receptor classes, types and subtypes, new studies need to be designed combining the toleragen with a selective antagonist to determine the precise receptor mediation of the magnitude of tolerance, and thus cross-tolerance. For example, the delta opioid DADLE infused with a mu selective opioid

  9. Effects of fentanyl administration on locomotor response in horses with the G57C μ-opioid receptor polymorphism.

    PubMed

    Wetmore, Lois A; Pascoe, Peter J; Shilo-Benjamini, Yael; Lindsey, Jane C

    2016-08-01

    OBJECTIVE To determine the locomotor response to the administration of fentanyl in horses with and without the G57C polymorphism of the μ-opioid receptor. ANIMALS 20 horses of various breeds and ages (10 horses heterozygous for the G57C polymorphism and 10 age-, breed-, and sex-matched horses that did not have the G57C polymorphism). PROCEDURES The number of steps each horse took was counted over consecutive 2-minute periods for 20 minutes to determine a baseline value. The horse then received a bolus of fentanyl (20 μg/kg, IV), and the number of steps was again counted during consecutive 2-minute periods for 60 minutes. The mean baseline value was subtracted from each 2-minute period after fentanyl administration; step counts with negative values were assigned a value of 0. Data were analyzed by use of a repeated-measures ANOVA. RESULTS Data for 19 of 20 horses (10 horses with the G57C polymorphism and 9 control horses without the G57C polymorphism) were included in the analysis. Horses with the G57C polymorphism had a significant increase in locomotor activity, compared with results for horses without the polymorphism. There was a significant group-by-time interaction. CONCLUSIONS AND CLINICAL RELEVANCE Horses heterozygous for the G57C polymorphism of the μ-opioid receptor had an increased locomotor response to fentanyl administration, compared with the response for horses without this polymorphism. The clinical impact of this finding should be investigated. PMID:27463545

  10. Abuse risks and routes of administration of different prescription opioid compounds and formulations

    PubMed Central

    2011-01-01

    Background Evaluation of tamper resistant formulations (TRFs) and classwide Risk Evaluation and Mitigation Strategies (REMS) for prescription opioid analgesics will require baseline descriptions of abuse patterns of existing opioid analgesics, including the relative risk of abuse of existing prescription opioids and characteristic patterns of abuse by alternate routes of administration (ROAs). This article presents, for one population at high risk for abuse of prescription opioids, the unadjusted relative risk of abuse of hydrocodone, immediate release (IR) and extended release (ER) oxycodone, methadone, IR and ER morphine, hydromorphone, IR and ER fentanyl, IR and ER oxymorphone. How relative risks change when adjusted for prescription volume of the products was examined along with patterns of abuse via ROAs for the products. Methods Using data on prescription opioid abuse and ROAs used from 2009 Addiction Severity Index-Multimedia Version (ASI-MV®) Connect assessments of 59,792 patients entering treatment for substance use disorders at 464 treatment facilities in 34 states and prescription volume data from SDI Health LLC, unadjusted and adjusted risk for abuse were estimated using log-binomial regression models. A random effects binary logistic regression model estimated the predicted probabilities of abusing a product by one of five ROAs, intended ROA (i.e., swallowing whole), snorting, injection, chewing, and other. Results Unadjusted relative risk of abuse for the 11 compound/formulations determined hydrocodone and IR oxycodone to be most highly abused while IR oxymorphone and IR fentanyl were least often abused. Adjusting for prescription volume suggested hydrocodone and IR oxycodone were least often abused on a prescription-by-prescription basis. Methadone and morphine, especially IR morphine, showed increases in relative risk of abuse. Examination of the data without methadone revealed ER oxycodone as the drug with greatest risk after adjusting for

  11. Neonatal Administration of Thimerosal Causes Persistent Changes in Mu Opioid Receptors in the Rat Brain

    PubMed Central

    Olczak, Mieszko; Duszczyk, Michalina; Mierzejewski, Pawel; Bobrowicz, Teresa

    2010-01-01

    Thimerosal added to some pediatric vaccines is suspected in pathogenesis of several neurodevelopmental disorders. Our previous study showed that thimerosal administered to suckling rats causes persistent, endogenous opioid-mediated hypoalgesia. Here we examined, using immunohistochemical staining technique, the density of μ-opioid receptors (MORs) in the brains of rats, which in the second postnatal week received four i.m. injections of thimerosal at doses 12, 240, 1,440 or 3,000 μg Hg/kg. The periaqueductal gray, caudate putamen and hippocampus were examined. Thimerosal administration caused dose-dependent statistically significant increase in MOR densities in the periaqueductal gray and caudate putamen, but decrease in the dentate gyrus, where it was accompanied by the presence of degenerating neurons and loss of synaptic vesicle marker (synaptophysin). These data document that exposure to thimerosal during early postnatal life produces lasting alterations in the densities of brain opioid receptors along with other neuropathological changes, which may disturb brain development. PMID:20803069

  12. Route of administration for illicit prescription opioids: a comparison of rural and urban drug users

    PubMed Central

    2010-01-01

    Background Nonmedical prescription opioid use has emerged as a major public health concern in recent years, particularly in rural Appalachia. Little is known about the routes of administration (ROA) involved in nonmedical prescription opioid use among rural and urban drug users. The purpose of this study was to describe rural-urban differences in ROA for nonmedical prescription opioid use. Methods A purposive sample of 212 prescription drug users was recruited from a rural Appalachian county (n = 101) and a major metropolitan area (n = 111) in Kentucky. Consenting participants were given an interviewer-administered questionnaire examining sociodemographics, psychiatric disorders, and self-reported nonmedical use and ROA (swallowing, snorting, injecting) for the following prescription drugs: buprenorphine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, OxyContin® and other oxycodone. Results Among urban participants, swallowing was the most common ROA, contrasting sharply with substance-specific variation in ROA among rural participants. Among rural participants, snorting was the most frequent ROA for hydrocodone, methadone, OxyContin®, and oxycodone, while injection was most common for hydromorphone and morphine. In age-, gender-, and race-adjusted analyses, rural participants had significantly higher odds of snorting hydrocodone, OxyContin®, and oxycodone than urban participants. Urban participants had significantly higher odds of swallowing hydrocodone and oxycodone than did rural participants. Notably, among rural participants, 67% of hydromorphone users and 63% of morphine users had injected the drugs. Conclusions Alternative ROA are common among rural drug users. This finding has implications for rural substance abuse treatment and harm reduction, in which interventions should incorporate methods to prevent and reduce route-specific health complications of drug use. PMID:20950455

  13. Acute and chronic fentanyl administration causes hyperalgesia independently of opioid receptor activity in mice.

    PubMed

    Waxman, Amanda R; Arout, Caroline; Caldwell, Megan; Dahan, Albert; Kest, Benjamin

    2009-10-01

    Although mu-receptor opioids are clinically important analgesics, they can also paradoxically cause hyperalgesia independently of opioid receptor activity, presumably via the action of neuroexcitatory glucoronide metabolites. However, it is unknown whether the commonly used mu-receptor opioid analgesic fentanyl, which is not subject to glucuronidation, can also induce hyperalgesia independently of opioid receptor activity. Thus, here we examined whether fentanyl increases nociception on the tail-withdrawal test in CD-1 mice concurrently treated with the opioid receptor antagonist naltrexone or in opioid receptor triple knock-out mice lacking mu, delta, and kappa opioid receptors. For both groups, an acute fentanyl bolus dose (0.25mg/kg, s.c.) and continuous fentanyl infusion (cumulative daily dose: 10mg/kg) did not cause analgesia at any time. Instead, fentanyl significantly decreased withdrawal latencies relative to pre-drug values for the next 15-60 min and for six days, respectively. MK-801 blocked and reversed hyperalgesia caused by the acute injection and continuous infusion of fentanyl, respectively, in naltrexone-treated CD-1 mice, indicating the contribution of NMDA receptors to fentanyl hyperalgesia. These data show that the synthetic opioid fentanyl causes hyperalgesia independently of prior or concurrent opioid receptor activity or analgesia. Since the biotransformation of fentanyl does not yield any known pronociceptive metabolites, these data challenge assumptions regarding the role of neuroexcitatory metabolites in opioid-induced hyperalgesia. PMID:19559072

  14. Peripheral administration of a μ-opioid receptor agonist DAMGO suppresses the anxiolytic and stimulatory effects of caffeine.

    PubMed

    Sudakov, S K; Nazarova, G A; Alekseeva, E V; Kolpakov, A A

    2015-01-01

    We studied the possibility of modulation of the stimulatory and anxiolytic effects of caffeine by activation of μ-opioid receptors in the gastrointestinal tract. Caffeine in a dose of 10 mg/kg (but not in a dose of 100 mg/kg) had a strong anxiolytic and psychostimulant effect. This effect was manifested in a significant increase in the time spent in the open arms of the elevated plus-maze, elevation of locomotor activity, and stimulation of metabolism. Administration of DAMGO to animals receiving caffeine in a dose of 10 mg/kg abolished the anxiolytic and psychostimulant effects of caffeine. By contrast, administration of DAMGO to rats receiving caffeine in a dose of 100 mg/kg had the anxiolytic effect. Activation of peripheral μ-opioid receptors is followed by the inhibition of the central μ-opioid system. We observed a decrease in the number of μ-opioid receptors in the midbrain and cerebral cortex and inhibition of β-endorphin release from nerve ending of the cingulate cortex in rats. These changes are probably followed by activation of the adenosine system in the brain. Caffeine dose should be increased to achieve the effect. Therefore, the anxiolytic and stimulatory effects of caffeine in a dose of 10 mg/kg are abolished under these conditions. By contrast, the anxiolytic effect of caffeine in a dose of 100 mg/kg (not observed under normal conditions) develops after this treatment. PMID:25573353

  15. μ Opioid Receptor Expression after Morphine Administration Is Regulated by miR-212/132 Cluster

    PubMed Central

    Garcia-Concejo, Adrian; Jimenez-Gonzalez, Ada; Rodríguez, Raquel E.

    2016-01-01

    Since their discovery, miRNAs have emerged as a promising therapeutical approach in the treatment of several diseases, as demonstrated by miR-212 and its relation to addiction. Here we prove that the miR-212/132 cluster can be regulated by morphine, through the activation of mu opioid receptor (Oprm1). The molecular pathways triggered after morphine administration also induce changes in the levels of expression of oprm1. In addition, miR-212/132 cluster is actively repressing the expression of mu opioid receptor by targeting a sequence in the 3’ UTR of its mRNA. These findings suggest that this cluster is closely related to opioid signaling, and function as a post-transcriptional regulator, modulating morphine response in a dose dependent manner. The regulation of miR-212/132 cluster expression is mediated by MAP kinase pathway, CaMKII-CaMKIV and PKA, through the phosphorylation of CREB. Moreover, the regulation of both oprm1 and of the cluster promoter is mediated by MeCP2, acting as a transcriptional repressor on methylated DNA after prolonged morphine administration. This mechanism explains the molecular signaling triggered by morphine as well as the regulation of the expression of the mu opioid receptor mediated by morphine and the implication of miR-212/132 in these processes. PMID:27380026

  16. Use of infusion devices for epidural or intrathecal administration of spinal opioids.

    PubMed

    Kwan, J W

    1990-08-01

    The use of infusion devices for epidural or intrathecal administration of spinal opioids is described. The risks of infection and mechanical catheter complications, the need for escalating doses, reservoir volume, drug stability, and cost are practical considerations associated with use of both external and internal infusion systems. Use of patient criteria to identify suitable candidates for intraspinal administration of pain medication helps ensure successful management. The criteria for intraspinal delivery pumps are safety, accuracy, reliability, ease of management by the patient and the health-care professional, and compatibility of the drug with the pump components. The primary factors to consider when comparing pumps to be used for intraspinal delivery of pain medication are the volume and flow rate requirements of the devices. External portable infusion devices are classified according to the mechanism of operation into three primary groups: syringe pumps, peristaltic mechanisms, and elastomeric reservoir pumps. Portable patient-controlled analgesia pumps that have syringes, flexible reservoir bags, and elastomeric reservoirs have been developed. Implanted systems with flow rates that are preset at the factory make pain management more difficult when the patient requires changes or escalations in doses over time. A programmable implanted pump is available. Two advantages of continuous epidural or intrathecal infusion are (1) the peaks and valleys of pain relief with bolus injections are eliminated and (2) the need for multiple injections is reduced. Patient-controlled analgesia (PCA) pumps enhance the efficacy of continuous infusions by allowing the patient to administer bolus doses to control acute pain. PMID:2202209

  17. Effectiveness of topical administration of opioids in palliative care: a systematic review.

    PubMed

    LeBon, Beata; Zeppetella, Giovambattista; Higginson, Irene J

    2009-05-01

    The discovery of peripheral opioid receptors has become the scientific basis for topical use of opioids in malignant and nonmalignant ulcers and oropharyngeal mucositis. This systematic review aimed to assess the quality of published literature and to examine whether topical opioids are effective in controlling pain in palliative care settings. After a systematic literature review, 19 studies (six randomized controlled trials [RCTs] and 13 case reports) met the inclusion criteria for the review. Eighteen studies favored topical opioids in pain relief, as evidenced by reductions in post-treatment pain scores, but time to onset and duration of analgesia varied widely. Because of the heterogeneity of the studies, meta-analysis was not possible. Despite clear clinical benefits described in small RCTs, there is a deficiency of higher-quality evidence on the role of topical opioids, and more robust primary studies are required to inform practice recommendations. N-of-1 trials should be encouraged for specific clinical circumstances. PMID:19321297

  18. Impact of Intraoperative Acetaminophen Administration on Postoperative Opioid Consumption in Patients Undergoing Hip or Knee Replacement

    PubMed Central

    Vaughan, Cathy; McGee, Ann

    2014-01-01

    Abstract Background: Opioid utilization for acute pain has been associated with numerous adverse events, potentially resulting in longer inpatient stays and increased costs. Objective: To examine the effect of intravenous (IV) acetaminophen administered intraoperatively on postoperative opioid consumption in adult subjects who underwent hip or knee replacement. Methods: This retrospective cohort study evaluated postoperative opioid consumption in 176 randomly selected adult subjects who underwent hip or knee replacement at Duke University Hospital (DUH). Eighty-eight subjects received a single, intraoperative, 1 g dose of IV acetaminophen. The other subjects did not receive any IV acetaminophen. This study evaluated mean opioid consumption (in oral morphine equivalents) during the 24-hour postoperative period in the 2 groups. Other endpoints included length of stay in the postanesthesia care unit (PACU), incidence of oversedation, need for acute opioid reversal, and adjunctive analgesic utilization. Results: Subjects who were given a single dose of intraoperative acetaminophen received an average of 149.3 mg of oral morphine equivalents during the 24 hours following surgery compared to 147.2 mg in participants who were not exposed to IV acetaminophen (P = .904). The difference in average length of PACU stay between the IV acetaminophen group (163 minutes) and those subjects not exposed to IV acetaminophen (169 minutes) was not statistically significant (P = .588). No subjects in the study experienced oversedation or required acute opioid reversal. Conclusion: There was not a statistically significant difference in postoperative opioid consumption between patients receiving and not receiving IV acetaminophen intraoperatively. PMID:25673891

  19. Nalfurafine hydrochloride, a selective κ opioid receptor agonist, has no reinforcing effect on intravenous self-administration in rhesus monkeys.

    PubMed

    Nakao, Kaoru; Hirakata, Mikito; Miyamoto, Yohei; Kainoh, Mie; Wakasa, Yoshio; Yanagita, Tomoji

    2016-01-01

    Nalfurafine hydrochloride [(E)-N-[17-(cyclopropylmethyl)-4,5α-epoxy-3,14-dihydroxymorphinan-6β-yl]-3-(furan-3-yl)-N-methylprop-2-enamide monohydrochloride; nalfurafine] is used in Japan as an antipruritic for the treatment of intractable pruritus in patients undergoing hemodialysis or with chronic liver disease. It is a potent and selective agonist at the κ opioid receptor, but also has weak and partial agonist activity at μ opioid receptors. Opioids, especially those acting at μ receptors, carry a risk of abuse. This is an important factor in the consideration of therapeutic risk vs. benefit in clinical use and the potential for misuse as a public health problem. It is therefore necessary to carefully evaluate the reinforcing effects of nalfurafine. To this end, we investigated intravenous self-administration of nalfurafine in rhesus monkeys. The number of self-administration of nalfurafine at doses of 0.0625, 0.125 and 0.25 μg/kg/infusion was not higher than that of saline in rhesus monkeys that frequently self-administered pentazocine (0.25 mg/kg/infusion). These results indicate that nalfurafine has no reinforcing effect in rhesus monkeys in the intravenous self-administration paradigm. PMID:26786553

  20. Striatal patch compartment lesions reduce stereotypy following repeated cocaine administration.

    PubMed

    Murray, Ryan C; Logan, Mary C; Horner, Kristen A

    2015-08-27

    Stereotypy can be characterized as inflexible, repetitive behaviors that occur following repeated exposure to psychostimulants, such as cocaine (COC). Stereotypy may be related to preferential activation of the patch (striosome) compartment of striatum, as enhanced relative activation of the patch compartment has been shown to positively correlate with the emergence of stereotypy following repeated psychostimulant treatment. However, the specific contribution of the patch compartment to COC-induced stereotypy following repeated exposure is unknown. To elucidate the involvement of the patch compartment to the development of stereotypy following repeated COC exposure, we determined if destruction of this sub-region altered COC-induced behaviors. The neurons of the patch compartment were ablated by bilateral infusion of the neurotoxin dermorphin-saporin (DERM-SAP; 17 ng/μl) into the striatum. Animals were allowed to recover for eight days following the infusion, and then were given daily injections of COC (25mg/kg) or saline for one week, followed by a weeklong drug-free period. Animals were then given a challenge dose of saline or COC, observed for 2h in activity chambers and sacrificed. The number of mu-labeled patches in the striatum were reduced by DERM-SAP pretreatment. In COC-treated animals DERM-SAP pretreatment significantly reduced the immobilization and intensity of stereotypy but increased locomotor activity. DERM-SAP pretreatment attenuated COC-induced c-Fos expression in the patch compartment, while enhancing COC-induced c-Fos expression in the matrix compartment. These data indicate that the patch compartment contributes to repetitive behavior and suggests that alterations in activity in the patch vs matrix compartments may underlie to this phenomenon. PMID:26100338

  1. Acute opioid administration induces hypothalamic-pituitary-adrenal activation and is mediated by genetic variation in interleukin (Il)1B.

    PubMed

    Kershaw, Stephanie G; Della Vedova, Chris B; Majumder, Irina; Ward, Michael B; Farquharson, Aaron L; Williamson, Paul A; White, Jason M

    2015-11-01

    There is a complex relationship between drug dependence and stress, with alcohol and other drugs of abuse both relieving stress and potentially inducing physiological stress responses in the user. Opioid drugs have been shown to modulate hypothalamic-pituitary-adrenal (HPA) activity in animal models and individual response to this modulation may play a role in continuation of drug use. Healthy young Caucasian adults were administered a single dose of immediate release oxycodone (20mg, n=30) or assigned to a control group (n=19) that was not administered the drug. At 0, 1, 2, 4 and 6h post-administration, blood and saliva samples were collected along with assessment of pupil diameter. The HPA response was determined by measurement of salivary cortisol through a commercially available enzyme-linked immunosorbent assay (ELISA). The results were compared to genotype at the -511 and -31 positions in the interleukin1B (IL1B) gene. No difference in cortisol production was initially observed between the two groups, however, when participants were separated based on their genotype for two single nucleotide polymorphisms in the promoter of the IL1B gene, which have been shown to occur at a higher frequency in opioid-dependent populations, individuals carrying the -511T and -31 C alleles (-511 C/T, -31 C/T or -511 T/T, -31 C/C) had a significantly (p<0.05) higher cortisol levels compared to individuals homozygous for the -511 C and -31T alleles. These results suggest that individuals carrying the -511T and -31 C alleles experience HPA activation in response to opioid administration and therefore may be less likely to undertake subsequent self-administration. PMID:26363312

  2. US Food and Drug Administration's Risk Evaluation and Mitigation Strategy for extended-release and long-acting opioids: pros and cons, and a European perspective.

    PubMed

    Mercadante, Sebastiano; Craig, David; Giarratano, Antonello

    2012-12-24

    Prescriptions for opioid analgesics to manage moderate-to-severe chronic non-cancer pain have increased markedly over the last decade. An unintentional consequence of greater prescription opioid utilization has been the parallel increase in misuse, abuse and overdose, which are serious risks associated with all opioid analgesics. In response to disturbing rises in prescription opioid abuse, the US Food and Drug Administration (FDA) has proposed the implementation of aggressive Risk Evaluation and Mitigation Strategies (REMS). While REMS could dramatically change the development, release, marketing and prescription of extended-release opioids, questions remain on how these programmes may influence prescribing practices, patient safety and ultimately patient access to these agents. The extent of the availability and misuse of prescription opioids in Europe is difficult to assess from the data currently available, due in large part to the considerable differences in prescribing patterns and regulations between countries. Balancing the availability of prescription opioids for those patients who have pain, while discouraging illicit use, is a complex challenge and requires effective efforts on many levels, particularly in Europe where policies are quite different between countries. PMID:23116252

  3. Effects of Acute and Repeated Administration of Oxycodone and Naloxone-Precipitated Withdrawal on Intracranial Self-Stimulation in Rats.

    PubMed

    Wiebelhaus, Jason M; Walentiny, D Matthew; Beardsley, Patrick M

    2016-01-01

    Incidence of prescription opioid abuse and overdose, often led by oxycodone, continues to increase, producing twice as many overdose deaths as heroin. Surprisingly, preclinical reports relevant to oxycodone's abuse-related effects are relatively sparse considering its history and patient usage. The goal of this study was to characterize dose- and time-dependent effects of acute and repeated oxycodone administration in a frequency-rate intracranial self-stimulation (ICSS) procedure, an assay often predictive of drug-related reinforcing effects, in male Sprague-Dawley rats. We hypothesized that oxycodone would produce a biphasic profile of rate-increasing and rate-decreasing effects maintained by ICSS similar to μ-opioid receptor agonists. Oxycodone (0.03, 0.3, 1, and 3 mg/kg, s.c.) produced dose- and time-dependent alterations on ICSS, with the predicted biphasic profile of rate-increasing effects at lower stimulation frequencies followed by rate-decreasing effects at higher frequencies. Peak effects were observed between 30 and 60 minutes, which were reversed by naloxone pretreatment (30 minutes). Tolerance to rate-decreasing effects was observed over a 5-day period when rats were treated with 1 mg/kg oxycodone twice a day. Subsequently, the dosing regimen was increased to 3 mg/kg twice a day over 10 days, although further marked tolerance did not develop. When then challenged with 10 mg/kg naloxone, a significant suppression below baseline levels of ICSS-maintained responding occurred indicative of dependence that recovered to baseline within 5 hours. The results of this study provide the first report of acute and chronic effects of oxycodone on responding maintained by ICSS presentation and the use of ICSS-maintained responding to characterize its tolerance and dependence effects. PMID:26491062

  4. Impact of age, sex and route of administration on adverse events after opioid treatment in the emergency department: A retrospective study

    PubMed Central

    Daoust, Raoul; Paquet, Jean; Lavigne, Gilles; Piette, Éric; Chauny, Jean-Marc

    2015-01-01

    BACKGROUND: The efficacy of opioids for acute pain relief in the emergency department (ED) is well recognized, but treatment with opioids is associated with adverse events ranging from minor discomforts to life-threatening events. OBJECTIVE: To assess the impact of age, sex and route of administration on the incidence of adverse events due to opioid administration in the ED. METHODS: Real-time archived data were analyzed retrospectively in a tertiary care urban hospital. All consecutive patients (≥16 years of age) who were assigned to an ED bed and received an opioid between March 2008 and December 2012 were included. Adverse events were defined as: nausea/vomiting (minor); systolic blood pressure (SBP) <90 mmHg, oxygen saturation (Sat) <92% and respiration rate <10 breaths/min (major) within 2 h of the first opioid doses. RESULTS: In the study period, 31,742 patients were treated with opioids. The mean (± SD) age was 55.8±20.5 years, and 53% were female. The overall incidence of adverse events was 12.0% (95% CI 11.6% to 12.4%): 5.9% (95% CI 5.6% to 6.2%) experienced nausea/vomiting, 2.4% (95% CI 2.2% to 2.6%) SBP <90 mmHg, 4.7% (95% CI 4.5% to 4.9%) Sat that dropped to <92% and 0.09% respiration rate <10 breaths/min. After controlling for confounding factors, these adverse events were associated with: female sex (more nausea/vomiting, more SBP <90 mmHg, less Sat <92%); age ≥65 years (less nausea/vomiting, more SBP <90 mmHg, more Sat <92%); and route of administration (intravenous > subcutaneous > oral). CONCLUSIONS: The incidence of adverse events associated with opioid administration in the ED is generally low and is associated with age, sex and route of administration. PMID:25664538

  5. Mu-opioid receptor activation in the medial shell of nucleus accumbens promotes alcohol consumption, self-administration and cue-induced reinstatement.

    PubMed

    Richard, Jocelyn M; Fields, Howard L

    2016-09-01

    Endogenous opioid signaling in ventral cortico-striatal-pallidal circuitry is implicated in elevated alcohol consumption and relapse to alcohol seeking. Mu-opioid receptor activation in the medial shell of the nucleus accumbens (NAc), a region implicated in multiple aspects of reward processing, elevates alcohol consumption while NAc opioid antagonists reduce it. However, the precise nature of the increases in alcohol consumption, and the effects of mu-opioid agonists on alcohol seeking and relapse are not clear. Here, we tested the effects of the mu-opioid agonist [D-Ala(2), N-MePhe(4), Gly-ol]-enkephalin (DAMGO) in rat NAc shell on lick microstructure in a free-drinking test, alcohol seeking during operant self-administration, extinction learning and expression, and cue-reinforced reinstatement of alcohol seeking. DAMGO enhanced the number, but not the size of drinking bouts. DAMGO also enhanced operant alcohol self-administration and cue-induced reinstatement, but did not affect extinction learning or elicit reinstatement in the absence of cues. Our results suggest that mu-opioid agonism in NAc shell elevates alcohol consumption, seeking and conditioned reinforcement primarily by enhancing the incentive motivational properties of alcohol and alcohol-paired cues, rather than by modulating palatability, satiety, or reinforcement. PMID:27089981

  6. Effect of the kappa-opioid receptor agonist, U69593, on reinstatement of extinguished amphetamine self-administration behavior.

    PubMed

    Schenk, S; Partridge, B

    2001-04-01

    Previous research has indicated that pretreatment with the kappa-opioid receptor agonist, U69593, decreased the ability of experimenter-administered cocaine to reinstate extinguished cocaine self-administration behavior. This effect was specific to cocaine-produced drug seeking since U69593 failed to attenuate the ability of experimenter-administered amphetamine to reinstate extinguished cocaine self-administration behavior. One possibility is that U69593 selectively attenuates the behavioral effects of the drug that was originally self-administered. In order to test this hypothesis, the present study examined the effect of U69593 (0.0 or 0.32 mg/kg) on the reinstatement of extinguished amphetamine self-administration behavior produced by experimenter-administered injections of cocaine and amphetamine. Following extinction of amphetamine self-administration (0.04 mg/kg/infusion) the ability of cocaine (0.0, 5.0, 10.0 or 20.0 mg/kg) or amphetamine (0.0, 0.3, 1.0 or 3.0 mg/kg) to reinstate extinguished self-administration behavior was measured. Both drugs reinstated extinguished responding and the reinstatement was attenuated by pretreatment with U69593. The data indicate that the ability of U69593 to decrease drug seeking is not restricted to subjects experienced with cocaine self-administration. Self-administration history does, however, determine the effect of U69593 on amphetamine-produced drug seeking. PMID:11526958

  7. Potent Inhibition of Alcohol Self-Administration in Alcohol-Preferring Rats by a κ-Opioid Receptor Antagonist

    PubMed Central

    Azar, Marc R.

    2014-01-01

    A substituted aryl amide derivative of 6-naltrexamine—17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4′-trimethylfluoro)benzamido]morphinan-hydrochloride—(compound 5), previously shown to be a potent κ-opioid receptor antagonist, was used to characterize the physicochemical properties and efficacy to decrease alcohol self-administration in alcohol-preferring rats (P-rats) and binge-like P-rats. Previous studies showed that compounds closely related to compound 5 possessed favorable properties regarding penetration of the blood-brain barrier. Pharmacokinetic studies showed that compound 5 had acceptable bioavailability. In contrast to other κ-receptor antagonists, in particular norbinaltorphimine, compound 5 showed favorable drug-like properties. Based on these findings, further studies were done. Safety studies showed that compound 5 was not hepatotoxic at doses 200-fold greater than an efficacious dose. The effects of compound 5 or naltrexone on the hepatotoxicity of thiobenzamide were investigated. In contrast to naltrexone, which exacerbated thiobenzamide-mediated hepatotoxicity, compound 5 was observed to be hepatoprotective. Based on the physicochemical properties of compound 5, the compound was examined in rat animal models of alcohol self-administration. The inhibition of ethanol self-administration by compound 5 in alcohol-dependent and alcohol-nondependent P-rats trained to self-administer a 10% (w/v) ethanol solution, using operant techniques, showed very potent efficacy (i.e., estimated ED50 values of 4–5 μg/kg). In a binge-like P-rat animal model, inhibition of alcohol self-administration by compound 5 had an estimated ED50 value of 8 μg/kg. The results suggest that compound 5 is a potent drug-like κ-opioid receptor antagonist of utility in alcohol cessation medications development. PMID:24817033

  8. Synthesis of mixed MOR/KOR efficacy cyclic opioid peptide analogs with antinociceptive activity after systemic administration.

    PubMed

    Perlikowska, Renata; Piekielna, Justyna; Gentilucci, Luca; De Marco, Rossella; Cerlesi, Maria Camilla; Calo, Girolamo; Artali, Roberto; Tömböly, Csaba; Kluczyk, Alicja; Janecka, Anna

    2016-02-15

    Cyclic pentapeptide Tyr-c[D-Lys-Phe-Phe-Asp]NH2, based on the structure of endomorphin-2 (EM-2), which shows high affinity to the μ-opioid receptor (MOR) and a very strong antinociceptive activity in mice was used as a parent compound for the structure-activity relationship studies. In this report we synthesized analogs of a general sequence Dmt-c[D-Lys-Xaa-Yaa-Asp]NH2, with D-1- or D-2-naphthyl-3-alanine (D-1-Nal or D-2-Nal) in positions 3 or 4. In our earlier papers we have indicated that replacing a phenylalanine residue by the more extended aromatic system of naphthylalanines may result in increased bioactivities of linear analogs. The data obtained here showed that only cyclopeptides modified in position 4 retained the sub-nanomolar MOR and nanomolar κ-opioid receptor (KOR) affinity, similar but not better than that of a parent cyclopeptide. In the in vivo mouse hot-plate test, the most potent analog, Dmt-c[D-Lys-Phe-D-1-Nal-Asp]NH2, exhibited higher than EM-2 but slightly lower than the cyclic parent peptide antinociceptive activity after peripheral (ip) and also central administration (icv). Conformational analyses in a biomimetic environment and molecular docking studies disclosed the structural determinants responsible for the different pharmacological profiles of position 3- versus position 4-modified analogs. PMID:26785295

  9. Association of Opioids and Sedatives with Increased Risk of In-Hospital Cardiopulmonary Arrest from an Administrative Database

    PubMed Central

    Overdyk, Frank J.; Dowling, Oonagh; Marino, Joseph; Qiu, Jiejing; Chien, Hung-Lun; Erslon, Mary; Morrison, Neil; Harrison, Brooke; Dahan, Albert; Gan, Tong J.

    2016-01-01

    Background While opioid use confers a known risk for respiratory depression, the incremental risk of in-hospital cardiopulmonary arrest, respiratory arrest, or cardiopulmonary resuscitation (CPRA) has not been studied. Our aim was to investigate the prevalence, outcomes, and risk profile of in-hospital CPRA for patients receiving opioids and medications with central nervous system sedating side effects (sedatives). Methods A retrospective analysis of adult inpatient discharges from 2008–2012 reported in the Premier Database. Patients were grouped into four mutually exclusive categories: (1) opioids and sedatives, (2) opioids only, (3) sedatives only, and (4) neither opioids nor sedatives. Results Among 21,276,691 inpatient discharges, 53% received opioids with or without sedatives. A total of 96,554 patients suffered CPRA (0.92 per 1000 hospital bed-days). Patients who received opioids and sedatives had an adjusted odds ratio for CPRA of 3.47 (95% CI: 3.40–3.54; p<0.0001) compared with patients not receiving opioids or sedatives. Opioids alone and sedatives alone were associated with a 1.81-fold and a 1.82-fold (p<0.0001 for both) increase in the odds of CPRA, respectively. In opioid patients, locations of CPRA were intensive care (54%), general care floor (25%), and stepdown units (15%). Only 42% of patients survived CPRA and only 22% were discharged home. Opioid patients with CPRA had mean increased hospital lengths of stay of 7.57 days and mean increased total hospital costs of $27,569. Conclusions Opioids and sedatives are independent and additive risk factors for in-hospital CPRA. The impact of opioid sparing analgesia, reduced sedative use, and better monitoring on CPRA incidence deserves further study. PMID:26913753

  10. Opioid intoxication

    MedlinePlus

    ... use of opioid-based drugs. These include morphine, heroin, oxycodone, and synthetic (man-made) opioid narcotics. Prescription ... United States, the most commonly abused opioids are heroin and methadone. People who become addicted to these ...

  11. Opioid intoxication

    MedlinePlus

    Intoxication - opioids ... In the United States, the most commonly abused opioids are heroin and methadone. People who become addicted ... of these drugs. Also, the use of prescription opioids for nonmedical reasons is an extensive and growing ...

  12. Effects of the kappa-opioid receptor agonist, U69593, on the development of sensitization and on the maintenance of cocaine self-administration.

    PubMed

    Schenk, S; Partridge, B; Shippenberg, T S

    2001-04-01

    Previous studies showed that prior administration of kappa-opioid agonists decreased the development of sensitization to some of the behavioral effects of cocaine. The present study sought to determine whether the development of sensitization to cocaine's reinforcing effects was also sensitive to antagonism by kappa-opioid agonists. During a pretreatment phase, the kappa-opioid agonist, U69593 (0.0 or 0.32 mg/kg) was administered prior to (1) 2 daily injections of cocaine (0.0 or 20.0 mg/kg), or (2) cocaine or saline administered via a yoking procedure. Cocaine pretreatment decreased the latency to acquisition of cocaine self-administration. However, prior administration of U69593 during the pretreatment phase failed to attenuate the development of this sensitized response to cocaine's reinforcing effect. In other groups, the effect of acute U69593 pretreatment on the maintenance of cocaine self-administration was examined during a 10 hr session. During training and testing, a stimulus was associated with each self-administered cocaine infusion for one group whereas responding of another group was reinforced by a cocaine infusion alone. On the test day, pretreatment with U69593 (0.32 mg/kg) decreased responding during each hour of the 10 hr session for the group that was reinforced with cocaine plus the cocaine-associated stimulus. U69593 failed to produce a long-lasting disruption of cocaine self-administration for rats that were trained and tested without the cocaine-associated stimulus. These data suggest that the acquisition and maintenance of cocaine self-administration are differentially sensitive to manipulations of kappa-opioid systems. Further, the disruption of cocaine self-administration by U69593 may be due to interactions with mechanisms that underlie facilitative effects of stimuli that have been associated with self-administered cocaine infusions. PMID:11182539

  13. COMPARATIVE METABOLISM OF ARSENIC IN MICE AFTER A SINGLE OR REPEATED ORAL ADMINISTRATION OF ARSENATE

    EPA Science Inventory

    COMPARATIVE METABOLISM OF ARSENIC IN MICE AFTER A SINGLE OR REPEATED ORAL ADMINISTRATION OF ARSENATE
    Michael F. Hughes*1, Elaina M. Kenyon1, Brenda C. Edwards1, Carol T. Mitchell1, Luz Maria Del Razo2 and David J. Thomas1
    1US EPA, ORD, NHEERL, ETD, PKB, Research Triangle Pa...

  14. ACCUMULATION AND METABOLISM OF ARSENIC IN MICE AFTER REPEATED ADMINISTRATION OF ARSENATE

    EPA Science Inventory

    Accumulation and metabolism of arsenic in mice after repeated oral administration of arsenate, Hughes, M. F., Kenyon, E. M., Edwards, B. C., Mitchell, C. T., Del Razo, L. M., and Thomas,
    D. J.

    The human carcinogen inorganic arsenic (iAs) is a pervasive environmental ...

  15. Repeated Post- or Presession Cocaine Administration: Roles of Dose and Fixed-Ratio Schedule

    ERIC Educational Resources Information Center

    Pinkston, Jonathan W.; Branch, Marc N.

    2004-01-01

    Effects of repeated administration of cocaine to animals behaving under operant contingencies have depended on when the drug is given. Moderate doses given presession have generally led to a decrease in the drug's effect, an outcome usually referred to as tolerance. When these same doses have been given after sessions, the usual result has been no…

  16. Developing Items to Measure Theory of Planned Behavior Constructs for Opioid Administration for Children: Pilot Testing.

    PubMed

    Vincent, Catherine; Riley, Barth B; Wilkie, Diana J

    2015-12-01

    The Theory of Planned Behavior (TpB) is useful to direct nursing research aimed at behavior change. As proposed in the TpB, individuals' attitudes, perceived norms, and perceived behavior control predict their intentions to perform a behavior and subsequently predict their actual performance of the behavior. Our purpose was to apply Fishbein and Ajzen's guidelines to begin development of a valid and reliable instrument for pediatric nurses' attitudes, perceived norms, perceived behavior control, and intentions to administer PRN opioid analgesics when hospitalized children self-report moderate to severe pain. Following Fishbein and Ajzen's directions, we were able to define the behavior of interest and specify the research population, formulate items for direct measures, elicit salient beliefs shared by our target population and formulate items for indirect measures, and prepare and test our questionnaire. For the pilot testing of internal consistency of measurement items, Cronbach alphas were between 0.60 and 0.90 for all constructs. Test-retest reliability correlations ranged from 0.63 to 0.90. Following Fishbein and Ajzen's guidelines was a feasible and organized approach for instrument development. In these early stages, we demonstrated good reliability for most subscales, showing promise for the instrument and its use in pain management research. Better understanding of the TpB constructs will facilitate the development of interventions targeted toward nurses' attitudes, perceived norms, and/or perceived behavior control to ultimately improve their pain behaviors toward reducing pain for vulnerable children. PMID:26527107

  17. The macrocyclic tetrapeptide [D-Trp]CJ-15,208 produces short-acting κ opioid receptor antagonism in the CNS after oral administration

    PubMed Central

    Eans, Shainnel O; Ganno, Michelle L; Reilley, Kate J; Patkar, Kshitij A; Senadheera, Sanjeewa N; Aldrich, Jane V; McLaughlin, Jay P

    2013-01-01

    Background and Purpose Cyclic peptides are resistant to proteolytic cleavage, therefore potentially exhibiting activity after systemic administration. We hypothesized that the macrocyclic κ opioid receptor (KOR)-selective antagonist [D-Trp]CJ-15,208 would demonstrate antagonist activity after systemic, that is, s.c. and oral (per os, p. o.), administration. Experimental Approach C57BL/6J mice were pretreated with [D-Trp]CJ-15,208 s.c. or p.o. before administration of the KOR-selective agonist U50,488 and the determination of antinociception in the warm-water tail-withdrawal assay. The locomotor activity of mice treated with [D-Trp]CJ-15,208 was determined by rotorod testing. Additional mice demonstrating cocaine conditioned place preference and subsequent extinction were pretreated daily with vehicle or [D-Trp]CJ-15,208 and then exposed to repeated forced swim stress or a single additional session of cocaine place conditioning before redetermining place preference. Key Results Pretreatment with [D-Trp]CJ-15,208 administered s.c. or p.o. dose-dependently antagonized the antinociception induced by i.p. administration of U50,488 in mice tested in the warm-water tail-withdrawal assay for less than 12 and 6 h respectively. [D-Trp]CJ-15,208 also produced limited (<25%), short-duration antinociception mediated through KOR agonism. Orally administered [D-Trp]CJ-15,208 dose-dependently antagonized centrally administered U50,488-induced antinociception, and prevented stress-, but not cocaine-induced, reinstatement of extinguished cocaine-seeking behaviour, consistent with its KOR antagonist activity, without affecting locomotor activity. Conclusions and Implications The macrocyclic tetrapeptide [D-Trp]CJ-15,208 is a short-duration KOR antagonist with weak KOR agonist activity that is active after oral administration and demonstrates blood–brain barrier permeability. These data validate the use of systemically active peptides such as [D-Trp]CJ-15,208 as potentially useful

  18. The effects of repeated parenteral administration of chelating agents on the distribution and excretion of uranium

    SciTech Connect

    Domingo, J.L.; Ortega, A.; Llobet, J.M.; Paternain, J.L.; Corbella, J.

    1989-04-01

    The effects of repeated ip administration of gallic acid, 4,5-dihydroxy-1,3-benzenedisulfonic acid (Tiron), diethylenetriaminepentaacetic acid (DTPA), and 5-aminosalicylic acid (5-AS) on the distribution and excretion of uranium were assessed in male Swiss mice. Only Tiron significantly increased the amount of uranium excreted into urine and feces. A significant decrease in the concentration of uranium in liver, spleen and bone was observed after administration of Tiron, whereas injection of gallic acid or DTPA resulted in a significant decrease in the concentration of the metal in the liver. The results show that Tiron was consistently the most effective chelator of those tested in the treatment of uranium poisoning after repeated daily administration of the metal.

  19. Pharmacological characterization of repeated administration of the first generation abused synthetic cannabinoid CP47,497.

    PubMed

    Grim, Travis W; Samano, Kimberly L; Ignatowska-Jankowska, Bogna; Tao, Qing; Sim-Selly, Laura J; Selley, Dana E; Wise, Laura E; Poklis, Alphonse; Lichtman, Aron H

    2016-05-01

    A series of in vivo and in vitro assays were conducted to characterize the pharmacological effects of the first generation abused synthetic cannabinoid CP47,497, a racemic bicyclic cannabinoid that is similar in structure to the potent, high-efficacy synthetic cannabinoid CP55,940. CP47,497 was less efficacious than CP55,940 in activating G-proteins and dose-dependently produced common CB1 receptor-dependent pharmacological effects (i.e. catalepsy, hypothermia, antinociception, and hypolocomotion). CP47,497 also substituted for Δ9-tetrahydrocannabinol (THC) in the mouse drug discrimination, indicating that both drugs elicited a similar interceptive stimulus. The pharmacological effects of CP47,497 underwent tolerance following repeated administration and showed cross-tolerance following repeated THC administration, further suggesting a common cannabimimetic mechanism of action. Finally, the CB1 receptor antagonist rimonabant precipitated similar magnitudes of somatic withdrawal responses in mice treated repeatedly with THC or CP47,497. Taken together, these data verify the acute cannabimimetic effects of CP47,497, and indicate tolerance and dependence following repeated administration. The assays used here provide a straightforward approach to characterize the emerging next generation of abused synthetic cannabinoids. PMID:27149200

  20. Preweaning cocaine exposure alters brain glucose metabolic rates following repeated amphetamine administration in the adult rat.

    PubMed

    Melnick, Susan M; Torres-Reveron, Annelyn; Dow-Edwards, Diana L

    2004-10-15

    Developmental cocaine exposure produces long-term alterations in function of many neuronal circuits. This study examined glucose metabolic rates following repeated amphetamine administration in adult male and female rats pretreated with cocaine during postnatal days (PND) 11-20. PND11-20 cocaine increased the response to amphetamine in many components of the motor system and the dorsal caudate-putamen, in particular, and decreased the metabolic response in the hypothalamus. While amphetamine alone produced widespread increases in metabolism, there were no cocaine-related effects in the mesolimbic, limbic or sensory structures. These data suggest that a brief cocaine exposure during development can alter ontogeny and result in abnormal neuronal responses to repeated psychostimulant administration in adulthood. PMID:15464226

  1. The pharmacological basis of opioids

    PubMed Central

    Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Bianchi, Enrica

    2015-01-01

    Summary An opioid is a chemical that binds to opioid receptors, which are widely distributed in the central and peripheral nervous system and gastrointestinal tract. The different effects elicited by activation of these receptors are due to their specific neuronal and extraneuronal distribution. The painkiller effect of opioids is induced by the synergy of the two events, namely reduction of pain threshold and emotional detachment from pain. The opioid effects transcending analgesia include sedation, respiratory depression, constipation and a strong sense of euphoria. There are opioid-like substances endogenously produced by the body. Naturally occurring peptides, called enkephalins, have opioid-like activities but are not derived from opium and exert opioid-like effects by interacting with opioid receptors on cell membranes. Yet, animals do contain the same morphine precursors and metabolites as opium poppy and are able to synthesize endogenous morphine alkaloid. Experimental and clinical studies show that opioids, at doses comparable to those of endogenous opioids, can activate pronociceptive systems, leading to pain hypersensitivity and short-term tolerance, a phenomenon encountered in postoperative pain management by acute opioid administration. Whether endogenous opioids play a role in the acute pain necessary to the survival of the individual, remains an open question. PMID:26811699

  2. The pharmacological basis of opioids.

    PubMed

    Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Bianchi, Enrica

    2015-01-01

    An opioid is a chemical that binds to opioid receptors, which are widely distributed in the central and peripheral nervous system and gastrointestinal tract. The different effects elicited by activation of these receptors are due to their specific neuronal and extraneuronal distribution. The painkiller effect of opioids is induced by the synergy of the two events, namely reduction of pain threshold and emotional detachment from pain. The opioid effects transcending analgesia include sedation, respiratory depression, constipation and a strong sense of euphoria. There are opioid-like substances endogenously produced by the body. Naturally occurring peptides, called enkephalins, have opioid-like activities but are not derived from opium and exert opioid-like effects by interacting with opioid receptors on cell membranes. Yet, animals do contain the same morphine precursors and metabolites as opium poppy and are able to synthesize endogenous morphine alkaloid. Experimental and clinical studies show that opioids, at doses comparable to those of endogenous opioids, can activate pronociceptive systems, leading to pain hypersensitivity and short-term tolerance, a phenomenon encountered in postoperative pain management by acute opioid administration. Whether endogenous opioids play a role in the acute pain necessary to the survival of the individual, remains an open question. PMID:26811699

  3. Pharmacogenomic considerations in opioid analgesia

    PubMed Central

    Vuilleumier, Pascal H; Stamer, Ulrike M; Landau, Ruth

    2012-01-01

    Translating pharmacogenetics to clinical practice has been particularly challenging in the context of pain, due to the complexity of this multifaceted phenotype and the overall subjective nature of pain perception and response to analgesia. Overall, numerous genes involved with the pharmacokinetics and dynamics of opioids response are candidate genes in the context of opioid analgesia. The clinical relevance of CYP2D6 genotyping to predict analgesic outcomes is still relatively unknown; the two extremes in CYP2D6 genotype (ultrarapid and poor metabolism) seem to predict pain response and/or adverse effects. Overall, the level of evidence linking genetic variability (CYP2D6 and CYP3A4) to oxycodone response and phenotype (altered biotransformation of oxycodone into oxymorphone and overall clearance of oxycodone and oxymorphone) is strong; however, there has been no randomized clinical trial on the benefits of genetic testing prior to oxycodone therapy. On the other hand, predicting the analgesic response to morphine based on pharmacogenetic testing is more complex; though there was hope that simple genetic testing would allow tailoring morphine doses to provide optimal analgesia, this is unlikely to occur. A variety of polymorphisms clearly influence pain perception and behavior in response to pain. However, the response to analgesics also differs depending on the pain modality and the potential for repeated noxious stimuli, the opioid prescribed, and even its route of administration. PMID:23226064

  4. Attentional Bias For Prescription Opioid Cues Among Opioid Dependent Chronic Pain Patients

    PubMed Central

    Garland, Eric L.; Froeliger, Brett; Passik, Steven D.; Howard, Matthew O.

    2012-01-01

    Recurrent use of prescription opioid analgesics by chronic pain patients may result in opioid dependence, which involves implicit neurocognitive operations that organize and impel craving states and compulsive drug taking behavior. Prior studies have identified an attentional bias (AB) towards heroin among heroin dependent individuals. The aim of this study was to determine whether opioid-dependent chronic pain patients exhibit an AB towards prescription opioidrelated cues. Opioid-dependent chronic pain patients (n = 32) and a comparison group of non-dependent opioid users with chronic pain (n = 33) completed a dot probe task designed to measure opioid AB. Participants also rated their opioid craving and self-reported arousal associated with opioid-related and neutral images, pain severity, and relief from pain treatments. Repeated-measures ANOVA revealed a significant group (opioid-dependent vs. non-dependent opioid user) × presentation duration (200 ms. vs. 2000 ms.) interaction, such that opioid-dependent individuals evidenced a significant AB towards opioid cues presented for 200 ms but not for cues presented for 2000 ms, whereas non-dependent opioid users did not exhibit a significant mean AB at either stimulus duration. Among opioid-dependent individuals, 200 ms opioid AB was significantly associated with opioid craving, while among non-dependent opioid users, 200 ms opioid AB was significantly associated with relief from pain treatments. Furthermore, dependent and non-dependent opioid users experienced opioid cues as significantly more arousing than neutral cues. Opioid dependence among chronic pain patients appears to involve an automatic AB towards opioid-related cues. When coupled with chronic pain, attentional fixation on opioid cues may promote compulsive drug use and addictive behavior. PMID:22968666

  5. FDA Approves Implant to Battle Opioid Addiction

    MedlinePlus

    ... 159050.html FDA Approves Implant to Battle Opioid Addiction Experts say steady dosing eliminates need to take ... U.S. Food and Drug Administration. "Opioid abuse and addiction have taken a devastating toll on American families. ...

  6. Varenicline impairs extinction and enhances reinstatement across repeated cycles of nicotine self-administration in rats.

    PubMed

    Macnamara, Claire L; Holmes, Nathan M; Westbrook, R Fred; Clemens, Kelly J

    2016-06-01

    Varenicline is a partial nicotine receptor agonist widely prescribed as a smoking cessation medication. Repeated (or long-term) use of varenicline has been proposed as a treatment option for tobacco addiction. However the effect of repeated varenicline use on motivation for nicotine is unknown. Here the intravenous nicotine self-administration paradigm in rats was used to model the consequences of varenicline treatment across repeated cycles of administration, extinction and reinstatement. Rats acquired nicotine self-administration across 20 days before undergoing 6 days of extinction, where each extinction session was preceded by a single injection of varenicline or saline. This was followed by a single varenicline-free nicotine-primed reinstatement test. All rats then reacquired nicotine self-administration for 10 days followed by a second cycle of extinction. Across this period, rats either received a second cycle of varenicline (VAR-VAR) or saline (SAL-SAL), or the alternative treatment (SAL-VAR, VAR-SAL), followed by a final reinstatement test. Treatment with varenicline increased responding across the first cycle of extinction, but did not affect responding in the reinstatement test. Across the second cycle, varenicline again increased responding across extinction, and critically, rats treated with varenicline across cycle 1 and saline across cycle 2 (Group VAR-SAL) exhibited more reinstatement than rats in any other group. The effect of VAR on nicotine seeking was not due to its effects on locomotor activity. Instead, the results suggest that a history of VAR can increase vulnerability to reinstatement/relapse when its treatment is discontinued. The possible mechanisms of this increased vulnerability are discussed. PMID:26907808

  7. Repeated cocaine administration promotes long-term potentiation induction in rat medial prefrontal cortex.

    PubMed

    Huang, Chiung-Chun; Lin, Hsiao-Ju; Hsu, Kuei-Sen

    2007-08-01

    Although drug-induced adaptations in the prefrontal cortex (PFC) may contribute to several core aspects of addictive behaviors, it is not clear yet whether drugs of abuse elicit changes in synaptic plasticity at the PFC excitatory synapses. Here we report that, following repeated cocaine administration (15 mg/kg/day intraperitoneal injection for 5 consecutive days) with a 3-day withdrawal, excitatory synapses to layer V pyramidal neurons in rat medial prefrontal cortex (mPFC) become highly sensitive to the induction of long-term potentiation (LTP) by repeated correlated presynaptic and postsynaptic activity. This promoted LTP induction is caused by cocaine-induced reduction of gamma-aminobutyric acid (GABA)(A) receptor-mediated inhibition of mPFC pyramidal neurons. In contrast, in slices from rats treated with saline or a single dose of cocaine, the same LTP induction protocol did not induce significant LTP unless the blockade of GABA(A) receptors. Blockade of the D1-like receptors specifically prevented the cocaine-induced enhancement of LTP. Repeated cocaine exposure reduced the GABA(A) receptor-mediated synaptic currents in mPFC pyramidal neurons. Biotinylation experiments revealed a significant reduction of surface GABA(A) receptor alpha1 subunit expression in mPFC slices from repeated cocaine-treated rats. These findings support an important role for cocaine-induced enhancement of synaptic plasticity in the PFC in the development of drug-associated behavioral plasticity. PMID:17050645

  8. Sex differences in behavioral and PKA cascade responses to repeated cocaine administration.

    PubMed

    Zhou, Luyi; Sun, Wei-Lun; Weierstall, Karen; Minerly, Ana Christina; Weiner, Jan; Jenab, Shirzad; Quinones-Jenab, Vanya

    2016-10-01

    Previous studies have shown sex different patterns in behavioral responses to cocaine. Here, we used between-subject experiment design to study whether sex differences exist in the development of behavioral sensitization and tolerance to repeated cocaine, as well as the role of protein kinase A (PKA) signaling cascade in this process. Ambulatory and rearing responses were recorded in male and female rats after 1 to 14 days of administration of saline or cocaine (15 mg/kg; ip). Correspondent PKA-associated signaling in the nucleus accumbens (NAc) and caudate-putamen (CPu) was measured at each time point. Our results showed that females exhibited higher cocaine-induced behavioral responses and developed behavioral sensitization and tolerance faster than males. Whereas females developed behavioral sensitization to cocaine after 2 days and tolerance after 14 days, male rats developed sensitization after 5 days. In addition, cocaine induced a sexual dimorphic pattern in the progression of neuronal adaptations on the PKA cascade signaling in region (NAc vs. CPu) and time (days of cocaine administration)-dependent manners. In general, more PKA signaling cascade changes were found in the NAc of males on day 5 and in the CPu of females with repeated cocaine injection. In addition, in females, behavioral activities positively correlated with FosB levels in the NAc and CPu and negatively correlated with Cdk5 and p35 in the CPu, while no correlation was observed in males. Our studies suggest that repeated cocaine administration induced different patterns of behavioral and molecular responses in the PKA cascade in male and female rats. PMID:27553823

  9. Different dosing regimens of repeated ketamine administration have opposite effects on novelty processing in rats.

    PubMed

    Schumacher, Anett; Sivanandan, Brindan; Tolledo, Edgor Cole; Woldegabriel, Jacob; Ito, Rutsuko

    2016-08-01

    Repeated exposure to sub-anesthetic doses of ketamine in rats has been shown to induce cognitive deficits, as well as behavioral changes akin to the negative symptoms of schizophrenia, giving much face validity to the use of ketamine administration as a pharmacological model of schizophrenia. This study sought to further characterize the behavioral effects of two different ketamine pre-treatment regimens, focusing primarily on the effects of repeated ketamine administration on novelty processing, a capacity that is disrupted in schizophrenia. Rats received 5 or 14 intra-peritoneal injections of 30mg/kg ketamine or saline across 5 or 7days, respectively. They were then tested in an associative mismatch detection task to examine their ability to detect novel configurations of familiar audio-visual sequences. Furthermore, rats underwent a sequential novel object and novel object location exploration task. Subsequently, rats were also tested on the delayed matching to place T-maze task, sucrose preference task and locomotor tests involving administering a challenge dose of amphetamine (AMPH). The high-dose ketamine pre-treatment regimen elicited impairments in mismatch detection and working memory. In contrast, the low-dose ketamine pre-treatment regimen improved performance of novelty detection. In addition, low-dose ketamine pre-treated rats showed locomotor sensitization following an AMPH challenge, while the high-dose ketamine pre-treated rats showed an attenuated locomotor response to AMPH, compared to control rats. These findings demonstrate that different regimens of repeated ketamine administration induce alterations in novelty processing in opposite directions, and that differential neural adaptations occurring in the mesolimbic dopamine system may underlie these effects. PMID:27064663

  10. Resistance of the hamster to amiodarone-induced pulmonary toxicity following repeated intraperitoneal administration.

    PubMed

    Leeder, R G; Evans, C D; Brien, J F; Massey, T E

    1994-10-01

    Amiodarone is an effective antidysrhythmic agent, restricted in use by the development of pulmonary toxicity. Several in vivo animal models have been used to study amiodarone-induced pulmonary toxicity. Intratracheal administration of amiodarone to the hamster has been used as a model for the critical amiodarone-induced pulmonary fibrosis (AIPF). In order to investigate the cellular mechanism of human AIPF, which occurs following oral or intravenous administration, an animal model of AIPF resulting from systemic administration of the drug would appear to be preferable. We have evaluated pulmonary toxicity following repeated intraperitoneal amiodarone administration to the hamster. Intraperitoneal treatment of hamsters for 1, 4, or 7 weeks with amiodarone (100 mg/kg/day) did not lead to pulmonary toxicity based on wet lung weight, hydroxyproline content, or histological examination. Furthermore, when comparing 1- and 7-week treatment groups, there was no pulmonary accumulation of either amiodarone or desethylamiodarone beyond levels found at 1 week. Therefore, failure to develop pulmonary toxicity may be due to an inability to accumulate sufficient amiodarone and/or desethylamiodarone. Intratracheal administration of amiodarone to rodents remains the only in vivo animal model for studying the mechanism(s) of AIPF. PMID:8085270

  11. Opioid Analgesics.

    PubMed

    Jamison, Robert N; Mao, Jianren

    2015-07-01

    Chronic pain is an international health issue of immense importance that is influenced by both physical and psychological factors. Opioids are useful in treating chronic pain but have accompanying complications. It is important for clinicians to understand the basics of opioid pharmacology, the benefits and adverse effects of opioids, and related problematic issues of tolerance, dependence, and opioid-induced hyperalgesia. In this article, the role of psychiatric comorbidity and the use of validated assessment tools to identify individuals who are at the greatest risk for opioid misuse are discussed. Additionally, interventional treatment strategies for patients with chronic pain who are at risk for opioid misuse are presented. Specific behavioral interventions designed to improve adherence with prescription opioids among persons treated for chronic pain, such as frequent monitoring, periodic urine screens, opioid therapy agreements, opioid checklists, and motivational counseling, are also reviewed. Use of state-sponsored prescription drug monitoring programs is also encouraged. Areas requiring additional investigation are identified, and the future role of abuse-deterrent opioids and innovative technology in addressing issues of opioid therapy and pain are presented. PMID:26141334

  12. Brexpiprazole Alters Monoaminergic Systems following Repeated Administration: an in Vivo Electrophysiological Study

    PubMed Central

    Mansari, Mostafa El; Bundgaard, Christoffer; Blier, Pierre

    2016-01-01

    Background: Brexpiprazole was recently approved as adjunctive therapy for depression and treatment of schizophrenia in adults. To complement results from a previous study in which its acute effects were characterized, the present study assessed the effect of repeated brexpiprazole administration on monoaminergic systems. Methods: Brexpiprazole (1mg/kg, subcutaneous) or vehicle was administered once daily for 2 and 14 days. Single-unit electrophysiological recordings from noradrenaline neurons in the locus coeruleus, serotonin neurons in the dorsal raphe nucleus, dopaminergic neurons in the ventral tegmental area, and pyramidal neurons in the hippocampus CA3 region were obtained in adult male Sprague-Dawley rats under chloral hydrate anesthesia within 4 hours after final dosing. Results: Brexpiprazole blunted D2 autoreceptor responsiveness, while firing activity of ventral tegmental area dopaminergic neurons remained unaltered. Brexpiprazole increased the firing rate of locus coeruleus noradrenaline neurons and increased noradrenaline tone on α2-adrenergic receptors in the hippocampus. Administration of brexpiprazole for 2 but not 14 days increased the firing rate of serotonin neurons in the dorsal raphe nucleus. In the hippocampus, serotonin1A receptor blockade significantly disinhibited pyramidal neurons after 2- and 14-day brexpiprazole administration. In contrast, no significant disinhibition occurred after 24-hour washout or acute brexpiprazole. Conclusions: Repeated brexpiprazole administration resulted in a marked occupancy of D2 autoreceptors, while discharge activity of ventral tegmental area dopaminergic neurons remained unaltered. Brexpiprazole enhanced serotonergic and noradrenergic tone in the hippocampus, effects common to antidepressant agents. Together, these results provide further insight in the neural mechanisms by which brexpiprazole exerts antidepressant and antipsychotic effects. PMID:26428352

  13. Lack of behavioral sensitization to repeated cocaine administration from postnatal days 1 to 10.

    PubMed

    Meyer, J S; Yacht, A C

    1993-09-01

    This research determined whether sensitization (or tolerance) to the behavioral effects of cocaine in rat pups would occur following repeated cocaine administration. Rats were injected daily with 20 mg/kg of cocaine HCl s.c. from postnatal day 1 to day 10, injected with saline vehicle only, or left untreated during this period. On day 11, animals from each group were challenged with either 0, .625, 1.25, or 2.50 mg/kg of cocaine and their behavioral responses were recorded. Prior cocaine treatment did not influence the acute effects of cocaine on ultrasonic vocalizations or on any observed motor responses. In contrast, the cocaine- and saline-treated pups differed in a similar manner from the untreated control group on several behavioral measures. These results indicate that the sensitizing effects of repeated cocaine administration are not manifested during the neonatal period. However, the stimulation (stress) of handling and injection may alter the subsequent responsivity of infant rats to a cocaine challenge. PMID:8225794

  14. Strain and cocaine-induced differential opioid gene expression may predispose Lewis but not Fischer rats to escalate cocaine self-administration.

    PubMed

    Valenza, Marta; Picetti, Roberto; Yuferov, Vadim; Butelman, Eduardo R; Kreek, Mary Jeanne

    2016-06-01

    The aim of the present study was to investigate alterations in gene expression of opioid system components induced by extended access (18 h) cocaine self-administration and to determine the impact of genetic background in the vulnerability to escalate cocaine intake. Comparing two inbred rat strains, we previously reported that Lewis rats progressively escalated cocaine consumption compared to Fischer rats, in a new translational model of intravenous cocaine self-administration, which included 14 sessions of 18-h operant sessions in which rats were allowed to select the cocaine unit dose to self-administer. We compare here Fischer and Lewis rats in the gene expression of endogenous opioid peptides (Pomc, Penk, Pdyn) and cognate receptors (Oprm, Oprk and Oprd) in reward-related brain regions, after exposure to either cocaine self-administration or yoked-saline, in the aforementioned translational paradigm. We performed a correlation analysis between the mRNA level, found in the Dorsal Striatum (DS), Nucleus accumbens (NAcc) shell and core respectively, and individual cocaine intake. Our findings show that the gene expression of all the aforementioned opioid genes exhibit strain-dependent differences in the DS, in absence of cocaine exposure. Also, different strain-specific cocaine-induced mRNA expression of Oprm and Oprk was found in DS. Only few differences were found in the ventral parts of the striatum. Moreover, gene expression level of Pdyn, Penk, Oprk, and Oprm in the DS was significantly correlated with cocaine intake only in Fischer rats. Overall, these data shed light on potential genetic differences which may predispose of subjects to initiate and escalate cocaine consumption. PMID:26777278

  15. Repeated ketamine administration redeems the time lag for citalopram's antidepressant-like effects.

    PubMed

    Zhang, G-F; Liu, W-X; Qiu, L-L; Guo, J; Wang, X-M; Sun, H-L; Yang, J-J; Zhou, Z-Q

    2015-06-01

    Current available antidepressants exhibit low remission rate with a long response lag time. Growing evidence has demonstrated acute sub-anesthetic dose of ketamine exerts rapid, robust, and lasting antidepressant effects. However, a long term use of ketamine tends to elicit its adverse reactions. The present study aimed to investigate the antidepressant-like effects of intermittent and consecutive administrations of ketamine on chronic unpredictable mild stress (CUMS) rats, and to determine whether ketamine can redeem the time lag for treatment response of classic antidepressants. The behavioral responses were assessed by the sucrose preference test, forced swimming test, and open field test. In the first stage of experiments, all the four treatment regimens of ketamine (10mg/kg ip, once daily for 3 or 7 consecutive days, or once every 7 or 3 days, in a total 21 days) showed robust antidepressant-like effects, with no significant influence on locomotor activity and stereotype behavior in the CUMS rats. The intermittent administration regimens produced longer antidepressant-like effects than the consecutive administration regimens and the administration every 7 days presented similar antidepressant-like effects with less administration times compared with the administration every 3 days. In the second stage of experiments, the combination of ketamine (10 mg/kg ip, once every 7 days) and citalopram (20 mg/kg po, once daily) for 21 days caused more rapid and sustained antidepressant-like effects than citalopram administered alone. In summary, repeated sub-anesthestic doses of ketamine can redeem the time lag for the antidepressant-like effects of citalopram, suggesting the combination of ketamine and classic antidepressants is a promising regimen for depression with quick onset time and stable and lasting effects. PMID:25795441

  16. Pharmacokinetics and tissue disposition of meloxicam in beef calves after repeated oral administration.

    PubMed

    Coetzee, J F; Mosher, R A; Griffith, G R; Gehring, R; Anderson, D E; KuKanich, B; Miesner, M

    2015-12-01

    The objective of this study was to investigate the pharmacokinetics and tissue disposition of meloxicam after repeated oral administration in calves. Thirteen male British × Continental beef calves aged 4 to 6 months and weighing 297-392 kg received 0.5 mg/kg meloxicam per os once daily for 4 days. Plasma meloxicam concentrations were determined in 8 calves over 6 days after first treatment. Calves were randomly assigned to be euthanized at 5, 10, 15 (n = 3/timepoint), and 19 days (n = 4) after final administration. Meloxicam concentrations were determined in plasma (LOQ= 0.025 μg/mL) and muscle, liver, kidney, and fat samples (LOQ = 2 ng/g) after extraction using validated LC-MS-MS methods. The mean (± SD) Cmax , Cmin , and Caverage plasma meloxicam concentrations were 4.52 ± 0.87 μg/mL, 2.95 ± 0.77 μg/mL, and 3.84 ± 0.81 μg/mL, respectively. Mean (± SD) tissue meloxicam concentrations were highest in liver (226.67 ± 118.16 ng/g) and kidney samples (52.73 ± 39.01 ng/g) at 5 days after final treatment. Meloxicam concentrations were below the LOQ in all tissues at 15 days after treatment. These findings suggest that tissue from meloxicam-treated calves will have low residue concentrations by 21 days after repeated oral administration. PMID:25708937

  17. Regulation of Gene Expression in Brain Tissues of Rats Repeatedly Treated by the Highly Abused Opioid Agonist, Oxycodone: Microarray Profiling and Gene Mapping Analysis

    PubMed Central

    Hassan, Hazem E.; Myers, Alan L.; Lee, Insong J.; Chen, Hegang; Coop, Andrew

    2010-01-01

    Although oxycodone is the most often used opioid agonist, it remains one of the most understudied drugs. We used microarray analysis to better understand the global changes in gene expression in brain tissues of rats repeatedly treated with oxycodone. Many genes were significantly regulated by oxycodone (e.g., Fkbp5, Per2, Rt1.Dα, Slc16a1, and Abcg2). Validation of the microarray data by quantitative real-time-polymerase chain reaction (Q-PCR) indicated that there was a strong significant correlation (r = 0.979, p < 0.0000001) between the Q-PCR and the microarray data. Using MetaCore (a computational platform), many biological processes were identified [e.g., organic anion transport (p = 7.251 × 10−4) and regulation of immune response (p = 5.090 × 10−4)]. Among the regulated genes, Abcg2 mRNA was up-regulated by 2.1-fold, which was further confirmed by immunoblotting (1.8-fold up-regulation). Testing the Abcg2 affinity status of oxycodone using an Abcg2 ATPase assay suggests that oxycodone behaves as an Abcg2 substrate only at higher concentrations (≥500 μM). Furthermore, brain uptake studies demonstrated that oxycodone-induced Abcg2 up-regulation resulted in a significant (p < 0.05) decrease (∼2-fold) in brain/plasma ratios of mitoxantrone. These results highlight markers/mediators of neuronal responses and identify regulatory pathways involved in the pharmacological action of oxycodone. These results also identify genes that potentially modulate tolerance, dependence, immune response, and drug-drug interactions. Finally, our findings suggest that oxycodone-induced up-regulation of Abcg2 enhanced the efflux of the Abcg2 substrate, mitoxantrone, limiting its brain accumulation and resulting in an undesirable drug-drug interaction. Extrapolating these results to other Abcg2 substrates (e.g., daunorubicin and doxorubicin) indicates that the brain uptake of these agents may be affected if they are administered concomitantly with oxycodone. PMID:19786507

  18. Effects of repeated administration of methylphenidate on reproductive parameters in male rats.

    PubMed

    Montagnini, Bruno Garcia; Silva, Luiza Sienna; dos Santos, Alice Hartmann; Anselmo-Franci, Janete Aparecida; Fernandes, Glaura Scantamburlo Alves; Mesquita, Suzana de Fátima Paccola; Gerardin, Daniela Cristina Ceccatto

    2014-06-22

    Methylphenidate (MPH) is a psychostimulant drug which acts by blocking the dopamine and norepinephrine transporters and is the main drug used to treat attention deficit hyperactivity disorder in children and adolescents. During puberty, changes in neurotransmitter systems (including dopaminergic system) are engaged on the release of gonadal hormones and the development of cephalic structures responsible for reproductive function. This study investigated the effects of repeated treatment with methylphenidate during development on reproductive parameters of adult male rats. Wistar rats received MPH 2.5 mg/kg, MPH 5.0 mg/kg, or distilled water (gavage) from postnatal day (PND) 21 to PND 60. At PND 100, an increase in percentage of abnormal tail morphology sperm in MPH 2.5 and increase in testicular interstitial tissue volume in MPH groups as well as in the number of type A spermatogonia in MPH 5.0 group were observed. This study demonstrated that repeated administration of methylphenidate during periods corresponding childhood to early adulthood interfered on testicular function in rats at adult life. PMID:24866909

  19. Circadian Phase-Shifting Effects of Repeated Ramelteon Administration in Healthy Adults

    PubMed Central

    Richardson, Gary S.; Zee, Phyllis C.; Wang-Weigand, Sherry; Rodriguez, Laura; Peng, Xuejun

    2008-01-01

    Study Objectives: To assess the ability of repeated daily oral ramelteon to facilitate re-entrainment of human circadian rhythms after an imposed phase advance of the sleep-wake cycle. Methods: A total of 75 healthy adult volunteers aged 18–45 years remained in a sleep laboratory for 6 days and 5 nights; a 5-h phase advance in their sleep-wake cycle was imposed under dim-light conditions. Oral ramelteon (1, 2, 4, or 8 mg once daily for 4 days) or placebo was administered 30 min before bedtime. The primary endpoint was the phase of the circadian rhythm as assessed by the time at which salivary melatonin concentrations declined below 3 pg/mL after morning awakening (dim-light melatonin offset [DLMoff]). Results: After 4 days of once-daily treatment, participants receiving 1, 2, or 4 mg ramelteon exhibited statistically significant phase shifts in DLMoff of −88.0 (16.6), −80.5 (14.8), and −90.5 (15.2) minutes respectively, versus −7.1 (18.6) minutes for placebo (least-squares mean(SEM), p = 0.002, p = 0.003, p = 0.001, respectively). Change in DLMoff for the 8 mg dose of ramelteon, −27.9 (16.4) minutes, was not significantly different than that for placebo (p = 0.392). Conclusions: Ramelteon (1, 2, or 4 mg per day) administered before bedtime significantly advanced the phase of the circadian rhythm after a 5-h phase advance in the sleep-wake cycle. These findings suggest that ramelteon has potential as a specific therapy for circadian rhythm sleep disorders. Citation: Richardson GS; Zee PC; Wang-Weigand S; Rodriguez L; Peng X. Circadian phase-shifting effects of repeated ramelteon administration in healthy adults. J Clin Sleep Med 2008;4(5):456–461. PMID:18853704

  20. Effects of exercise conditioning on thermoregulatory responses to repeated administration of chlorpyrifos.

    PubMed

    Rowsey, Pamela Johnson; Metzger, Bonnie L; Carlson, John; Gordon, Christopher J

    2003-05-01

    Little is known about the effects of physical activity (i.e., exercise training) on susceptibility to environmental toxicants. Chlorpyrifos (CHP), an organophosphate (OP) insecticide, affects thermoregulation, causing an acute period of hypothermia followed by a delayed fever. Since exercise conditioning alters the thermoregulatory responses of rodents, this study examined whether exercise training would alter the thermoregulatory response to repeated CHP administration in the female Sprague-Dawley rat. Core temperature (T(c)) and motor activity (MA) were monitored by radiotelemetry in rats housed at an ambient temperature (T(a)) of 22 degrees C. The rats either were provided with continuous access to running wheels (exercise group) or were housed in standard cages without wheels (sedentary group). The exercise group rats ran predominantly at night with an average of 7.6 km/24h. After 8 weeks the rats in both groups were gavaged daily with corn oil or 10mg/kg CHP (dissolved in corn oil) for 4 days. CHP induced an immediate hypothermic response followed by a delayed fever throughout the next day in the sedentary group rats after the first three doses of CHP. The exercise group rats showed no hypothermia after the first dose of CHP. However, they became hypothermic after the second and third doses of CHP. The exercise group rats developed a smaller daytime fever after each dose of CHP compared to the sedentary group rats. Overall, exercise training attenuated the hypothermic and febrile effects of repeated CHP. Thus, the data suggest that a sedentary lifestyle may increase the sensitivity to OP insecticides. Exercise training was also associated with a more rapid recovery of plasma cholinesterase activity. PMID:12706752

  1. Repeated administration of an acetylcholinesterase inhibitor attenuates nicotine taking in rats and smoking behavior in human smokers.

    PubMed

    Ashare, R L; Kimmey, B A; Rupprecht, L E; Bowers, M E; Hayes, M R; Schmidt, H D

    2016-01-01

    Tobacco smoking remains the leading cause of preventable death worldwide and current smoking cessation medications have limited efficacy. Thus, there is a clear need for translational research focused on identifying novel pharmacotherapies for nicotine addiction. Our previous studies demonstrated that acute administration of an acetylcholinesterase inhibitor (AChEI) attenuates nicotine taking and seeking in rats and suggest that AChEIs could be repurposed for smoking cessation. Here, we expand upon these findings with experiments designed to determine the effects of repeated AChEI administration on voluntary nicotine taking in rats as well as smoking behavior in human smokers. Rats were trained to self-administer intravenous infusions of nicotine (0.03 mg kg(-1) per 0.59 ml) on a fixed-ratio-5 schedule of reinforcement. Once rats maintained stable nicotine taking, galantamine or donepezil was administered before 10 consecutive daily nicotine self-administration sessions. Repeated administration of 5.0 mg kg(-1) galantamine and 3.0 mg kg(-1) donepezil attenuated nicotine self-administration in rats. These effects were reinforcer-specific and not due to adverse malaise-like effects of drug treatment as repeated galantamine and donepezil administration had no effects on sucrose self-administration, ad libitum food intake and pica. The effects of repeated galantamine (versus placebo) on cigarette smoking were also tested in human treatment-seeking smokers. Two weeks of daily galantamine treatment (8.0 mg (week 1) and 16.0 mg (week 2)) significantly reduced smoking rate as well as smoking satisfaction and reward compared with placebo. This translational study indicates that repeated AChEI administration reduces nicotine reinforcement in rats and smoking behavior in humans at doses not associated with tolerance and/or adverse effects. PMID:26784967

  2. Determination of co-administrated opioids and benzodiazepines in urine using column-switching solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    PubMed

    Xiong, Lingjuan; Wang, Rong; Liang, Chen; Teng, Xiaomei; Jiang, Fengli; Zeng, Libo; Ye, Haiying; Ni, Chunfang; Yuan, Xiaoliang; Rao, Yulan; Zhang, Yurong

    2015-05-22

    Co-administration of opioids with benzodiazepines is very common around the world. A semi-automated method was developed for the determination of four opioids and two benzodiazepines as well as their metabolites (including glucuronide metabolites) in human urine, based on on-line column-switching-solid-phase extraction (CS-SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CS-SPE was performed by loading 200μL of urine sample to an Oasis HLB cartridge. Detection was achieved using a LC-MS/MS system equipped with an electrospray ionization source (ESI). For unequivocal identification and confirmation, two selected reaction monitoring transitions were registered for each compound, and no co-elution of interferences was observed at the expected retention time. Significant ion suppressions were observed for most analytes during chromatographic runs, but isotope-labeled internal standards (ISs) were used and found to be useful to compensate for the determination error caused by the matrix effect. The assay's linearity ranged from 1-20ng/mL to 800-1000ng/mL for 23 compounds, except for lorazepam (LOR), whose linearity was in the range of 1-100ng/mL. This method showed to be precise and accurate. The relative standard deviation (RSD) % values of within-run precision, between-run precision and total precision were not greater than 10.4% (n=3), 12.9% (n=5) and 15.1% (n=15), respectively. Accuracy values were in the range of 87.5-110%. Limits of detection (LODs) ranged from 0.2ng/mL to 5ng/mL, and limits of quantification (LOQs) ranged from 1ng/mL to 20ng/mL. The method was applied to the assay of 12 samples from forensic cases, which exemplified the co-administration of benzodiazepines (BZDs) by some heroin abusers. This method was of high sensitivity, selectivity and reliability, minimum sample manipulation, semi-automation, and fairly high throughput (analysis time per sample was 20min). The method developed will be useful for the detection of co-administrated

  3. Hyperintense Dentate Nuclei on T1-Weighted MRI: Relation to Repeat Gadolinium Administration

    PubMed Central

    Adin, M.E.; Kleinberg, L.; Vaidya, D.; Zan, E.; Mirbagheri, S.; Yousem, D.M.

    2016-01-01

    BACKGROUND AND PURPOSE A hyperintense appearance of the dentate nucleus on T1-weighted MR images has been related to various clinical conditions, but the etiology remains indeterminate. We aimed to investigate the possible associations between a hyperintense appearance of the dentate nucleus on T1-weighted MR images in patients exposed to radiation and factors including, but not limited to, the cumulative number of contrast-enhanced MR images, amount of gadolinium administration, dosage of ionizing radiation, and patient demographics. MATERIALS AND METHODS The medical records of 706 consecutive patients who were treated with brain irradiation at The Johns Hopkins Medical Institutions between 1995 and 2010 were blindly reviewed by 2 readers. RESULTS One hundred eighty-four subjects were included for dentate nuclei analysis. Among the 184 subjects who cumulatively underwent 2677 MR imaging studies following intravenous gadolinium administration, 103 patients had hyperintense dentate nuclei on precontrast T1-weighted MR images. The average number of gadolinium-enhanced MR imaging studies performed in the group with normal dentate nuclei was significantly lower than that of the group with hyperintense dentate nuclei. The average follow-up time was 62.5 months. No significant difference was observed between hyperintense and normal dentate nuclei groups in terms of exposed radiation dose, serum creatinine and calcium/phosphate levels, patient demographics, history of chemotherapy, and strength of the scanner. No dentate nuclei abnormalities were found on the corresponding CT scans of patients with hyperintense dentate nuclei (n = 44). No dentate nuclei abnormalities were found in 53 healthy volunteers. CONCLUSIONS Repeat performance of gadolinium-enhanced studies likely contributes to a long-standing hyperintense appearance of dentate nuclei on precontrast T1-weighted-MR images. PMID:26294649

  4. Pharmacokinetics and pharmacodynamics following single and repeated nightly administrations of loprazolam, a new benzodiazepine hypnotic.

    PubMed Central

    McInnes, G T; Bunting, E A; Ings, R M; Robinson, J; Ankier, S I

    1985-01-01

    The pharmacokinetics of oral loprazolam and pharmacodynamic responses on the morning following nightly drug administration were examined after single and after seven consecutive 1 mg doses in six non-fasting healthy subjects. The serum concentration-time profiles for unchanged loprazolam measured by a specific high pressure liquid chromatography/gas chromatography (h.p.l.c./g.c.) method and for benzodiazepine material measured by radioimmunoassay (RIA) were qualitatively similar although RIA levels were consistently higher. Approximate elimination half-life of unchanged loprazolam after single doses was 8.0 h. For RIA measured material, approximate half-life was 11.7 h following acute administration and 12.8 h after seven consecutive doses. Compared to results after single doses, maximum serum concentration and AUC were greater following 1 week's treatment. Using RIA results, the increases were 27.2% (95% CL 6.9 to 47.4%) and 35.1% (95% CL 15.8 to 54.3%) respectively and using h.p.l.c./g.c. data, 11% (95% CL - 22.6% to 44.5%) and 41% (95% CL - 50.9 to 133.0%). After repeated doses of loprazolam, there were no significant changes with respect to results after single doses in psychomotor function assessed objectively by critical flicker fusion threshold or choice reaction time, or in sleep quality or behaviour on awakening assessed subjectively by 10 cm analogue scales. Mean time to maximum serum concentration was 4.95 h with considerable inter-individual variability (range 1-12 h) and there was a lag time of 1-1.5 h before drug was detectable in blood.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2860916

  5. Endogenous opioids and reward.

    PubMed

    Van Ree, J M; Niesink, R J; Van Wolfswinkel, L; Ramsey, N F; Kornet, M M; Van Furth, W R; Vanderschuren, L J; Gerrits, M A; Van den Berg, C L

    2000-09-29

    The discovery of endogenous opioids has markedly influenced the research on the biology of addiction and reward brain processes. Evidence has been presented that these brain substances modulate brain stimulation reward, self-administration of different drugs of abuse, sexual behaviour and social behaviour. There appears to be two different domains in which endogenous opioids, present in separate and distinct brain regions, are involved. One is related to the modulation of incentive motivational processes and the other to the performance of certain behaviours. It is concluded that endogenous opioids may play a role in the vulnerability to certain diseases, such as addiction and autism, but also when the disease is present, such as alcoholism. PMID:11033317

  6. Lymphoid follicle destruction and immunosuppression after repeated CpG oligodeoxynucleotide administration.

    PubMed

    Heikenwalder, Mathias; Polymenidou, Magdalini; Junt, Tobias; Sigurdson, Christina; Wagner, Hermann; Akira, Shizuo; Zinkernagel, Rolf; Aguzzi, Adriano

    2004-02-01

    DNA containing unmethylated cytidyl guanosyl (CpG) sequences, which are underrepresented in mammalian genomes but prevalent in prokaryotes, is endocytosed by cells of the innate immune system, including macrophages, monocytes and dendritic cells, and activates a pathway involving Toll-like receptor-9 (TLR9). CpG-containing oligodeoxynucleotides (CpG-ODN) are potent stimulators of innate immunity, and are currently being tested as adjuvants of antimicrobial, antiallergic, anticancer and antiprion immunotherapy. Little is known, however, about the consequences of repeated CpG-ODN administration, which is advocated for some of these applications. Here we report that daily injection of 60 microg CpG-ODN dramatically alters the morphology and functionality of mouse lymphoid organs. By day 7, lymphoid follicles were poorly defined; follicular dendritic cells (FDC) and germinal center B lymphocytes were suppressed. Accordingly, CpG-ODN treatment for > or =7 d strongly reduced primary humoral immune responses and immunoglobulin class switching. By day 20, mice developed multifocal liver necrosis and hemorrhagic ascites. All untoward effects were strictly dependent on CpG and TLR9, as neither the CpG-ODN treatment of Tlr9(-/-) mice nor the repetitive challenge of wild-type mice with nonstimulatory ODN (AT-ODN) or with the TLR3 agonist polyinosinic:cytidylic acid (polyI:C) were immunotoxic or hepatotoxic. PMID:14745443

  7. In vitro interactions with repeated grapefruit juice administration--to peel or not to peel?

    PubMed

    Brill, Shlomo; Zimmermann, Christian; Berger, Karin; Drewe, Juergen; Gutmann, Heike

    2009-03-01

    Interactions of acutely administered grapefruit juice (GFJ) with cytochrome P450 isoform 3A4 (CYP3A4) and P-glycoprotein (Pgp) function are well established. In this study, we investigated in vitro the effect of repeated administration of GFJ and its major constituents (the flavonoid naringin, its aglycone naringenin and the furanocoumarin bergamottin) on mRNA expression of MDR1 and CYP3A4 in LS180 cells. Since the bergamottin content is higher in the peel than in the fruit, we compared GFJ containing peel (GFJP+) with juice without any peel extract (GFJP-). GFJP- (1%) showed no significant effect on MDR1 and CYP3A4 mRNA expression, whereas 1% GFJP+ increased expression of MDR1 3.7-fold (P<0.01) and CYP3A4 2.3-fold (P<0.05). Of the tested constituents, only 10 microM bergamottin and 200 microM naringenin induced MDR1 mRNA levels 2.9- and 4.0-fold, respectively (P<0.01 for both), and CYP3A4 mRNA levels 3.2- and 15.6-fold (P<0.01 for both), respectively. Western blot analysis and rhodamine 123 uptake experiments partly confirmed these findings on the protein and the functional level. In summary, GFJ containing no peel extract may have a lower potential for interactions with CYP3A4 or P-glycoprotein. PMID:19148864

  8. Repeated Administration of Hyaluronic Acid Coated Liposomes with Improved Pharmacokinetics and Reduced Immune Response.

    PubMed

    Zhang, Quan; Deng, Caifeng; Fu, Yao; Sun, Xun; Gong, Tao; Zhang, Zhirong

    2016-06-01

    PEGylated liposomes (PEG-Lip) have been widely used as a drug carrier for their good stealth property in blood circulation. However, the second injection of PEG-Lip was reported to result in the accelerated blood clearance (ABC) phenomenon and trigger hypersensitivity reactions in sensitive individuals for its complement activation effect. To avoid adverse immune responses, HA was selected to modify liposomes to afford HA modified liposomes (HA-Lip). Repeated administrations of PEG-Lip and HA-Lip were performed in rats. Our results showed that PEG-Lip induced the ABC phenomenon accompanied by a greatly increased accumulation of PEG-Lip in the liver. In contrast, HA-Lip showed good stealth property without inducing either the ABC phenomenon or an increase in liver uptake. Moreover, HA-Lip did not trigger complement activation in human serum in vitro and in rat blood in vivo. Consequently, HA modification represents a viable strategy to prolong the blood circulation time of liposomes without inducing the ABC phenomenon and adverse immune responses. PMID:27112287

  9. Opioid Use in Fibromyalgia: A Cautionary Tale.

    PubMed

    Goldenberg, Don L; Clauw, Daniel J; Palmer, Roy E; Clair, Andrew G

    2016-05-01

    Multiple pharmacotherapies are available for the treatment of fibromyalgia (FM), including opioid analgesics. We postulate that the mechanism of action of traditional opioids predicts their lack of efficacy in FM. Literature searches of the MEDLINE and Cochrane Library databases were conducted using the search term opioid AND fibromyalgia to identify relevant articles, with no date limitations set. Citation lists in returned articles and personal archives of references were also examined for additional relevant items, and articles were selected based on the expert opinions of the authors. We found no evidence from clinical trials that opioids are effective for the treatment of FM. Observational studies have found that patients with FM receiving opioids have poorer outcomes than patients receiving nonopioids, and FM guidelines recommend against the use of opioid analgesics. Despite this, and despite the availability of alternative Food and Drug Administration-approved pharmacotherapies and the efficacy of nonpharmacologic therapies, opioids are commonly used in the treatment of FM. Factors associated with opioid use include female sex; geographic variation; psychological factors; a history of opioid use, misuse, or abuse; and patient or physician preference. The long-term use of opioid analgesics is of particular concern in the United States given the ongoing public health emergency relating to excess prescription opioid consumption. The continued use of opioids to treat FM despite a proven lack of efficacy, lack of support from treatment guidelines, and the availability of approved pharmacotherapy options provides a cautionary tale for their use in other chronic pain conditions. PMID:26975749

  10. Use of Remifentanil in a Novel Clinical Paradigm to Characterize Onset and Duration of Opioid Blockade by Samidorphan, a Potent μ-Receptor Antagonist.

    PubMed

    Shram, Megan J; Silverman, Bernard; Ehrich, Elliot; Sellers, Edward M; Turncliff, Ryan

    2015-06-01

    A novel clinical study design was used to evaluate the blockade of a selective short-acting μ-opioid agonist (remifentanil) in 24 opioid-experienced subjects. Samidorphan (3-carboxamido-4-hydroxynaltrexone) is a novel opioid modulator with μ-antagonist properties. Objective (pupil diameter) and subjective (visual analog scale) responses to repeated remifentanil and saline infusion challenges were assessed after single oral administration of placebo (day 1) and samidorphan (day 2). Complete blockade persisted with samidorphan for 24 hours for pupil miosis and 48 hours for the drug liking visual analog scale. Samidorphan effects persisted beyond measurable samidorphan exposure (t½ = 7 hours). Samidorphan was associated with complete blockade of remifentanil, and the duration supports daily administration. This study used a novel approach with multiple administrations of remifentanil to successfully demonstrate a durable effect with samidorphan and a rapid and potent blockade of physiological and subjective μ-opioid effects. PMID:25928699

  11. Use of Remifentanil in a Novel Clinical Paradigm to Characterize Onset and Duration of Opioid Blockade by Samidorphan, a Potent μ-Receptor Antagonist

    PubMed Central

    Shram, Megan J.; Silverman, Bernard; Ehrich, Elliot; Sellers, Edward M.; Turncliff, Ryan

    2015-01-01

    Abstract A novel clinical study design was used to evaluate the blockade of a selective short-acting μ-opioid agonist (remifentanil) in 24 opioid-experienced subjects. Samidorphan (3-carboxamido-4-hydroxynaltrexone) is a novel opioid modulator with μ-antagonist properties. Objective (pupil diameter) and subjective (visual analog scale) responses to repeated remifentanil and saline infusion challenges were assessed after single oral administration of placebo (day 1) and samidorphan (day 2). Complete blockade persisted with samidorphan for 24 hours for pupil miosis and 48 hours for the drug liking visual analog scale. Samidorphan effects persisted beyond measurable samidorphan exposure (t½ = 7 hours). Samidorphan was associated with complete blockade of remifentanil, and the duration supports daily administration. This study used a novel approach with multiple administrations of remifentanil to successfully demonstrate a durable effect with samidorphan and a rapid and potent blockade of physiological and subjective μ-opioid effects. PMID:25928699

  12. Adjuncts to opioid therapy.

    PubMed

    Goldstein, Frederick J

    2002-09-01

    Administration of opioids to alleviate moderate to severe acute pain and chronic cancer pain is an established management process. However, advancements in clinical pharmacologic research have shown that opioids are also effective in chronic noncancerous pain. Many patients properly treated for prolonged periods with opioids develop tolerance and subsequently, physical dependence. This process is not necessarily harmful to the patient and will not cause the patient to develop an addiction (properly defined as psychologic dependence). For many patients who have been on opioid therapy for months or years, analgesic effectiveness tragically becomes less. In addition, opioid-induced constipation can be severe and cause pain; patients do not develop tolerance to this adverse reaction. Therefore, such issues become a management problem and require additional intervention. Currently, many different classes of drugs can serve as effective adjuncts to opioids for treatment of pain. Adding adjunctive medication to opioid therapy improves pain management primarily by nonopioid mechanisms of action. Clinical outcomes of such combinations include greater analgesia and attenuation of opioid-induced adverse reactions such as nausea and vomiting, constipation, sedation, and respiratory depression. Adjuncts include acetaminophen, antiarrhythmics, anticonvulsants, antidepressants, antipsychotics, baclofen, benzodiazepines, capsaicin, calcium channel blockers, clonidine hydrochloride, central nervous system stimulants, corticosteroids, local anesthetics, N-methyl-D-aspartate receptor antagonists, nonsteroidal antiinflammatory drugs, pentoxifylline, and scopolamine. Some adjuncts (eg, acetaminophen) are routinely used today, whereas others (eg, nifedipine [calcium channel blocker]) are used on a limited basis but have great potential for more widespread application. All professionals (eg, nurses, pharmacists, physicians, physicians' assistants, social workers, members of the clergy

  13. Opioid use and dropout in patients receiving oral naltrexone with or without single administration of injection naltrexone

    PubMed Central

    Sullivan, Maria A.; Bisaga, Adam; Glass, Andrew; Mishlen, Kaitlyn; Pavlicova, Martina; Carpenter, Kenneth M.; Mariani, John J; Levin, Frances R.; Nunes, Edward V.

    2015-01-01

    Background Adherence to oral naltrexone has been poor and can be improved somewhat with behavioral therapy. We compared Behavioral Naltrexone Therapy (BNT) to Compliance Enhancement (CE) and tested efficacy of single-dose injection naltrexone (XR-NTX; 384 mg) with behavioral therapies at further improving aherence to oral naltrexone. Methods A 24-week, randomized, placebo-controlled trial (N=125) compared four treatment conditions following inpatient detoxification and oral naltrexone induction: (1) BNT+XR-NTX; (2) BNT+ placebo injection; (3) CE+ XR-NTX; and (4) CE+placebo injection. All participants were maintained on oral naltrexone throughout the trial. Primary outcome was retention in treatment. Results Of 89 randomized participants, 78.7% (70/89) completed 4 weeks, 58.2% (54/89) completed 8 weeks, 47.2% (42/89) completed 12 weeks, and 25.8% (23/89) completed 24 weeks. A Cox proportional hazards regression modeled time to dropout as a function of treatment condition, baseline opioid dependence severity (bags per day of heroin use), and their interaction. Interaction of conditions by baseline severity was significant (X23 = 9.19, p = .027). For low-severity patients (<6 bags/day), retention was highest in the BNT-XRNTX group (60% at 6 months), as hypothesized. For high-severity (> 6 bags/day) patients, BNT-XR-NTX did not perform as well, due to high early attrition. Conclusion For low-severity heroin users, single-dose XR-NTX improved long-term treatment retention when combined with behavioral therapy. In higher-severity opioid-dependent patients, XR-NTX was less helpful, perhaps because, combined with oral naltrexone, it produced higher blood levels and more withdrawal discomfort. When cost considerations recommend oral naltrexone following XR-NTX, the latter should be phased in slowly. PMID:25555621

  14. [Pharmacotherapy of cancer pain : 2. Use of opioids.].

    PubMed

    Cherny, N I; Portenoy, R K; Raber, M; Zenz, M

    1995-01-01

    The adequate use of opioids in the treatment of chronic cancer pain requires sound knowledge of selection criteria for the various opioids, the routes of administration, dosages, dosing schemes and possible side effects. Drug selection depends on the intensity of pain rather than on the specific pathophysiology. Mild to moderate pain can often be treated effectively by so-called "weak" opioids. These include codeine, dihydrocodeine and dextropropoxyphene. Non-opioid analgesics, like acetylsalicylic acid or paracetamol can be added according to the "analgesic ladder" proposed by the World Health Organization (WHO). If adequate pain relief is not achieved "strong" opioids are required. The route of administration that is the safest and the least invasive for the patient should be chosen. Non-invasive (oral, rectal, sublingual, transdermal and intranasal) and invasive routes (intravenous, subcutaneous, spinal and epidural) are available (Table 8). Noninvasive routes are preferred, and most patients can be maintained on oral opioids. Alternatively, in some patients pain can be managed by the sublingual (buprenorphine) route. A transdermal preparation exists for fentanyl, but has not yet been approved for the German market. If the oral route cannot be used or if large doses are required, it will be necessary to change to an invasive route. Intravenous bolus injections provide the fastest onset of analgesic action. They are mostly used in very severe pain. Repeated injections can be avoided by using intravenous or subcutaneous infusions. Various types of pumps delivering analgesics at constant basal infusion rates with the option of rescue doses in case of breakthrough pain are available (patient-controlled analgesia=PCA). Opioids frequently used for s. c. infusion are morphine and hydromorphone. Adjuvant drugs (antiemetics, anxiolytics) can be added. Epidural or intrathecal administration of opioids should only be used in intractable pain or if severe side effects, such

  15. Loss of parvalbumin-immunoreactivity in mouse brain regions after repeated intermittent administration of esketamine, but not R-ketamine.

    PubMed

    Yang, Chun; Han, Mei; Zhang, Ji-Chun; Ren, Qian; Hashimoto, Kenji

    2016-05-30

    Clinical use of the rapid antidepressant drug ketamine is limited, due to psychotomimetic side effects. R-ketamine appears to be a potent, long-lasting and safer antidepressant, relative to S-ketamine (esketamine), since it is free of psychotomimetic side effects. Repeated, intermittent administration of esketamine (10mg/kg, once per week for 8-weeks), but not R-ketamine, caused loss of parvalbumin (PV)-immunoreactivity in the medial prefrontal cortex and hippocampus of mouse brains, regions associated with psychosis. This study suggests that repeated intermittent use of R-ketamine is safer than esketamine in the treatment of depression. PMID:27043274

  16. The evolution of vertebrate opioid receptors

    PubMed Central

    Stevens, Craig W.

    2011-01-01

    The proteins that mediate the analgesic and other effects of opioid drugs and endogenous opioid peptides are known as opioid receptors. Opioid receptors consist of a family of four closely-related proteins belonging to the large superfamily of G-protein coupled receptors. The three types of opioid receptors shown unequivocally to mediate analgesia in animal models are the mu (MOR), delta (DOR), and kappa (KOR) opioid receptor proteins. The role of the fourth member of the opioid receptor family, the nociceptin or orphanin FQ receptor (ORL), is not as clear as hyperalgesia, analgesia, and no effect was reported after administration of ORL agonists. There are now cDNA sequences for all four types of opioid receptors that are expressed in the brain of six species from three different classes of vertebrates. This review presents a comparative analysis of vertebrate opioid receptors using bioinformatics and data from recent human genome studies. Results indicate that opioid receptors arose by gene duplication, that there is a vector of opioid receptor divergence, and that MOR shows evidence of rapid evolution. PMID:19273128

  17. Modulation of pre- and postsynaptic dopamine D2 receptor function by the selective kappa-opioid receptor agonist U69593.

    PubMed

    Acri, J B; Thompson, A C; Shippenberg, T

    2001-03-15

    The repeated administration of selective kappa-opioid receptor agonists prevents the locomotor activation produced by acute cocaine administration and the development of cocaine-induced behavioral sensitization. Previous studies have shown that dopamine (DA) D2 autoreceptors modulate the synthesis and release of DA in the striatum. Evidence that kappa agonist treatment downregulates DA D2 receptors in this same brain region has recently been obtained. Accordingly, the present studies were undertaken to examine the influence of repeated kappa-opioid receptor agonist administration on pre- and postsynaptic DA D2 receptor function in the dorsal striatum using pre- and postsynaptic receptor-selective doses of quinpirole. Rats were injected once daily with the selective kappa-opioid receptor agonist U69593 (0.16-0.32 mg/kg s.c.) or vehicle for 3 days. Microdialysis studies assessing basal and quinpirole-evoked (0.05 mg/kg s.c.) DA levels were conducted 2 days later. Basal and quinpirole-stimulated locomotor activity were assessed in a parallel group of animals. The no-net flux method of quantitative microdialysis revealed no effect of U69593 on basal DA dynamics, in that extracellular DA concentration and extraction fraction did not differ in control and U69593-treated animals. Acute administration of quinpirole significantly decreased striatal DA levels in control animals, but in animals treated with U69593, the inhibitory effects of quinpirole were significantly reduced. Quinpirole produced a dose-related increase in locomotor activity in control animals, and this effect was significantly attenuated in U69593-treated animals. These data reveal that prior repeated administration of a selective kappa-opioid receptor agonist attenuates quinpirole-induced alterations in DA neurotransmission and locomotor activity. These results suggest that both pre- and postsynaptic striatal DA D2 receptors may be downregulated following repeated kappa-opioid receptor agonist

  18. Comparison of a drug versus money and drug versus drug self-administration choice procedure with oxycodone and morphine in opioid addicts.

    PubMed

    Comer, Sandra D; Metz, Verena E; Cooper, Ziva D; Kowalczyk, William J; Jones, Jermaine D; Sullivan, Maria A; Manubay, Jeanne M; Vosburg, Suzanne K; Smith, Mary E; Peyser, Deena; Saccone, Phillip A

    2013-09-01

    This double-blind, placebo-controlled study investigated the effects of oral morphine (0, 45, 135 mg/70 kg) and oral oxycodone (0, 15, 45 mg/70 kg) on buprenorphine-maintained opioid addicts. As a 3: 1 morphine : oxycodone oral dose ratio yielded equivalent subjective and physiological effects in nondependent individuals, this ratio was used in the present study. Two self-administration laboratory procedures - that is, a drug versus money and a drug versus drug procedure - were assessed. Study participants (N=12) lived in the hospital and were maintained on 4 mg/day sublingual buprenorphine. When participants chose between drug and money, money was preferred over all drug doses; only high-dose oxycodone was self-administered more than placebo. When participants chose between drug and drug, both drugs were chosen more than placebo, high doses of each drug were chosen over low doses, and high-dose oxycodone was preferred over high-dose morphine. The subjective, performance-impairing, and miotic effects of high-dose oxycodone were generally greater than those of high-dose morphine. The study demonstrated that a 3: 1 oral dose ratio of morphine : oxycodone was not equipotent in buprenorphine-dependent individuals. Both self-administration procedures were effective for assessing the relative reinforcing effects of drugs; preference for one procedure should be driven by the specific research question of interest. PMID:23839029

  19. Comparison of a drug versus money and drug versus drug self-administration choice procedure with oxycodone and morphine in opioid addicts

    PubMed Central

    Comer, Sandra D; Metz, Verena E; Cooper, Ziva D; Kowalczyk, William J; Jones, Jermaine D; Sullivan, Maria A; Manubay, Jeanne M; Vosburg, Suzanne K; Smith, Mary E; Peyser, Deena; Saccone, Phillip A

    2014-01-01

    This double-blind, placebo-controlled study investigated effects of oral morphine (0, 45, 135 mg/70kg) and oral oxycodone (0, 15, 45 mg/70kg) in buprenorphine-maintained opioid addicts. Since a 3:1 morphine:oxycodone dose ratio had yielded equivalent subjective and physiological effects in non-dependent individuals, this ratio was used in the present study. Two self-administration laboratory procedures, i.e. a drug vs. money and a drug vs. drug procedure, were assessed. Study participants (N=12) lived in the hospital and were maintained on 4 mg/day sublingual buprenorphine. When participants chose between drug and money, money was preferred over all drug doses; only high-dose oxycodone was self-administered more than placebo. When participants chose between drug and drug, both drugs were chosen more than placebo, high doses of each drug were chosen over low doses, and high-dose oxycodone was preferred over high-dose morphine. The subjective, performance-impairing, and miotic effects of high-dose oxycodone were generally greater compared to high-dose morphine. The study demonstrated that a 3:1 dose ratio of morphine:oxycodone was not equipotent in buprenorphine-dependent subjects. Both self-administration procedures were effective for assessing the relative reinforcing effects of drugs; preference for one procedure should be driven by the specific research question of interest. PMID:23839029

  20. Dopamine and serotonin imbalances in the left anterior cingulate and pyriform cortices following the repeated intermittent administration of cocaine.

    PubMed

    Heidbreder, C A; Oertle, T; Feldon, J

    1999-03-01

    Studies on the neurobiology of cocaine abuse suggest that cocaine directly modifies the activity of dopamine neurons projecting from the dopamine-synthesizing cells of the ventral tegmental area to the nucleus accumbens. The repeated use of cocaine produces persistent adaptations within the mesocorticolimbic system and the resulting changes in monoamine neurotransmission may lead to behavioral sensitization. The present series of experiments sought to determine the effects of the repeated, intermittent challenge that took place two days after discontinuation of the pretreatment regimen; (ii) the ex vivo levels of biogenic monoamines, choline and acetylcholine in the nucleus accumbens, the dorsolateral caudate nucleus, as well as the anterior cingulate, frontal motor, frontal somatosensory and pyriform cortices; and (iii) the degree of neurochemical relationship between the left and right hemispheres. The repeated administration of cocaine produced sensitized behavioral responses to a subsequent challenge. Neurochemical correlates of repeated cocaine administration were observed at the cortical level and included a significant decrease in serotonin levels in the left anterior cingulate and pyriform cortices and an increase in dopamine metabolism in the left pyriform cortex. Furthermore, a shift in the interhemispheric coupling coefficient matrix for dopamine neurotransmission was observed in both the pyriform cortex and nucleus accumbens of cocaine-sensitized animals suggesting that, in these structures, the two hemispheres are operating independently. These results demonstrate that cocaine produces alterations in specific dopaminergic and serotonergic pathways that arise from the mesencephalon and project towards both the anterior cingulate and pyriform cortices. PMID:10199606

  1. Repeated cocaine administration increases B-cell leukemia/lymphoma 2 phosphorylation in the rat dorsal striatum.

    PubMed

    Ahn, Sung Min; Jang, Dong Hye; Choe, Eun Sang

    2010-01-01

    Protein phosphorylation caused by drug administration is a critical step in the regulation of behavioral alterations. This study was conducted to determine how repeated exposure to cocaine phosphorylates B-cell leukemia/lymphoma 2 (Bcl2), which may be responsible for the regulation of behavioral alterations in the rat dorsal striatum. The results revealed that repeated systemic injections of cocaine (20 mg/kg) once a day for 7 consecutive days increased the phosphorylation of Bcl2 at serine 70 (Bcl2-S70). However, this increase was reduced by the blockade of dopamine D1 receptors, group I metabotropic glutamate receptors (mGluRs), and N-methyl-D-aspartate (NMDA) receptors. In addition, elevation of behavioral locomotor activity after repeated exposure to cocaine was partially reduced by the inhibition of Bcl2. These data suggest that stimulation of dopamine D1 receptors, group I mGluRs, and NMDA receptors following repeated cocaine administration is necessary for the induction of Bcl2-S70 phosphorylation, which contributes to the expression of behavioral sensitization. PMID:19879923

  2. Short-term repeated corticosterone administration enhances glutamatergic but not GABAergic transmission in the rat motor cortex.

    PubMed

    Kula, Joanna; Blasiak, Anna; Czerw, Anna; Tylko, Grzegorz; Sowa, Joanna; Hess, Grzegorz

    2016-04-01

    It has been demonstrated that stress impairs performance of skilled reaching and walking tasks in rats due to the action of glucocorticoids involved in the stress response. Skilled reaching and walking are controlled by the primary motor cortex (M1); however, it is not known whether stress-related impairments in skilled motor tasks are related to functional and/or structural alterations within the M1. We studied the effects of single and repeated injections of corticosterone (twice daily for 7 days) on spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) recorded from layer II/III pyramidal neurons in ex vivo slices of the M1, prepared 2 days after the last administration of the hormone. We also measured the density of dendritic spines on pyramidal cells and the protein levels of selected subunits of AMPA, NMDA, and GABAA receptors after repeated corticosterone administration. Repeatedly administered corticosterone induced an increase in the frequency but not in the amplitude of sEPSCs, while a single administration had no effect on the recorded excitatory currents. The frequency and amplitude of sIPSCs as well as the excitability of pyramidal cells were changed neither after single nor after repeated corticosterone administration. Treatment with corticosterone for 7 days did not modify the density of dendritic spines on pyramidal neurons. Corticosterone influenced neither the protein levels of GluA1, GluA2, GluN1, GluN2A, and GluN2B subunits of glutamate receptors nor those of α1, β2, and γ2 subunits of the GABAA receptor. The increase in sEPSCs frequency induced by repeated corticosterone administration faded out within 7 days. These data indicate that prolonged administration of exogenous corticosterone selectively and reversibly enhances glutamatergic, but not GABAergic transmission in the rat motor cortex. Our results suggest that corticosterone treatment results in an enhancement of spontaneous glutamate release from

  3. Repeated administration of low-dose cisplatin in mice induces fibrosis.

    PubMed

    Sharp, Cierra N; Doll, Mark A; Dupre, Tess V; Shah, Parag P; Subathra, Marimuthu; Siow, Deanna; Arteel, Gavin E; Megyesi, Judit; Beverly, Levi J; Siskind, Leah J

    2016-03-15

    Cisplatin, a chemotherapeutic used for the treatment of solid cancers, has nephrotoxic side effects leading to acute kidney injury (AKI). Cisplatin cannot be given to patients that have comorbidities that predispose them to an increased risk for AKI. Even without these comorbidities, 30% of patients administered cisplatin will develop kidney injury, requiring the oncologist to withhold or reduce the next dose, leading to a less effective therapeutic regimen. Although recovery can occur after one episode of cisplatin-induced AKI, longitudinal studies have indicated that multiple episodes of AKI lead to the development of chronic kidney disease, an irreversible disease with no current treatment. The standard mouse model of cisplatin-induced AKI consists of one high dose of cisplatin (>20 mg/kg) that is lethal to the animal 3 days later. This model does not accurately reflect the dosing regimen patients receive nor does it allow for the long-term study of kidney function and biology. We have developed a repeated dosing model whereby cisplatin is given once a week for 4 wk. Comparison of the repeated dosing model with the standard dosing model demonstrated that inflammatory cytokines and chemokines were induced in the repeated dosing model, but levels of cell death were lower in the repeated dosing model. The repeated dosing model had increased levels of fibrotic markers (fibronectin, transforming growth factor-β, and α-smooth muscle actin) and interstitial fibrosis. These data indicate that the repeated dosing model can be used to study the AKI to chronic kidney disease progression as well as the mechanisms of this progression. PMID:26739893

  4. Neuraxial opioid-induced itch and its pharmacological antagonism.

    PubMed

    Ko, Mei-Chuan

    2015-01-01

    Given its profound analgesic nature, neuraxial opioids are frequently used for pain management. Unfortunately, the high incident rate of itch/pruritus after spinal administration of opioid analgesics reported in postoperative and obstetric patients greatly diminishes patient satisfaction and thus the value of the analgesics. Many endeavors to solve the mystery behind neuraxial opioid-induced itch had not been successful, as the pharmacological antagonism other than the blockade of mu opioid receptors remains elusive. Nevertheless, as the characteristics of all opioid receptor subtypes have become more understood, more studies have shed light on the potential effective treatments. This review discusses the mechanisms underlying neuraxial opioid-induced itch and compares pharmacological evidence in nonhuman primates with clinical findings across diverse drugs. Both nonhuman primate and human studies corroborate that mixed mu/kappa opioid partial agonists seem to be the most effective drugs in ameliorating neuraxial opioid-induced itch while retaining neuraxial opioid-induced analgesia. PMID:25861787

  5. Neuraxial Opioid-Induced Itch and Its Pharmacological Antagonism

    PubMed Central

    2015-01-01

    Given its profound analgesic nature, neuraxial opioids are frequently used for pain management. Unfortunately, the high incident rate of itch/pruritus after spinal administration of opioid analgesics reported in postoperative and obstetric patients greatly diminishes patient satisfaction and thus the value of the analgesics. Many endeavors to solve the mystery behind neuraxial opioid-induced itch had not been successful, as the pharmacological antagonism other than the blockade of mu opioid receptors remains elusive. Nevertheless, as the characteristics of all opioid receptor subtypes have become more understood, more studies have shed light on the potential effective treatments. This review discusses the mechanisms underlying neuraxial opioid-induced itch and compares pharmacological evidence in nonhuman primates with clinical findings across diverse drugs. Both nonhuman primate and human studies corroborate that mixed mu/kappa opioid partial agonists seem to be the most effective drugs in ameliorating neuraxial opioid-induced itch while retaining neuraxial opioid-induced analgesia. PMID:25861787

  6. Augmented behavioral response and enhanced synaptosomal calcium transport induced by repeated cocaine administration are decreased by calcium channel blockers

    PubMed Central

    Mills, K.; Ansah, T.A.; Ali, S.F.; Mukherjee, S.; Shockley, D.C.

    2009-01-01

    Recent studies suggest that calcium influx via L-type calcium channels is necessary for psychostimulant-induced behavioral sensitization. In addition, chronic amphetamine upregulates subtype Cav1.2-containing L-type calcium channels. In the present studies, we assessed the effect of calcium channel blockers (CCBs) on cocaine-induced behavioral sentitization and determined whether the functional activity of L-type calcium channels is altered after repeated cocaine administration. Rats were administered daily intraperitoneal injections of either flunarizine (40 mg/kg), diltiazem (40 mg/kg) or cocaine (20 mg/kg) and the combination of the CCB’s and cocaine for 30 days. Motor activities were monitored on Day 1, and every 6th day during the 30-day treatment period. Daily cocaine administration produced increased locomotor activity. Maximal augmentation of behavioral response to repeated cocaine administration was observed on Day 18. Flunarizine pretreatment abolished the augmented behavioral response to repeated cocaine administration while diltiazem was less effective. Measurement of tissue monoamine levels on Day 18 revealed cocaine-induced increases in DA and 5-HT in the nucleus accumbens. By contrast to behavioral response, diltiazem was more effective in attenuating increases in monoamine levels than flunarizine. Cocaine administration for 18 days produced increases in calcium-uptake in synaptosomes prepared from the nucleus accumbens and frontal cortex. Increases in calcium-uptake were abolished by flunarizine- and diltiazem-pretreatment. Taken together, the augmented cocaine-induced behavioral response on Day 18 may be due to increased calcium uptake in the nucleus accumbens leading to increased dopamine (DA) and serotonin (5-HT) release. Flunarizine and diltiazem attenuated the behavioral response by decreasing calcium uptake and decreasing neurochemical release. PMID:17689567

  7. Modulation of the behavioral and neurochemical effects of psychostimulants by kappa-opioid receptor systems.

    PubMed

    Shippenberg, T S; Chefer, V I; Zapata, A; Heidbreder, C A

    2001-06-01

    The repeated, intermittent use of cocaine and other drugs of abuse produces profound and often long-lasting alterations in behavior and brain chemistry. It has been suggested that these consequences of drug use play a critical role in drug craving and relapse to addiction. This article reviews the effects of psychostimulant administration on dopaminergic and excitatory amino acid neurotransmission in brain regions comprising the brain's motive circuit and provides evidence that the activation of endogenous kappa-opioid receptor systems in these regions opposes the behavioral and neurochemical consequences of repeated drug use. The role of this opioid system in mediating alterations in mood and affect that occur during abstinence from repeated psychostimulant use are also discussed. PMID:11458540

  8. EFFECT OF REPEATED ORGANOPHOSPHATE ADMINISTRATION ON CARBACHOL-STIMULATED PHOSPHOINSITIDE HYDROLYSIS IN RAT BRAIN

    EPA Science Inventory

    The effects of repeated exposure to two organophosphates on the turnover of phosphoinositides, the second messenger system coupled to the M1 and M3 subtypes of muscarinic receptors, were examined in rat hippocampus. epeated diisopropylfluorophosphate (DFP) exposure (0.2-0.8 mg/kg...

  9. EFFECT OF EPISODIC WEEKLY NICOTINE ADMINISTRATION ON REPEATED ACQUISITION IN RATS.

    EPA Science Inventory

    Our prior research showed both tolerance and sensitization to nicotine?s effects on motor activity with weekly dosing. This experiment determined the generality of this finding to conditioned behavior. After extended training on a repeated acquisition/performance schedule all ra...

  10. Effects of repeated oral corticosterone administration on performance and stress parameters of laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of repeated stress during rearing on performance and physiology of laying hens was studied using a corticosterone (Cort) model. 240 Hisex laying hens were reared in environmentally controlled battery cages. At 7, 11, and 15 wk of age they were exposed for 1 wk to the following treatments...

  11. Clinical pharmacology of non opioid analgesics in neonates.

    PubMed

    Allegaert, K; de Hoon, J; Van Overmeire, B; Devlieger, H

    2005-01-01

    An integrated approach of neonatal analgesia starts with the systematic evaluation of pain and should be followed by effective interventions, mainly based on the appropriate (i.e. safe and effective) administration of analgesics. In contrast to the more potent opioids, data on the pharmacokinetics and -dynamics of non-opioid analgesics in this specific population are still rare or even lacking. We therefore evaluated various aspects of developmental pharmacology of non-opioid analgesics (paracetamol, ibuprofen, acetylsalicyl acid) in neonates. We first performed a single dose propacetamol study in preterm and term neonates. Based on these preliminary findings, a repeated dose administration scheme was developed and tested and maturational aspects from preterm till teenage were documented. Although non-selective COX-inhibitors might be effective in the treatment of postoperative or inflammatory pain syndromes in neonates, potential efficacy should be balanced against the drugs' safety profile. Neonatal renal clearance strongly depends on glomerular filtration rate (GFR) and GFR itself strongly depends on the vaso-dilatative of prostaglandins on the afferent arterioli. We therefore evaluated the impact of the administration of ibuprofen or acetylsalicylic acid on renal clearance in preterm infants and hereby used amikacin clearance as a surrogate marker. We hereby documented the negative effect of ibuprofen on glomerular filtration rate in preterm infants up to 34 weeks and we were able to show that ibuprofen and acetylsalicylic acid had an equal impact on the glomerular filtration rate. PMID:16408826

  12. FDA Boxed Warning for Immediate-Release Opioids.

    PubMed

    Food And Drug Administration Public Health Service U S Department Of Health And Human Services

    2016-06-01

    On March 22, 2016, the Food and Drug Administration (FDA) announced enhanced warnings for immediate-release opioid pain medications related to risks of misuse, abuse, addiction, overdose, and death. The new safety warnings also added to all prescription opioid medications to inform prescribers and patients of additional risks related to opioid use. PMID:27301692

  13. Upregulation of the opioid receptor complex by the chronic administration of morphine: a biochemical marker related to the development of tolerance and dependence.

    PubMed

    Rothman, R B; Long, J B; Bykov, V; Xu, H; Jacobson, A E; Rice, K C; Holaday, J W

    1991-01-01

    Studies conducted after the development of the rapid filtration assay for opiate receptors, and before the recognition of multiple opioid receptors, failed to detect changes in opioid receptors induced by chronic morphine. Recent experiments conducted in our laboratories were designed to examine the hypothesis that only one of several opioid receptor types might be altered by chronic morphine. Using binding surface analysis and irreversible ligands to increase the "resolving power" of the ligand binding assay, the results indicated that chronic morphine increased both the Bmax and Kd of the opioid receptor complex, labeled with either [3H][D-Ala2,D-Leu5]enkephalin, [3H][D-Ala2-MePhe4,Gly-ol5]enkephalin or [3H]6-desoxy-6 beta-fluoronaltreone. In the present study rats were pretreated with drugs known to attenuate the development of tolerance and dependence [the irreversible mu-receptor antagonist, beta-funaltrexamine (beta-FNA), and the inhibitor of tryptophan hydroxylase, para-chlorophenylalanine], prior to subcutaneous implantation of morphine pellets. The results demonstrated that 1) unlike chronic naltrexone, beta-FNA failed to upregulate opioid receptors and 2) both beta-funaltrexamine and PCPA pretreatment attenuated the chronic morphine-induced increase in the Bmax, but not the Kd, of the opioid receptor complex. These results provide evidence that naltrex-one-induced upregulation of the opioid receptor complex might occur indirectly as a consequence of interactions at beta-funaltrexamine-insensitive opioid receptors and that morphine-induced upregulation (increased Bmax) of the opioid receptor complex is a relevant in vitro marker related to the development of tolerance and dependence. These data collectively support the hypothesis that endogenous antiopiate peptides play an important role in the development of tolerance and dependence to morphine. PMID:1646998

  14. Toxicology study assessing efficacy and safety of repeated administration of lipid/DNA complexes to mouse lung.

    PubMed

    Alton, E W F W; Boyd, A C; Cheng, S H; Davies, J C; Davies, L A; Dayan, A; Gill, D R; Griesenbach, U; Higgins, T; Hyde, S C; Innes, J A; McLachlan, G; Porteous, D; Pringle, I; Scheule, R K; Sumner-Jones, S

    2014-01-01

    For gene therapy to improve lung function in cystic fibrosis (CF) subjects, repeated administration of the gene transfer agent over the lifetime of patients is likely to be necessary. This requirement limits the utility of adenoviral and adeno-associated viral vectors (both previously evaluated in CF gene therapy trials) because of induced adaptive immune responses that render repeated dosing ineffective. For CF gene therapy trials, non-viral vectors are currently the only viable option. We previously showed that the cationic lipid formulation GL67A is the most efficient of several non-viral vectors analysed for airway gene transfer. Here, we assessed the efficacy and safety of administering 12 inhaled doses of GL67A complexed with pGM169, a CpG-free plasmid encoding human CFTR complementary DNA, into mice. We show that repeated administration of pGM169/GL67A to murine lungs is feasible, safe and achieves reproducible, dose-related and persistent gene expression (>140 days after each dose) using an aerosol generated by a clinically relevant nebuliser. This study supports progression into the first non-viral multidose lung trial in CF patients. PMID:24196086

  15. Constipation in people prescribed opioids

    PubMed Central

    2010-01-01

    Introduction Constipation is reported in 52% of people with advanced malignancy. This figure rises to 87% in people who are terminally ill and taking opioids. Constipation may be the most common adverse effect of opioids. There is no reason to believe that people with chronic non-malignant disease who take opioids will be any less troubled by this adverse effect. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of: oral laxatives, rectally applied medications, and opioid antagonists for constipation in people prescribed opioids? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2009 (BMJ 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). Results We found 23 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: arachis oil enemas, bisacodyl, co-danthrusate/co-danthramer, docusate, glycerol suppositories, ispaghula husk, lactulose, liquid paraffin, macrogols plus electrolyte solutions, magnesium salts, methylcellulose, opioid antagonists, phosphate enemas, senna, sodium citrate micro-enema, and sodium picosulfate. PMID:21718572

  16. Opioid and non-opioid mechanisms of footshock-induced analgesia: role of the spinal dorsolateral funiculus.

    PubMed

    Lewis, J W; Terman, G W; Watkins, L R; Mayer, D J; Liebeskind, J C

    1983-05-01

    Exposure to inescapable footshock causes either an opioid or non-opioid mediated analgesia in the rat depending on the temporal parameters of its administration. Lesions of the spinal dorsolateral funiculus significantly reduce both the opioid and non-opioid forms of this footshock-induced analgesia. Thus, these two neurochemically discrete pain-inhibitory systems appear to depend on the integrity of the same descending path, one known to be activated by morphine and by analgesic brain stimulation. PMID:6860939

  17. Treatment response after repeated administration of C1 esterase inhibitor for successive acute hereditary angioedema attacks.

    PubMed

    Craig, Timothy J; Bewtra, Againdra K; Hurewitz, David; Levy, Robyn; Janss, Gerti; Jacobson, Kraig W; Packer, Flint; Bernstein, Jonathan A; Rojavin, Mikhail A; Machnig, Thomas; Keinecke, Heinz-Otto; Wasserman, Richard L

    2012-01-01

    Placebo-controlled studies established the efficacy of replacement therapy with C1 esterase inhibitor (C1-INH) concentrate for treating single acute hereditary angioedema (HAE) attacks, but only limited data from prospective studies are available on repeated treatment of successive HAE attacks. This study evaluates the association between repeated treatments with 20 U/kg of C1-INH concentrate (Berinert; CSL Behring, Marburg, Germany) for HAE attacks at any body location and treatment response. In a post hoc analysis of an open-label extension study (International Multicenter Prospective Angioedema C1-INH Trial [I.M.P.A.C.T.2]), the association between repeated treatment with C1-INH and times to onset of symptom relief and complete resolution of HAE symptoms was assessed in patients who were treated for at least 15 attacks by linear regression on the ordinal attack number. Eighteen patients received C1-INH concentrate for at least 15 HAE attacks over a mean duration of 34 months. Demographic and baseline characteristics of these patients were similar to those of all patients in the study. The distribution of body locations and the intensity of HAE attacks were similar for each of the first 15 attacks and subsequent attacks. The extent of previous use of C1-INH concentrate had no effect on the time to onset of symptom relief, the time to complete resolution of HAE symptoms, or the time between attacks treated with C1-INH concentrate; the median of individual linear regression coefficients was not statistically significantly different from 0. Treatment with 20 U/kg of C1-INH concentrate provided consistent treatment response in patients treated for multiple successive HAE attacks at any body location. (Clinicaltrials.gov identifier: NCT00292981). PMID:22856636

  18. Sputum Tobramycin Concentrations in Cystic Fibrosis Patients with Repeated Administration of Inhaled Tobramycin

    PubMed Central

    Emerson, Julia; Moss, Richard; Genatossio, Alan; McNamara, Sharon; Burns, Jane L.; Anderson, Gail; Rosenfeld, Margaret

    2013-01-01

    Abstract Background Dosing of tobramycin solution for inhalation (TSI) in cystic fibrosis (CF) patients was based on single-dose pharmacokinetic studies. This investigation was prompted by evidence of possible antibiotic accumulation in respiratory secretions with repeated dosing. The objectives were to evaluate whether tobramycin accumulates in respiratory secretions with repeated inhalation, compare total and biologically active tobramycin concentrations in CF sputum, and evaluate sputum induction for obtaining secretions for drug concentration assay. Methods : Individuals with CF ≥10 years of age were enrolled at the beginning of a course of TSI, 300 mg twice daily for 28 days. Two study visits were conducted, 1–2 days and 24–28 days after initiation of TSI treatment. Induced sputum and expectorated sputum samples were collected for measurement of trough and peak tobramycin concentrations at each visit. Total tobramycin concentrations were measured by high-pressure liquid chromatography and bioactive concentrations by bioassay. Results Twenty participants completed the study. Trough concentrations were similar at visits 1 and 2, as were peak concentrations. Trough bioactive and total tobramycin concentrations were similar (mean ratio 1.2, 95% CI 0.56, 1.87), but peak bioactive concentrations were significantly lower than peak total concentrations (mean ratio 0.33, 95% CI 0.23, 0.44). Sputum induction was well tolerated. Conclusions : No evidence of significant drug accumulation in respiratory secretions with repeat dosing of TSI was seen. Peak bioactive concentrations, although lower than peak total concentrations, were still generally well within the bactericidal range. Sputum induction as a method for determining airway drug concentrations appears safe and feasible. PMID:22620494

  19. Repeated cocaine administration results in supersensitivity of striatal D-2 dopamine autoreceptors to pergolide

    SciTech Connect

    Dwoskin, L.P.; Peris, J.; Yasuda, R.P.; Philpott, K.; Zahniser, N.R.

    1988-01-01

    Groups of rats administered cocaine-HCl (10 mg/kg, i.p.) or saline either acutely or once daily for 8 or 14 days were killed 24 hrs after the last dose. In striatal slices prelabelled with (/sup 3/H)DA, modulation of (/sup 3/H)-overflow by pergolide was used to measure D-2 autoreceptor activity. Compared to the contemporaneous control group pergolide produced a greater inhibition only in striatal slices from rats treated repeatedly with cocaine. In radioligand binding studies using striatal membranes from control rats, pergolide had a 500-fold greater affinity for the D-2, as opposed to the D-1, dopamine (DA) receptor subtype. These results indicate that repeated treatment with cocaine produces supersensitive striatal D-2 release-modulating autoreceptors consistent with a compensatory change to diminish the effect of elevated synaptic concentrations of DA produced by cocaine. In contrast, supersensitivity of D-2 receptors was not detected in (/sup 3/H)spiperone binding assays. 31 references, 2 figures, 1 table.

  20. Repeated administrations of carbon nanotubes in male mice cause reversible testis damage without affecting fertility

    NASA Astrophysics Data System (ADS)

    Bai, Yuhong; Zhang, Yi; Zhang, Jingping; Mu, Qingxin; Zhang, Weidong; Butch, Elizabeth R.; Snyder, Scott E.; Yan, Bing

    2010-09-01

    Soluble carbon nanotubes show promise as materials for in vivo delivery and imaging applications. Several reports have described the in vivo toxicity of carbon nanotubes, but their effects on male reproduction have not been examined. Here, we show that repeated intravenous injections of water-soluble multiwalled carbon nanotubes into male mice can cause reversible testis damage without affecting fertility. Nanotubes accumulated in the testes, generated oxidative stress and decreased the thickness of the seminiferous epithelium in the testis at day 15, but the damage was repaired at 60 and 90 days. The quantity, quality and integrity of the sperm and the levels of three major sex hormones were not significantly affected throughout the 90-day period. The fertility of treated male mice was unaffected; the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those that mated with untreated male mice.

  1. Cholinesterase inhibition and alterations of hepatic metabolism by oral acute and repeated chlorpyrifos administration to mice.

    PubMed

    Cometa, Maria Francesca; Buratti, Franca Maria; Fortuna, Stefano; Lorenzini, Paola; Volpe, Maria Teresa; Parisi, Laura; Testai, Emanuela; Meneguz, Annarita

    2007-05-01

    Chlorpyrifos (CPF) is a broad spectrum organophosphorus insecticide bioactivated in vivo to chlorpyrifos-oxon (CPFO), a very potent anticholinesterase. A great majority of available animal studies on CPF and CPFO toxicity are performed in rats. The use of mice in developmental neurobehavioural studies and the availability of transgenic mice warrant a better characterization of CPF-induced toxicity in this species. CD1 mice were exposed to a broad range of acute (12.5-100.0mg/kg) and subacute (1.56-25mg/kg/day from 5 to 30 days) CPF oral doses. Functional and biochemical parameters such as brain and serum cholinesterase (ChE) and liver xenobiotic metabolizing system, including the biotransformation of CPF itself, have been studied and the no observed effect levels (NOELs) identified. Mice seem to be more susceptible than rats at least to acute CPF treatment (oral LD(50) 4.5-fold lower). The species-related differences were not so evident after repeated exposures. In mice a good correlation was observed between brain ChE inhibition and classical cholinergic signs of toxicity. After CPF-repeated treatment, mice seemed to develop some tolerance to CPF-induced effects, which could not be attributed to an alteration of P450-mediated CPF hepatic metabolism. CPF-induced effects on hepatic microsomal carboxylesterase (CE) activity and reduced glutathione (GSH) levels observed at an early stage of treatment and then recovered after 30 days, suggest that the detoxifying mechanisms are actively involved in the protection of CPF-induced effects and possibly in the induction of tolerance in long term exposure. The mouse could be considered a suitable experimental model for future studies on the toxic action of organophosphorus pesticides focused on mechanisms, long term and age-related effects. PMID:17382447

  2. Intracerebroventricular opioids for intractable pain

    PubMed Central

    Raffa, Robert B; Pergolizzi, Joseph V

    2012-01-01

    When pain is refractory to systemic opioid and non-opioid analgesic therapy and palliative chemoradiation or ablative or stimulant neurosurgical procedures are not possible, palliative treatment becomes limited, particularly if the patient wishes to be at home at the end of life. Intracerebroventricular (ICV) infusion of morphine in the home setting might be presented as an option. The present article reviews the basic and clinical evidence of the efficacy and safety of ICV administration of opioids. Information was gathered from various bibliographic sources, including PubMed and others, and summarized and evaluated to assess the efficacy and safety of ICV opioids for pain relief. Results from ICV infusion of morphine into terminally ill patients refractory to other pain treatments have been reported since the early 1980s. Good efficacy has been achieved for the vast majority of patients, without serious development of analgesic tolerance. There have also been a low incidence of adverse effects, such as constipation and respiratory depression, and a significant retention of alertness associated with this route of administration. Intracerebroventricular infusion of opioid analgesics thus appears to be a safe and effective therapy for the palliative treatment of refractory pain. PMID:22295988

  3. Effects of Repeated Oral Administration of Pazufloxacin Mesylate and Meloxicam on the Antioxidant Status in Rabbits

    PubMed Central

    Khan, Adil Mehraj; Rampal, Satyavan

    2014-01-01

    Prolonged antibiotic and antiinflammatory therapy for complicated infections exposes the body to xenobiotics that can produce several adverse effects for which oxidative damage is the proposed underlying mechanism. In this context, we evaluated the effect of pazufloxacin, a fluoroquinolone antimicrobial, and meloxicam, a nonsteroidal antiinflammatory drug, on antioxidant parameters and lipid peroxidation in rabbits after oral administration for 21 d. Reduced glutathione levels were significantly decreased in rabbits (n = 4 per group) given pazufloxacin, meloxicam, or their combination. In addition, glutathione peroxidase activity was induced in the rabbits treated with pazufloxacin only. Administration of pazufloxacin and meloxicam, as single agents as well as in combination, produced significant lipid peroxidation compared with levels in untreated controls. In conclusion, both pazufloxacin and meloxicam potentially can induce oxidative damage in rabbits. PMID:25199097

  4. Repeated oral administration of capsaicin increases anxiety-like behaviours with prolonged stress-response in rats.

    PubMed

    Choi, Y-J; Kim, J Y; Yoo, S B; Lee, J-H; Jahng, J W

    2013-09-01

    This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02 percent capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy counts and rostral grooming were significantly increased, and caudal grooming decreased, in capsaicin-treated rats during the ambulatory activity test. In elevated plus maze test, not only the time spent in open arms but also the percent arm entry into open arms was reduced in capsaicin-treated rats compared with control rats. In forced swim test, although swimming duration was decreased, struggling increased in the capsaicin group, immobility duration did not differ between the groups. Repeated oral capsaicin did not affect the basal levels of plasma corticosterone; however, the stress-induced elevation of plasma corticosterone was prolonged in capsaicin treated rats. Oral capsaicin exposure significantly increased c-Fos expression not only in the nucleus tractus of solitarius but also in the paraventricular nucleus. Results suggest that repeated oral exposure to capsaicin increases anxiety-like behaviours in rats, and dysfunction of the hypothalamic-pituitary-adrenal axis may play a role in its pathophysiology. PMID:23938388

  5. Opioid System Modulates the Immune Function: A Review

    PubMed Central

    Liang, Xuan; Liu, Renyu; Chen, Chunhua; Ji, Fang; Li, Tianzuo

    2016-01-01

    Opioid receptors and their ligands produce powerful analgesia that is effective in perioperative period and chronic pain managements accompanied with various side effects including respiratory depression, constipation and addiction etc. Opioids can also interfere with the immune system, not only participating in the function of the immune cells, but also modulating innate and acquired immune responses. The traditional notion of opioids is immunosuppressive. Recent studies indicate that the role of opioid receptors on immune function is complicated, working through various different mechanisms. Different opioids or opioids administrations show various effects on the immune system: immunosuppressive, immunostimulatory, or dual effect. It is important to elucidate the relationship between opioids and immune function, since immune system plays critical role in various physiological and pathophysiological processes, including the inflammation, tumor growth and metastasis, drug abuse, and so on. This review article tends to have an overview of the recent work and perspectives on opioids and the immune function. PMID:26985446

  6. Attenuation of cocaine self-administration in squirrel monkeys following repeated administration of the MGluR5 antagonist MPEP: Comparison with dizocilpine

    PubMed Central

    Platt, Donna M.; Rowlett, James K.; Spealman, Roger D.

    2008-01-01

    Rationale The mGluR5 antagonist MPEP has effects that suggest potential as a pharmacotherapy for cocaine addiction. MPEP can attenuate self-administration of cocaine in animals; however, studies usually involved only acute treatment with MPEP and a single dose of self-administered cocaine. Cocaine addicts use varied amounts of cocaine over long periods of time, and an effective pharmacotherapy would almost certainly require more chronic treatment. Objectives The present study: 1) compared the effects of repeated treatment with MPEP or the NMDA receptor antagonist dizocilpine on the reinforcing effects of a range of doses of cocaine and 2) determined the pharmacological specificity of the effects of the drugs in attenuating cocaine self-administration compared to food-reinforced behavior. An effective pharmacotherapy should selectively reduce cocaine self-administration. Methods Groups of monkeys responded under a fixed-ratio schedule of i.v. cocaine self-administration or food-pellet delivery. The effects of daily treatment with MPEP and dizocilpine were determined under both the schedule of i.v. cocaine injection and food delivery. Results Treatment with MPEP and dizocilpine significantly reduced cocaine self-administration, producing rightward and downward shifts in the ascending limb of the cocaine dose-response function. MPEP and dizocilpine selectively and significantly attenuated self-administration of a low reinforcing dose of cocaine compared to food without evidence of tolerance. Conclusions Both MPEP and dizocilpine functioned as partially surmountable antagonists of the reinforcing effects of cocaine. The similar effects of the two drugs raises the possibility that MPEP attenuated the reinforcing effects of cocaine, at least in part, via mGluR5-mediated inhibition of NMDA receptor activity. PMID:18509621

  7. Repeated neonatal propofol administration induces sex-dependent long-term impairments on spatial and recognition memory in rats.

    PubMed

    Gonzales, Edson Luck T; Yang, Sung Min; Choi, Chang Soon; Mabunga, Darine Froy N; Kim, Hee Jin; Cheong, Jae Hoon; Ryu, Jong Hoon; Koo, Bon-Nyeo; Shin, Chan Young

    2015-05-01

    Propofol is an anesthetic agent that gained wide use because of its fast induction of anesthesia and rapid recovery post-anesthesia. However, previous studies have reported immediate neurodegeneration and long-term impairment in spatial learning and memory from repeated neonatal propofol administration in animals. Yet, none of those studies has explored the sex-specific long-term physical changes and behavioral alterations such as social (sociability and social preference), emotional (anxiety), and other cognitive functions (spatial working, recognition, and avoidance memory) after neonatal propofol treatment. Seven-day-old Wistar-Kyoto (WKY) rats underwent repeated daily intraperitoneal injections of propofol or normal saline for 7 days. Starting fourth week of age and onwards, rats were subjected to behavior tests including open-field, elevated-plus-maze, Y-maze, 3-chamber social interaction, novel-object-recognition, passive-avoidance, and rotarod. Rats were sacrificed at 9 weeks and hippocampal protein expressions were analyzed by Western blot. Results revealed long-term body weight gain alterations in the growing rats and sex-specific impairments in spatial (female) and recognition (male) learning and memory paradigms. A markedly decreased expression of hippocampal NMDA receptor GluN1 subunit in female- and increased expression of AMPA GluR1 subunit protein expression in male rats were also found. Other aspects of behaviors such as locomotor activity and coordination, anxiety, sociability, social preference and avoidance learning and memory were not generally affected. These results suggest that neonatal repeated propofol administration disrupts normal growth and some aspects of neurodevelopment in rats in a sex-specific manner. PMID:25995824

  8. Repeated Neonatal Propofol Administration Induces Sex-Dependent Long-Term Impairments on Spatial and Recognition Memory in Rats

    PubMed Central

    Gonzales, Edson Luck T.; Yang, Sung Min; Choi, Chang Soon; Mabunga, Darine Froy N.; Kim, Hee Jin; Cheong, Jae Hoon; Ryu, Jong Hoon; Koo, Bon-Nyeo; Shin, Chan Young

    2015-01-01

    Propofol is an anesthetic agent that gained wide use because of its fast induction of anesthesia and rapid recovery post-anesthesia. However, previous studies have reported immediate neurodegeneration and long-term impairment in spatial learning and memory from repeated neonatal propofol administration in animals. Yet, none of those studies has explored the sex-specific long-term physical changes and behavioral alterations such as social (sociability and social preference), emotional (anxiety), and other cognitive functions (spatial working, recognition, and avoidance memory) after neonatal propofol treatment. Seven-day-old Wistar-Kyoto (WKY) rats underwent repeated daily intraperitoneal injections of propofol or normal saline for 7 days. Starting fourth week of age and onwards, rats were subjected to behavior tests including open-field, elevated-plus-maze, Y-maze, 3-chamber social interaction, novel-object-recognition, passive-avoidance, and rotarod. Rats were sacrificed at 9 weeks and hippocampal protein expressions were analyzed by Western blot. Results revealed long-term body weight gain alterations in the growing rats and sex-specific impairments in spatial (female) and recognition (male) learning and memory paradigms. A markedly decreased expression of hippocampal NMDA receptor GluN1 subunit in female- and increased expression of AMPA GluR1 subunit protein expression in male rats were also found. Other aspects of behaviors such as locomotor activity and coordination, anxiety, sociability, social preference and avoidance learning and memory were not generally affected. These results suggest that neonatal repeated propofol administration disrupts normal growth and some aspects of neurodevelopment in rats in a sex-specific manner. PMID:25995824

  9. Prescription opioids. III. Disposition of oxycodone in oral fluid and blood following controlled single-dose administration.

    PubMed

    Cone, Edward J; DePriest, Anne Z; Heltsley, Rebecca; Black, David L; Mitchell, John M; LoDico, Charles; Flegel, Ron

    2015-04-01

    Oxycodone (OC) is recommended to be included as an analyte tested in the proposed Substance Abuse and Mental Health Services Administration (SAMHSA's) Mandatory Guidelines for Federal Workplace Drug Testing Programs using Oral Fluid (OF) Specimens. This study demonstrates the time course of OC and metabolites, noroxycodone (NOC), oxymorphone (OM) and noroxymorphone (NOM), in near-simultaneous paired OF and whole blood (BL) specimens by liquid chromatography-tandem mass spectrometry (LC-MS-MS) (limit of detection = 1 ng/mL OF, 5 ng/mL BL). A single dose of OC 20 mg controlled-release was administered to 12 healthy subjects followed by specimen collections for 52 h. Analyte prevalence was as follows: OF, OC > NOC > OM; and BL, OC > NOC > NOM. OC and NOC were frequently detected within 15-30 min in OF and 30 min to 2 h in BL. NOM and OM appeared between 1.5-5 h post-dose. The mean OF-to-BL (OF:BL) ratios and correlations were 5.4 for OC (r = 0.719) and 1.0 for NOC (r = 0.651). The period of detection for OF exceeded BL by ∼2-fold at similar cutoff concentrations. At a 1 ng/mL cutoff for OF, the mean detection time was 34 h for OC and NOC. These data provide new information that should facilitate interpretation of OC test results. PMID:25589778

  10. Hepatotoxicity assessment of Mn-doped ZnS quantum dots after repeated administration in mice.

    PubMed

    Yang, Yanjie; Lv, Shuang-Yu; Yu, Bianfei; Xu, Shuang; Shen, Jianmin; Zhao, Tong; Zhang, Haixia

    2015-01-01

    Doped ZnS quantum dots (QDs) have a longer dopant emission lifetime and potentially lower cytotoxicity compared to other doped QDs. The liver is the key organ for clearance and detoxification of xenobiotics by phagocytosis and metabolism. The present study was designed to synthesize and evaluate the hepatotoxicity of Mn-doped ZnS QDs and their polyethylene glycol-coated counterparts (1 mg/kg and 5 mg/kg) in mice. The results demonstrated that daily injection of Mn-doped ZnS QDs and polyethylene glycol-coated QDs via tail vein for 7 days did not influence body weight, relative liver weight, serum aminotransferases (alanine aminotransferase and aspartate aminotransferase), the levels of antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase), or malondialdehyde in the liver. Analysis of hepatocyte ultrastructure showed that Mn-doped ZnS QDs and polyethylene glycol-coated QDs mainly accumulated in mitochondria at 24 hours after repeated intravenous injection. No damage to cell nuclei or mitochondria was observed with either of the QDs. Our results indicate that Mn-doped ZnS QDs did not cause obvious damage to the liver. This study will assist in the development of Mn-doped ZnS QDs-based bioimaging and biomedical applications in the future. PMID:26396512

  11. Hepatotoxicity assessment of Mn-doped ZnS quantum dots after repeated administration in mice

    PubMed Central

    Yang, Yanjie; Lv, Shuang-Yu; Yu, Bianfei; Xu, Shuang; Shen, Jianmin; Zhao, Tong; Zhang, Haixia

    2015-01-01

    Doped ZnS quantum dots (QDs) have a longer dopant emission lifetime and potentially lower cytotoxicity compared to other doped QDs. The liver is the key organ for clearance and detoxification of xenobiotics by phagocytosis and metabolism. The present study was designed to synthesize and evaluate the hepatotoxicity of Mn-doped ZnS QDs and their polyethylene glycol-coated counterparts (1 mg/kg and 5 mg/kg) in mice. The results demonstrated that daily injection of Mn-doped ZnS QDs and polyethylene glycol-coated QDs via tail vein for 7 days did not influence body weight, relative liver weight, serum aminotransferases (alanine aminotransferase and aspartate aminotransferase), the levels of antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase), or malondialdehyde in the liver. Analysis of hepatocyte ultrastructure showed that Mn-doped ZnS QDs and polyethylene glycol-coated QDs mainly accumulated in mitochondria at 24 hours after repeated intravenous injection. No damage to cell nuclei or mitochondria was observed with either of the QDs. Our results indicate that Mn-doped ZnS QDs did not cause obvious damage to the liver. This study will assist in the development of Mn-doped ZnS QDs-based bioimaging and biomedical applications in the future. PMID:26396512

  12. Prescription Opioids during Pregnancy

    MedlinePlus

    ... brand names ConZip®, Ryzolt®, Ultram®) The street drug heroin also is an opioid. What problems can opioids ... to buy them illegally. People often start using heroin after becoming addicted to prescription opioids. Sometimes opioids ...

  13. The hydrosoluble fiber Plantago ovata husk improves levodopa (with carbidopa) bioavailability after repeated administration.

    PubMed

    Diez, M Jose; Garcia, Juan J; Prieto, Carlos; Fernandez, Nelida; Sahagun, Ana; Sierra, Matilde

    2008-08-15

    The influence of treatment duration (7 or 14 days) with Plantago ovata husk/levodopa/carbidopa in the bioavailability and other pharmacokinetic parameters of levodopa were evaluated in rabbits. Fiber was administered at two different doses, 100 and 400 mg/kg, and the dosage of levodopa/carbidopa was 20:5 mg/kg. These doses were administered once a day. When 100 mg/kg of fiber was administered, the mean AUC value obtained for levodopa increased 20.2% from day 1 to day 7, and 27.2% from day 1 to day 14; C(max) was 8.6% higher on day 7 and 11.7% higher on day 14. When administering 400 mg/kg of fiber, the increase in AUC values was 17.6% on day 7 and 24.9% on day 14, and that of C(max) 11.1% on day 7 and 11.3% on day 14. The concentration determined immediately before drug administration (C(min)) increased progressively with the duration of treatment, and the highest increase (53.2%) was observed on day 14 with 100 mg/kg of fiber. There was also a delay in levodopa elimination (higher MRT and lower Cl) in a fiber-dose dependent manner. In summary, we found that there was an improvement in the extent of levodopa absorbed with higher final concentrations and that levodopa elimination was slower with the administration of P. ovata husk. PMID:18474374

  14. The Changing Use of Intravenous Opioids in an Emergency Department

    PubMed Central

    Sutter, Mark E.; Wintemute, Garen J.; Clarke, Samuel O.; Roche, Bailey M.; Chenoweth, James A.; Gutierrez, Rory; Albertson, Timothy E.

    2015-01-01

    Introduction Government agencies are increasingly emphasizing opioid safety in hospitals. In 2012, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) started a sentinel event program, the “Safe Use of Opioids in Hospitals.” We sought to determine if opioid use patterns in our emergency department (ED) changed from 2011, before the program began, to 2013, after start of the program. Methods This was a retrospective study of all adult ED patients who received an intravenous opioid and had a serum creatinine measured. We recorded opioids used, dose prescribed, and serum creatinine. As an index of the safety of opioids, uses of naloxone after administration of an opioid was recorded. Results Morphine is still the most commonly used opioid by doses given, but its percentage of opioids used decreased from 68.9% in 2011 to 52.8% in 2013. During the same period, use of hydromorphone increased from 27.5% to 42.9%, while the use of fentanyl changed little (3.6% to 4.3%). Naloxone administration was rare after an opioid had been given. Opioids were not dosed in an equipotent manner. Conclusion The use of hydromorphone in our ED increased by 56% (absolute increase of 15.4%), while the use of morphine decreased by 30.5% (absolute decrease 16.1%) of total opioid use from 2011 to 2013. The JCAHO program likely was at least indirectly responsible for this change in relative dosing of the opioids. Based on frequency of naloxone administered after administration of an opioid, the use of opioids was safe. PMID:26759658

  15. Urinary excretion of enzymes following repeated parenteral administration of cadmium to rats

    SciTech Connect

    Bonner, F.W.; King, L.J.; Parke, D.V.

    1980-06-01

    The effect of daily parenteral administration of cadmium (0.75, 1.5, and 3.0 mg/kg) on the urinary excretion of enzymes has been studied in the young male rat. Aspartate aminotransferase, alkaline phosphatase, ..gamma..-glutamyl transpeptidase, and leucine aminopeptidase all showed an initial significant increase around the second day of dosage, the intensity of which was dose related. A second phase of enzymuria occurred later, the onset of which was dose related. High-dose-group animals (3.0 mg/kg) exhibited this increase around Day 15, while the median (1.5 mg/kg) and low- (0.75 mg/kg)dose-group animals developed enzymuria around Days 21 and 38, respectively. This second phase of elevated enzyme levels in the urine was persistent, and is believed to represent the development of renal damage.

  16. Development of peripheral opioid antagonists' new insights into opioid effects.

    PubMed

    Moss, Jonathan; Rosow, Carl E

    2008-10-01

    The recent approval by the US Food and Drug Administration of 2 medications--methylnaltrexone and alvimopan--introduces a new class of therapeutic entities to clinicians. These peripherally acting mu-opioid receptor antagonists selectively reverse opioid actions mediated by receptors outside the central nervous system, while preserving centrally mediated analgesia. Methylnaltrexone, administered subcutaneously, has been approved in the United States, Europe, and Canada. In the United States, it is indicated for the treatment of opioid-induced constipation in patients with advanced illness (eg, cancer, AIDS) who are receiving palliative care, when response to laxative therapy has not been sufficient. Alvimopan, an orally administered medication, has been approved in the United States to facilitate recovery of gastrointestinal function after bowel resection and primary anastomosis. Clinical and laboratory studies performed during the development of these drugs have indicated that peripheral receptors mediate other opioid effects, including decreased gastric emptying, nausea and vomiting, pruritus, and urinary retention. Laboratory investigations with these compounds suggest that opioids affect fundamental cellular processes through mechanisms that were previously unknown. These mechanisms include modifications of human immunodeficiency virus penetration, tumor angiogenesis, vascular permeability, and bacterial virulence. PMID:18828971

  17. Correlates of prescription opioid initiation and long-term opioid use in veterans with persistent pain

    PubMed Central

    Dobscha, Steven K.; Morasco, Benjamin J.; Duckart, Jonathan P.; Macey, Tara; Deyo, Richard A.

    2012-01-01

    Objectives Little is known about how opioid prescriptions for chronic pain are initiated. We sought to describe patterns of prescription opioid initiation, identify correlates of opioid initiation, and examine correlates of receipt of chronic opioid therapy (COT) among veterans with persistent non-cancer pain. Methods Using Veterans Affairs (VA) administrative data, we identified 5,961 veterans from the Pacific Northwest with persistent elevated pain intensity scores who had not been prescribed opioids in the prior 12 months. We compared veterans not prescribed opioids over the subsequent 12 months to those prescribed any opioid and to those prescribed COT (≥90 consecutive days). Results During the study year, 34% of the sample received an opioid prescription, and 5% received COT. Most first opioid prescriptions were written by primary care clinicians. Veterans prescribed COT were younger, had greater pain intensity, and high rates of psychiatric and substance use disorders (SUDs) compared to veterans in the other two groups. Among patients receiving COT, 29% were prescribed long-acting opioids, 37% received one or more urine drug screens, and 24% were prescribed benzodiazepines. Adjusting for age, sex, and baseline pain intensity, major depression (OR 1.24 [1.10–1.39]; 1.48 [1.14–1.93]) and nicotine dependence (1.34 [1.17–1.53]; 2.02 [1.53–2.67]) were associated with receiving any opioid prescription and with COT, respectively. Discussion Opioid initiations are common among veterans with persistent pain, but most veterans are not prescribed opioids long-term. Psychiatric disorders and SUDs are associated with receiving COT. Many Veterans receiving COT are concurrently prescribed benzodiazepines and many do not receive urine drug screening; additional study regarding practices that optimize safety of COT in this population is indicated. PMID:23269280

  18. Mu Opioid Splice Variant MOR-1K Contributes to the Development of Opioid-Induced Hyperalgesia

    PubMed Central

    Oladosu, Folabomi A.; Conrad, Matthew S.; O’Buckley, Sandra C.; Rashid, Naim U.; Slade, Gary D.; Nackley, Andrea G.

    2015-01-01

    Background A subset of the population receiving opioids for the treatment of acute and chronic clinical pain develops a paradoxical increase in pain sensitivity known as opioid-induced hyperalgesia. Given that opioid analgesics are one of few treatments available against clinical pain, it is critical to determine the key molecular mechanisms that drive opioid-induced hyperalgesia in order to reduce its prevalence. Recent evidence implicates a splice variant of the mu opioid receptor known as MOR-1K in the emergence of opioid-induced hyperalgesia. Results from human genetic association and cell signaling studies demonstrate that MOR-1K contributes to decreased opioid analgesic responses and produces increased cellular activity via Gs signaling. Here, we conducted the first study to directly test the role of MOR-1K in opioid-induced hyperalgesia. Methods and Results In order to examine the role of MOR-1K in opioid-induced hyperalgesia, we first assessed pain responses to mechanical and thermal stimuli prior to, during, and following chronic morphine administration. Results show that genetically diverse mouse strains (C57BL/6J, 129S6, and CXB7/ByJ) exhibited different morphine response profiles with corresponding changes in MOR-1K gene expression patterns. The 129S6 mice exhibited an analgesic response correlating to a measured decrease in MOR-1K gene expression levels, while CXB7/ByJ mice exhibited a hyperalgesic response correlating to a measured increase in MOR-1K gene expression levels. Furthermore, knockdown of MOR-1K in CXB7/ByJ mice via chronic intrathecal siRNA administration not only prevented the development of opioid-induced hyperalgesia, but also unmasked morphine analgesia. Conclusions These findings suggest that MOR-1K is likely a necessary contributor to the development of opioid-induced hyperalgesia. With further research, MOR-1K could be exploited as a target for antagonists that reduce or prevent opioid-induced hyperalgesia. PMID:26270813

  19. Prescription Opioid Epidemic and Infant Outcomes

    PubMed Central

    Dudley, Judith; Martin, Peter R.; Harrell, Frank E.; Warren, Michael D.; Hartmann, Katherine E.; Ely, E. Wesley; Grijalva, Carlos G.; Cooper, William O.

    2015-01-01

    BACKGROUND AND OBJECTIVES: Although opioid pain relievers are commonly prescribed in pregnancy, their association with neonatal outcomes is poorly described. Our objectives were to identify neonatal complications associated with antenatal opioid pain reliever exposure and to establish predictors of neonatal abstinence syndrome (NAS). METHODS: We used prescription and administrative data linked to vital statistics for mothers and infants enrolled in the Tennessee Medicaid program between 2009 and 2011. A random sample of NAS cases was validated by medical record review. The association of antenatal exposures with NAS was evaluated by using multivariable logistic regression, controlling for maternal and infant characteristics. RESULTS: Of 112 029 pregnant women, 31 354 (28%) filled ≥1 opioid prescription. Women prescribed opioid pain relievers were more likely than those not prescribed opioids (P < .001) to have depression (5.3% vs 2.7%), anxiety disorder (4.3% vs 1.6%) and to smoke tobacco (41.8% vs 25.8%). Infants with NAS and opioid-exposed infants were more likely than unexposed infants to be born at a low birth weight (21.2% vs 11.8% vs 9.9%; P < .001). In a multivariable model, higher cumulative opioid exposure for short-acting preparations (P < .001), opioid type (P < .001), number of daily cigarettes smoked (P < .001), and selective serotonin reuptake inhibitor use (odds ratio: 2.08 [95% confidence interval: 1.67–2.60]) were associated with greater risk of developing NAS. CONCLUSIONS: Prescription opioid use in pregnancy is common and strongly associated with neonatal complications. Antenatal cumulative prescription opioid exposure, opioid type, tobacco use, and selective serotonin reuptake inhibitor use increase the risk of NAS. PMID:25869370

  20. 13-week repeated dose toxicity study of l-tyrosine in rats by daily oral administration.

    PubMed

    Shibui, Yusuke; Manabe, Yasuhiro; Kodama, Terutaka; Gonsho, Akinori

    2016-01-01

    To evaluate the potential toxicity of l-tyrosine, 4 groups of Crl:CD(SD) rats of both sexes were administered l-tyrosine in water suspension by gavage once daily for 13 weeks at doses of 0 (vehicle), 200, 600 or 2000 mg/kg bw/day. Findings related to l-tyrosine administration were as follows. Edema of the cornified layer at the limiting ridge or forestomach was seen in 600 mg/kg bw/day female group and in both sexes of 2000 mg/kg bw/day group. In the liver, increased weight and hypertrophy of centrilobular hepatocytes were seen in both sexes at 2000 mg/kg bw/day, associated with slight increases in ALT and AST. Regarding the kidney morphology and function, increased hyaline droplets in the proximal tubules and increased urinary protein were seen in the 2000 mg/kg bw/day male group. In addition, increased kidney weight was also observed in both sexes of the 2000 mg/kg bw/day group, although the histological changes attributable to the weight increase remained unclear. As for blood chemistry, increases in triglycerides, total cholesterol, phospholipids, potassium ion, calcium, total protein, and α1 globulin were also seen in both sexes at 2000 mg/kg bw/day. Thus, in this study the no-observed-adverse-effect level (NOAEL) of l-tyrosine was considered to be 600 mg/kg bw/day for males and 200 mg/kg bw/day for females. PMID:26646752

  1. Absorption and dosage of theophylline in the horse after single and repeated administration of a microencapsulated preparation.

    PubMed

    Roncada, P; Tomasi, L; Montesissa, C; Grossi, G; Stracciari, G L; Anfossi, P

    1995-01-01

    The kinetics of 2 formulations of theophylline were studied in horses. In an initial cross-over study (Phase I) serum concentration-time curves were determined for granulated and microencapsulated theophylline after a single oral administration (5 mg/kg bwt). In Phase II microencapsulated theophylline was administered at 5 mg/kg bwt/12 h for 10 days at feeding time, as in normal clinical practice. Although no significant differences between the 2 preparations were found with respect to the main kinetic parameters, the microencapsulated form was more evenly and completely absorbed from the digestive tract; furthermore, after the repeated treatment, its trough-peak serum concentrations were always within the therapeutic window and no toxic effects were observed in treated animals. PMID:7774541

  2. Upregulation of metabotropic glutamate receptor 8 mRNA expression in the rat forebrain after repeated amphetamine administration

    PubMed Central

    Parelkar, Nikhil K; Wang, John Q.

    2008-01-01

    Metabotropic glutamate receptors (mGluRs) are G-protein-coupled receptors and are densely expressed in the forebrain of adult rats. Accumulative evidence suggests a critical role of mGluRs in the regulation of normal physiological activity of neurons and pathogenesis of mental illnesses such as schizophrenia, depression, and substance addiction. In this study, we investigated alterations in mGluR8 subtype mRNA expression in the rat forebrain in response to repeated intraperitoneal administration of amphetamine (twice daily for 12 days, 5 mg/kg per injection) using quantitative in situ hybridization. We found that mGluR8 mRNA levels were profoundly increased in the dorsal (caudate putamen) and ventral (nucleus accumbens) striatum 1 day after the discontinuation of amphetamine treatments. Such increases were sustained up to 21 days of withdrawal. Increases in mGluR8 mRNAs were also found in the cerebral cortex, including the cingulate and sensory cortex but not the piriform cortex, at 1 and 21 days. These data demonstrate a positive response of mGluR8 in mRNA abundance in most forebrain regions to repeated stimulant exposure. PMID:18255232

  3. Effects of methiothepin on changes in brain serotonin release induced by repeated administration of high doses of anorectic serotoninergic drugs

    NASA Technical Reports Server (NTRS)

    Gardier, A. M.; Kaakkola, S.; Erfurth, A.; Wurtman, R. J.

    1992-01-01

    We previously observed, using in vivo microdialysis, that the potassium-evoked release of frontocortical serotonin (5-HT) is suppressed after rats receive high doses (30 mg/kg, i.p., daily for 3 days) of fluoxetine, a selective blocker of 5-HT reuptake. We now describe similar impairments in 5-HT release after repeated administration of two other 5-HT uptake blockers, zimelidine and sertraline (both at 20 mg/kg, i.p. for 3 days) as well as after dexfenfluramine (7.5 mg/kg, i.p. daily for 3 days), a drug which both releases 5-HT and blocks its reuptake. Doses of these indirect serotonin agonists were about 4-6 times the drug's ED50 in producing anorexia, a serotonin-related behavior. In addition, methiothepin (20 microM), a non-selective receptor antagonist, locally perfused through the dialysis probe 24 h after the last drug injection, enhanced K(+)-evoked release of 5-HT at serotoninergic nerve terminals markedly in control rats and slightly in rats treated with high doses of dexfenfluramine or fluoxetine. On the other hand, pretreatment with methiothepin (10 mg/kg, i.p.) one hour before each of the daily doses of fluoxetine or dexfenfluramine given for 3 days, totally prevented the decrease in basal and K(+)-evoked release of 5-HT. Finally, when methiothepin was injected systemically the day before the first of 3 daily injections of dexfenfluramine, it partially attenuated the long-term depletion of brain 5-HT and 5-HIAA levels induced by repeated administration of high doses of dexfenfluramine. These data suggest that drugs which bring about the prolonged blockade of 5-HT reuptake - such as dexfenfluramine and fluoxetine - can, by causing prolonged increases in intrasynaptic 5-HT levels as measured by in vivo microdialysis, produce receptor-mediated long-term changes in the processes controlling serotonin levels and dynamics.

  4. Opioid Analgesics and Nicotine: More Than Blowing Smoke.

    PubMed

    Yoon, Jin H; Lane, Scott D; Weaver, Michael F

    2015-09-01

    Practitioners are highly likely to encounter patients with concurrent use of nicotine products and opioid analgesics. Smokers present with more severe and extended chronic pain outcomes and have a higher frequency of prescription opioid use. Current tobacco smoking is a strong predictor of risk for nonmedical use of prescription opioids. Opioid and nicotinic-cholinergic neurotransmitter systems interact in important ways to modulate opioid and nicotine effects: dopamine release induced by nicotine is dependent on facilitation by the opioid system, and the nicotinic-acetylcholine system modulates self-administration of several classes of abused drugs-including opioids. Nicotine can serve as a prime for the use of other drugs, which in the case of the opioid system may be bidirectional. Opioids and compounds in tobacco, including nicotine, are metabolized by the cytochrome P450 enzyme system, but the metabolism of opioids and tobacco products can be complicated. Accordingly, drug interactions are possible but not always clear. Because of these issues, asking about nicotine use in patients taking opioids for pain is recommended. When assessing patient tobacco use, practitioners should also obtain information on products other than cigarettes, such as cigars, pipes, smokeless tobacco, and electronic nicotine delivery systems (ENDS, or e-cigarettes). There are multiple forms of behavioral therapy and pharmacotherapy available to assist patients with smoking cessation, and opioid agonist maintenance and pain clinics represent underutilized opportunities for nicotine intervention programs. PMID:26375198

  5. Mediation of opioid analgesia by a truncated 6-transmembrane GPCR

    PubMed Central

    Lu, Zhigang; Xu, Jin; Rossi, Grace C.; Majumdar, Susruta; Pasternak, Gavril W.; Pan, Ying-Xian

    2015-01-01

    The generation of potent opioid analgesics that lack the side effects of traditional opioids may be possible by targeting truncated splice variants of the μ-opioid receptor. μ-Opioids act through GPCRs that are generated from the Oprm1 gene, which undergoes extensive alternative splicing. The most abundant set of Oprm1 variants encode classical full-length 7 transmembrane domain (7TM) μ-opioid receptors that mediate the actions of the traditional μ-opioid drugs morphine and methadone. In contrast, 3-iodobenzoyl-6β-naltrexamide (IBNtxA) is a potent analgesic against thermal, inflammatory, and neuropathic pain that acts independently of 7TM μ-opioid receptors but has no activity in mice lacking a set of 6TM truncated μ-opioid receptor splice variants. Unlike traditional opioids, IBNtxA does not depress respiration or result in physical dependence or reward behavior, suggesting it acts through an alternative μ-opioid receptor target. Here we demonstrated that a truncated 6TM splice variant, mMOR-1G, can rescue IBNtxA analgesia in a μ-opioid receptor–deficient mouse that lacks all Oprm1 splice variants, ablating μ-opioid activity in these animals. Intrathecal administration of lentivirus containing the 6TM variant mMOR-1G restored IBNtxA, but not morphine, analgesia in Oprm1-deficient animals. Together, these results confirm that a truncated 6TM GPCR is both necessary and sufficient for IBNtxA analgesia. PMID:26011641

  6. Repeated Administration of Inhibitors for Ion Pumps Reduce Markedly Tumor Growth in Vivo

    PubMed Central

    Hrgovic, Igor; Glavic, Zeljko; Kovacic, Zeljko; Mulic, Smaila; Zunic, Lejla; Hrgovic, Zlatko

    2014-01-01

    ABSTRACT Introduction: Measurements of extracellular pH show that the micro environment of malignant tumors is more acidic than that of normal cells, whereas pH does not differ appreciable in normal and malignant cells. The acid micro environment of tumors is created by the secretion of tumor factors and ATP hydrolysis in hypoxic tumor tissue. In order to survive in a low pH-environment tumor cells develop regulatory mechanisms which keep their intracellular pH stable. Two of the most important systems are the Na+/H+ ion pump and the Na-dependent HCO3-/Cl- pump of stilbenian derivatives. Material and methods: Experiments were carried out on DBA mice of both sexes at the age of 4 month. Laboratory animals were grown in our institute and supplied with food and aqua ad libitum. Results: After termination of the experiments the mean tumor diameter in the control group was 12.4±0.8mm, in group A it was 6.9±0.6mm, and in group B we measured 6.6±3.1mm. At the final day the tumor size in treated animals was twice as small as in the control group. In addition we observed the rate of survival. In the control group only 18% of the animals were still alive at day 18. Considering the rate of survival a statistically significant difference between treated and untreated animals was observed. The survival of tumor cells is dependent on the function of these ion pumps which keep their intracellular pH values constant in the setting of an acid extracellular environment. Conclusion: The activity of the ion pump is especially important at the beginning of cell division and in cell proliferation. Our in vivo experiments demonstrate that prolonged administration of intratumoral ion pump inhibitors suppresses tumor growth as well as enhances survival of tumor-bearing animals. Research of inhibitors of ion pumps and their action in tumor growth opens new perspectives into pathophysiology of malignant tumors and may create new therapeutic options. PMID:24937925

  7. Prevalence and correlates of co-prescribing psychotropic medications with long-term opioid use nationally in the Veterans Health Administration.

    PubMed

    Barry, Declan T; Sofuoglu, Mehmet; Kerns, Robert D; Wiechers, Ilse R; Rosenheck, Robert A

    2015-06-30

    We used national data for fiscal year 2012 to examine demographic, psychiatric and medical diagnoses, indications for psychotropics, and service use correlates of psychotropic medication fills in Veterans with at least 10 opioid prescriptions during the year (the highest 29% of opioid users); and whether the Veteran was treated in a specialty mental health clinic. Of the 328,398 Veterans who filled at least 10 opioid prescriptions, 77% also received psychotropics, of whom: 74% received antidepressants, 55% anxiolytics/sedatives/hypnotics, and 26% three or more classes of psychotropic medications. Altogether, 87% had a psychiatric or medical indication; and 54% received mental health treatment. Veterans treated in a mental health clinic were prescribed more psychotropics and were more likely to have a documented psychiatric or medical indication than those treated solely in other settings. Indicated psychiatric diagnoses were the strongest predictors of specific class of psychotropics prescribed; anxiety disorder and insomnia were most strongly associated with anxioloytics/sedatives/hypnotics receipt. Since psychotropics and opioids can produce harmful side effects, especially when combined, and since they are likely prescribed by separate providers in different settings, coordinated consideration of the risks and benefits of co-prescribing these medications may be needed, along with further study of related adverse events. PMID:25863822

  8. What are the risks and knowledge deficits for prescribing and administering opioids in the ward environment? A quality project on assessing and improving knowledge.

    PubMed

    Markocic, S; Humphries, M; Tarne, K; Watts, M; Collins, L

    2016-03-01

    Investigations into Medical Emergency Team (MET) calls and related clinical incident reviews at a large district teaching hospital provided evidence that over sedation can be a significant issue post opioid administration and that safe and effective pain management requires accurate opioid knowledge and patient assessment skills. The aim of the study was to develop education that was directed at identified knowledge deficits, and to evaluate the impact of this tailored education program on knowledge of safe prescribing and administration of opioids. Knowledge levels were explored using a structured questionnaire in a pre and post-test design. A convenience sample of 34 nurses and 5 junior medical officers across three surgical wards in a tertiary referral hospital had their knowledge assessed. Results showed significant improvement when repeat questionnaires were given two weeks post-delivery of education. Mean scores were 68% at baseline and 89% two weeks post completion of the education program. The greatest improvement in scores was recorded for drug knowledge including dose, half-life and administration. The findings from this study suggest that the opioid education program is effective in improving the knowledge of safe prescribing and administration of opioids, however further studies are required. PMID:26589096

  9. Opioid-induced hyperalgesia and burn pain.

    PubMed

    Holtman, Joseph R; Jellish, W Scott

    2012-01-01

    The treatment of pain produced during the management of burn injury has been an ongoing problem for physicians caring for these patients. The main therapeutic option for analgesia has been the repeated and prolonged use of opioids. The adverse effects of opioids are well known but the long term use of opioids which produces tolerance with accompanying dose escalation and dependence is most problematic. Another potentially important consequence of opioid exposure that sometimes masks as tolerance is that of opioid induced hyperalgesia. This syndrome is manifest as enhanced pain, sensitivity and loss of analgesic efficacy in patients treated with opioids who actually become sensitized to painful stimuli. This article focuses on the treatment of burn pain and how current analgesic therapies with opioids may cause hyperalgesia and affect the adequacy of treatment for burn pain. This article also provides possible modalities to help therapeutically manage these patients and considers future analgesic strategies which may help to improve pain management in this complicated patient population. PMID:23143613

  10. Clenbuterol Distribution and Residues in Goat Tissues After the Repeated Administration of a Growth-Promoting Dose.

    PubMed

    Zhao, Zhen; Yao, Ting; Qin, Yuchang; Yang, Xiaowei; Li, Jun; Li, Junguo; Gu, Xu

    2015-01-01

    This study was conducted to investigate the deposition and depletion process of clenbuterol (CL) in goat tissues, plasma and urine after the repeated administration of a growth-promoting dose. The experiment was conducted in 24 goats (21 treated and 3 controls). Treated animals were administered orally in a dose of 16 µg/kg body mass once daily for 21 consecutive days and randomly sacrificed on days 0.25, 1, 3, 7, 14, 21 and 28 of the withdrawal period. CL in goat tissues was extracted with organic solvents and determined using liquid chromatography tandem mass spectrometry. The depletion rates of tissue differed significantly. The highest concentrations of CL in all tissues are detected on day 0.25 of treatment discontinuation. After administration had been discontinued for 28 days, CL still residues in all tissues, especially, in whole eye, where the concentrations reach 363.29 ± 31.60 μg/kg. These findings confirmed that the whole eye, which are rich in pigment, showed a much higher concentration than any other studied tissue during the withdrawal period. PMID:25910488

  11. Hippocampal Aβ expression, but not phosphorylated tau, predicts cognitive deficits following repeated peripheral poly I:C administration.

    PubMed

    White, J D; Eimerbrink, M J; Hayes, H B; Hardy, A; Van Enkevort, E A; Peterman, J L; Chumley, M J; Boehm, G W

    2016-10-15

    Alzheimer's disease is marked by the accumulation of the amyloid-beta (Aβ) peptide, and increases in phosphorylation of the microtubule associated protein, tau. Changes in these proteins are considered responsible, in part, for the progressive neuronal degeneration and cognitive deficits seen in AD. We examined the effect of repeated consecutive peripheral poly I:C injections on cognitive deficits, central Aβ, and phosphorylated tau accumulation, following three treatment durations: 7, 14, and 21 days. Forty-eight hours after the final injection, animals were trained in a contextual fear-conditioning paradigm, and tested 24h later. Immediately after testing, the hippocampus was collected to quantify Aβ and phosphorylated tau accumulation. Results showed that, although poly I:C-induced Aβ was significantly elevated at all time points examined, poly I:C only disrupted cognition after 14 and 21 days of administration. Moreover, elevations in phosphorylated tau were not seen until the 14-day time point. Interestingly, phosphorylated tau expression then declined at the 21-day time point. Finally, we demonstrated that Aβ levels are a stronger predictor of cognitive dysfunction, explaining 37% of the variance, whereas phosphorylated tau levels only accounted for 0.2%. Taken together, these results support the hypothesis that inflammation-induced elevation in Aβ disrupts cognition, independently of phosphorylated tau, and suggest that long-term administration of poly I:C may provide a model to investigate the contribution of long-term inflammation toward the development of Alzheimer's-like pathology. PMID:27449203

  12. Influence of single and repeated cannabidiol administration on emotional behavior and markers of cell proliferation and neurogenesis in non-stressed mice.

    PubMed

    Schiavon, Angélica Pupin; Bonato, Jéssica Mendes; Milani, Humberto; Guimarães, Francisco Silveira; Weffort de Oliveira, Rúbia Maria

    2016-01-01

    Therapeutic effects of antidepressants and atypical antipsychotics may arise partially from their ability to stimulate neurogenesis. Cannabidiol (CBD), a phytocannabinoid present in Cannabis sativa, presents anxiolytic- and antipsychotic-like effects in preclinical and clinical settings. Anxiolytic-like effects of repeated CBD were shown in chronically stressed animals and these effects were parallel with increased hippocampal neurogenesis. However, antidepressant-like effects of repeated CBD administration in non-stressed animals have been scarcely reported. Here we investigated the behavioral consequences of single or repeated CBD administration in non-stressed animals. We also determined the effects of CBD on cell proliferation and neurogenesis in the dentate gyrus (DG) and subventricular zone (SVZ). Single CBD 3mg/kg administration resulted in anxiolytic-like effect in mice submitted to the elevated plus maze (EPM). In the tail suspension test (TST), single or repeated CBD administration reduced immobility time, an effect that was comparable to those of imipramine (20 mg/kg). Moreover, repeated CBD administration at a lower dose (3 mg/kg) increased cell proliferation and neurogenesis, as seen by an increased number of Ki-67-, BrdU- and doublecortin (DCX)-positive cells in both in DG and SVZ. Despite its antidepressant-like effects in the TST, repeated CBD administration at a higher dose (30 mg/kg) decreased cell proliferation and neurogenesis in the hippocampal DG and SVZ. Our findings show a dissociation between behavioral and proliferative effects of repeated CBD and suggest that the antidepressant-like effects of CBD may occur independently of adult neurogenesis in non-stressed Swiss mice. PMID:26187374

  13. [Misuse of opioid analgesics. An internet analysis].

    PubMed

    Krüger, R; Meißner, W; Zimmer, A

    2014-10-01

    Apart from the prescribed administration and indications for pain relief, opioids are also used for unintended purposes. Information for misuse is circulated on the internet. In order to analyze the abuse of opioids and opiates,which are only available by prescription, defined search keywords were entered into the search engine of a German language internet forum on drugs in 2010 and 2013 and the results were evaluated. Items to be assessed and analyzed were the frequency of naming various substances and (in the first analysis only) aspects of their incorporation as well as user reports on various aspects of use (e.g. drug procurement, administration, effects and side effects). Tramadol was the most frequently quoted opioid followed by codeine, tilidine, morphine and oxycodone. Other opioids were named in only 10 % of the entries. Oral intake was the most frequently mentioned mode of administration followed by parenteral and nasal routes. These findings can support caregivers to identify unintended use of opioids and to increase awareness of the most frequently used opioids and modes of administration. PMID:25106826

  14. Effects of chronic and repeated repeated coritcosterone administration in rearing chickens on physiology, the onset of lay and egg production in hens.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A corticosterone (CORT) model was used to study the effects of repeated stress during rearing phase on physiology and performance of hens’ in subsequent laying period. Two hundred and seventy Hy-line laying birds were reared in environmentally controlled battery cages. At 7, 11, and 15 wk of age bir...

  15. Dopamine D4 receptors linked to protein kinase G are required for changes in dopamine release followed by locomotor activity after repeated cocaine administration.

    PubMed

    Oh, Jeong Hwan; Lee, Dong Kun; Shim, Yoon-Bo; Ryu, In Soo; Seo, Su Yeon; Kim, Jieun; Yang, Ju Hwan; Cho, Hyun-Wook; Choe, Eun Sang

    2015-05-01

    We previously found that the dopamine D2-type receptors (D2 and D3 receptors), coupled to protein kinase G (PKG), upregulate locomotor activity after repeated cocaine administration. In this study, D4 receptors, another type of D2 receptor also coupled to PKG, were examined to determine their requirement in the regulation of locomotor activity after repeated cocaine administration. The results demonstrated that repeated injections of cocaine (20 mg/kg), given once a day for seven consecutive days, significantly increased extracellular dopamine concentrations. Intra-caudate infusion of the D4 receptor agonist, PD168077 (10 nmol), and the PKG inhibitor, KT5823 (2 nmol), significantly decreased the repeated cocaine-induced increase in dopamine levels and locomotor activity. However, intra-caudate infusion of KT5823, but not PD168077, decreased ∆FosB immunoreactivity elevated by repeated cocaine administration. These findings suggest that D4 receptors linked to PKG could be a key modulator for dopamine release required for changes in locomotor activity caused by repeated cocaine exposure. PMID:25702161

  16. Neuroprotection and functional recovery conferred by administration of kappa- and delta 1-opioid agonists in a rat model of global ischemia.

    PubMed

    Charron, Charlaine; Messier, Claude; Plamondon, Hélène

    2008-02-27

    Studies that have evaluated the beneficial effect of pre-ischemic treatment of kappa-opioid receptor agonists have used short-term reperfusion intervals. We examined the long-term impact of the pre-ischemic peripheral injection of U50,488H (trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-benzeneacetamide), a selective kappa-opioid receptor agonist, on neuronal damage and behavioral deficits following global ischemia in rats. Four groups of ischemic rats were pretreated with various doses of U50,488H (i.p. 0, 5, 15, 30 mg/kg) 15 min prior to vessel occlusion. Two groups of sham-operated animals that received either saline or U50,488H (30 mg/kg) acted as controls. The injection of 30 mg/kg U50,488H led to a 65% increase in CA1 neuron survival 35 days post-ischemia. CA1 neuronal protection translated into significant improvement of ischemia-induced spatial memory deficits assessed in the 8-arm radial maze. However, there was no difference in activity in the open field. We also found that the pre-ischemic intracerebroventricular injection of 5 mug of the delta1-opioid receptor agonist DPDPE ([d-Pen(2,5)]-enkephalin) produced a 59% increase in CA1 neuron survival 7 days post-ischemia. Similar to U50,488H, DPDPE had no significant impact on locomotor activity. These findings support a role for kappa- and delta-opioid receptors in attenuation of ischemia-induced hippocampal damage and cognitive impairments. PMID:18031772

  17. A comparative pharmacokinetic and pharmacodynamic study of FSK0808 versus reference filgrastim after repeated subcutaneous administration in healthy Japanese men.

    PubMed

    Matsuguma, Kyoko; Matsuki, Shunji; Sakamoto, Kei; Shiramoto, Masanari; Nakagawa, Misato; Kimura, Miyuki; Irie, Shin; Kaneko, Daiki; Ohnishi, Akihiro

    2015-03-01

    FSK0808, a biosimilar of filgrastim, is a recombinant human granulocyte colony-stimulating factor developed by Fuji Pharmaceuticals and Mochida Pharmaceutical Co., Ltd. We conducted a double-blind, randomized, crossover study in healthy Japanese men, comparing the number of CD34-positive cells (CD34(+) cells) after repeated subcutaneous administration of either FSK0808 or the reference filgrastim (Gran(®) ). As primary endpoints, we compared the maximum number of CD34(+) cells (CD34(+)  Cmax ) and the time to reach CD34(+) Cmax (CD34(+) tmax ). As secondary endpoints, we compared the area under the curve for the number of CD34(+) cells over time at the 410 hours time point (CD34(+) AUC0-410 ), the parameters used to calculate the pharmacodynamic index of the absolute neutrophil count, and the pharmacokinetic parameters. Regarding the CD34(+) Cmax and the CD34(+) AUC0-410 values, the 95% confidence interval (CI) of the differences between the mean values for each drug was within the range of log(0.8)-log(1.25). With respect to the differences in the median values between drugs, the ratio against the reference filgrastim median value in the 95% CI was within the range of ± 0.2 for the CD34(+) tmax value. From these results, we considered that these drugs display equivalent pharmacodynamic and pharmacokinetic properties. PMID:27128214

  18. Corticotropin releasing factor-1 receptor antagonism alters the biochemical, but not behavioral effects of repeated interleukin-1β administration

    PubMed Central

    Wilhelm, Clare J.; Murphy-Crews, Aaron; Menasco, Daniel J.; Huckans, Marilyn S.; Loftis, Jennifer M.

    2011-01-01

    Activation of the immune system via administration of cytokines is used for the treatment of chronic viral infections such as hepatitis C and for cancers resistant to radiotherapy. Cytokine-based treatments induce a range of “sickness” behaviors (e.g. depression, anxiety, pain, anorexia, and fatigue). Activation of the hypothalamic pituitary-adrenal axis via the induction of corticotropin releasing factor (CRF) may underlie these unwanted side effects. This study used repeated systemic injections of the pro-inflammatory cytokine interleukin-1β (IL-1β) to model the sickness behaviors and biochemical effects of immune system activation. We assessed the ability of CRF type I receptor (CRF1) antagonism to reduce biochemical and behavioral signs of sickness induced by IL-1β treatment. Forty Wistar rats were assigned to one of four groups: 1) saline + vehicle; 2) saline + DMP904 (CRF1 antagonist); 3) IL-1β + vehicle; 4) IL-1β + DMP904. Rats received intraperitoneal injections of either DMP904 or vehicle and of IL-1β or saline for six days. Sickness behavior was evaluated using body weight assessments and forced swim testing (FST). Blood and brain samples were collected to measure cytokine, p38 mitogen activated protein kinase (MAPK), and phospho-p38 MAPK levels using multiplex techniques. There were significant reductions in body weights and FST immobility times associated with IL-1β administration. Rats administered IL-1β had significantly higher serum levels of IL-10, but not interferon-γ. Within the hippocampus, IL-1β reduced levels of p38 MAPK, but had no impact on levels of phospho-p38 MAPK except in the presence of DMP904. When administered alone, DMP904 had no significant effect on p38 MAPK or phospho-p38 MAPK in the hippocampus, but when given with IL-1β led to increased phosphorylation of p38 MAPK. IL-1β and DMP904 reduced levels of p38 MAPK within the hypothalamus, while co-administration of IL-1β and DMP904 abolished the effects of either drug

  19. Corticotropin releasing factor-1 receptor antagonism alters the biochemical, but not behavioral effects of repeated interleukin-1β administration.

    PubMed

    Wilhelm, Clare J; Murphy-Crews, Aaron; Menasco, Daniel J; Huckans, Marilyn S; Loftis, Jennifer M

    2012-01-01

    Activation of the immune system via administration of cytokines is used for the treatment of chronic viral infections such as hepatitis C and for cancers resistant to radiotherapy. Cytokine-based treatments induce a range of "sickness" behaviors (e.g. depression, anxiety, pain, anorexia, and fatigue). Activation of the hypothalamic pituitary-adrenal axis via the induction of corticotropin releasing factor (CRF) may underlie these unwanted side effects. This study used repeated systemic injections of the pro-inflammatory cytokine interleukin-1β (IL-1β) to model the sickness behaviors and biochemical effects of immune system activation. We assessed the ability of CRF type I receptor (CRF(1)) antagonism to reduce biochemical and behavioral signs of sickness induced by IL-1β treatment. Forty Wistar rats were assigned to one of four groups: 1) saline+vehicle; 2) saline+DMP904 (CRF(1) antagonist); 3) IL-1β+vehicle; 4) IL-1β+DMP904. Rats received intraperitoneal injections of either DMP904 or vehicle and of IL-1β or saline for six days. Sickness behavior was evaluated using body weight assessments and forced swim testing (FST). Blood and brain samples were collected to measure cytokine, p38 mitogen-activated protein kinase (MAPK), and phospho-p38 MAPK levels using multiplex techniques. There were significant reductions in body weights and FST immobility times associated with IL-1β administration. Rats administered IL-1β had significantly higher serum levels of IL-10, but not interferon-γ. Within the hippocampus, IL-1β reduced levels of p38 MAPK, but had no impact on levels of phospho-p38 MAPK except in the presence of DMP904. When administered alone, DMP904 had no significant effect on p38 MAPK or phospho-p38 MAPK in the hippocampus, but when given with IL-1β led to increased phosphorylation of p38 MAPK. IL-1β and DMP904 reduced levels of p38 MAPK within the hypothalamus, while co-administration of IL-1β and DMP904 abolished the effects of either drug alone

  20. Effects of acute and repeated administration of N-methyl-D-aspartate (NMDA) into the ventral tegmental area: locomotor activating effects of NMDA and cocaine.

    PubMed

    Schenk, S; Partridge, B

    1997-09-26

    Repeated, intermittent administration of psychostimulants produces an enhancement of the subsequent behavioral effects of these drugs. This behavioral sensitization has been implicated in maintenance of and relapse to drug-taking. As a result, there has been great interest in elucidating the mechanisms underlying both the development and expression of sensitization. An accumulation of data from studies of stimulant-induced locomotor activity has implicated excitatory amino acids in the development of behavioral sensitization. In the present study, N-methyl-D-aspartate (NMDA) (0.6, 1.25 or 2.5 microg) infused bilaterally into the ventral tegmental area (VTA) produced dose-dependent locomotor activation. The locomotor activating effect of NMDA was increased following repeated NMDA administration (two exposures to intra-VTA NMDA), suggesting sensitization. However, repeated intra-VTA NMDA failed to sensitize rats to the locomotor activating effects of systemically administered cocaine (5.0, 10.0 or 20.0 mg/kg). These findings are consistent with the notion that repeated activation of NMDA receptors is sufficient for the development of behavioral sensitization to NMDA. Other neuroadaptations produced by repeated psychostimulant administration are required in order for the development of sensitization to the behavioral effects of those drugs. PMID:9374190

  1. Regulation of opioid receptors by cocaine.

    PubMed

    Unterwald, E M

    2001-06-01

    Cocaine is a widely abused psychostimulant. Its direct actions include inhibition of dopamine, serotonin, and norepinephrine reuptake into presynaptic nerve terminals, thereby potentiating the actions of these transmitters in the synapse. A variety of studies have demonstrated that cocaine can also have profound effects on the endogenous opioid system. Compelling evidence points to the importance of mu opioid receptors in human cocaine addiction and craving. Animal studies support these findings and demonstrate that chronic cocaine administration can result in alterations in opioid receptor expression and function as measured by changes in critical signal transduction pathways. This chapter reviews studies on the regulation of opioid receptors as the result of exposure to cocaine. PMID:11458541

  2. Intranasal administration of crushed ALO-02 (extended-release oxycodone with sequestered naltrexone): A randomized, controlled abuse-potential study in nondependent recreational opioid users.

    PubMed

    Setnik, Beatrice; Bramson, Candace; Bass, Almasa; Levy-Cooperman, Naama; Malhotra, Bimal; Matschke, Kyle; Sommerville, Kenneth W; Wolfram, Gernot; Geoffroy, Pierre

    2015-12-01

    ALO-02 is an abuse-deterrent formulation consisting of capsules filled with pellets of extended-release oxycodone surrounding sequestered naltrexone. This randomized, double-blind, placebo-/active-controlled, 4-way crossover study examined the abuse potential of crushed ALO-02 administered intranasally to healthy, nondependent, recreational opioid users. Following drug discrimination and naloxone challenge, eligible participants (n = 32) entered a 4-way crossover treatment phase: crushed single dose of 1 of 2 placebos, ALO-02 30 mg/3.6 mg (oxycodone/naltrexone) or oxycodone immediate-release (IR) 30 mg. Primary end points were Drug Liking and High, measured on visual analog scales (VAS) summarized as maximum effect (Emax ) and effect occurring over 2 hours postdose (AUE0-2  h ). Crushed ALO-02 resulted in significantly lower scores versus oxycodone IR on Drug Liking (Emax , 60.5 vs 92.8; AUE0-2  h , 105.4 vs 160.0, respectively) and High (Emax , 25.2 vs 86.9; AUE0-2  h , 27.1 vs 136.4, respectively; n = 28; P < .0001). Adverse events occurred most frequently with oxycodone IR, followed by ALO-02, then placebo, and were considered mild and consistent with opioid therapy. Crushed ALO-02 administered intranasally to nondependent recreational opioid users resulted in significantly lower scores on Drug Liking/High VAS and other positive subjective measures versus crushed oxycodone IR, suggesting less abuse potential. Demonstration of actual abuse deterrence in the real world requires further research. PMID:26011742

  3. Repeated systemic administrations of both aminobisphosphonates and human Vγ9Vδ2 T cells efficiently control tumor development in vivo.

    PubMed

    Santolaria, Thibault; Robard, Myriam; Léger, Alexandra; Catros, Véronique; Bonneville, Marc; Scotet, Emmanuel

    2013-08-15

    Peripheral Vγ9Vδ2 T lymphocytes compose a major γδ T cell subset in primates with broad reactivity against tumor cells. Vγ9Vδ2 T cells are specifically activated by phosphorylated isoprenoid pathway metabolites called "phosphoagonists." Accordingly, pharmacologic inhibitors of the mevalonate pathway, such as aminobisphosphonates (NBP) that upregulate the intracellular production of phosphoagonists, increase antitumor Vγ9Vδ2 T cell responses. Immunotherapeutic protocols exploiting GMP-grade agonist molecules targeting human Vγ9Vδ2 T lymphocytes have yielded promising, yet limited, signs of antitumor efficacy and therefore need to be improved for next-generation immunotherapies. In this study, we used a model of s.c. human tumor xenografts in severely immunodeficient mice to assess the antitumor efficacy of systemic NBP treatments when combined with the adoptive transfer of human Vγ9Vδ2 T cells. We show that infusion of Vγ9Vδ2 T cells, 24 h after systemic NBP treatment, efficiently delays tumor growth in mice. Importantly, our results indicate efficient but transient in vivo NBP-induced sensitization of tumor cells to human Vγ9Vδ2-T cell recognition. Accordingly, repeated and combined administrations of both NBP and γδ T cells yielded improved antitumor responses in vivo. Because Vγ9Vδ2 T cells show similar responsiveness toward both autologous and allogeneic tumors and are devoid of alloreactivity, these results provide preclinical proof of concept for optimized antitumor immunotherapies combining NBP treatment and adoptive transfer of allogeneic human γδ T cells. PMID:23836057

  4. Desensitization of ovalbumin-sensitized mice by repeated co-administrations of di-(2-ethylhexyl) phthalate and ovalbumin

    PubMed Central

    Larsen, Søren T; Nielsen, Gunnar D

    2009-01-01

    Background The plasticizer di-(2-ethylhexyl) phthalate (DEHP) has been shown to stimulate a non-allergy related immune response with increased levels of IgG1 and IgG2a, but not IgE, after co-administration with the model allergen ovalbumin (OVA) in mice. In mice, decreased IgG1 and increased IgG2a have been associated with the development of mucosal tolerance towards inhaled allergens. As DEHP selectively promote formations of IgG1 and IgG2a without stimulating the IgE response, it was hypothesized that DEHP may suppress an established IgE mediated allergic response. Mice pre-sensitised to OVA were repeatedly co-exposed to DEHP and OVA and the effects were evaluated on the levels of OVA-specific antibodies, ex vivo cytokine levels and the degree of lung inflammation after challenge with an OVA aerosol. Findings Compared to the OVA-sensitised control mice, multiple co-exposures to DEHP+OVA reduced the IgG1 level and reduced the IgE/IgG2a ratio. This suggests that DEHP may attenuate allergic sensitisation, as the IgE/IgG2a ratio has been shown to correlate with the degree of anaphylaxis. Nevertheless, no effect of DEHP exposures was seen on inflammatory cells in bronchoalveolar lavage fluid and on cytokine levels in spleen cell culture. Conclusion Data from humane and murine studies suggest that DEHP may attenuate the allergic response. More studies are necessary in order to assess the size of this effect and to rule out the underlying mechanism. PMID:19900263

  5. Treating Opioid-Induced Constipation in Older Adults: New Options.

    PubMed

    Sani, Halima; Mahan, Rebecca J

    2015-10-01

    Numerous factors, such as changes in gastrointestinal physiology, reduced mobility, decreased liquid and nutritional intake, and certain comorbidities, predispose older adults to constipation. Use of opioid medications further compounds this problem. Unlike other side effects associated with opioid use, patients do not develop tolerance to constipation and other opioid-induced bowel dysfunctions. Although opioid-induced constipation has a prevalence rate of 80% in this population, it remains highly undertreated. Despite this problem, there have been limited therapeutic options available for older adults suffering from opioid-induced constipation. On September 16, 2014, a new oral agent, naloxegol, a peripherally acting muopioid receptor antagonist (PAMORA), approved by the Food and Drug Administration, provides new hope for patients. This paper explores clinical complications associated with opioid-induced constipation in older adults, analyzes the efficacy and safety of laxatives and PAMORAs, and defines the future role of naloxegol in this vulnerable population. PMID:26450143

  6. Central antinociception induced by ketamine is mediated by endogenous opioids and μ- and δ-opioid receptors.

    PubMed

    Pacheco, Daniela da Fonseca; Romero, Thiago Roberto Lima; Duarte, Igor Dimitri Gama

    2014-05-01

    It is generally believed that NMDA receptor antagonism accounts for most of the anesthetic and analgesic effects of ketamine, however, it interacts at multiple sites in the central nervous system, including NMDA and non-NMDA glutamate receptors, nicotinic and muscarinic cholinergic receptors, and adrenergic and opioid receptors. Interestingly, it was shown that at supraspinal sites, ketamine interacts with the μ-opioid system and causes supraspinal antinociception. In this study, we investigated the involvement of endogenous opioids in ketamine-induced central antinociception. The nociceptive threshold for thermal stimulation was measured in Swiss mice using the tail-flick test. The drugs were administered via the intracerebroventricular route. Our results demonstrated that the opioid receptor antagonist naloxone, the μ-opioid receptor antagonist clocinnamox and the δ-opioid receptor antagonist naltrindole, but not the κ-opioid receptor antagonist nor-binaltorphimine, antagonized ketamine-induced central antinociception in a dose-dependent manner. Additionally, the administration of the aminopeptidase inhibitor bestatin significantly enhanced low-dose ketamine-induced central antinociception. These data provide evidence for the involvement of endogenous opioids and μ- and δ-opioid receptors in ketamine-induced central antinociception. In contrast, κ-opioid receptors not appear to be involved in this effect. PMID:24675031

  7. Medication-Assisted Treatment For Opioid Addiction in Opioid Treatment Programs. Treatment Improvement Protocol (TIP) Series 43

    ERIC Educational Resources Information Center

    Tinkler, Emily; Vallejos Bartlett, Catalina; Brooks, Margaret; Gilbert, Johnatnan Max; Henderson, Randi; Shuman, Deborah, J.

    2005-01-01

    TIP 43 provides best-practice guidelines for medication-assisted treatment of opioid addiction in opioid treatment programs (OTPs). The primary intended audience for this volume is substance abuse treatment providers and administrators who work in OTPs. Recommendations in the TIP are based on both an analysis of current research and determinations…

  8. Buprenorphine for opioid dependence.

    PubMed

    Ling, Walter

    2009-05-01

    As a treatment agent for opioid dependence, buprenorphine is a nearly ideal medication at our current stage of medication development. Unlike methadone, buprenorphine dosage can be rapidly adjusted with minimal potential for inducing severe consequences. In addition to its intrinsic safety, buprenorphine's relatively low abuse liability in the combination product (i.e., with naloxone as Suboxone) makes it even more acceptable in regulatory quarters as well as to prescribing physicians. The approval of buprenorphine as a pharmacotherapy for opioid dependence returns to physicians the ability to treat their opioid-dependent patients with an effective opioid-based treatment for the first time in nearly 100 years. Buprenorphine is an opioid, however, and potential for misuse remains, even in combination with naloxone. Whether buprenorphine will be increasingly accepted as a treatment for opioid-dependent patients depends on clinicians recognizing the advantages of its uniquely useful properties while still heeding the need to manage their patients' therapy with reasonable vigilance. PMID:19402772

  9. Opioids and endocrine dysfunction

    PubMed Central

    Hester, Joan

    2012-01-01

    The endocrine effects of opioids used for the management of persistent pain are poorly understood by clinicians and patients, and hormone levels are rarely measured. It is recognized that opioids exert this effect via the hypothalamic-pituitary-gonadal axis. Additional effects on adrenal hormones, weight, blood pressure and bone density may also occur. Symptoms and signs of sex hormone deficiency occur in both men and women but are under-reported and are often clinically unrecognized. The potential effects of long term opioid therapy on the endocrine system should be explained to patients before opioid therapy is commenced. Monitoring of sex hormones is recommended; if there are deficiencies opioids should be tapered and withdrawn, if this is clinically acceptable. If opioid therapy has to continue, hormone replacement therapy should be initiated and monitored by an endocrinologist. PMID:26516462

  10. Repeated intravenous administrations of teneurin-C terminal associated peptide (TCAP)-1 attenuates reinstatement of cocaine seeking by corticotropin-releasing factor (CRF) in rats.

    PubMed

    Erb, Suzanne; McPhee, Matthew; Brown, Zenya J; Kupferschmidt, David A; Song, Lifang; Lovejoy, David A

    2014-08-01

    The teneurin c-terminal associated peptides (TCAP) have been implicated in the regulation of the stress response, possibly via a corticotropin-releasing factor (CRF)-related mechanism. We have previously shown that repeated intracerebroventricular (ICV) injections of TCAP-1 attenuate the reinstatement of cocaine seeking by CRF in rats. Here, we determined whether intravenous (IV) administrations of TCAP-1 would likewise attenuate CRF-induced reinstatement, and whether this effect would vary depending on the rat's history of cocaine self administration. Rats were trained to self-administer cocaine for 10 days, during once daily sessions that were either 3h ("short access"; ShA) or 6h ("long access"; LgA). Rats were then given five daily injections of TCAP-1 (0, 300, or 3,000 pmol, IV) in their home cage. Subsequently, they were returned to the self-administration chambers where extinction of cocaine seeking and testing for CRF-induced reinstatement of cocaine seeking was carried out. Repeated IV administrations of TCAP-1 were efficacious in attenuating CRF-induced reinstatement of cocaine seeking, but at different doses in ShA and LgA rats. Taken together, the findings extend previous work showing a consistent effect of repeated ICV TCAP-1 on CRF-induced reinstatement of cocaine seeking, and point to a potential therapeutic benefit of TCAP-1 in attenuating cocaine seeking behaviors. PMID:24768621

  11. The socially evaluated cold-pressor test (SECPT) for groups: effects of repeated administration of a combined physiological and psychological stressor.

    PubMed

    Minkley, Nina; Schröder, Thomas P; Wolf, Oliver T; Kirchner, Wolfgang H

    2014-07-01

    The combined administration of physiological (cold pressor) and psychological (social-evaluative threat) stressors, as in the socially evaluated cold pressor test (SECPT; Schwabe et al., 2008) activates the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. Thus far, the SECPT has been administered exclusively to individual participants, which requires substantial personal effort and time. Therefore, the aim of the present study was to investigate whether and to what extent cardiovascular parameters (SNS) and salivary cortisol concentrations (HPA axis) are affected over the course of repeated SECPT administration in a group design. The SECPT was conducted in groups of seven or more persons and repeated twice with a 24-h interval between each administration. During the stress test, the participants (n=61) were videotaped and observed continuously while they immersed their hands into ice-cold (1 °C, experimental group) or room-temperature (20 °C, control group) water. Blood pressure, heart rate, salivary cortisol concentration, and subjective stress perception were measured. All of these parameters increased significantly during each of the three stress exposures; in contrast, they remained constant in the control group. Moreover, the heart rate response towards the stressor decreased significantly over the course of the repeated stress exposures and salivary cortisol concentration of the experimental group was elevated before the third SECPT administration. Our results indicate that the group SECPT activates the SNS and the HPA, leading to increased blood pressure, heart rate, and cortisol concentration. Moreover, the repeated administration leads to habituation exclusively of heart rate. PMID:24845183

  12. The effects of acute and repeated administration of ketamine on attentional performance in the five-choice serial reaction time task in rats.

    PubMed

    Nikiforuk, Agnieszka; Popik, Piotr

    2014-08-01

    Ketamine, the non-competitive antagonist of the N-methyl-d-aspartate receptors, is used in clinical and preclinical studies to produce schizophrenia-like cognitive impairments. However, the impact of ketamine on attentional functions remains poorly characterised. In the present study, we further examine the effects of ketamine on attentional processes assessed in the five-choice serial reaction time task (5-CSRTT) in rats. The applied schedules of ketamine administration have been previously demonstrated to evoke frontal-dependent set-shifting impairments. Rats were trained to reach a stable baseline performance. Afterwards, animals received a single injection of ketamine (0, 3 and 10 mg/kg, IP) 45 min before the 5-CSRTT session (experiment 1). In experiment 2, ketamine (0 and 30 mg/kg, IP) was administered after the daily test session for 10 consecutive days. The rats' performance was assessed at 22 h following ketamine administration and for 4 days after the last dose. Acute and repeated administration of ketamine disrupted rats performance on the 5-CSRTT. Reduced speed of responding and an increased number of omissions were noted in the absence of reduced food motivation. The within-session pattern of responding differed between rats treated acutely and repeatedly with ketamine. Specifically, repeated drug administration evoked an increase in omissions toward the end of the session, and this effect was not secondary to the reduced motivation. Ketamine affected performance during the withdrawal period only when testing with variable inter-trial intervals. The repeated administration of ketamine can impair rats' ability to sustain attention over the course of session, suggesting some utility for modelling attentional disturbances. PMID:24846536

  13. Using buprenorphine for outpatient opioid detoxification.

    PubMed

    Manlandro, James J

    2007-09-01

    The Drug Addiction Treatment Act of 2000 (DATA 2000) was established to create a new paradigm for medication-assisted treatment of persons with opiate addiction in the United States. Before enactment of DATA 2000, the use of opioid medications to treat patients with opioid addiction was permissible only in federally approved treatment programs, ie, "methadone clinics." The only medications permitted were Schedule II drugs (eg, methadone hydrochloride and l-alpha-acetylmethadol [LAAM]), which could only be dispensed, not prescribed. Under provisions of DATA 2000, qualified physicians in a medical office and other appropriate settings outside the opioid treatment program system may prescribe and/or dispense Schedule III, IV, and V opioid medications for treating persons with opioid addiction if such medications have been specifically approved by the US Food and Drug Administration for that indication. Opioid addiction treatment programs were commonly known as methadone clinics. Such programs now may also dispense buprenorphine hydrochloride and the buprenorphine hydrochloride-naloxone combination. PMID:17908825

  14. [Breakthrough pain and short-acting opioids].

    PubMed

    Beutlhauser, T; Oeltjenbruns, J; Schäfer, M

    2013-06-01

    Conventional opioid therapy consists of the regular administration of extended-release opioids following fixed time intervals and, as needed, the supplemental use of an immediate-release formulation. For the patient needs of such rescue medication, recent studies distinguished different scenarios, such as an inadequate daily opioid dose or time interval (end-of-dose failure) from so-called breakthrough pain where the attacks can suddenly occur either spontaneously (idiopathic pain) or due to certain provocations (incident pain) despite optimal dose adjustment. In line with this time course, a fast and short-lasting elevation of the opioid plasma concentration seems to be reasonable. Although in a recent European survey breakthrough pain attacks in the majority of cancer pain patients were sufficiently treated with immediate-release opioids, currently running clinical trials examine whether the application of transmucosal or intranasal fentanyl with their known reduced time to maximum plasma concentrations show a possible advantage in comparison to immediate-release opioids. In these clinical trials the pain intensity and number of pain episodes were significantly reduced following transmucosal or intranasal fentanyl; however, the magnitude of these effects does not convincingly appear to be clinically relevant. Among other reasons this may be related to the fact that those patients who would perhaps benefit from such treatment have not yet been identified. PMID:23754483

  15. [Pain and opioids].

    PubMed

    Murányi, Marianna; Radák, Zsolt

    2008-12-14

    Noxious stimuli cause pain to protect the body from harmful situations and attract attention to pathophysiologic changes of the body. Specific receptors of pain (nociceptors) can be found all over our body. Pain initiates protecting mechanisms such as vegetative and motor reflexes, and emotional, behavioral changes. However, chronic pain is practically useless and leads to psychopathological changes. There are several ways to relieve pain including non-steroid anti-inflammatory agents, opioids, neurosurgical and non-invasive methods. Central and peripheral effects of opioids can be realized through opioid receptors of the central and the enteric nervous system. In the central nervous system, they can inhibit the perception of pain or change the emotional reactions. Opioids are indicated in postoperative pain, neuropathic pain and cancer. However, the use of opioids has severe side-effects such as breathing depression and the development of tolerance and dependence which do not make opioids optimal painkillers. There are several laboratories in Hungary and abroad working on the design of optimal pain relievers. Furthermore, the euphoric effects of opioids lead to abuse which makes the research important on the mechanisms of opioid addiction. Taken together, opioid research, the design of new compounds and the exploration of the mechanisms of opiate addiction are very important. PMID:19073443

  16. Parenteral opioids for maternal pain management in labour

    PubMed Central

    Ullman, Roz; Smith, Lesley A; Burns, Ethel; Mori, Rintaro; Dowswell, Therese

    2014-01-01

    Background Parenteral opioids are used for pain relief in labour in many countries throughout the world. Objectives To assess the acceptability, effectiveness and safety of different types, doses and modes of administration of parenteral opioids given to women in labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (30 April 2011) and reference lists of retrieved studies. Selection criteria We included randomised controlled trials examining the use of intramuscular or intravenous opioids (including patient controlled analgesia) for women in labour. We looked at studies comparing an opioid with another opioid, placebo, other non-pharmacological interventions (TENS) or inhaled analgesia. Data collection and analysis At least two review authors independently assessed study eligibility, collected data and assessed risk of bias. Main results We included 57 studies involving more than 7000 women that compared an opioid with placebo, another opioid administered intramuscularly or intravenously or compared with TENS to the back. The 57 studies reported on 29 different comparisons, and for many outcomes only one study contributed data. Overall, the evidence was of poor quality regarding the analgesic effect of opioids, satisfaction with analgesia, adverse effects and harm to women and babies. There were few statistically significant results. Many of the studies had small sample sizes, and low statistical power. Overall findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour, although up to two-thirds of women who received opioids reported moderate or severe pain and/or poor or moderate pain relief one or two hours after administration. Opioid drugs were associated with maternal nausea, vomiting and drowsiness, although different opioid drugs were associated with different adverse effects. There was no clear evidence of adverse effects of opioids on the newborn. We

  17. [Forced opioid detoxification under general anesthesia--a new challenge for anesthetists and intensive care physicians].

    PubMed

    Hensel, M; Volk, T; Kox, W J

    1999-05-01

    Treatment of opioid addicts by means of competitive opioid receptor antagonists was developed at the University of Vienna in 1987 by Loimer and co-workers. They compared two withdrawal regimens: The short Opiate withdrawal using a staggered naloxone regimen and the rapid opiate detoxification during general anesthesia by means of high doses of naloxone. Based on the latter concept, various modifications have been developed world-wide using either naloxone or as an alternative, naltrexone, an antagonist available for oral administration only. However, there are considerable objections to opioid detoxification during general anasthesia. The main criticism is based an the supposedly unacceptable high risk:benefit-ratio, the higher costs, the lack of psycho-social support, and the lack of prospective studies. However, first results suggest that rapid detoxification procedures are more successful in decreasing relapse than methods which are based on psychiatric treatment alone. As sympathetic hyperfunction is common in rapid detoxification procedures using high doses of opioid receptor antagonists, it is essential to avoid severe autonomic imbalance with possible subsequent impairment of organ functions. To prevent those disturbances, general anesthesia plays an important role. So far, there is almost no information about such methods in the anesthesiological literature. In this article the clinical relevance of such methods is discussed summarizing both the available literature and our own experience and we conclude that rapid opioid detoxification under general anesthesia is a safe and efficient method to suppress withdrawal symptoms. This treatment may be of benefit in patients who particularly suffer from severe withdrawal symptoms and who have failed repeatedly to complete conventional withdrawal. PMID:10372215

  18. Repeated methylphenidate administration during lactation reduces maternal behavior, induces maternal tolerance, and increases anxiety-like behavior in pups in adulthood.

    PubMed

    Ponchio, R A; Teodorov, E; Kirsten, T B; Coelho, C P; Oshiro, A; Florio, J C; Bernardi, M M

    2015-01-01

    Methylphenidate (MPD) is a dopamine uptake inhibitor and the most commonly prescribed drug for the treatment of attention-deficit/hyperactivity disorder in children. Several studies have shown that such stimulants as cocaine and amphetamine that are administered during gestation and lactation may disrupt maternal behavior. Also, MPD is used in lactation. Repeated MPD administration can induce either sensitization or tolerance. The aim of the present study was to investigate whether repeated MPD administration alters maternal behavior and promotes tolerance or sensitization in these females. The effects in adult offspring were also examined in models of anxiety. Methylphenidate (5mg/kg) was administered from lactation day 2 to 4, and maternal pup retrieval behavior was assessed. This treatment was continued until lactation day 7. At weaning, the dams received a challenge dose of MPD, and general activity was evaluated in the open field. Striatal monoamine and metabolite levels were also measured to determine whether this treatment promotes behavioral or biochemical plasticity. The long-term behavioral effects of MPD exposure were evaluated in pups in adulthood. The results showed an increase in the latency to retrieve the first, second, and third pups and a decrease in the number of dams that retrieved all pups. After a challenge dose of MPD, the dams exhibited a decrease in locomotion frequency, an increase in immobility duration in the open field, and a decrease in striatal serotonin levels. In pups, anxiety-like behavior increased in the light/dark box test. These results indicate that repeated MPD administration during early lactation impairs maternal behavior, likely by decreasing maternal motivation. Repeated MPD administration induced maternal tolerance at weaning after a challenge dose of MPD, suggesting the development of central nervous system plasticity. In pups, maternal exposure to MPD during early lactation induced long-term effects and increased

  19. Opioid Peptidomimetics: Leads for the Design of Bioavailable Mixed Efficacy Mu Opioid Receptor (MOR) Agonist/Delta Opioid Receptor (DOR) Antagonist Ligands

    PubMed Central

    Mosberg, Henry I.; Yeomans, Larisa; Harland, Aubrie A.; Bender, Aaron M.; Sobczyk-Kojiro, Katarzyna; Anand, Jessica P.; Clark, Mary J.; Jutkiewicz, Emily M.; Traynor, John R.

    2013-01-01

    We have previously described opioid peptidomimetic, 1, employing a tetrahydroquinoline scaffold and modeled on a series of cyclic tetrapeptide opioid agonists. We have recently described modifications to these peptides that confer a mu opioid receptor (MOR) agonist, delta opioid receptor (DOR) antagonist profile, which has been shown to reduce the development of tolerance to the analgesic actions of MOR agonists. Several such bifunctional ligands have been reported, but none has been demonstrated to cross the blood brain barrier. Here we describe the transfer of structural features that evoked MOR agonist/DOR antagonist behavior in the cyclic peptides to the tetrahydroquinoline scaffold and show that the resulting peptidomimetics maintain the desired pharmacological profile. Further, the 4R diastereomer of 1 was fully efficacious and approximately equipotent to morphine in the mouse warm water tail withdrawal assay following intraperitoneal administration and thus a promising lead for the development of opioid analgesics with reduced tolerance. PMID:23419026

  20. Ligand-biased activation of extracellular signal-regulated kinase 1/2 leads to differences in opioid induced antinociception and tolerance.

    PubMed

    Bobeck, Erin N; Ingram, Susan L; Hermes, Sam M; Aicher, Sue A; Morgan, Michael M

    2016-02-01

    Opioids produce antinociception by activation of G protein signaling linked to the mu-opioid receptor (MOPr). However, opioid binding to the MOPr also activates β-arrestin signaling. Opioids such as DAMGO and fentanyl differ in their relative efficacy for activation of these signaling cascades, but the behavioral consequences of this differential signaling are not known. The purpose of this study was to evaluate the behavioral significance of G protein and internalization dependent signaling within ventrolateral periaqueductal gray (vlPAG). Antinociception induced by microinjecting DAMGO into the vlPAG was attenuated by blocking Gαi/o protein signaling with administration of pertussis toxin (PTX), preventing internalization with administration of dynamin dominant-negative inhibitory peptide (dyn-DN) or direct inhibition of ERK1/2 with administration of the MEK inhibitor, U0126. In contrast, the antinociceptive effect of microinjecting fentanyl into the vlPAG was not altered by administration of PTX or U0126, and was enhanced by administration of dyn-DN. Microinjection of DAMGO, but not fentanyl, into the vlPAG induced phosphorylation of ERK1/2, which was blocked by inhibiting receptor internalization with administration of dyn-DN, but not by inhibition of Gαi/o proteins. ERK1/2 inhibition also prevented the development and expression of tolerance to repeated DAMGO microinjections, but had no effect on fentanyl tolerance. These data reveal that ERK1/2 activation following MOPr internalization contributes to the antinociceptive effect of some (e.g., DAMGO), but not all opioids (e.g., fentanyl) despite the known similarities for these agonists to induce β-arrestin recruitment and internalization. PMID:26497105

  1. A review of opioid prescription in a teaching hospital in Colombia

    PubMed Central

    Moyano, Jairo; Figueras, Albert

    2012-01-01

    Introduction: Review of opioid prescriptions in a hospital provides valuable information to health care professionals which may contribute to proper pain management; opioid utilization studies may help uncover factors that can be improved for better prescribing. To evaluate the use of opioid analgesics in a university hospital, a review of opioids prescribed in hospitalized patients was developed. Methods: Information was obtained from the pharmacy database and medical records. The study period was 1 month. Results: Medical records of 1156 patients admitted in July 2009 were analyzed. The most widely prescribed opioid was tramadol; the preferred administration route was intravenous; the main indication was severe pain; and major prescribers were from surgical departments. Discussion: Underutilization of potent opioids for acute and chronic pain seems to occur. Conclusion: Most prescribers prefer weak opioids, given intravenously to treat acute and chronic pain, while some patients may benefit from the prescription of more potent opioids. PMID:23049273

  2. ACCUMULATION AND TISSUE DISPOSITION OF PARTICLE ASSOCIATED ELEMENTS IN THE RAT AFTER REPEATED INTRATRACHAEL ADMINISTRATION OF SOURCE PARTICLES

    EPA Science Inventory

    The goal of this study was to determine the fate of source particle tracer elements following repeated intratracheal instillation (IT) to rats. PM samples comprised Mt. St. Helens ash (MSH) with no water-soluble metals, and oil flyash emission PM (EPM) with water-leachable solubl...

  3. Endogenous opioids and feeding behavior: A decade of further progress (2004-2014). A Festschrift to Dr. Abba Kastin.

    PubMed

    Bodnar, Richard J

    2015-10-01

    Functional elucidation of the endogenous opioid system temporally paralleled the creation and growth of the journal, Peptides, under the leadership of its founding editor, Dr. Abba Kastin. He was prescient in publishing annual and uninterrupted reviews on Endogenous Opiates and Behavior that served as a microcosm for the journal under his stewardship. This author published a 2004 review, "Endogenous opioids and feeding behavior: a thirty-year historical perspective", summarizing research in this field between 1974 and 2003. The present review "closes the circle" by reviewing the last 10 years (2004-2014) of research examining the role of endogenous opioids and feeding behavior. The review summarizes effects upon ingestive behavior following administration of opioid receptor agonists, in opioid receptor knockout animals, following administration of general opioid receptor antagonists, following administration of selective mu, delta, kappa and ORL-1 receptor antagonists, and evaluating opioid peptide and opioid receptor changes in different food intake models. PMID:25843025

  4. Neuroprotective actions of GR89696, a highly potent and selective kappa-opioid receptor agonist.

    PubMed Central

    Birch, P. J.; Rogers, H.; Hayes, A. G.; Hayward, N. J.; Tyers, M. B.; Scopes, D. I.; Naylor, A.; Judd, D. B.

    1991-01-01

    1. The effect of a novel, highly potent and selective kappa-opioid receptor agonist, GR89696, has been evaluated in two animal models of cerebral ischaemia: transient bilateral carotid artery occlusion in the Mongolian gerbil and permanent, unilateral middle cerebral artery occlusion in the mouse. 2. In the Mongolian gerbil model, administration of GR89696 (3 to 30 micrograms kg-1, s.c.), immediately before and at 4 h after insult, produced a dose-dependent reduction in the hippocampal CA1 neuronal cell loss resulting from a 7-min bilateral carotid occlusion. Similar effects were obtained with two other kappa-agonists, GR86014 (1 mgkg-1, s.c.) and GR91272 (1 mgkg-1, s.c.). The neuroprotective effect of GR89696 was completely blocked by prior administration of the opioid receptor antagonist, naltrexone, at 10 mgkg-1, s.c. Repeated post-treatment with GR89696 (100 micrograms kg-1, s.c.) or GR44821 (10 mgkg-1, s.c.) was also effective in protecting completely the hippocampal CA1 neurones from ischaemia-induced neurodegeneration. 3. In the permanent, unilateral middle cerebral artery occlusion model in the mouse, repeated administration of GR89696 at 300 micrograms kg-1, s.c. produced a 50% reduction in cerebrocortical infarct volume. In these experiments GR89696 was dosed 5 min, 4, 8, 12, 16, 20 and 24 h after occlusion on the first day and then three times daily for the next three days. GR89696 (300 micrograms kg-1) also produced a significant 35% reduction in infarct volume in this model when the initiation of dosing was delayed for 6 h after the insult. 4. The results indicate that the potent kappa-opioid receptor agonist, GR89696, is neuroprotective in both global and focal cerebral ischaemia models and suggest that, with this class of compound, there may be a considerable time window for pharmacological intervention. PMID:1657267

  5. Pharmacokinetics of repeated sodium salicylate administration to laying hens: evidence for time dependent increase in drug elimination from plasma and eggs.

    PubMed

    Poźniak, Błażej; Grabowski, Tomasz; Motykiewicz-Pers, Karolina; Bobrek, Kamila; Rak, Lech; Bobusia, Katarzyna; Gaweł, Andrzej; Świtała, Marcin

    2015-01-01

    Salicylates were the first non-steroid anti-inflammatory drugs (NSAIDs) to be used in any species and are still widely used in humans and livestock. However, the data on their pharmacokinetics in animals is limited, especially after repeated administration. Evidence exist that in chickens (Gallus gallus) salicylate (SA) may induce its own elimination. The aim of this study was to investigate salicylate pharmacokinetics and egg residues during repeated administration of sodium salicylate (SS) to laying hens. Pharmacokinetics of SA was assessed during 14 d oral administration of SS at daily doses of 50 mg/kg and 200 mg/kg body weight to laying hens. On the 1st, 7th and 14th d a 24 h-long pharmacokinetic study was carried out, whereas eggs were collected daily. Salicylate concentrations in plasma and eggs were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model. Mean residence time (MRT), minimal plasma concentration (Cmin, C16h) and elimination half-life (T1/2el) of SA showed gradual decrease in layers administered with a lower dose. Total body clearance (ClB) increased. Layers administered with the higher dose showed a decrease only in the T1/2el. In the low dose group, SA was found only in the egg white and was low throughout the experiment. Egg whites from the higher dose group showed initially high SA levels which significantly decreased during the experiment. Yolk SA levels were lower and showed longer periods of accumulation and elimination. Repeated administration of SS induces SA elimination, although this effect may differ depending on the dose and production type of a chicken. Decreased plasma drug concentration may have clinical implications during prolonged SS treatment. PMID:25893240

  6. Pharmacokinetics of Repeated Sodium Salicylate Administration to Laying Hens: Evidence for Time Dependent Increase in Drug Elimination from Plasma and Eggs

    PubMed Central

    Poźniak, Błażej; Grabowski, Tomasz; Motykiewicz-Pers, Karolina; Bobrek, Kamila; Rak, Lech; Bobusia, Katarzyna; Gaweł, Andrzej; Świtała, Marcin

    2015-01-01

    Salicylates were the first non-steroid anti-inflammatory drugs (NSAIDs) to be used in any species and are still widely used in humans and livestock. However, the data on their pharmacokinetics in animals is limited, especially after repeated administration. Evidence exist that in chickens (Gallus gallus) salicylate (SA) may induce its own elimination. The aim of this study was to investigate salicylate pharmacokinetics and egg residues during repeated administration of sodium salicylate (SS) to laying hens. Pharmacokinetics of SA was assessed during 14 d oral administration of SS at daily doses of 50 mg/kg and 200 mg/kg body weight to laying hens. On the 1st, 7th and 14th d a 24 h-long pharmacokinetic study was carried out, whereas eggs were collected daily. Salicylate concentrations in plasma and eggs were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model. Mean residence time (MRT), minimal plasma concentration (Cmin, C16h) and elimination half-life (T1/2el) of SA showed gradual decrease in layers administered with a lower dose. Total body clearance (ClB) increased. Layers administered with the higher dose showed a decrease only in the T1/2el. In the low dose group, SA was found only in the egg white and was low throughout the experiment. Egg whites from the higher dose group showed initially high SA levels which significantly decreased during the experiment. Yolk SA levels were lower and showed longer periods of accumulation and elimination. Repeated administration of SS induces SA elimination, although this effect may differ depending on the dose and production type of a chicken. Decreased plasma drug concentration may have clinical implications during prolonged SS treatment. PMID:25893240

  7. Combined administration of gonadotropin-releasing hormone, progesterone, and meloxicam is an effective treatment for the repeat-breeder cow.

    PubMed

    Amiridis, G S; Tsiligianni, Th; Dovolou, E; Rekkas, C; Vouzaras, D; Menegatos, I

    2009-09-01

    In practice, the etiologic treatment of the repeat-breeder cow is nearly infeasible. In this study, we tested the hypothesis that a combined treatment would benefit the conception rate of repeat-breeder cows. The components of this regimen target ovulation defects, late progesterone (P4) rise, and premature luteolysis. In a 5-year period, 402 repeat-breeder cows were divided in five groups, and treatment regimens consisted of the following: gonadotropin-releasing hormone (GnRH; Group 1, n=115, 0.012mg buserelin im 4 to 6h before artificial insemination); P4 (Group 2, n=51, 100mg P4 intravaginally, on Days 5 to 7); meloxicam (Group 3, n=31, 0.5mgkg(-1), 24h(-1) melomicronxicam sc, on Days 16 to 18); GnRH+P4+meloxicam (Group 4, n=98); and no treatment (Group 5, control, n=107). Artificial insemination was conducted only after overt estrus; thereafter, the duration of the estrous cycle was assessed in all cows that were detected to return to heat. The conception and pregnancy rate was compared among groups. The proportion of cows that returned to estrus after artificial insemination did not differ among groups; the duration of estrous cycle was the shortest in Group 1 and the longest in Group 4. In Group 4, pregnancy rate was higher (P<0.05) than that of Groups 1 and 5 (35.71% vs. 20.00% and 17.76% for Groups 4, 1, and 5, respectively), but though numerically higher, it did not differ statistically from that of Groups 2 (27.45%) and 3 (22.58%). Our results imply that a multifaceted protocol has to be applied for the successful treatment of the repeat-breeder cow. PMID:19501897

  8. Buprenorphine for opioid addiction

    PubMed Central

    Ling, Walter; Mooney, Larissa; Torrington, Matthew

    2014-01-01

    SUMMARY Buprenorphine is a partial opioid agonist of the µ-receptor, and is used as a daily dose sublingual tablet or filmstrip for managing opioid addiction. In the USA, the Drug Addiction Treatment Act of 2000 made buprenorphine the only opioid medication for opioid addiction that can be prescribed in an office-based setting. Owing to its high affinity for the µ-receptor, buprenorphine inhibits the reinforcing effect of exogenous opioids. The ceiling effect of buprenorphine's µ-agonist activity reduces the potential for drug overdose and confers low toxicity even at high doses. Buprenorphine pharmacotherapy has proven to be a treatment approach that supports recovery from addiction while reducing or curtailing the use of opioids. This article examines buprenorphine pharmacotherapy for opioid addiction, focusing on the situation in the USA, and is based on a review of pertinent literature, and the authors’ research and clinical experience. The references in this paper were chosen according to the authors’ judgment of quality and relevance, and with respect to their familiarity and involvement in related research. PMID:24654720

  9. The epidemic of prescription opioid abuse, the subsequent rising prevalence of heroin use, and the federal response.

    PubMed

    Kanouse, Andrew B; Compton, Peggy

    2015-06-01

    Opioids are a mainstay in the treatment of pain both chronically and acutely. In the past 20 years, the prescribing of opioids has increased exponentially. As the population for whom opioids are indicated has grown, with the number of opioid prescriptions written increased, so have indicators of opioid misuse, abuse, morbidity, and mortality. The purpose of this article is to review and explore the combination of factors of events that led to the current "epidemic" of prescription opioid abuse and overdose deaths, as well as the subsequent resurgence of heroin use among opioid addicts. Federal initiatives to mount war on prescription opioid abuse are reviewed, including responses from the White House, Drug Enforcement Agency (DEA), Food and Drug Administration (FDA), and interagency initiatives. Many initiatives are currently in place to combat the rising rates of morbidity and mortality associated with opioids, and those involved are hopeful in their efforts to curb the epidemic of this deadly phenomenon. PMID:26095479

  10. Opioid control of gonadotrophin secretion in humans.

    PubMed

    Genazzani, A R; Genazzani, A D; Volpogni, C; Pianazzi, F; Li, G A; Surico, N; Petraglia, F

    1993-11-01

    Hypothalamus-pituitary-axis (HPA) is constantly under the modulatory effect of many substances, such as neurotransmitters, neuromodulators and steroid hormones. Recently, the involvement of endogenous opioid peptides (EOP) in the control of the neuroendocrine mechanism modulating gonadotrophin secretion has been supported by several authors. It has been demonstrated that acute morphine administration decreases luteinizing hormone (LH) plasma levels and this is due to an inhibitory modulation on gonadotrophin releasing hormone discharge from the hypothalamic neurons. EOP are usually increased by stressful situations. In stress-induced amenorrhoea, the presence of low LH plasma levels and an abnormal LH pulsatile secretion has been related to an increased opioid activity, thus supporting the integrative role of opioids between hormonal and neuronal afferences of brain. PMID:8276950

  11. Deficits in neuronal cytochrome P450 activity attenuate opioid analgesia but not opioid side effects.

    PubMed

    Hough, Lindsay B; Nalwalk, Julia W; Cleary, Rachel A; Phillips, James G; Fang, Cheng; Yang, Weizhu; Ding, Xinxin

    2014-10-01

    Morphine-like analgesics act on µ opioid receptors in the CNS to produce highly effective pain relief, but the same class of receptors also mediates non-therapeutic side effects. The analgesic properties of morphine were recently shown to require the activity of a brain neuronal cytochrome P450 epoxygenase, but the significance of this pathway for opioid side effects is unknown. Here we show that brain P450 activity is not required for three of morphine׳s major side effects (respiratory depression, constipation, and locomotor stimulation). Following systemic or intracerebroventricular administration of morphine, transgenic mice with brain neuron - specific reductions in P450 activity showed highly attenuated analgesic responses as compared with wild-type (control) mice. However, brain P450-deficient mice showed normal morphine-induced side effects (respiratory depression, locomotor stimulation, and inhibition of intestinal motility). Pretreatment of control mice with the P450 inhibitor CC12 similarly reduced the analgesia, but not these side effects of morphine. Because activation of brain µ opioid receptors produces both opioid analgesia and opioid side effects, dissociation of the mechanisms for the therapeutic and therapy-limiting effects of opioids has important consequences for the development of analgesics with reduced side effects and/or limited addiction liability. PMID:25062792

  12. New opioid prescribing guidelines favor non-opioid alternatives.

    PubMed

    2016-05-01

    Determined to make a dent in the growing problem of opioid addiction, the CDC has unveiled new guidelines for opioid prescribing for chronic pain. The recommendations urge providers to be more judicious in their prescribing, opting for opioids only after carefully weighing substantial risks and benefits. Public health authorities note the rampant use and misuse of opioids have "blurred the lines" between prescription opioids and illicit opioids. The new guidelines are designed to help frontline providers balance the need to manage their patients' chronic pain with the duty to curb dangerous prescribing practices. The recommendations are built around three principles: favor non-opioid alternatives for most cases of chronic pain, use the lowest effective dose when prescribing opioids, and exercise caution/monitor patients who are treated with opioids. PMID:27266000

  13. Kinetics of selected di-n-butyl phthalate metabolites and fetal testosterone following repeated and single administration in pregnant rats.

    PubMed

    Clewell, Rebecca A; Kremer, John J; Williams, Carla C; Campbell, Jerry L; Sochaski, Mark A; Andersen, Melvin E; Borghoff, Susan J

    2009-01-01

    Human exposure to phthalic acid diesters occurs through a variety of pathways as a result of their widespread use in consumer products and plastics. Repeated doses of di-n-butyl phthalate (DBP) from gestation day (GD) 12 to 19 disrupt testosterone synthesis and male sexual development in the fetal rat. Currently little is known about the disposition of DBP metabolites, such as monobutyl phthalate (MBP) and its glucuronide conjugate (MBP-G), during gestation after repeated exposure to DBP. In order to gain a better understanding of the effect of repeated dosing on maternal and fetal metabolism and distribution, pregnant Sprague-Dawley rats were given a single dose of 500 mg/kg DBP on GD 19 or daily doses of 50, 100, and 500 mg/(kg day) from GD 12 to 19 via corn oil gavage. Dose-response evaluation revealed a non-linear increase in maternal and fetal plasma concentrations of MBP. Maternal and fetal MBP levels were slightly lower in animals after 8 days of dosing at 500 mg/(kg day). Fetal plasma MBP levels closely followed maternal plasma, while the appearance and elimination of MBP-G in fetal plasma were significantly delayed. MBP-G accumulated over time in the amniotic fluid. Inhibition of testosterone was rapid in fetal testes when exposed to DBP (500 mg/(kg day)) on GD 19. Within 24h, the level of inhibition in the fetus was similar between animals exposed to a single or multiple daily doses of 500 mg/(kg day). Examination of testosterone time-course data indicates a rapid recovery to normal levels within 24h post-dosing at DBP doses of 50 and 100 mg/(kg day), with a rebound to higher than normal concentrations at later time-points. MBP kinetics in fetal testes allows direct comparison of active metabolite concentrations and testosterone response in the fetal testes. PMID:19010379

  14. Effect of repeated administration of antidepressant drugs on the serum and brain concentration of testosterone and its metabolites.

    PubMed

    Przegaliński, E; Warchoł-Kania, A; Budziszewska, B; Jaworska, L

    1987-01-01

    A repeated oral treatment (twice daily, for 21 consecutive days) with 10 mg/kg of antidepressants imipramine, amitriptyline, citalopram, mianserin affects the level of testosterone and its metabolites (5 alpha-dihydrotestosterone and estradiol-17 beta) in the serum and brain structures (cerebral cortex, hypothalamus). Citalopram and mianserin increased significantly the serum testosterone concentration, while imipramine and amitriptyline reduced the concentration of 5 alpha-dihydrotestosterone. In the cerebral cortex a reduction in 5 alpha-dihydrotestosterone after imipramine, and in the hypothalamus a decrease in testosterone level after amitriptyline were observed. None of the investigated drugs influenced estradiol-17 beta concentration in the serum or in the brain. PMID:3503989

  15. Involvement of peripheral mu opioid receptors in scratching behavior in mice.

    PubMed

    Yamamoto, Atsuki; Sugimoto, Yukio

    2010-12-15

    Pruritus is a common adverse effect of opioid treatment. However, the mechanism by which pruritus is induced by opioid administration is unclear. In this study, we examined the effects of the intradermal injection of loperamide, a peripherally restricted opioid receptor agonist, on the itch sensation. When injected intradermally into the rostral part of the back in mice, loperamide elicited scratching behavior. We also examined the effects of the selective mu opioid receptor agonist [d-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin acetate (DAMGO), the selective delta opioid receptor agonist [d-Pen(2,5)]-enkephalin (DPDPE), and the selective kappa opioid receptor agonist U-50488H on scratching behavior in mice in order to determine which subtype is involved in opioid-induced pruritus. Following intradermal injection into the rostral part of the back in mice, DAMGO elicited scratching behavior, while DPDPE and U-50488H did not. This suggests that peripheral mu opioid activation elicits the itch sensation. Next, we focused on the treatment of opioid-induced itch sensation without central adverse effects. Naloxone methiodide is a peripherally restricted opioid receptor antagonist. In the present study, naloxone methiodide significantly suppressed scratching behavior induced by loperamide and DAMGO. These findings suggest that mu opioid receptors play a primary role in peripheral pruritus and that naloxone methiodide may represent a possible remedy for opioid-induced itching. PMID:20863827

  16. Repeated administrations of human umbilical cord blood cells improve disease outcomes in a mouse model of Sanfilippo syndrome type III B.

    PubMed

    Willing, Alison E; Garbuzova-Davis, Svitlana N; Zayko, Olga; Derasari, Hiranya M; Rawls, Ashley E; James, Chris R; Mervis, Ron F; Sanberg, Cyndy D; Kuzmin-Nichols, Nicole; Sanberg, Paul R

    2014-01-01

    Sanfilippo syndrome type III B (MPS III B) is an inherited disorder characterized by a deficiency of α-N-acetylglucosaminidase (Naglu) enzyme leading to accumulation of heparan sulfate in lysosomes and severe neurological deficits. We have previously shown that a single administration of human umbilical cord mononuclear cells (hUCB MNCs) into Naglu knockout mice decreased behavioral abnormalities and tissue pathology. In this study, we tested whether repeated doses of hUCB MNCs would be more beneficial than a single dose of cells. Naglu mice at 3 months of age were randomly assigned to either a Media-only group or one of three hUCB MNC treatment groups--single low dose (3 × 10(6) cells), single high dose (1.8 × 10(7) cells), or multiple doses (3 × 10(6) cells monthly for 6 months) delivered intravenously; cyclosporine was injected intraperitoneally to immune suppress the mice for the duration of the study. An additional control group of wild-type mice was also used. We measured anxiety in an open field test and cognition in an active avoidance test prior to treatment and then at monthly intervals for 6 months. hUCB MNCs restored normal anxiety-like behavior in these mice (p < 0.001). The repeated cell administrations also restored hippocampal cytoarchitecture, protected the dendritic tree, decreased GM3 ganglioside accumulation, and decreased microglial activation, particularly in the hippocampus and cortex. These data suggest that the neuroprotective effect of hUCB MNCs can be enhanced by repeated cell administrations. PMID:25565636

  17. Repeated Administrations of Human Umbilical Cord Blood Cells Improve Disease Outcomes in a Mouse Model of Sanfilippo Syndrome Type III B.

    PubMed

    Willing, Alison E; Garbuzova-Davis, Svitlana N; Zayko, Olga; Derasari, Hiranya M; Rawls, Ashley E; James, Chris R; Mervis, Ron F; Sanberg, Cyndy D; Kuzmin-Nichols, Nicole; Sanberg, Paul R

    2013-12-30

    Sanfilippo syndrome type III B (MPS III B) is an inherited disorder characterized by a deficiency of ?-N-acetylglucosaminidase (Naglu) enzyme leading to accumulation of heparan sulfate in lysosomes and severe neurological deficits. We have previously shown that a single administration of human umbilical cord mononuclear cells (hUCB MNC) into Nagluknockout mice decreased behavioral abnormalities and tissue pathology. In this study, we tested whether repeated doses of hUCB MNCs would be more beneficial than a single dose of cells. Naglumice at 3 months of age were randomly assigned to either a Media only group, or one of three hUCB MNC treatment groups - single low dose (3x10(6) cells), single high dose (1.8x10(7) cells) or multiple doses (3x10(6) cells monthly for 6 months) delivered intravenously (i.v.); cyclosporine was injected i.p. to immune suppress the mice for the duration of the study. An additional control group of wild type mice was also used. We measured anxiety in an open field test and cognition inactive avoidance test prior to treatment and then at monthly intervals for 6 months. hUCB MNCs restored normal anxiety-like behavior in these mice (p < 0.001). The repeated cell administrations also restored hippocampal cytoarchitecture, protected the dendritic tree, decreased GM3 ganglioside accumulation and decreased microglial activation, particularly in hippocampus and cortex. These data suggest that the neuroprotective effect of hUCB MNCs can be enhanced by repeated cell administrations. PMID:24380668

  18. The critical role of spinal 5-HT7 receptors in opioid and non-opioid type stress-induced analgesia.

    PubMed

    Yesilyurt, Ozgur; Seyrek, Melik; Tasdemir, Serdar; Kahraman, Serdar; Deveci, Mehmet Salih; Karakus, Emre; Halici, Zekai; Dogrul, Ahmet

    2015-09-01

    The opioid and non-opioid types of stress-induced analgesia have been well defined. One of the non-opioid type involve the endocannabinoid system. We previously reported that the spinal serotonin 7 receptor (5-HT7) blockers inhibit both morphine and cannabinoid-induced analgesia, thus we hypothesized that descending serotonergic pathways-spinal 5-HT7 receptor loop might contribute to stress-induced analgesia. Stress-induced analgesia was induced with warm (32°C) or cold (20°C) water swim stress in male Balb-C mice. The effects of intrathecal injection of a selective 5-HT7 receptor antagonist, SB 269970, of the denervation of serotonergic neurons by intrathecal administration of 5,7-dihydroxytryptamine (5,7-DHT) and of lesions of the dorsolateral funiculus on opioid and non-opioid type stress-induced analgesia were evaluated with the tail-flick and hot plate tests. The expression of 5-HT7 receptors mRNA in the dorsal lumbar region of spinal cord were analyzed by RT-PCR following spinal serotonin depletion or dorsolateral funiculus lesion. The effects of the selective 5-HT7 receptor agonists LP 44 and AS 19 were tested on nociception. Intrathecal SB 269970 blocked both opioid and non-opioid type stress-induced analgesia. Dorsolateral funiculus lesion or denervation of the spinal serotonergic neurons resulted in a marked decrease in 5-HT7 receptor expression in the dorsal lumbar spinal cord, accompanied by inhibition of opioid and non-opioid type stress-induced analgesia. However, the systemic or intrathecal LP 44 and AS 19 alone did not produce analgesia in unstressed mice. These results indicate that descending serotonergic pathways and the spinal 5-HT7 receptor loop play a crucial role in mediating both opioid and non-opioid type stress-induced analgesia. PMID:25917322

  19. Women Who Abuse Prescription Opioids: Findings from the Addiction Severity Index-Multimedia Version® Connect Prescription Opioid Database

    PubMed Central

    Green, Traci C.; Grimes Serrano, Jill M.; Licari, Andrea; Budman, Simon H.; Butler, Stephen F.

    2009-01-01

    Background Evidence suggests gender differences in abuse of prescription opioids. This study aimed to describe characteristics of women who abuse prescription opioids in a treatment-seeking sample and to contrast gender differences among prescription opioid abusers. Methods Data collected November 2005 to April 2008 derived from the Addiction Severity Index Multimedia Version Connect (ASI-MV® Connect) database. Bivariate and multivariable logistic regression examined correlates of prescription opioid abuse stratified by gender. Results 29,906 assessments from 220 treatment centers were included, of which 12.8% (N=3,821) reported past month prescription opioid abuse. Women were more likely than men to report use of any prescription opioid (29.8% females vs. 21.1% males, p< 0.001) and abuse of any prescription opioid (15.4% females vs. 11.1% males, p < 0.001) in the past month. Route of administration and source of prescription opioids displayed gender-specific tendencies. Women-specific correlates of recent prescription opioid abuse were problem drinking, age <54, inhalant use, residence outside of West US Census region, and history of drug overdose. Men-specific correlates were age <34, currently living with their children, residence in the South and Midwest, hallucinogen use, and recent depression. Women prescription opioid abusers were less likely to report a pain problem although they were more likely to report medical problems than women who abused other drugs. Conclusions Gender-specific factors should be taken into account in efforts to screen and identify those at highest risk of prescription opioid abuse. Prevention and intervention efforts with a gender-specific approach are warranted. PMID:19409735

  20. Outpatient provider contact prior to unintentional opioid overdose

    PubMed Central

    Lin, Lewei (Allison); Bohnert, Amy; Ilgen, Mark; Pfeiffer, Paul Nelson; Ganoczy, Dara; Blow, Fred

    2015-01-01

    Objectives Prescribed opioid medications are the most commonly implicated substances in unintentional overdoses. Outpatient health care encounters represent a potential opportunity to intervene to reduce opioid overdose risk. This study assessed the timing and type of outpatient provider contacts prior to overdose. Methods This study examined all adult patients nationally in the Veterans Health Administration (VHA) who died from unintentional prescription opioid overdose in fiscal years 2004–2007 and used VHA services anytime within two years of their deaths (n=1,813). For those whose last treatment contact was in an outpatient setting (n=1,457), demographic, clinical and treatment characteristics were compared among patients categorized by the location of their last contact. Results 33% (N=479) of those last seen in outpatient settings were seen within one week and 62% (N=910) within one month of their overdose. A substantial proportion of patients were last seen within one month of death in mental health or substance disorder outpatient settings (30% N=438). The majority of patients did not fill an opioid prescription on their last outpatient visit prior to unintentional opioid overdose. Conclusions The majority of patients who died by unintentional overdose on prescription opioids were seen within a month of their overdose in outpatient settings. These settings may provide an opportunity to prevent patients from dying from prescription opioid overdoses, and interventions to reduce risk should not be limited to visits that resulted in an opioid prescription. PMID:26129993

  1. The Useage of Opioids and their Adverse Effects in Gastrointestinal Practice: A Review

    PubMed Central

    Khansari, MahmoudReza; Sohrabi, MasourReza; Zamani, Farhad

    2013-01-01

    Opium is one of the oldest herbal medicines currently used as an analgesic, sedative and antidiarrheal treatment. The effects of opium are principally mediated by the μ-, κ- and δ-opioid receptors. Opioid substances consist of all natural and synthetic alkaloids that are derived from opium. Most of their effects on gastrointestinal motility and secretion result from suppression of neural activity. Inhibition of gastric emptying, increase in sphincter tone, changes in motor patterns, and blockage of peristalsis result from opioid use. Common adverse effects of opioid administration include sedation, dizziness, nausea, vomiting, constipation, dependency and tolerance, and respiratory depression. The most common adverse effect of opioid use is constipation. Although stool softeners are frequently used to decrease opioid-induced bowel dysfunction, however they are not efficacious. Possibly, the use of specific opioid receptor antagonists is a more suitable approach. Opioid antagonists, both central and peripheral, could affect gastrointestinal function and visceromotor sensitivity, which suggests an important role for endogenous opioid peptides in the control of gastrointestinal physiology. Underlying diseases or medications known to influence the central nervous system (CNS) often accelerate the opioid’s adverse effects. However, changing the opioid and/or route of administration could also decrease their adverse effects. Appropriate patient selection, patient education and discussion regarding potential adverse effects may assist physicians in maximizing the effectiveness of opioids, while reducing the number and severity of adverse effects. PMID:24829664

  2. Opioids and sexual reward.

    PubMed

    Paredes, R G

    2014-06-01

    Various lines of research indicate that sexual reward is mediated by opioids in both males and females. In the first part I review basic ideas about sexual reward in humans followed by a description of what is known in rodents, where most of the studies have been done. Although a direct method to measure opioid release during mating is not yet available, there is a substantial amount of indirect evidence in humans and animals indicating that opioids are released during the execution of sexual behavior. Studies using the conditioned place preference (CPP) method where the effects of opioids upon sex induced reward have been evaluated will also be described. Evidence will also be presented indicating that the medial preoptic area (MPOA) plays a crucial role in the expression of opioid mediated sex-reward in males and females. This area is also important in other naturally occurring reward related behaviors such as singing. Opioids might be part of a system that mediates the rewarding properties of natural behaviors that are intrinsically rewarding. PMID:24239788

  3. Buprenorphine for opioid dependence

    PubMed Central

    Ling, Walter

    2014-01-01

    As a treatment agent for opioid dependence, buprenorphine is a nearly ideal medication at our current stage of medication development. Unlike methadone, buprenorphine dosage can be rapidly adjusted with minimal potential for inducing severe consequences. In addition to its intrinsic safety, buprenorphine's relatively low abuse liability in the combination product (i.e., with naloxone as Suboxone®) makes it even more acceptable in regulatory quarters as well as to prescribing physicians. The approval of buprenorphine as a pharmacotherapy for opioid dependence returns to physicians the ability to treat their opioid-dependent patients with an effective opioid-based treatment for the first time in nearly 100 years. Buprenorphine is an opioid, however, and potential for misuse remains, even in combination with naloxone. Whether buprenorphine will be increasingly accepted as a treatment for opioid-dependent patients depends on clinicians recognizing the advantages of its uniquely useful properties while still heeding the need to manage their patients' therapy with reasonable vigilance. PMID:19402772

  4. Brain regional acetylcholinesterase activity and muscarinic acetylcholine receptors in rats after repeated administration of cholinesterase inhibitors and its withdrawal

    SciTech Connect

    Kobayashi, Haruo . E-mail: hk1664@iwate-u.ac.jp; Suzuki, Tadahiko; Sakamoto, Maki; Hashimoto, Wataru; Kashiwada, Keiko; Sato, Itaru; Akahori, Fumiaki; Satoh, Tetsuo

    2007-03-15

    Activity of acetylcholinesterase (AChE) and specific binding of [{sup 3}H]quinuclidinyl benzilate (QNB), [{sup 3}H]pirenzepine (PZP) and [{sup 3}H]AF-DX 384 to muscarinic acetylcholine receptor (mAChR) preparations in the striatum, hippocampus and cortex of rats were determined 1, 6 and 11 days after the last treatment with an organophosphate DDVP, a carbamate propoxur or a muscarinic agonist oxotremorine as a reference for 7 and 14 days. AChE activity was markedly decreased in the three regions 1 day after the treatment with DDVP for 7 and 14 days with a gradual recovery 6 to 11 days, and much less decreased 1, 6 and 11 days after the treatment with propoxur for 7 days but not for 14 days in the hippocampus and cortex. The binding of [{sup 3}H]-QNB, PZP and AF-DX 384 in the three regions was generally decreased by the treatment with DDVP for 7 and 14 days. Such down-regulations were generally restored 6 or 11 days after the treatment for 7 but not for 14 days. The down-regulation or up-regulation as measured by [{sup 3}H]-QNB, PZP and AF-DX 384 was observed 1, 6 or 11 days after treatment with propoxur for 7 days and/or 14 days. Repeated treatment with oxotremorine produced similar effects except AChE activity to DDVP. These results suggest that repeated inhibition of AChE activity may usually cause down-regulation of mAChRs with some exception in the hippocampus when a reversible antiChE propoxur is injected.

  5. Endogenous and xenobiotic metabolite profiling of liver extracts from SCID and chimeric humanized mice following repeated oral administration of troglitazone.

    PubMed

    Barnes, Alan J; Baker, David R; Hobby, Kirsten; Ashton, Simon; Michopoulos, Filippos; Spagou, Konstantina; Loftus, Neil J; Wilson, Ian D

    2014-01-01

    1. Metabonomic analysis, via a combination of untargeted and targeted liquid chromatography-mass spectrometry (LC-MS) and untargeted (1)H NMR spectroscopy-based metabolite profiling, was performed on aqueous (AQ) and organic liver extracts from control (SCID) and chimeric humanized (PXB) mice dosed with troglitazone at 0, 300 and 600 mg/kg/day for seven days. 2. LC-MS analysis of AQ liver extracts showed a more "human-like" profile for troglitazone metabolites for PXB, compared with SCID, mice. 3. LC-MS detected differences in endogenous metabolites, particularly lipid species in dosed mice, including elevated triacylglycerols and 1-alkyl,2-acylglycerophosphates as well as lowered diacylglycerophosphocholines and 1-alkyl,2-acylglycerophosphocholines for PXB compared with SCID mouse liver extracts. Following drug administration changes in the relative proportions of the ions for various unsaturated fatty acids were observed for both types of mouse, some of which were specific to PXB or SCID mice. 4.  (1)H NMR spectroscopy revealed that AQ PXB mouse liver extracts had elevated amounts of inosine, fumarate, creatine, aspartate, trimethylamine N-oxide, glycerophosphocholine, phosphocholine, choline, glutamine, glutamate, acetate, alanine and lactate relative to SCID mice and decreased histidine, glycogen, α- and β-glucose, taurine, and glutathione. Increased uracil and tyrosine concentrations were detected for PXB mice on troglitazone administration. 5. Metabonomic profiling thus showed clear differences between humanized and SCID mice, including after administration of troglitazone. PMID:24350779

  6. Repeated low-dose kainate administration in C57BL/6J mice produces temporal lobe epilepsy pathology but infrequent spontaneous seizures.

    PubMed

    Umpierre, Anthony D; Bennett, Isaiah V; Nebeker, Lismore D; Newell, Thomas G; Tian, Bruce B; Thomson, Kyle E; White, H Steve; White, John A; Wilcox, Karen S

    2016-05-01

    More efficient or translationally relevant approaches are needed to model acquired temporal lobe epilepsy (TLE) in genetically tractable mice. The high costs associated with breeding and maintaining transgenic, knock-in, or knock-out lines place a high value on the efficiency of induction and animal survivability. Herein, we describe our approaches to model acquired epilepsy in C57BL/6J mice using repeated, low-dose kainate (KA) administration paradigms. Four paradigms (i.p.) were tested for their ability to induce status epilepticus (SE), temporal lobe pathology, and the development of epilepsy. All four paradigms reliably induce behavioral and/or electrographic SE without mortality over a 7d period. Two of the four paradigms investigated produce features indicative of TLE pathology, including hippocampal cell death, widespread astrogliosis, and astrocyte expression of mGluR5, a feature commonly reported in TLE models. Three of the investigated paradigms were able to produce aberrant electrographic features, such as interictal spiking in cortex. However, only one paradigm, previously published by others, produces spontaneous recurrent seizures over an eight week period. Presentation of spontaneous seizures is rare (N=2/14), with epilepsy preferentially developing in animals having a high number of seizures during SE. Overall, repeated, low-dose KA administration improves the efficiency and pathological relevance of a systemic KA insult, but does not produce a robust epilepsy phenotype under the experimental paradigms described herein. PMID:26896834

  7. Opioid analgesics: does potency matter?

    PubMed

    Passik, Steven D; Webster, Lynn

    2014-01-01

    Prescription opioid analgesics with a wide range of potencies are currently used for the treatment of chronic pain. Yet understanding the clinical relevance and therapeutic consequences of opioid potency remains ill defined. Both patients and clinicians alike have misperceptions about opioid potency, expecting that less-potent opioids will be less effective or fearing that more-potent opioids are more dangerous or more likely to be abused. In this review, common myths about the potency of opioid analgesics will be discussed. Clinicians should understand that pharmacologic potency per se does not necessarily imply more effective analgesia or higher abuse liability. Published dose conversion tables may not accurately calculate the dose for effective and safe rotation from one opioid to another in patients receiving long-term opioid therapy because they are based on limited data that may not apply to chronic pain. Differences in pharmacologic potency are largely accounted for by the actual doses prescribed, according to individualized patient need. Factors for achieving effective analgesia and reducing the risks involved with opioid use include careful medication selection based on patient characteristics, appropriate dosing titration and opioid rotation practices, knowledge of product formulation characteristics (eg, extended release, immediate release, and tamper-resistant features), and an awareness of differences in opioid pharmacokinetics and metabolism. Clinicians should remain vigilant in monitoring patients on any opioid medication, regardless of classification along the opioid potency continuum. PMID:25162606

  8. The effects of repeated administration of camphor-crataegus berry extract combination on blood pressure and on attentional performance - a randomized, placebo-controlled, double-blind study.

    PubMed

    Erfurt, L; Schandry, R; Rubenbauer, S; Braun, U

    2014-09-25

    The present study investigated the effects of repeated administration of Korodin(®), a combination of camphor and crataegus berry extract, on blood pressure and attentional functioning. This study was conducted based on a randomized, placebo-controlled, double-blind design. 54 persons participated (33 female, 21 male) with a mean age of 24.3 years. Blood pressure and body mass index were in the normal range. Participants received 20 drops of either Korodin(®) or a placebo for four times with interjacent time intervals of about 10 min. Blood pressure was measured sphygmomanometrically before and after each administration. Attentional performance was quantified by using two paper-and-pencil tests, the d2 Test of Attention and Digit Symbol Test. Greater increases in blood pressure occurred after the four Korodin(®) administrations in comparison to the four placebo administrations. The performance in two parameters of d2 Test of Attention was consistently superior after the intake of Korodin(®). The excellent tolerability and safety of Korodin(®), even after a total consumption of 80 drops, was confirmed. PMID:25172798

  9. Effect of repeated oral administration of Bifidobacterium longum BB536 on apomorphine-induced rearing behavior in mice.

    PubMed

    Orikasa, Shuzo; Nabeshima, Kazumi; Iwabuchi, Noriyuki; Xiao, Jin-Zhong

    2016-01-01

    Schizophrenia is a chronic psychiatric illness. Disruption of the dopaminergic system has been suggested to be the pathogenic cause of this disease. The effect of Bifidobacterium longum BB536 (BB536) on schizophrenic behavior was investigated in an animal model. Daily administration of BB536 (10(9) CFU/mouse, p.o. for 2 weeks) was found to reduce rearing behavior augmented by the dopamine receptor agonist apomorphine and to decrease the resting level of plasma corticosterone and the ratio of kynurenine to tryptophan. These results suggest the potential of BB536 for supplemental treatment of the symptoms of schizophrenia. PMID:27508116

  10. Ovarian response to repeated administration of alternating exogenous gonadotropin regimens in the ocelot (Leopardus pardalis) and tigrinus (Leopardus tigrinus).

    PubMed

    da Paz, Regina Celia Rodrigues; Dias, Eduardo Antunes; Adania, Cristina Harumi; Barnabe, Valquíria Hippólito; Barnabe, Renato Campanarut

    2006-10-01

    Exogenous gonadotropins are used to stimulate ovarian follicular growth and ovulation in mammalian species, including wild cats. However, successes in application of assisted reproduction techniques in nondomestic felids have been sparse. Our objectives were to assess the effectiveness of alternating gonadotropin regimens on ovarian responses. Five adult female ocelots and four adult female tigrinus were treated four to six times, using alternating eCG/hCG and pFSH/pLH at 4-month intervals. Laparoscopies were done to assess follicular development and to collect oocytes from matures follicles. The average number of follicles and corpus luteum (CL) per stimulation was higher in ocelots (7.0 +/- 0.8; mean +/- S.E.M.) than in tigrinus (2.5 +/- 0.4; P < 0.05), but the percentage of mature oocytes did not differ between the two species (mean range, 54-55%). Within species, both gonadotropin regimens were equally effective in inducing follicular growth and oocyte maturation. The total number of ovarian structures and oocyte maturation percentages did not decrease in either species with sequential stimulations. In summary, female ocelots and tigrinus continued to respond to repeated alternating ovarian stimulation protocols. In conclusion, the use of alternating gonadotropin regimens may permit more intensive reproductive management in these endangered cats. PMID:16472853

  11. Gene profiling the response to repeated cocaine self-administration in dorsal striatum: a focus on circadian genes.

    PubMed

    Lynch, Wendy J; Girgenti, Matthew J; Breslin, Florence J; Newton, Samuel S; Taylor, Jane R

    2008-06-01

    Alterations in gene expression in the dorsal striatum caused by chronic cocaine exposure have been implicated in the long-term behavioral changes associated with cocaine addiction. To gain further insight into the molecular alterations that occur as a result of cocaine self-administration, we conducted a microarray analysis of gene expression followed by bioinformatic gene network analysis that allowed us to identify adaptations at the level of gene expression as well as into interconnected networks. Changes in gene expression were examined in the dorsal striatum of rats 1 day after they had self-administered cocaine for 7 days under a 24-h access, discrete trial paradigm (averaging 98 mg/kg/day). Here we report the regulation of the circadian genes Clock, Bmal1, Cryptochrome1, Period2, as well as several genes that are regulated by/associated with the circadian system (i.e., early growth response 1, dynorphin). We also observed regulation of other relevant genes (i.e., Nur77, beta catenin). These changes were then linked to curated pathways and formulated networks which identified circadian rhythm processes as affected by cocaine self-administration. These data strongly suggest involvement of circadian-associated genes in the brain's response to cocaine and may contribute to an understanding of addictive behavior including disruptions in sleep and circadian rhythmicity. PMID:18452895

  12. Local tolerance and systemic toxicity of single and repeated intramuscular administrations of two different formulations of the RTS,S malaria candidate vaccine in rabbits.

    PubMed

    Segal, Lawrence; Morelle, Danielle; Blee, Mark; Moore, Emma; Damsten, Micaela; Liu, Kai Chiu; Destexhe, Eric; Garçon, Nathalie

    2015-03-01

    RTS,S malaria antigen is weakly immunogenic as such and needs to be formulated with an adjuvant to improve the magnitude and duration of the immune responses to RTS,S. Two Adjuvant Systems, AS01 and AS02 were evaluated during the development of the RTS,S vaccine. The evaluation included non-clinical studies in rabbits to evaluate the local intramuscular tolerance following administration on a single occasion, and the local and systemic effects following repeated administrations of RTS,S/AS01 or RTS,S/AS02 formulations. In the first study, rabbits were injected on one occasion with RTS,S/AS01, RTS,S/AS02 or controls, and the local intramuscular tolerance was evaluated up to 3 days after injection. In the second study, the different formulations were injected on Days 0, 14, 28 and 42. General health status, haematology and blood chemistry parameters were monitored on a regular basis. Macroscopic and microscopic evaluations were made after termination of the study. No sign of toxicity was detected following single or repeated administrations of the adjuvanted RTS,S formulations. Changes in haematology or clinical chemistry parameters were indicative of a developing immune response in the groups receiving either RTS,S formulation. All examined parameters returned to normal within 28 days after the last injection. The absence of toxicological effects following the injection of RTS,S/AS01 or RTS,S/AS02 in rabbits was supportive of further clinical evaluation of these two formulations. PMID:25545314

  13. Reduction of Aggressive Episodes After Repeated Transdermal Nicotine Administration in a Hospitalized Adolescent with Autism Spectrum Disorder

    PubMed Central

    Lewis, Alan S.; Qayyum, Zheala; Koslosky, Kourtney; Picciotto, Marina R.; Volkmar, Fred R.

    2016-01-01

    Aggression remains a major cause of morbidity in patients with autism spectrum disorder (ASD). Current pharmacotherapy for aggression is not always effective and is often associated with morbidity. Nicotinic acetylcholinergic neurotransmission may play a prominent role in ASD pathophysiology based on human and animal studies, and preclinical studies show nicotine administration can reduce aggression-related behaviors. Transdermal nicotine has been used to treat agitation in neuropsychiatric conditions with cholinergic dysfunction. Here we report the use of transdermal nicotine as an adjunctive medication to treat aggression in a hospitalized adolescent with ASD. Nicotine patch was recurrently well tolerated, and reduced the need for emergency medication and restraint. These findings suggest further study of transdermal nicotine for aggression comorbid with ASD is warranted. PMID:25982311

  14. Baseline reward circuitry activity and trait reward responsiveness predict expression of opioid analgesia in healthy subjects

    PubMed Central

    Wanigasekera, Vishvarani; Lee, Michael C.; Rogers, Richard; Kong, Yazhuo; Leknes, Siri; Andersson, Jesper; Tracey, Irene

    2012-01-01

    Variability in opioid analgesia has been attributed to many factors. For example, genetic variability of the μ-opioid receptor (MOR)-encoding gene introduces variability in MOR function and endogenous opioid neurotransmission. Emerging evidence suggests that personality trait related to the experience of reward is linked to endogenous opioid neurotransmission. We hypothesized that opioid-induced behavioral analgesia would be predicted by the trait reward responsiveness (RWR) and the response of the brain reward circuitry to noxious stimuli at baseline before opioid administration. In healthy volunteers using functional magnetic resonance imaging and the μ-opioid agonist remifentanil, we found that the magnitude of behavioral opioid analgesia is positively correlated with the trait RWR and predicted by the neuronal response to painful noxious stimuli before infusion in key structures of the reward circuitry, such as the orbitofrontal cortex, nucleus accumbens, and the ventral tegmental area. These findings highlight the role of the brain reward circuitry in the expression of behavioral opioid analgesia. We also show a positive correlation between behavioral opioid analgesia and opioid-induced suppression of neuronal responses to noxious stimuli in key structures of the descending pain modulatory system (amygdala, periaqueductal gray, and rostral–ventromedial medulla), as well as the hippocampus. Further, these activity changes were predicted by the preinfusion period neuronal response to noxious stimuli within the ventral tegmentum. These results support the notion of future imaging-based subject-stratification paradigms that can guide therapeutic decisions. PMID:23045652

  15. Correlates and Consequences of Opioid Misuse among High-Risk Young Adults

    PubMed Central

    Schrager, Sheree M.; Silva, Karol; Jackson Bloom, Jennifer; Iverson, Ellen; Lankenau, Stephen E.

    2014-01-01

    Background. Prescription opioids are the most frequently misused class of prescription drug among young adults aged 18–25, yet trajectories of opioid misuse and escalation are understudied. We sought to model opioid misuse patterns and relationships between opioid misuse, sociodemographic factors, and other substance uses. Methods. Participants were 575 young adults age 16–25 who had misused opioids in the last 90 days. Latent class analysis was performed with models based on years of misuse, recency of misuse, and alternate modes of administration within the past 12 months, 3 months, and 30 days. Results. Four latent classes emerged that were differentially associated with heroin, cocaine, and methamphetamine use, tranquilizer misuse, daily opioid misuse, and opioid withdrawal. Alternate modes of administering opioids were associated with increased risk for these outcomes. Sociodemographic factors, homelessness, prescription history, and history of parental drug use were significantly associated with riskier opioid misuse trajectories. Conclusion. Young adults who reported more debilitating experiences as children and adolescents misused opioids longer and engaged in higher risk alternate modes of administering opioids. Data on decisions both to use and to alter a drug's form can be combined to describe patterns of misuse over time and predict important risk behaviors. PMID:25506462

  16. The effect of a novel pentadecapeptide BPC 157 on development of tolerance and physical dependence following repeated administration of diazepam.

    PubMed

    Jelovac, N; Sikiric, P; Rucman, R; Petek, M; Perovic, D; Marovic, A; Anic, T; Seiwerth, S; Mise, S; Pigac, B; Duplancie, B; Turkovic, B; Dodig, G; Prkacin, I; Stancic-Rokotov, D; Zoricic, I; Aralica, G; Sebecic, B; Ziger, T; Slobodnjak, Z

    1999-09-30

    A novel gastric pentadecapeptide BPC 157 with different beneficial activities and anticonvulsant effect interacting with GABAergic system could improve diazepam efficacy coadministered (10 microg/kg, 10 ng/kg i.p.) with diazepam (5.0 mg/kg i.p.) twice daily for 10 days, since diazepam chronic medication would otherwise predispose for diazepam- tolerance/withdrawal development (shorter latency to convulsion after convulsant). In diazepam chronically treated mice, it attenuated diazepam tolerance (provoked by later acute administration of diazepam together with convulsant) and postponed physical dependence/withdrawal effects (provoked by later administration of isoniazid). In tolerance assay, at 42 h after the end of conditioning regimen, shorter preconvulsive latencies than in healthy (non-diazepam conditioned) mice following isoniazid (800 mg/kg i.p.) (as hallmark of tolerance) were observed if diazepam (5.0 mg/kg i.p.) was again given acutely to mice previously conditioned with diazepam alone (use of picrotoxin 3.0 mg/kg i.p., as convulsant, with acute application of diazepam in previously diazepam conditioned mice did not lead to tolerance hallmark). This was completely avoided in diazepam+BPC 157 10 microg or diazepam+BPC 157 10 ng chronically treated animals. In physical dependence assay (isoniazid challenge assessed at 6, 14, 42 and 72 h after conditioning medication), when compared to diazepam non-conditioned healthy mice, in diazepam conditioned mice residual anticonvulsive activity was not present already at the earliest post-conditioning interval (i.e., not different latency to isoniazid-convulsions), whereas shorter preconvulsive latencies (as physical dependence/withdrawal hallmark) were noted in diazepam conditioned mice following isoniazid challenge at 42 h and at 72 h after end of conditioning treatment. In diazepam+BPC 157 10 microg- conditioned mice, a residual anticonvulsive activity (i.e., longer latency to isoniazid convulsion) was noted at 6 h

  17. Validation of a Brief Measure of Opioid Dependence: The Rapid Opioid Dependence Screen (RODS)

    PubMed Central

    Wickersham, Jeffrey A.; Azar, Marwan M.; Cannon, Christopher M.; Altice, Frederick L.; Springer, Sandra A.

    2015-01-01

    The Rapid Opioid Dependence Screen (RODS) is an 8-item measure of opioid dependence designed for quick, targeted screening in clinical and research settings. Based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition, criteria, the RODS has an average administration of less than 2 minutes and can easily be administered as a stand-alone instrument or as part of a comprehensive interview. This study reports on the initial validation of the RODS among a sample of 97 newly incarcerated, HIV-positive individuals. Using the Mini International Neuropsychiatric Interview as the primary measure of opioid dependence, the RODS showed good-to-strong sensitivity (.97), specificity (.76), positive predictive value (.69), and negative predictive value (.98), while concordance analysis revealed moderate diagnostic agreement (κ = .67). Psychometric properties revealed strong internal consistency (α = .92) and inter-item correlations (.66 to .87). PMID:25559628

  18. Effect of repeated gaboxadol administration on night sleep and next-day performance in healthy elderly subjects.

    PubMed

    Mathias, Stefan; Zihl, Josef; Steiger, Axel; Lancel, Marike

    2005-04-01

    Aging is associated with dramatic reductions in sleep continuity and sleep intensity. Since gaboxadol, a selective GABA(A) receptor agonist, has been demonstrated to improve sleep consolidation and promote deep sleep, it may be an effective hypnotic, particularly for elderly patients with insomnia. In the present study, we investigated the effects of subchronic gaboxadol administration on nocturnal sleep and its residual effects during the next days in elderly subjects. This was a randomized, double-blind, placebo-controlled, balanced crossover study in 10 healthy elderly subjects without sleep complaints. The subjects were administered either placebo or 15 mg gaboxadol hydrochloride at bedtime on three consecutive nights. Sleep was recorded during each night from 2300 to 0700 h and tests assessing attention (target detection, stroop test) and memory function (visual form recognition, immediate word recall, digit span) were applied at 0900, 1400, and 1700 h during the following days. Compared with placebo, gaboxadol significantly shortened subjective sleep onset latency and increased self-rated sleep intensity and quality. Polysomnographic recordings showed that it significantly decreased the number of awakenings, the amount of intermittent wakefulness, and stage 1, and increased slow wave sleep and stage 2. These effects were stable over the three nights. None of the subjects reported side effects. Next-day cognitive performance was not affected by gaboxadol. Gaboxadol persistently improved subjective and objective sleep quality and was devoid of residual effects. Thus, at the employed dose, it seems an effective hypnotic in elderly subjects. PMID:15602499

  19. Muscarinic receptor plasticity in the brain of senescent rats: down-regulation after repeated administration of diisopropyl fluorophosphate

    SciTech Connect

    Pintor, A.; Fortuna, S.; Volpe, M.T.; Michalek, H.

    1988-01-01

    Potential age-related differences in the response of Fischer 344 rats to subchronic treatment with diisopropylfluorophosphate (DFP) were evaluated in terms of brain cholinesterase (ChE) inhibition and muscarinic receptor sites. Male 3- and 24-month old rats were sc injected with sublethal doses of DFP for 2 weeks and killed 48 hrs after the last treatment. In the cerebral cortex, hippocampus and striatum of control rats a significant age-related reduction of ChE and of maximum number of /sup 3/H-QNB binding sites (Bmax) was observed. The administration of DFP to senescent rats resulted in more pronounced and longer lasting syndrome of cholinergic stimulation, with marked body weight loss and 60% mortality. The percentage inhibition of brain ChE induced by DFP did not differ between young and senescent rats. As expected, in young rats DFP caused a significant decrease of Bmax, which in the cerebral cortex reached about 40%. In the surviving senescent rats, the percentage decrease of Bmax due to DFP with respect to age-matched controls was very similar to that of young animals, especially in the cerebral cortex. Thus there is great variability in the response of aged rats to DFP treatment, from total failure of adaptive mechanisms resulting in death to considerable muscarinic receptor plasticity.

  20. Cellular mechanisms underlying the interaction between cannabinoid and opioid system.

    PubMed

    Parolaro, D; Rubino, T; Viganò, D; Massi, P; Guidali, C; Realini, N

    2010-04-01

    Recently, the presence of functional interaction between the opioid and cannabinoid system has been shown in various pharmacological responses. Although there is an increasing interest for the feasible therapeutic application of a co-administration of cannabinoids and opioids in some disorders (i.e. to manage pain, to modulate immune system and emotions) and the combined use of the two drugs by drug abusers is becoming largely diffuse, only few papers focused on cellular and molecular mechanisms underlying this interaction. This review updates the biochemical and molecular underpinnings of opioid and cannabinoid interaction, both within the central nervous system and periphery. The most convincing theory for the explanation of this reciprocal interaction involves (i) the release of opioid peptides by cannabinoids or endocannabinoids by opioids, (ii) the existence of a direct receptor-receptor interaction when the receptors are co-expressed in the same cells, and (iii) the interaction of their intracellular pathways. Finally, the cannabinoid/opioid interaction might be different in the brain rewarding networks and in those accounting for other pharmacological effects (antinociception, modulation of emotionality and cognitive behavior), as well as between the central nervous system and periphery. Further insights about the cannabinoid/opioid interaction could pave the way for new and promising therapeutic approaches. PMID:20017730

  1. Opioid Use Disorders.

    PubMed

    Sharma, Bikash; Bruner, Ann; Barnett, Gabrielle; Fishman, Marc

    2016-07-01

    Opioid use and addiction in adolescents and young adults is a health problem of epidemic proportions, with devastating consequences for youth and their families. Opioid overdose is a life-threatening emergency that should be treated with naloxone, and respiratory support if necessary. Overdose should always be an opportunity to initiate addiction treatment. Detoxification is often a necessary, but never sufficient, component of treatment for OUDs. Treatment for OUDs is effective but treatment capacity is alarmingly limited and under-developed. Emerging consensus supports the incorporation of relapse prevention medications such as buprenorphine and extended release naltrexone into comprehensive psychosocial treatment including counseling and family involvement. PMID:27338968

  2. Pharmacokinetics of difloxacin and its concentration in body fluids and endometrial tissues of mares after repeated intragastric administration

    PubMed Central

    2005-01-01

    Abstract Pharmacokinetics of difloxacin and its distribution within the body fluids and endometrium of 6 mares were studied after intragastric (IG) administration of 5 individual doses. Difloxacin concentrations were serially measured in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal fluid, and endometrium over 120 h. Bacterial susceptibility to difloxacin was determined for 174 equine pathogens over a 7-month period. Maximum serum concentration (Cmax) was 2.25 ± 0.70 μg/mL at 3.12 ± 2.63 h and Cmax after the 5th dose was 2.41 ± 0.86 μg/mL at 97.86 ± 1.45 h. The mean elimination half-life (t1/2) was 8.75 ± 2.77 h and area under the serum concentration versus time curve (AUC) was 25.13 ± 8.79 μg h/mL. Highest mean synovial fluid concentration was 1.26 ± 0.49 μg/mL at 100 h. Highest mean peritoneal fluid concentration was 1.50 ± 0.56 μg/mL at 98 h. Highest mean endometrial concentration was 0.78 ± 0.48 μg/g at 97.5 h. Mean cerebrospinal fluid concentration was 0.87 ± 0.52 μg/mL at 99 h. Highest mean urine concentration was 92.05 ± 30.35 μg/mL at 104 h. All isolates of Salmonella spp. and Pasteurella spp. were susceptible. In general, gram-negative organisms were more susceptible than gram-positives. Difloxacin appears to be safe, adequately absorbed, and well distributed to body fluids and endometrial tissues of mares and may be useful in the treatment of susceptible bacterial infections in adult horses. PMID:16187554

  3. Pharmacokinetics of difloxacin and its concentration in body fluids and endometrial tissues of mares after repeated intragastric administration.

    PubMed

    Adams, Aric R; Haines, Gregory R; Brown, Murray P; Gronwall, Ronald; Merritt, Kelly

    2005-07-01

    Pharmacokinetics of difloxacin and its distribution within the body fluids and endometrium of 6 mares were studied after intragastric (IG) administration of 5 individual doses. Difloxacin concentrations were serially measured in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal fluid, and endometrium over 120 h. Bacterial susceptibility to difloxacin was determined for 174 equine pathogens over a 7-month period. Maximum serum concentration (Cmax) was 2.25 +/- 0.70 microg/mL at 3.12 +/- 2.63 h and Cmax after the 5th dose was 2.41 +/- 0.86 microg/mL at 97.86 +/- 1.45 h. The mean elimination half-life (t(1/2)) was 8.75 +/- 2.77 h and area under the serum concentration versus time curve (AUC) was 25.13 +/- 8.79 microg h/mL. Highest mean synovial fluid concentration was 1.26 +/- 0.49 microg/mL at 100 h. Highest mean peritoneal fluid concentration was 1.50 +/- 0.56 microg/mL at 98 h. Highest mean endometrial concentration was 0.78 +/- 0.48 microg/g at 97.5 h. Mean cerebrospinal fluid concentration was 0.87 +/- 0.52 microg/mL at 99 h. Highest mean urine concentration was 92.05 +/- 30.35 microg/mL at 104 h. All isolates of Salmonella spp. and Pasteurella spp. were susceptible. In general, gram-negative organisms were more susceptible than gram-positives. Difloxacin appears to be safe, adequately absorbed, and well distributed to body fluids and endometrial tissues of mares and may be useful in the treatment of susceptible bacterial infections in adult horses. PMID:16187554

  4. Endogenous opioids and excessive alcohol consumption.

    PubMed Central

    Gianoulakis, C

    1993-01-01

    Alcohol is one of the most popular drugs of abuse in our society, and alcoholism is an important cause of absenteeism at work and a major health and social problem. Ethanol induces a number of effects, such as disinhibition, a feeling of general well-being, tolerance and physical dependence. Since there are no specific receptors with which ethanol interacts, it has been proposed that ethanol exerts its effects by altering the activity of a number of neuronal and neuroendocrine systems. Studies have indicated that alcohol influences the activity of the dopaminergic, serotonergic and opioidergic systems. The implication of the endogenous opioid system in mediating some of the effects of ethanol is indicated by the observations that some of the behavioral and pharmacological effects of ethanol are similar to those of the opiates. Indeed, injections of small amounts of morphine increased ethanol consumption, while the administration of naltrexone decreased ethanol consumption among rats and other experimental animals, in a number of experimental paradigms, suggesting that endogenous opioids may play an important role in controlling voluntary ethanol consumption. This paper reviews studies of the effects of ethanol on the activity of the endogenous opioid system and on the importance of endogenous opioids in controlling alcohol consumption. PMID:7690585

  5. Cellular Composition of the Spleen and Changes in Splenic Lysosomes in the Dynamics of Dyslipidemia in Mice Caused by Repeated Administration of Poloxamer 407.

    PubMed

    Goncharova, N V; Shurlygina, A V; Mel'nikova, E V; Karmatskikh, O L; Avrorov, P A; Loktev, K V; Korolenko, T A

    2015-11-01

    We studied the effect of dyslipidemia induced by poloxamer 407 (300 mg/kg twice a week for 30 days) on cellular composition of the spleen and splenocyte lysosomes in mice. Changes in blood lipid profile included elevated concentrations of total cholesterol, aterogenic LDL, and triglycerides most pronounced in 24 h after the last poloxamer 407 injection; gradual normalization of lipid profile was observed in 4 days (except triglycerides) and 10 days. The most pronounced changes in the spleen (increase in organ weight and number of cells, inhibition in apoptosis, and reduced accumulation of vital dye acridine orange in lysosomes) were detected on day 4; on day 10, the indices returned to normal. Cathepsin D activity in the spleen also increased at these terms. The relationship between changes in the cellular composition of the spleen and dynamics of serum lipid profile in mice in dyslipidemia caused by repeated administrations of relatively low doses of poloxamer 407 is discussed. PMID:26608379

  6. Repeated dose (28-day) administration of silver nanoparticles of varied size and coating does not significantly alter the indigenous murine gut microbiome.

    PubMed

    Wilding, Laura A; Bassis, Christine M; Walacavage, Kim; Hashway, Sara; Leroueil, Pascale R; Morishita, Masako; Maynard, Andrew D; Philbert, Martin A; Bergin, Ingrid L

    2016-01-01

    Silver nanoparticles (AgNPs) have been used as antimicrobials in a number of applications, including topical wound dressings and coatings for consumer products and biomedical devices. Ingestion is a relevant route of exposure for AgNPs, whether occurring unintentionally via Ag dissolution from consumer products, or intentionally from dietary supplements. AgNP have also been proposed as substitutes for antibiotics in animal feeds. While oral antibiotics are known to have significant effects on gut bacteria, the antimicrobial effects of ingested AgNPs on the indigenous microbiome or on gut pathogens are unknown. In addition, AgNP size and coating have been postulated as significantly influential towards their biochemical properties and the influence of these properties on antimicrobial efficacy is unknown. We evaluated murine gut microbial communities using culture-independent sequencing of 16S rRNA gene fragments following 28 days of repeated oral dosing of well-characterized AgNPs of two different sizes (20 and 110 nm) and coatings (PVP and Citrate). Irrespective of size or coating, oral administration of AgNPs at 10 mg/kg body weight/day did not alter the membership, structure or diversity of the murine gut microbiome. Thus, in contrast to effects of broad-spectrum antibiotics, repeat dosing of AgNP, at doses equivalent to 2000 times the oral reference dose and 100-400 times the effective in vitro anti-microbial concentration, does not affect the indigenous murine gut microbiome. PMID:26525505

  7. Comparative toxicokinetic/toxicodynamic study of rubber antioxidants, 2-mercaptobenzimidazole and its methyl substituted derivatives, by repeated oral administration in rats.

    PubMed

    Sakemi, Kazue; Ito, Rieno; Umemura, Takashi; Ohno, Yasuo; Tsuda, Mitsuhiro

    2002-12-01

    2-Mercaptobenzimidazole (MBI), a rubber antioxidant, is known to exhibit potent thyroid toxicity in rats, whereas its methylated derivatives are much less toxic. To characterize this methyl-substituent effect on the thyroid toxicity of MBI, comparative toxicokinetic analyses have been conducted in the present study. MBI and the MMBIs [4-methylated MBI (4-MMBI) and 5-methylated MBI (5-MMBI), and a 1:1 mixture of these 4- and 5-methylated isomers (MMBI mix)] suspended in corn oil were repeatedly administered (at 0.3-0.6 mmol/kg) to male Wistar rats by gavage once daily for 2 weeks. After the first and last administrations, blood and urine samples were collected, and the levels of unchanged compounds and their desulfurated metabolites were determined by high performance liquid chromatography. After repeated oral administration (roa), the C(max) and area under concentration-time curve (AUC) of MBI were markedly increased, while the MMBIs essentially were cleared from the blood within 10 h. After roa, the C(max) and AUC of 4-MMBI decreased markedly, suggesting metabolic enzyme induction. However, the toxicokinetic parameters of 5-MMBI were not markedly altered by roa. The inhibitory potencies (IC(50)) against lactoperoxidase of MBI, 4-MMBI, and 5-MMBI were 20.6 micro M, 45.6 micro M and 31.6 micro M, respectively. Thus, we suggest that the marked decrease of thyroid toxicity by methyl substitution of MBI is caused mainly by a decrease in systemic exposure to the compounds and partly by a decrease in inhibition of thyroid hormone synthesis. PMID:12451444

  8. Effect of Intra CA1 and Intraperitoneal Administration of Opioid Receptor Modulating Agents on The Anxiolytic Properties of Nano and Conventional ZnO in Male Rats

    PubMed Central

    Torabi, Mozhgan; Kesmati, Mahnaz; Eshagh Harooni, Hooman; Varzi, Hosein Najafzadeh

    2014-01-01

    Objective Nano components are today’s new wonder material. However, the safety or toxicity of these components in humans is not yet clear. In a previous study we indicated that nano ZnO (nZnO) has a stronger anxiolytic effect compared to the conventional ZnO (cZnO). The present study was designed to evaluate the intraperitoneal administration of an opioidergic receptor agonist and antagonist of as well as the intra CA1 administration of an opioidergic receptor antagonist on the anxiolytic properties of nano and conventional ZnO in adult male Wistar rats. Materials and Methods In this experimental study, rats received drugs via two modes of injection; intraperitoneal (IP.) and intra CA1 (intra hippocampus, CA1 area). Firstly, nZnO (5, 10, 20 mg/kg), cZnO (5, 10, 20 mg/kg), morphine 6 mg/kg, and naloxone 1 mg/kg were injected IP and naloxone 1µg/rat was injected intra CA1. Subsequently, morphine and na- loxone (IP and intra CA1) were co-injected with the effective dose of nZnO and cZnO. An elevated plus maze was used to evaluate anxiety related behavior and anxiety parameters 30 minutes after the second injection. Results The results indicated that the anxiolytic effects of nZnO 5 mg/kg and cZnO 10 mg/kg were equal. When injected intraperitoneally, naloxone increased anxiety but did not inhibit the anxiolytic effect of nZnO and cZnO. The anxiolytic effects of morphine potentiated the anxio- lytic effects of ZnO, particularly nZno. When introduced via intra CA1 injection naloxone alone had no effect on anxiety behaviors and did not inhibit the anxiolytic effect of nZnO. Conclusion It seems that the opioidergic system activity involved in the anxiolytic effect of nano and conventional ZnO may operate through shared and unshared pathways. PMID:24567946

  9. Repeated administration of a mutant cocaine esterase: effects on plasma cocaine levels, cocaine-induced cardiovascular activity, and immune responses in rhesus monkeys.

    PubMed

    Collins, Gregory T; Brim, Remy L; Noon, Kathleen R; Narasimhan, Diwahar; Lukacs, Nicholas W; Sunahara, Roger K; Woods, James H; Ko, Mei-Chuan

    2012-07-01

    Previous studies have demonstrated the capacity of a long-acting mutant form of a naturally occurring bacterial double mutant cocaine esterase (DM CocE) to antagonize the reinforcing, discriminative, convulsant, and lethal effects of cocaine in rodents and reverse the increases in mean arterial pressure (MAP) and heart rate (HR) produced by cocaine in rhesus monkeys. This study was aimed at characterizing the immunologic responses to repeated dosing with DM CocE and determining whether the development of anti-CocE antibodies altered the capacity of DM CocE to reduce plasma cocaine levels and ameliorate the cardiovascular effects of cocaine in rhesus monkeys. Under control conditions, intravenous administration of cocaine (3 mg/kg) resulted in a rapid increase in the plasma concentration of cocaine (n = 2) and long-lasting increases in MAP and HR (n = 3). Administration of DM CocE (0.32 mg/kg i.v.) 10 min after cocaine resulted in a rapid hydrolysis of cocaine with plasma levels below detection limits within 5 to 8 min. Elevations in MAP and HR were significantly reduced within 25 and 50 min of DM CocE administration, respectively. Although slight (10-fold) increases in anti-CocE antibodies were observed after the fourth administration of DM CocE, these antibodies did not alter the capacity of DM CocE to reduce plasma cocaine levels or ameliorate cocaine's cardiovascular effects. Anti-CocE titers were transient and generally dissipated within 8 weeks. Together, these results suggest that highly efficient cocaine esterases, such as DM CocE, may provide a novel and effective therapeutic for the treatment of acute cocaine intoxication in humans. PMID:22518021

  10. Dynorphin A (1-13) Neurotoxicity In Vitro: Opioid and Non-Opioid Mechanisms in Mouse Spinal Cord Neurons

    PubMed Central

    Hauser, Kurt F.; Foldes, Jane K.; Turbek, Carol S.

    2016-01-01

    Dynorphin A is an endogenous opioid peptide that preferentially activates κ opioid receptors and is antinociceptive at physiological concentrations. Levels of dynorphin A and a major metabolite, dynorphin A (1-13), increase significantly following spinal cord trauma and reportedly contribute to neurodegeneration associated with secondary injury. Interestingly, both κ opioid and N-methyl-D-aspartate (NMDA) receptor antagonists can modulate dynorphin toxicity, suggesting that dynorphin is acting (directly or indirectly) through κ opioid and/or NMDA receptor (NMDAR) types. Despite these findings, few studies have systematically explored dynorphin toxicity at the cellular level in defined populations of neurons co-expressing κ opioid and NMDA receptors. To address this question, we isolated populations of neurons enriched in both κ opioid and NMDA receptors from embryonic mouse spinal cord and examined the effects of dynorphin A (1-13) on intracellular calcium concentration ([Ca2+]i) and neuronal survival in vitro. Time-lapse photography was used to repeatedly follow the same neurons before and during experimental treatments. At micromolar concentrations, dynorphin A (1-13) elevated [Ca2+]i and caused a significant loss of neurons. The excitotoxic effects were prevented by MK-801 (Dizocilpine) (10 μM), 2-amino-5-phosphopentanoic acid (AP-5) (100 μM), or 7-chlorokynurenic acid (100 μM)— suggesting that dynorphin A (1-13) was acting (directly or indirectly) through NMDA receptors. In contrast, co-treatment with (−)-naloxone (3 μM), or the more selective κ opioid receptor antagonist nor-binaltorphimine (3 μM), exacerbated dynorphin A (1-13)-induced neuronal loss; however, cell losses were not enhanced by the inactive stereoisomer (+)-naloxone (3 μM). Neuronal losses were not seen with exposure to the opioid antagonists alone (10 μM). Thus, opioid receptor blockade significantly increased toxicity, but only in the presence of excitotoxic levels of

  11. Repeated cocaine administration decreases calcineurin (PP2B) but enhances DARPP-32 modulation of sodium currents in rat nucleus accumbens neurons.

    PubMed

    Hu, Xiu-Ti; Ford, Kerstin; White, Francis J

    2005-05-01

    Our previous studies have demonstrated that repeated cocaine (COC) administration reduces voltage-sensitive sodium and calcium currents (I(Na) or VSSCs and I(Ca) or VSCCs, respectively) in medium spiny nucleus accumbens (NAc) neurons of rats. The present findings further indicate that chronic COC-induced I(Na) reduction in NAc neurons is regulated by decreased dephosphorylation and enhanced phosphorylation of Na(+) channels. Whole-cell voltage-clamp recordings revealed that dephosphorylation of Na(+) channels by calcineurin (CaN) enhanced I(Na), while inhibition of protein phosphatase 1 (PP1) by phosphorylated dopamine- and cAMP-regulated phosphoprotein (M(r)=32 kDa) (DARPP-32) at the site of threonine 34 (p-Thr.34-DARPP-32) suppressed I(Na), in freshly dissociated NAc neurons of saline-pretreated rats. However, the effects of CaN on enhancing I(Na) were significantly attenuated, and the action of p-Thr.34-DARPP-32 to decrease I(Na) was mimicked, although not potentiated, by repeated COC pretreatment. Dephosphorylation of Na(+) channels by PP1 also enhanced I(Na), but this effect of PP1 on I(Na) was not apparently affected by repeated COC administration. Western blot analysis indicates that the protein levels of CaN and DARPP-32 were significantly decreased and increased, respectively, while the PP1 levels were unchanged, in the COC-withdrawn NAc as compared to saline-pretreated controls. Combined with previous findings, our results indicate that both CaN and PP1 modulate the increase in I(Na) via enhancing dephosphorylation, while p-Thr.34-DARPP-32 reduces I(Na) by inhibiting PP1-induced dephosphorylation, thereby stabilizing the phosphorylation state, of Na(+) channels in NAc neurons. They also suggest that chronic COC-induced I(Na) reduction may be attributed to a reduction in Ca(2+) signaling, which disrupts the physiological balance of phosphorylation and dephosphorylation of Na(+) channels. PMID:15726118

  12. Opioid Drugs in Patients With Liver Disease: A Systematic Review

    PubMed Central

    Soleimanpour, Hassan; Safari, Saeid; Shahsavari Nia, Kavous; Sanaie, Sarvin; Alavian, Seyed Moayed

    2016-01-01

    Context The liver, one of the most important organs of the body, is known to be responsible for several functions. The functional contribution of the liver to the metabolism of carbohydrates, protein, drugs and toxins, fats and cholesterol and many other biological processes are still unknown. Liver disorders are classified into two types: acute and chronic. Different drugs are used in liver diseases to treat and control pain. Most pain relief medications such as opioids are metabolized via the liver; therefore, the adverse reactions of drugs are probably higher for patients with liver disease. The current study aimed to evaluate the effects of opioid drugs on patients with liver disease; therefore, it is necessary to select suitable opioids for such patients. Evidence Acquisition This review was written by referring to research literature including 70 articles and four textbooks published from 1958 to 2015 on various reputable sites. Searches were carried out on the key phrases of narcotic pain relievers (opioids), acute and chronic hepatic failure, opioid adverse drug reactions, drug-induced liver injury (DILI) and other similar keywords. References included a variety of research papers (descriptive and analytical), intervention and review articles. Results In patients with liver disease, administration of opioid analgesics should be observed, accurately. As a general rule, lower doses of drugs should be administered at regular intervals based on the signs of drug accumulation. Secondly, the interactions of opioid drugs with different levels of substrates of the P450 cytochrome enzyme should be considered. Conclusions Pain management in patients with liver dysfunction is always challenging to physicians because of the adverse reactions of drugs, especially opioids. Opioids should be used cautiously since they can cause sedation, constipation and sudden encephalopathy effects. Since the clearance of these drugs in patients with hepatic insufficiency is decreased

  13. Pleasure-related analgesia activates opioid-insensitive circuits.

    PubMed

    Kut, Elvan; Candia, Victor; von Overbeck, Jan; Pok, Judit; Fink, Daniel; Folkers, Gerd

    2011-03-16

    Recent findings suggest that pain and pleasure share common neurochemical circuits, and studies in animals and humans show that opioid-mediated descending pathways can inhibit or facilitate pain. We explored the role of endogenous opioid neurotransmission in pleasure-related analgesia. μ-Opioidergic activity was blocked with 0.2 mg/kg naloxone to assess its effects on hedonic responses to pleasant emotional pictures (International Affective Picture System) and its modulating effects on heat pain tolerance. Naloxone did not alter subjective and autonomous reactions to pleasure induction or overall mood of participants. In addition, pleasure-related increases in pain tolerance persisted after reversal of endogenous μ-opioidergic neurotransmission. Subjective pain intensity and unpleasantness ratings increased after naloxone administration. These findings suggest that, in addition to opioid-sensitive circuits, mainly opioid-insensitive pain-modulating circuits are activated during pleasure-related analgesia. PMID:21411655

  14. Opioid Antagonist Impedes Exposure.

    ERIC Educational Resources Information Center

    Merluzzi, Thomas V.; And Others

    1991-01-01

    Thirty spider-phobic adults underwent exposure to 17 phobic-related, graded performance tests. Fifteen subjects were assigned to naltrexone, an opioid antagonist, and 15 were assigned to placebo. Naltrexone had a significant effect on exposure, with naltrexone subjects taking significantly longer to complete first 10 steps of exposure and with…

  15. Opioid-induced constipation.

    PubMed

    Gyawali, Bishal; Hayashi, Naomi; Tsukuura, Hiroaki; Honda, Kazunori; Shimokata, Tomoya; Ando, Yuichi

    2015-01-01

    Opioid-induced constipation (OIC) is a very troublesome, difficult to manage and a nearly universal complication of chronic opioid use to control pain associated with advanced illness. Some studies have reported that OIC is so intolerable in some patients that they skip their opioid medications and bear pain instead of OIC. Laxatives have commonly been used as a prophylaxis and treatment of OIC but they are frequently ineffective because the commonly available laxatives do not target the underlying mechanism of OIC, which is the blockade of peripheral mu-receptors. Recently, there have been a number of advances in the treatment of OIC, which any physician involved with opioid-prescribing discipline should be aware of. This review will update the new options and strategies available for treating OIC along with the relevant clinical trials. Finally, this review also provides a recommendation on the preferred way to approach a patient with OIC in the modern era as well as highlight on the importance of doctor-patient communication in this setting. PMID:26061717

  16. Treating Pain with Opioids

    MedlinePlus

    ... it costs. Ask if they have a drug discount program that can help you pay less for your medicine. Buy your medicine from the pharmacy that gives you the cheapest price.  Sign up for patient assistance programs: Most companies that make medicines have programs that Opioids: Howhaerleptpheeoypulesetdh? ...

  17. Neurobiology of opioid dependence in creating addiction vulnerability

    PubMed Central

    Evans, Christopher J.; Cahill, Catherine M.

    2016-01-01

    Opioid drugs are potent modulators of many physiological and psychological processes. When given acutely, they can elicit the signature responses of euphoria and analgesia that societies have coveted for centuries. Repeated, or chronic, use of opioids induces adaptive or allostatic changes that modify neuronal circuitry and create an altered normality — the “drug-dependent” state. This state, at least that exhibited by those maintained continuously on long-acting opioid drugs such as methadone or buprenorphine, is generally indistinguishable from the drug-naïve state for most overt behaviors. The consequences of the allostatic changes (cellular, circuit, and system adaptations) that accompany the drug-dependent state are revealed during drug withdrawal. Drug cessation triggers a temporally orchestrated allostatic re-establishment of neuronal systems, which is manifested as opposing physiological and psychological effects to those exhibited by acute drug intoxication. Some withdrawal symptoms, such as physical symptoms (sweating, shaking, and diarrhea) resolve within days, whilst others, such as dysphoria, insomnia, and anxiety, can linger for months, and some adaptations, such as learned associations, may be established for life. We will briefly discuss the cellular mechanisms and neural circuitry that contribute to the opioid drug-dependent state, inferring an emerging role for neuroinflammation. We will argue that opioid addictive behaviors result from a learned relationship between opioids and relief from an existing or withdrawal-induced anxiogenic and/or dysphoric state. Furthermore, a future stressful life event can recall the memory that opioid drugs alleviate negative affect (despair, sadness, and anxiety) and thereby precipitate craving, resulting in relapse. A learned association of relief of aversive states would fuel drug craving in vulnerable people living in an increasingly stressful society. We suggest that this route to addiction is

  18. Neurobiology of opioid dependence in creating addiction vulnerability.

    PubMed

    Evans, Christopher J; Cahill, Catherine M

    2016-01-01

    Opioid drugs are potent modulators of many physiological and psychological processes. When given acutely, they can elicit the signature responses of euphoria and analgesia that societies have coveted for centuries. Repeated, or chronic, use of opioids induces adaptive or allostatic changes that modify neuronal circuitry and create an altered normality - the "drug-dependent" state. This state, at least that exhibited by those maintained continuously on long-acting opioid drugs such as methadone or buprenorphine, is generally indistinguishable from the drug-naïve state for most overt behaviors. The consequences of the allostatic changes (cellular, circuit, and system adaptations) that accompany the drug-dependent state are revealed during drug withdrawal. Drug cessation triggers a temporally orchestrated allostatic re-establishment of neuronal systems, which is manifested as opposing physiological and psychological effects to those exhibited by acute drug intoxication. Some withdrawal symptoms, such as physical symptoms (sweating, shaking, and diarrhea) resolve within days, whilst others, such as dysphoria, insomnia, and anxiety, can linger for months, and some adaptations, such as learned associations, may be established for life. We will briefly discuss the cellular mechanisms and neural circuitry that contribute to the opioid drug-dependent state, inferring an emerging role for neuroinflammation. We will argue that opioid addictive behaviors result from a learned relationship between opioids and relief from an existing or withdrawal-induced anxiogenic and/or dysphoric state. Furthermore, a future stressful life event can recall the memory that opioid drugs alleviate negative affect (despair, sadness, and anxiety) and thereby precipitate craving, resulting in relapse. A learned association of relief of aversive states would fuel drug craving in vulnerable people living in an increasingly stressful society. We suggest that this route to addiction is contributive to

  19. Repeated ketamine administration alters N-methyl-D-aspartic acid receptor subunit gene expression: Implication of genetic vulnerability for ketamine abuse and ketamine psychosis in humans

    PubMed Central

    Xu, Ke; Lipsky, Robert H

    2015-01-01

    For more than 40 years following its approval by the Food and Drug Administration (FDA) as an anesthetic, ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, has been used as a tool of psychiatric research. As a psychedelic drug, ketamine induces psychotic symptoms, cognitive impairment, and mood elevation, which resemble some symptoms of schizophrenia. Recreational use of ketamine has been increasing in recent years. However, little is known of the underlying molecular mechanisms responsible for ketamine-associated psychosis. Recent animal studies have shown that repeated ketamine administration significantly increases NMDA receptor subunit gene expression, in particular subunit 1 (NR1 or GluN1) levels. This results in neurodegeneration, supporting a potential mechanism where up-regulation of NMDA receptors could produce cognitive deficits in chronic ketamine abuse patients. In other studies, NMDA receptor gene variants are associated with addictive behavior. Here, we focus on the roles of NMDA receptor gene subunits in ketamine abuse and ketamine psychosis and propose that full sequencing of NMDA receptor genes may help explain individual vulnerability to ketamine abuse and ketamine-associated psychosis. PMID:25245072

  20. Repeated administration of propofol upregulated the expression of c-Fos and cleaved-caspase-3 proteins in the developing mouse brain

    PubMed Central

    Cui, Yin; Ling-Shan, Gou; Yi, Liu; Xing-Qi, Wang; Xue-Mei, Zhuang; Xiao-Xing, Yin

    2011-01-01

    Objectives and Aim: This study was designed to analyze the relationship between the expression of c-Fos protein and apoptosis in the hippocampus following propofol administration in infant mice. There are reports that certain drugs, including the general anesthetics applied in pediatrics and obstetrics, could block N-methyl-D-aspartate glutamate receptors and activate γ-aminobutyric acid type A receptors. Furthermore, some anesthetics could trigger neuroapoptosis and the expression of c-Fos in the developing rodent brain. Propofol is a general anesthetic increasingly used in pediatrics and obstetrics, and is reported to be able to interact with both γ-aminobutyric acid type A and N-methyl-D-aspartate glutamate receptors. No adequate evaluations have been available as to whether the dosage of propofol to maintain anaesthesia could trigger the expression of c-Fos and apoptosis. Materials and Methods: Intraperitoneal injections of propofol (50, 100 and 150 mg/kg) or vehicle were administered every 90 minutes (4 times) in infant mice (5–7 days old). 30 minutes after the final administration, the protein expressions of c-Fos and cleaved-caspase-3 in the hippocampus were determined by immunohistochemistry and Western blotting. Results: It was demonstrated that the expressions of cleaved-caspase-3 and c-Fos were upregulated in the hippocampal CA3 region in this study. Conclusions: The upregulated c-Fos expression induced by repeated injections of propofol might evoke neuroapoptosis. PMID:22144767

  1. The Economic Impact of Opioid Use in the Management of Chronic Nonmalignant Pain.

    PubMed

    Lipman, Arthur; Webster, Lynn

    2015-10-01

    Chronic nonmalignant pain (CNMP), defined as persistent pain that is not attributable to a potentially life-limiting condition and has a duration of at least 3 months, is widespread in the United States. Moderate-to-severe CNMP often is treated with opioid analgesics, and there is ongoing debate regarding appropriate allocation of opioids to treat CNMP because long-term treatment can result in problematic side effects, drug misuse, or abuse leading to detrimental medical, social, and economic consequences. Furthermore, therapeutic strategies arising from concerns about the misuse of opioids may impede the treatment of patients who require strong analgesics for adequate pain relief. While current CNMP management includes nonpharmacologic and pharmacologic approaches, including acetaminophen, nonsteroidal anti-inflammatory drugs, and opioids, there is debate regarding the risk-benefit profile of opioids for chronic pain treatment. Mitigation of opioid misuse and abuse and proper administration of opioid analgesics must be balanced against providing appropriate analgesia. To accomplish this, managed care policies could implement guidelines that focus on evaluating risk characteristics for opioid misuse and abuse, use opioid dose-sparing strategies, and encourage the use of alternative analgesics or nonpharmacologic therapy when appropriate. The purpose of this review is to examine challenges and costs associated with CNMP management using opioids and to summarize alternative therapeutic approaches. PMID:26402389

  2. Oral Administration of Recombinant Lactococcus lactis Expressing HSP65 and Tandemly Repeated P277 Reduces the Incidence of Type I Diabetes in Non-Obese Diabetic Mice

    PubMed Central

    Ma, Yanjun; Liu, Jingjing; Hou, Jing; Dong, Yuankai; Lu, Yong; Jin, Liang; Cao, Rongyue; Li, Taiming; Wu, Jie

    2014-01-01

    Diabetes mellitus type 1 (DM1) is an autoimmune disease that gradually destroys insulin-producing beta-cells. We have previously reported that mucosal administration of fusion protein of HSP65 with tandem repeats of P277 (HSP65-6P277) can reduce the onset of DM1 in non-obese diabetic (NOD) mice. To deliver large amounts of the fusion protein and to enhance long-term immune tolerance effects, in the present study, we investigated the efficacy of using orally administrated L. lactis expressing HSP65-6P277 to reduce the incidence of DM1 in NOD mice. L. lactis strain NZ9000 was engineered to express HSP65-6P277 either constitutively or by nisin induction. After immunization via gavage with the recombinant L. lactis strains to groups of 4-week old female NOD mice for 36 weeks, we observed that oral administration of recombinant L. Lactis resulted in the prevention of hyperglycemia, improved glucose tolerance and reduced insulitis. Immunologic analysis showed that treatment with recombinant L. lactis induced HSP65- and P277- specific T cell immuno-tolerance, as well as antigen-specific proliferation of splenocytes. The results revealed that the DM1-preventing function was in part caused by a reduction in the pro-inflammatory cytokine IFN-γ and an increase in the anti-inflammatory cytokine IL-10. Orally administered recombinant L. lactis delivering HSP65-6P277 may be an effective therapeutic approach in preventing DM1. PMID:25157497

  3. Neurobiological mechanisms involved in nicotine dependence and reward: participation of the endogenous opioid system

    PubMed Central

    Berrendero, Fernando; Robledo, Patricia; Trigo, José Manuel; Martín-García, Elena; Maldonado, Rafael

    2010-01-01

    Nicotine is the primary component of tobacco that maintains the smoking habit and develops addiction. The adaptive changes of nicotinic acetylcholine receptors produced by repeated exposure to nicotine play a crucial role in the establishment of dependence. However, other neurochemical systems also participate in the addictive effects of nicotine including glutamate, cannabinoids, GABA and opioids. This review will cover the involvement of these neurotransmitters in nicotine addictive properties, with a special emphasis on the endogenous opioid system. Thus, endogenous enkephalins and beta-endorphins acting on mu-opioid receptors are involved in nicotine rewarding effects, whereas opioid peptides derived from prodynorphin participate in nicotine aversive responses. An upregulation of mu-opioid receptors has been reported after chronic nicotine treatment that could counteract the development of nicotine tolerance, whereas the downregulation induced on kappa-opioid receptors seems to facilitate nicotine tolerance. Endogenous enkephalins acting on mu-opioid receptors also play a role in the development of physical dependence to nicotine. In agreement with these actions of the endogenous opioid system, the opioid antagonist naltrexone has shown to be effective for smoking cessation in certain subpopulations of smokers. PMID:20170672

  4. Opioid-induced preconditioning: recent advances and future perspectives.

    PubMed

    Peart, Jason N; Gross, Eric R; Gross, Garrett J

    2005-01-01

    Opioids, named by Acheson for compounds with morphine-like actions despite chemically distinct structures, have received much research interest, particularly for their central nervous system (CNS) actions involved in pain management, resulting in thousands of scientific papers focusing on their effects on the CNS and other organ systems. A more recent area which may have great clinical importance concerns the role of opioids, either endogenous or exogenous compounds, in limiting the pathogenesis of ischemia-reperfusion injury in heart and brain. The role of endogenous opioids in hibernation provides tantalizing evidence for the protective potential of opioids against ischemia or hypoxia. Mammalian hibernation, a distinct energy-conserving state, is associated with depletion of energy stores, intracellular acidosis and hypoxia, similar to those which occur during ischemia. However, despite the potentially detrimental cellular state induced with hibernation, the myocardium remains resilient for many months. What accounts for the hypoxia-tolerant state is of great interest. During hibernation, circulating levels of opioid peptides are increased dramatically, and indeed, are considered a "trigger" of hibernation. Furthermore, administration of opioid antagonists can effectively reverse hibernation in mammals. Therefore, it is not surprising that activation of opioid receptors has been demonstrated to preserve cellular status following a hypoxic insult, such as ischemia-reperfusion in many model systems including the intestine [Zhang, Y., Wu, Y.X., Hao, Y.B., Dun, Y. Yang, S.P., 2001. Role of endogenous opioid peptides in protection of ischemic preconditioning in rat small intestine. Life Sci. 68, 1013-1019], skeletal muscle [Addison, P.D., Neligan, P.C., Ashrafpour, H., Khan, A., Zhong, A., Moses, M., Forrest, C.R., Pang, C.Y., 2003. Noninvasive remote ischemic preconditioning for global protection of skeletal muscle against infarction. Am. J. Physiol. Heart Circ

  5. The relationship between the pharmacokinetics and pharmacodynamics of spinal opioids. Minireview based on a doctoral thesis.

    PubMed

    Sjöström, S

    1988-01-01

    Spinal opioids have been used clinically since the late seventies to treat acute, traumatic, obstetric and chronic pain. In this article the influence of the pharmacokinetics on the dynamics of intrathecal and epidural opioid administration are discussed with reference to current knowledge. PMID:2905092

  6. Emerging therapies for patients with symptoms of opioid-induced bowel dysfunction

    PubMed Central

    Leppert, Wojciech

    2015-01-01

    Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and opioid-induced constipation, which significantly impair patients’ quality of life and may lead to undertreatment of pain. Traditional laxatives are often prescribed for OIBD symptoms, although they display limited efficacy and exert adverse effects. Other strategies include prokinetics and change of opioids or their administration route. However, these approaches do not address underlying causes of OIBD associated with opioid effects on mostly peripheral opioid receptors located in the GI tract. Targeted management of OIBD comprises purely peripherally acting opioid receptor antagonists and a combination of opioid receptor agonist and antagonist. Methylnaltrexone induces laxation in 50%–60% of patients with advanced diseases and OIBD who do not respond to traditional oral laxatives without inducing opioid withdrawal symptoms with similar response (45%–50%) after an oral administration of naloxegol. A combination of prolonged-release oxycodone with prolonged-release naloxone (OXN) in one tablet (a ratio of 2:1) provides analgesia with limited negative effect on the bowel function, as oxycodone displays high oral bioavailability and naloxone demonstrates local antagonist effect on opioid receptors in the GI tract and is totally inactivated in the liver. OXN in daily doses of up to 80 mg/40 mg provides equally effective analgesia with improved bowel function compared to oxycodone administered alone in patients with chronic non-malignant and cancer-related pain. OIBD is a common complication of long-term opioid therapy and may lead to quality of life deterioration and undertreatment of pain. Thus, a complex assessment and management that addresses underlying causes and patomechanisms of OIBD is recommended. Newer strategies comprise methylnaltrexone or OXN administration in the management of OIBD

  7. The acceptability of repeat Internet-based hybrid diet assessment of previous 24-h dietary intake: administration of the Oxford WebQ in UK Biobank.

    PubMed

    Galante, Julieta; Adamska, Ligia; Young, Alan; Young, Heather; Littlejohns, Thomas J; Gallacher, John; Allen, Naomi

    2016-02-28

    Although dietary intake over a single 24-h period may be atypical of an individual's habitual pattern, multiple 24-h dietary assessments can be representative of habitual intake and help in assessing seasonal variation. Web-based questionnaires are convenient for the participant and result in automatic data capture for study investigators. This study reports on the acceptability of repeated web-based administration of the Oxford WebQ--a 24-h recall of frequency from a set food list suitable for self-completion from which energy and nutrient values can be automatically generated. As part of the UK Biobank study, four invitations to complete the Oxford WebQ were sent by email over a 16-month period. Overall, 176 012 (53% of those invited) participants completed the online version of the Oxford WebQ at least once and 66% completed it more than once, although only 16% completed it on all four occasions. The response rate for any one round of invitations varied between 34 and 26%. On most occasions, the Oxford WebQ was completed on the same day that they received the invitation, although this was less likely if sent on a weekend. Participants who completed the Oxford WebQ tended to be white, female, slightly older, less deprived and more educated, which is typical of health-conscious volunteer-based studies. These findings provide preliminary evidence to suggest that repeated 24-h dietary assessment via the Internet is acceptable to the public and a feasible strategy for large population-based studies. PMID:26652593

  8. Short-Term Effects of Repeated Olfactory Administration of Homeopathic Sulphur or Pulsatilla on Electroencephalographic Alpha Power in Healthy Young Adults

    PubMed Central

    Bell, Iris R.; Brooks, Audrey J.; Howerter, Amy; Jackson, Nicholas; Schwartz, Gary E.

    2011-01-01

    Introduction Homeopathic pathogenetic trials usually rely on symptom self report measures. Adding objective biomarkers could enhance detection of subtle initial remedy effects. The present feasibility study examined electroencephalographic (EEG) effects of repeated olfactory administration of two polycrest remedies. Methods College student volunteers (ages 18–30, both sexes) from an introductory psychology course were screened for good health and relatively elevated Sulphur OR Pulsatilla symptom scores on the Homeopathic Constitutional Type Questionnaire. Subjects underwent a series of 3 once-weekly double-blind sessions during which they repeatedly sniffed the remedy matched to their CTQ type and solvent controls. Each remedy was given in a 6c, 12c, and 30c potency, one potency per week, in randomly assigned order. Solvent controls included both plain distilled water and a water-ethanol (95%) solution. All sniff test solutions were further diluted just prior to laboratory sessions (0.5 ml test solution in 150 ml distilled water). Within a session, remedies and control solvents were administered via 2-second sniffs (8 sniffs of each of 4 different succussion levels for the potency in randomized order). Primary outcome variable was relative EEG power (alpha 1 8–10 hertz; alpha 2 10–12 hertz) averaged over 19 electrode sites, including all succussions for a given potency. Results Mixed-effect models revealed significant main effects for remedy type (Sulphur>Pulsatilla) in both alpha bands, controlling for gender, baseline resting EEG alpha, and solvent control responses. Additional analyses showed significant non-linear interactions between dilution and time (weekly session) in alpha 2 for both remedies and alpha 1 for Sulphur. Conclusion EEG alpha offers an objective biomarker of remedy effects for future studies and potential method for distinguishing time-dependent effects of specific remedies and remedy potencies from one another. PMID:21962194

  9. Impaired recovery of brain muscarinic receptor sites following an adaptive down-regulation induced by repeated administration of diisopropyl fluorophosphate in aged rats

    SciTech Connect

    Pintor, A.; Fortuna, S.; De Angelis, S.; Michalek, H. )

    1990-01-01

    Potential age-related differences in the recovery rate of brain cholinesterase activity (ChE) and muscarinic acetylcholine receptor binding sites (mAChRs) following reduction induced by repeated treatment with diisopropyl fluorophosphate (DFP) were evaluated in Sprague-Dawley rats. Male 3- and 24-month old rats were s.c. injected with DFP on alternate days for 2 weeks and killed 48 hr and 7, 14, 21, 28 and 35 days after the last treatment. In the hippocampus and striatum, but not in the cerebral cortex, of control rats there as a significant age-related decline of ChE activity and maximal density of 3H-QNB binding sites (Bmax). The repeated administration of DFP during the first week caused a syndrome of cholinergic stimulation both in aged and young rats. The syndrome was more pronounced, in terms of intensity and duration in aged than in young animals resulting in 40 and 12% mortality, respectively; during the second week the syndrome attenuated in the two age-groups. The percentage inhibition of brain ChE at the end of DFP treatment did not differ between young and surviving aged rats. The down-regulation of mACRs was present in the three brain regions of both young and age rats (from 20 to 40%). Factorial analysis of variance showed significant differences for age, recovery rate, and significant interaction between age and recovery rate, both for ChE and mAChRs in young rats the three brain areas.

  10. Responsible opioid use.

    PubMed

    Compton, Peggy; Weaver, Michael F

    2015-06-01

    Editor's Note The journal is delighted to introduce a new feature in this issue that focuses on the complex and multifaceted issue of managing pain and related symptoms while responsibly attending to minimizing substance abuse. How should the seemingly disparate disciplines of drug abuse and symptom control interact? Should these be two separate fields or should practitioners/investigators in one also be qualified in the other? Is that even feasible? We are honored to have two leading, academically based clinician scientists coordinating this new feature. Peggy Compton is Professor and Associate Dean for Academic Affairs at the School of Nursing & Health Studies, Georgetown University in Washington, DC. Many readers know of Peggy's work from her years on the faculty of the University of California at Los Angeles (UCLA). Peggy brings both clinical and scientific addictionology expertise as well as the invaluable perspective of nursing to this arena. Her collaborator is Michael F. Weaver. Mike is Professor of Psychiatry and Behavioral Sciences, and Medical Director of the Center for Neurobehavioral Research on Addictions, at the University of Texas Health Sciences Center at Houston. Prior to moving to Texas, Dr. Weaver became internationally known for his work in addiction medicine at the Medical College of Virginia. We look forward to detailed explorations of many interacting issues in symptom control and substance abuse in the articles featured in this new journal feature in coming issues. The commentary below, the article by Kanouse and Compton, the Issue Brief issued by the U.S. Department of Health and Human Services, and my editorial, all of which appear in this journal issue, introduce the new feature, which I am confident will make valuable contributions to the pain management and substance abuse literature. Arthur G. Lipman, Editor ABSTRACT Abusers of prescription opioids represent two distinct populations: those who develop addiction via opioids prescribed

  11. Opioids: The Prescription Drug & Heroin Overdose Epidemic

    MedlinePlus

    ... Resources Law Enforcement Resources Opioids: The Prescription Drug & Heroin Overdose Epidemic Opioids are natural or synthetic chemicals ... in your brain or body. Common opioids include heroin and prescription drugs such as oxycodone, hydrocodone, and ...

  12. Treating Chronic Pain with Opioids: Comparing Effectiveness and Cost

    MedlinePlus

    Treating Chronic Pain with Opioids: Comparing Effectiveness and Cost What are opioids? Opioids are very strong prescription ... using opioids. We compared the effectiveness, safety, and cost of different opioids. We chose these as Consumer ...

  13. 78 FR 2676 - Draft Guidance for Industry on Abuse-Deterrent Opioids-Evaluation and Labeling; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Abuse-Deterrent Opioids... Food and Drug Administration (FDA) is announcing the availability of a draft guidance for industry... availability of a draft guidance for industry entitled ``Abuse-Deterrent Opioids--Evaluation and...

  14. Combating an Epidemic of Prescription Opioid Abuse.

    PubMed

    Pon, Doreen; Awuah, Kwaku; Curi, Danielle; Okyere, Ernest; Stern, Craig S

    2015-11-01

    The past decade has witnessed an alarming increase in the number of deaths due to prescription opioids that has paralleled the rise in the number of opioid prescriptions dispensed. Prescription drug monitoring programs, abuse-deterrent formulations and proper disposal of opioids have been promoted to help combat the opioid epidemic. We discuss changes that dentists, the third most frequent prescribers of opioids, can implement to help reduce the risk of prescription opioid abuse in their communities. PMID:26798885

  15. Two opioid forms of stress analgesia: studies of tolerance and cross-tolerance.

    PubMed

    Terman, G W; Lewis, J W; Liebeskind, J C

    1986-03-12

    We have previously reported that stress analgesia sensitive to and insensitive to opiate antagonists can be differentially produced in rats by varying the severity or temporal pattern of inescapable footshock. In these studies, we give further evidence for the opioid and non-opioid bases of these paradigms of stress analgesia. We find that naloxone-sensitive analgesia demonstrates tolerance with repeated stress and cross-tolerance with morphine, whereas naloxone-insensitive analgesia demonstrates neither of these characteristics. Moreover, different forms of opioid, but not non-opioid, stress analgesia manifest cross-tolerance with each other. These data are discussed in terms of the similarities and differences between two forms of opioid stress analgesia. PMID:3955348

  16. The safety profile of a cationic lipid-mediated cystic fibrosis gene transfer agent following repeated monthly aerosol administration to sheep.

    PubMed

    Alton, Eric W F W; Baker, Alison; Baker, Eilidh; Boyd, A Christopher; Cheng, Seng H; Coles, Rebecca L; Collie, D David S; Davidson, Heather; Davies, Jane C; Gill, Deborah R; Gordon, Catherine; Griesenbach, Uta; Higgins, Tracy; Hyde, Stephen C; Innes, J Alastair; McCormick, Dominique; McGovern, Michael; McLachlan, Gerry; Porteous, David J; Pringle, Ian; Scheule, Ronald K; Shaw, Darren J; Smith, Sionagh; Sumner-Jones, Stephanie G; Tennant, Peter; Vrettou, Christina

    2013-12-01

    Clinically effective gene therapy for Cystic Fibrosis has been a goal for over 20 years. A plasmid vector (pGM169) that generates persistent expression and reduced host inflammatory responses in mice has raised prospects for translation to the clinic. The UK CF Gene Therapy Consortium is currently evaluating long-term repeated delivery of pGM169 complexed with the cationic lipid GL67A in a large Multidose Trial. This regulatory-compliant evaluation of aerosol administration of nine doses of pGM169/GL67A at monthly intervals, to the sheep lung, was performed in preparation for the Multidose Trial. All sheep tolerated treatment well with no adverse effects on haematology, serum chemistry, lung function or histopathology. Acute responses were observed in relation to bronchoalveolar cellularity comprising increased neutrophils and macrophage numbers 1 day post-delivery but these increases were transient and returned to baseline. Importantly there was no cumulative inflammatory effect or lung remodelling with successive doses. Molecular analysis confirmed delivery of pGM169 DNA to the airways and pGM169-specific mRNA was detected in bronchial brushing samples at day 1 following doses 1, 5 and 9. In conclusion, nine doses of pGM169/GL67A were well tolerated with no significant evidence of toxicity that would preclude adoption of a similar strategy in CF patients. PMID:24090839

  17. Repeated alcohol administration during adolescence causes changes in the mesolimbic dopaminergic and glutamatergic systems and promotes alcohol intake in the adult rat.

    PubMed

    Pascual, Maria; Boix, Jordi; Felipo, Vicente; Guerri, Consuelo

    2009-02-01

    Adolescence is a developmental period which the risk of drug and alcohol abuse increases. Since mesolimbic dopaminergic system undergoes developmental changes during adolescence, and this system is involved in rewarding effects of drugs of abuse, we addressed the hypothesis that ethanol exposure during juvenile/adolescent period over-activates mesolimbic dopaminergic system inducing adaptations which can trigger long-term enduring behavioural effects of alcohol abuse. We treated juvenile/adolescent or adult rats with ethanol (3 g/kg) for two-consecutive days at 48-h intervals over 14-day period. Here we show that intermittent ethanol treatment during the juvenile/adolescence period alters subsequent ethanol intake. In vivo microdialysis demonstrates that ethanol elicits a similar prolonged dopamine response in the nucleus accumbens of both adolescent and adult animals pre-treated with multiple doses of ethanol, although the basal dopamine levels were higher in ethanol-treated adolescents than in adult-treated animals. Repeated ethanol administration also down-regulates the expression of DRD2 and NMDAR2B phosphorylation in prefrontal cortex of adolescent animals, but not of adult rats. Finally, ethanol treatment during adolescence changes the acetylation of histones H3 and H4 in frontal cortex, nucleus accumbens and striatum, suggesting chromatin remodelling changes. In summary, our findings demonstrate the sensitivity of adolescent brain to ethanol effects on dopaminergic and glutamatergic neurotransmission, and suggest that abnormal plasticity in reward-related processes and epigenetic mechanisms could contribute to the vulnerability of adolescents to alcohol addiction. PMID:19077056

  18. Acute, but not repeated, administration of the neurotensin NTS1 receptor agonist PD149163 decreases conditioned footshock-induced ultrasonic vocalizations in rats

    PubMed Central

    Prus, Adam J.; Hillhouse, Todd M.; LaCrosse, Amber L.

    2014-01-01

    Neurotensin is an endogenous neuropeptide that has significant interactions with monoamine neurotransmitter systems. To date, neurotensin NTS1 receptor agonists, such as PD149163, have been primarily evaluated for the treatment for schizophrenia, drug addiction, and pain. Recently, PD149163 was found to attenuate fear-potentiated startle in rats, an experimental procedure used for screening anxiolytic drugs. The present study sought to extend these findings through testing PD149163 in a conditioned footshock-induced ultrasonic vocalization (USV) model. Conditioning was conducted in Male Wistar rats using chambers equipped with shock grid floors and an ultrasonic vocalization detector. PD149163 and the 5-HT1A receptor partial agonist buspirone produced a statistically significant reduction of 22 kHz USV counts. The typical antipsychotic haloperidol also reduced 22 kHz USV counts, but did so at cataleptic doses. Ten days of repeated administration of PD149163 abolished the inhibitory effects of PD149163 on 22 kHz USVs. These findings further support an anxiolytic profile for PD149163. However, tolerance to these effects may limit the utility of these drugs for the treatment of anxiety. PMID:24275076

  19. Structural and functional interactions between six-transmembrane μ-opioid receptors and β2-adrenoreceptors modulate opioid signaling

    PubMed Central

    Samoshkin, Alexander; Convertino, Marino; Viet, Chi T.; Wieskopf, Jeffrey S.; Kambur, Oleg; Marcovitz, Jaclyn; Patel, Pinkal; Stone, Laura S.; Kalso, Eija; Mogil, Jeffrey S.; Schmidt, Brian L.; Maixner, William; Dokholyan, Nikolay V.; Diatchenko, Luda

    2015-01-01

    The primary molecular target for clinically used opioids is the μ-opioid receptor (MOR). Besides the major seven-transmembrane (7TM) receptors, the MOR gene codes for alternatively spliced six-transmembrane (6TM) isoforms, the biological and clinical significance of which remains unclear. Here, we show that the otherwise exclusively intracellular localized 6TM-MOR translocates to the plasma membrane upon coexpression with β2-adrenergic receptors (β2-ARs) through an interaction with the fifth and sixth helices of β2-AR. Coexpression of the two receptors in BE(2)-C neuroblastoma cells potentiates calcium responses to a 6TM-MOR ligand, and this calcium response is completely blocked by a selective β2-antagonist in BE(2)-C cells, and in trigeminal and dorsal root ganglia. Co-administration of 6TM-MOR and β2-AR ligands leads to substantial analgesic synergy and completely reverses opioid-induced hyperalgesia in rodent behavioral models. Together, our results provide evidence that the heterodimerization of 6TM-MOR with β2-AR underlies a molecular mechanism for 6TM cellular signaling, presenting a unique functional responses to opioids. This signaling pathway may contribute to the hyperalgesic effects of opioids that can be efficiently blocked by β2-AR antagonists, providing a new avenue for opioid therapy. PMID:26657998

  20. Targeting the opioid growth factor: opioid growth factor receptor axis for treatment of human ovarian cancer.

    PubMed

    Zagon, Ian S; Donahue, Renee; McLaughlin, Patricia J

    2013-05-01

    The opioid growth factor (OGF) - opioid growth factor receptor (OGFr) axis is a biological pathway that is present in human ovarian cancer cells and tissues. OGF, chemically termed [Met(5)]-enkephalin, is an endogenous opioid peptide that interfaces with OGFr to delay cells moving through the cell cycle by upregulation of cyclin-dependent inhibitory kinase pathways. OGF inhibitory activity is dose dependent, receptor mediated, reversible, protein and RNA dependent, but not related to apoptosis or necrosis. The OGF-OGFr axis can be targeted for treatment of human ovarian cancer by (i) administration of exogenous OGF, (ii) genetic manipulation to over-express OGFr and (iii) use of low dosages of naltrexone, an opioid antagonist, which stimulates production of OGF and OGFr for subsequent interaction following blockade of the receptor. The OGF-OGFr axis may be a feasible target for treatment of cancer of the ovary (i) in a prophylactic fashion, (ii) following cytoreduction or (iii) in conjunction with standard chemotherapy for additive effectiveness. In summary, preclinical data support the transition of these novel therapies for treatment of human ovarian cancer from the bench to bedside to provide additional targets for treatment of this devastating disease. PMID:23856908

  1. The opioid system majorly contributes to preference for fat emulsions but not sucrose solutions in mice.

    PubMed

    Sakamoto, Kazuhiro; Okahashi, Tatsuya; Matsumura, Shigenobu; Okafuji, Yoko; Adachi, Shin-ichi; Tsuzuki, Satoshi; Inoue, Kazuo; Fushiki, Tohru

    2015-01-01

    Rodents show a stronger preference for fat than sucrose, even if their diet is isocaloric. This implies that the preference mechanisms for fat and sucrose differ. To compare the contribution of the opioid system to the preference of fat and sucrose, we examined the effects of mu-, delta-, kappa-, and non-selective opioid receptor antagonists on the preference of sucrose and fat, assessed by a two-bottle choice test and a licking test, in mice naïve to sucrose and fat ingestion. Administration of non-selective and mu-selective opioid receptor antagonists more strongly inhibited the preference of fat than sucrose. While the preference of fat was reduced to the same level as water by the antagonist administration that of sucrose was still greater than water. Our results suggest that the preference of fat relies strongly on the opioid system, while that of sucrose is regulated by other mechanisms in addition to the opioid system. PMID:25516200

  2. Long-Acting Injectable Naltrexone for the Management of Patients with Opioid Dependence

    PubMed Central

    Kjome, Kimberly L.; Moeller, F. Gerard

    2011-01-01

    Opioid dependence is a condition with serious clinical ramifications. Treatment has focused on detoxification, agonist therapy with methadone or buprenorphine, or remission maintenance with the opioid antagonist, naltrexone. Treatment with oral naltrexone has been limited by poor treatment adherence and relapse. Studies with long-acting formulations have shown increased treatment adherence. Extended-release injectable naltrexone has been used for the treatment of alcohol dependence, and has recently received an indication for treatment of opioid dependence from the US Food and Drug Administration. Dosing occurs once monthly and existing data with long-acting naltrexone supports efficacy of treatment for opioid dependence; however published data is sparse. Treatment with long-acting naltrexone should be monitored for hepatotoxicity, and patients should be made aware of increased risk of overdose with administration of opioids during and immediately after discontinuation of long-acting naltrexone. PMID:22879745

  3. Patterns and Correlates of Prescription Opioid Use in OEF/OIF Veterans with Chronic Non-Cancer Pain

    PubMed Central

    Macey, Tara A.; Morasco, Benjamin J.; Duckart, Jonathan P.; Dobscha, Steven K.

    2013-01-01

    Objectives Little is known about the treatment Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans receive for chronic non-cancer pain (CNCP). We sought to describe the prevalence of prescription opioid use, types and doses of opioids received, and identify correlates of receiving prescription opioids for CNCP among OEF/OIF veterans. Design Retrospective review of VA administrative data. Setting Ambulatory clinics within a VA regional healthcare network. Patients OEF/OIF veterans who had at least 3 elevated pain screening scores within a 12-month period in 2008. Within this group, those prescribed opioids (n=485) over the next 12 months were compared to those not prescribed opioids (n=277). In addition, patients receiving opioids short term (<90 days, n=284) were compared to patients receiving them long-term (≥90 consecutive days, n=201). Results Of 762 OEF/OIF veterans with CNCP, 64% were prescribed at least one opioid medication over the 12 months following their index dates. Of those prescribed an opioid, 59% were prescribed opioids short-term and 41% were prescribed opioids long-term. The average morphine-equivalent opioid dose for short-term users was 23.7 mg (SD=20.5) compared with 40.8 mg (SD=36.1) for long-term users (p<0.001). Fifty-one percent of long-term opioid users were prescribed short-acting opioids only and one-third were also prescribed sedative-hypnotics. In adjusted analyses, diagnoses of low back pain, migraine headache, post-traumatic stress disorder, and nicotine use disorder were associated with an increased likelihood of receiving an opioid prescription. Conclusion Prescription opioid use is common among OEF/OIF veterans with CNCP and is associated with several pain diagnoses and medical conditions. PMID:21899715

  4. Opioids for low back pain.

    PubMed

    Deyo, Richard A; Von Korff, Michael; Duhrkoop, David

    2015-01-01

    Back pain affects most adults, causes disability for some, and is a common reason for seeking healthcare. In the United States, opioid prescription for low back pain has increased, and opioids are now the most commonly prescribed drug class. More than half of regular opioid users report back pain. Rates of opioid prescribing in the US and Canada are two to three times higher than in most European countries. The analgesic efficacy of opioids for acute back pain is inferred from evidence in other acute pain conditions. Opioids do not seem to expedite return to work in injured workers or improve functional outcomes of acute back pain in primary care. For chronic back pain, systematic reviews find scant evidence of efficacy. Randomized controlled trials have high dropout rates, brief duration (four months or less), and highly selected patients. Opioids seem to have short term analgesic efficacy for chronic back pain, but benefits for function are less clear. The magnitude of pain relief across chronic non-cancer pain conditions is about 30%. Given the brevity of randomized controlled trials, the long term effectiveness and safety of opioids are unknown. Loss of long term efficacy could result from drug tolerance and emergence of hyperalgesia. Complications of opioid use include addiction and overdose related mortality, which have risen in parallel with prescription rates. Common short term side effects are constipation, nausea, sedation, and increased risk of falls and fractures. Longer term side effects may include depression and sexual dysfunction. Screening for high risk patients, treatment agreements, and urine testing have not reduced overall rates of opioid prescribing, misuse, or overdose. Newer strategies for reducing risks include more selective prescription of opioids and lower doses; use of prescription monitoring programs; avoidance of co-prescription with sedative hypnotics; and reformulations that make drugs more difficult to snort, smoke, or inject. PMID

  5. The Selective Monoacylglycerol Lipase Inhibitor MJN110 Produces Opioid-Sparing Effects in a Mouse Neuropathic Pain Model.

    PubMed

    Wilkerson, Jenny L; Niphakis, Micah J; Grim, Travis W; Mustafa, Mohammed A; Abdullah, Rehab A; Poklis, Justin L; Dewey, William L; Akbarali, Hamid; Banks, Matthew L; Wise, Laura E; Cravatt, Benjamin F; Lichtman, Aron H

    2016-04-01

    Serious clinical liabilities associated with the prescription of opiates for pain control include constipation, respiratory depression, pruritus, tolerance, abuse, and addiction. A recognized strategy to circumvent these side effects is to combine opioids with other antinociceptive agents. The combination of opiates with the primary active constituent of cannabis (Δ(9)-tetrahydrocannabinol) produces enhanced antinociceptive actions, suggesting that cannabinoid receptor agonists can be opioid sparing. Here, we tested whether elevating the endogenous cannabinoid 2-arachidonoylglycerol through the inhibition of its primary hydrolytic enzyme monoacylglycerol lipase (MAGL), will produce opioid-sparing effects in the mouse chronic constriction injury (CCI) of the sciatic nerve model of neuropathic pain. The dose-response relationships of i.p. administration of morphine and the selective MAGL inhibitor 2,5-dioxopyrrolidin-1-yl 4-(bis(4-chlorophenyl)methyl)piperazine-1-carboxylate (MJN110) were tested alone and in combination at equieffective doses for reversal of CCI-induced mechanical allodynia and thermal hyperalgesia. The respective ED50 doses (95% confidence interval) of morphine and MJN110 were 2.4 (1.9-3.0) mg/kg and 0.43 (0.23-0.79) mg/kg. Isobolographic analysis of these drugs in combination revealed synergistic antiallodynic effects. Acute antinociceptive effects of the combination of morphine and MJN110 required μ-opioid, CB1, and CB2 receptors. This combination did not reduce gastric motility or produce subjective cannabimimetic effects in the drug discrimination assay. Importantly, combinations of MJN110 and morphine given repeatedly (i.e., twice a day for 6 days) continued to produce antiallodynic effects with no evidence of tolerance. Taken together, these findings suggest that MAGL inhibition produces opiate-sparing events with diminished tolerance, constipation, and cannabimimetic side effects. PMID:26791602

  6. Current Evidence for Spinal Opioid Selection in Postoperative Pain

    PubMed Central

    2014-01-01

    Background Spinal opioid administration is an excellent option to separate the desirable analgesic effects of opioids from their expected dose-limiting side effects to improve postoperative analgesia. Therefore, physicians must better identify either specific opioids or adequate doses and routes of administration that result in a mainly spinal site of action rather than a cerebral analgesic one. Methods The purpose of this topical review is to describe current available clinical evidence to determine what opioids reach high enough concentrations to produce spinally selective analgesia when given by epidural or intrathecal routes and also to make recommendations regarding their rational and safety use for the best management of postoperative pain. To this end, a search of Medline/Embase was conducted to identify all articles published up to December 2013 on this topic. Results Recent advances in spinal opioid bioavailability, based on both animals and humans trials support the theory that spinal opioid bioavailability is inversely proportional to the drug lipid solubility, which is higher in hydrophilic opioids like morphine, diamorphine and hydromorphone than lipophilic ones like alfentanil, fentanyl and sufentanil. Conclusions Results obtained from meta-analyses of RTCs is considered to be the 'highest' level and support their use. However, it's a fact that meta-analyses based on studies about treatment of postoperative pain should explore clinical surgery heterogeneity to improve patient's outcome. This observation forces physicians to use of a specific procedure surgical-based practical guideline. A vigilance protocol is also needed to achieve a good postoperative analgesia in terms of efficacy and security. PMID:25031805

  7. Differential effects of LY235959, a competitive antagonist of the NMDA receptor on kappa-opioid receptor agonist induced responses in mice and rats.

    PubMed

    Bhargava, H N; Thorat, S N

    1997-02-01

    The effects of the competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, LY235959, were determined on the analgesic and hypothermic effects as well as on the development of tolerance to these effects of U-50,488H, a kappa-opioid receptor agonist in mice and rats. In the mouse, a single injection of LY235959 given 10 min prior to U-50,488H did not modify the analgesic action of the latter. Similarly, chronic administration of LY235959 twice a day for 4 days did not modify U-50,488H-induced analgesia in mice. Repeated pretreatment of mice with LY235959 dose-dependently attenuated the development of tolerance to the analgesic actions of U-50,488H. In the rat, LY235959 by itself produced a significant analgesia and prior treatment of rats with LY235959 enhanced the analgesic action of U-50,488H. Similar effects were seen with the hypothermic action. Pretreatment of rats with LY235959 attenuated the development of tolerance to the analgesic but not to the hypothermic action of U-50,488H. These results provide evidence that LY235959 produces differential actions on nociception and thermic responses by itself and when given acutely with U-50,488H in mice and rats. However, when the animals are pretreated with LY235959, similar inhibitory effects are observed on the development of tolerance to the analgesic action of U-50,488H in both the species. These studies demonstrate an involvement of the NMDA receptor in the development of kappa-opioid tolerance and suggest that the biochemical consequences of an opioid's interaction with the opioid receptor are not the only factors that contribute to the acute and chronic actions of opioid analgesic drugs. PMID:9045999

  8. Opioid neurotransmission in the post-ictal analgesia: involvement of mu(1)-opioid receptor.

    PubMed

    Coimbra, N C; Freitas, R L; Savoldi, M; Castro-Souza, C; Segato, E N; Kishi, R; Weltson, A; Resende, G C

    2001-06-01

    Pentylenetetrazol (PTZ), a non-competitive antagonist that blocks GABA-mediated Cl(-) flux, was used in the present work to induce seizures in animals. The aim of this work is to study the neurochemical basis of the antinociception induced by convulsions elicited by peripheral administration of PTZ (64 mg/kg). The analgesia was measured by the tail-flick test, in eight rats per group. Convulsions were followed by significative increase in the tail-flick latencies (TFL), for at least 120 min of the post-ictal period. Peripheral administration of naltrexone (5 mg/kg, 10 mg/kg and 20 mg/kg) caused a significant decrease in the TFL in seizing animals, as compared to controls. These data were corroborated with peripheral administration of naloxonazine (10 mg/kg and 20 mg/kg), a mu(1)-opioid blocker, in the same doses used for non-specific antagonist. These results indicate that endogenous opioids may be involved in the post-ictal analgesia. The involvement of mu(1)-opioid receptor was also considered. PMID:11382405

  9. The effect of repeated intramuscular alfentanil injections on experimental pain and abuse liability indices in healthy males

    PubMed Central

    Tompkins, D. Andrew; Smith, Michael T.; Bigelow, George E.; Moaddel, Ruin; Venkata, S.L. Vatem; Strain, Eric C.

    2013-01-01

    Objective Opioid-induced hyperalgesia (OIH), increased sensitivity to noxious stimuli following repeated opioid exposures, has been demonstrated in pre-clinical studies. However, there is no accepted, prospective model of OIH following repeated opioid exposures currently available in humans. This study assessed a potential prospective OIH model. Methods Double-blind intramuscular (IM) injections of a short-acting opioid, (alfentanil 15 mcg/kg; N=8) were compared to active placebo (diphenhydramine 25 mg; N=3) on cold and pressure pain testing and standard abuse liability measures in eight 10-hour sessions (1 injection/session) over 4–5 weeks in healthy pain-free males. Decreases from session baseline pain threshold (PThr) and tolerance (PTol) were calculated to represent hyperalgesia, and were assessed both within and across sessions. Results Mean decreases in cold PTol were seen in the alfentanil group at 180 minutes (−3.8 seconds, +/−26.5) and 480 minutes (−1.63 seconds, +/−31.5) after drug administration. There was a trend for differences between conditions on cold PThr hyperalgesia but not for pressure PThr. Alfentanil participants had greater mean ratings on LIKING and HIGH visual analog scales at peak effects (30 minutes), but these scores did not change across sessions. Discussion Repeated alfentanil exposures over 4–5 weeks resulted in within session decreases in cold pain tolerance from baseline but these differences were not substantially different from diphenhydramine controls. The results did not support the phenomenon of OIH in this model, although definitive conclusions regarding the existence of OIH in humans likely requires a larger sample size or an alternative model. PMID:23446076

  10. State Legal Restrictions and Prescription-Opioid Use among Disabled Adults.

    PubMed

    Meara, Ellen; Horwitz, Jill R; Powell, Wilson; McClelland, Lynn; Zhou, Weiping; O'Malley, A James; Morden, Nancy E

    2016-07-01

    Background In response to rising rates of opioid abuse and overdose, U.S. states enacted laws to restrict the prescribing and dispensing of controlled substances. The effect of these laws on opioid use is unclear. Methods We tested associations between prescription-opioid receipt and state controlled-substances laws. Using Medicare administrative data for fee-for-service disabled beneficiaries 21 to 64 years of age who were alive throughout the calendar year (8.7 million person-years from 2006 through 2012) and an original data set of laws (e.g., prescription-drug monitoring programs), we examined the annual prevalence of beneficiaries with four or more opioid prescribers, prescriptions yielding a daily morphine-equivalent dose (MED) of more than 120 mg, and treatment for nonfatal prescription-opioid overdose. We estimated how opioid outcomes varied according to eight types of laws. Results From 2006 through 2012, states added 81 controlled-substance laws. Opioid receipt and potentially hazardous prescription patterns were common. In 2012 alone, 47% of beneficiaries filled opioid prescriptions (25% in one to three calendar quarters and 22% in every calendar quarter); 8% had four or more opioid prescribers; 5% had prescriptions yielding a daily MED of more than 120 mg in any calendar quarter; and 0.3% were treated for a nonfatal prescription-opioid overdose. We observed no significant associations between opioid outcomes and specific types of laws or the number of types enacted. For example, the percentage of beneficiaries with a prescription yielding a daily MED of more than 120 mg did not decline after adoption of a prescription-drug monitoring program (0.27 percentage points; 95% confidence interval, -0.05 to 0.59). Conclusions Adoption of controlled-substance laws was not associated with reductions in potentially hazardous use of opioids or overdose among disabled Medicare beneficiaries, a population particularly at risk. (Funded by the National Institute on