Curcumin Attenuates Opioid Tolerance and Dependence by Inhibiting Ca2+/Calmodulin-Dependent Protein Kinase II α Activity

PubMed Central

Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena

2015-01-01

Chronic use of opioid analgesics has been hindered by the development of opioid addiction and tolerance. We have reported that curcumin, a natural flavonoid from the rhizome of Curcuma longa, attenuated opioid tolerance, although the underlying mechanism remains unclear. In this study, we tested the hypothesis that curcumin may inhibit Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein kinase that has been previously proposed to be critical for opioid tolerance and dependence. In this study, we used state-of-the-art polymeric formulation technology to produce poly(lactic-co-glycolic acid) (PLGA)-curcumin nanoparticles (nanocurcumin) to overcome the drug’s poor solubility and bioavailability, which has made it extremely difficult for studying in vivo pharmacological actions of curcumin. We found that PLGA-curcumin nanoparticles reduced the dose requirement by 11- to 33-fold. Pretreatment with PLGA-curcumin (by mouth) prevented the development of opioid tolerance and dependence in a dose-dependent manner, with ED50 values of 3.9 and 3.2 mg/kg, respectively. PLGA-curcumin dose-dependently attenuated already-established opioid tolerance (ED50 = 12.6 mg/kg p.o.) and dependence (ED50 = 3.1 mg/kg p.o.). Curcumin or PLGA-curcumin did not produce antinociception by itself or affect morphine (1–10 mg/kg) antinociception. Moreover, we found that the behavioral effects of curcumin on opioid tolerance and dependence correlated with its inhibition of morphine-induced CaMKIIα activation in the brain. These results suggest that curcumin may attenuate opioid tolerance and dependence by suppressing CaMKIIα activity. PMID:25515789

The challenge of perioperative pain management in opioid-tolerant patients

PubMed Central

Coluzzi, Flaminia; Bifulco, Francesca; Cuomo, Arturo; Dauri, Mario; Leonardi, Claudio; Melotti, Rita Maria; Natoli, Silvia; Romualdi, Patrizia; Savoia, Gennaro; Corcione, Antonio

2017-01-01

The increasing number of opioid users among chronic pain patients, and opioid abusers among the general population, makes perioperative pain management challenging for health care professionals. Anesthesiologists, surgeons, and nurses should be familiar with some pharmacological phenomena which are typical of opioid users and abusers, such as tolerance, physical dependence, hyperalgesia, and addiction. Inadequate pain management is very common in these patients, due to common prejudices and fears. The target of preoperative evaluation is to identify comorbidities and risk factors and recognize signs and symptoms of opioid abuse and opioid withdrawal. Clinicians are encouraged to plan perioperative pain medications and to refer these patients to psychiatrists and addiction specialists for their evaluation. The aim of this review was to give practical suggestions for perioperative management of surgical opioid-tolerant patients, together with schemes of opioid conversion for chronic pain patients assuming oral or transdermal opioids, and patients under maintenance programs with methadone, buprenorphine, or naltrexone. PMID:28919771

Opioid agonist efficacy predicts the magnitude of tolerance and the regulation of mu-opioid receptors and dynamin-2.

PubMed

Pawar, Mohit; Kumar, Priyank; Sunkaraneni, Soujanya; Sirohi, Sunil; Walker, Ellen A; Yoburn, Byron C

2007-06-01

It has been proposed that opioid agonist efficacy may play a role in tolerance and the regulation of opioid receptor density. To address this issue, the present studies estimated the in vivo efficacy of three opioid agonists and then examined changes in spinal mu-opioid receptor density following chronic treatment in the mouse. In addition, tolerance and regulation of the trafficking protein dynamin-2 were determined. To evaluate efficacy, the method of irreversible receptor alkylation was employed and the efficacy parameter tau estimated. Mice were injected with the irreversible mu-opioid receptor antagonist clocinnamox (0.32-25.6 mg/kg, i.p), and 24 h later, the analgesic potency of s.c. morphine, oxycodone and etorphine were determined. Clocinnamox dose-dependently antagonized the analgesic effects of morphine, etorphine and oxycodone. The shift to the right of the dose-response curves was greater for morphine and oxycodone compared to etorphine and the highest dose of clocinnamox reduced the maximal effect of morphine and oxycodone, but not etorphine. The order of efficacy calculated from these results was etorphine>morphine>oxycodone. Other mice were infused for 7 days with oxycodone (10-150 mg/kg/day, s.c.) or etorphine (50-250 microg/kg/day, s.c.) and the analgesic potency of s.c. morphine determined. The low efficacy agonist (oxycodone) produced more tolerance than the high efficacy agonist (etorphine) at equi-effective infusion doses. In saturation binding experiments, the low efficacy opioid agonists (morphine, oxycodone) did not regulate the density of spinal mu-opioid receptors, while etorphine produced approximately 40% reduction in mu-opioid receptor density. Furthermore, etorphine increased spinal dynamin-2 abundance, while oxycodone did not produce any significant change in dynamin-2 abundance. Overall, these data indicate that high efficacy agonists produce less tolerance at equi-effective doses. Furthermore, increased efficacy was associated with

Opioid tolerance and urine drug testing among initiates of extended-release or long-acting opioids in Food and Drug Administration's Sentinel System.

PubMed

Larochelle, Marc R; Cocoros, Noelle M; Popovic, Jennifer; Dee, Elizabeth C; Kornegay, Cynthia; Ju, Jing; Racoosin, Judith A

A risk evaluation and mitigation strategy for extended-release and long-acting (ER/LA) opioid analgesics was approved by the Food and Drug Administration in 2012. Our objective was to assess frequency of opioid tolerance and urine drug testing for individuals initiating ER/LA opioid analgesics. Retrospective cohort study. Sentinel, a distributed database with electronic healthcare data on >190 million predominantly commercially insured members. Members under age 65 initiating ER/LA opioid analgesics between January 2009 and December 2013. We examined the proportion of opioid-tolerant-only ER/LA opioid analgesic initiates meeting tolerance criteria: receipt of ≥30 mg oxycodone equivalents per day in 7 days prior to the first opioid-tolerant-only dispensing. We separately examined the proportion of new users of extended-release oxycodone (ERO) and other ER/LA opioid analgesics with a claim for a urine drug test in the 30 days prior to, and separately for the 183 days after, dispensing. We identified 79,824 ERO, 7,343 extended-release hydromorphone, and 91,778 transdermal fentanyl opi-oid-tolerant-only episodes. Tolerance criteria were met in 64 percent of ERO, 64 percent of extended-release hydromorphone and 40 percent of transdermal fentanyl episodes. We identified 210,581 incident ERO and 311,660 other ER/LA opioid analgesic episodes. Use of urine drug testing for ERO compared with other ER/LA opioid analgesics was: 4 percent vs 14 percent respectively in the 30 days prior to initiation and 9 percent vs 23 percent respectively in the 183 days following initiation. These results suggest potential areas for improving appropriate ER/LA opioid analgesic prescribing practices.

Antagonists of toll like receptor 4 maybe a new strategy to counteract opioid-induced hyperalgesia and opioid tolerance.

PubMed

Li, Qian

2012-12-01

Long term opioid treatment results in hyperalgesia and tolerance, which is a troublesome phenomenon in clinic application. Recent studies have revealed a critical role of toll-like receptor 4 (TLR4) in the neuropathological process of opioid-induced hyperalgesia and tolerance. TLR4 is predominantly expressed by microglial cells and is a key modulator in the activation of the innate immune system. Activation of TLR4 may initiate the activation of microglia and hence a number of neurotransmitters and neuromodulators that could enhance neuronal excitability are released. Blockade of TLR4 activation by its antagonists alleviate neuropathic pain. We hypothesized that opioid antagonists such as naloxone and naltrexone, which were also demonstrated to be TLR4 antagonist, may have clinic application value in attenuation of opioid-induced hyperalgesia and tolerance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hydromorphone efficacy and treatment protocol impact on tolerance and mu-opioid receptor regulation.

PubMed

Kumar, Priyank; Sunkaraneni, Soujanya; Sirohi, Sunil; Dighe, Shveta V; Walker, Ellen A; Yoburn, Byron C

2008-11-12

This study examined the antinociceptive (analgesic) efficacy of hydromorphone and hydromorphone-induced tolerance and regulation of mu-opioid receptor density. Initially s.c. hydromorphone's time of peak analgesic (tail-flick) effect (45 min) and ED50 using standard and cumulative dosing protocols (0.22 mg/kg, 0.37 mg/kg, respectively) were determined. The apparent analgesic efficacy (tau) of hydromorphone was then estimated using the operational model of agonism and the irreversible mu-opioid receptor antagonist clocinnamox. Mice were injected with clocinnamox (0.32-25.6 mg/kg, i.p.) and 24 h later, the analgesic potency of hydromorphone was determined. The tau value for hydromorphone was 35, which suggested that hydromorphone is a lower analgesic efficacy opioid agonist. To examine hydromorphone-induced tolerance, mice were continuously infused s.c. with hydromorphone (2.1-31.5 mg/kg/day) for 7 days and then morphine cumulative dose response studies were performed. Other groups of mice were injected with hydromorphone (2.2-22 mg/kg/day) once, or intermittently every 24 h for 7 days. Twenty-four hours after the last injection, mice were tested using morphine cumulative dosing studies. There was more tolerance with infusion treatments compared to intermittent treatment. When compared to higher analgesic efficacy opioids, hydromorphone infusions induced substantially more tolerance. Finally, the effect of chronic infusion (31.5 mg/kg/day) and 7 day intermittent (22 mg/kg/day) hydromorphone treatment on spinal cord mu-opioid receptor density was determined. Hydromorphone did not produce any change in mu-opioid receptor density following either treatment. These results support suggestions that analgesic efficacy is correlated with tolerance magnitude and regulation of mu-opioid receptors when opioid agonists are continuously administered. Taken together, these studies indicate that analgesic efficacy and treatment protocol are important in determining tolerance and

Epigenetic regulation of opioid-induced hyperalgesia, dependence, and tolerance in mice.

PubMed

Liang, De-Yong; Li, XiangQi; Clark, J David

2013-01-01

Repeated administration of opioids such as morphine induces persistent behavioral changes including opioid-induced hyperalgesia (OIH), tolerance, and physical dependence. In the current work we explored how the balance of histone acetyltransferase (HAT) versus histone deacetylase (HDAC) might regulate these morphine-induced changes. Nociceptive thresholds, analgesia, and physical dependence were assessed during and for a period of several weeks after morphine exposure. To probe the roles of histone acetylation, the HAT inhibitor curcumin or a selective HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was administered daily to groups of animals. Histone acetylation in spinal cord was assessed by Western blot and immunohistochemistry. Concurrent administration of curcumin with morphine for 4 days significantly reduced development of opioid-induced mechanical allodynia, thermal hyperalgesia, tolerance, and physical dependence. Conversely, the HDAC inhibitor SAHA enhanced these responses. Interestingly, SAHA treatment after the termination of opioid administration sustained these behavioral changes for at least 4 weeks. Histone H3 acetylation in the dorsal horn of the spinal cord was increased after chronic morphine treatment, but H4 acetylation was unchanged. Moreover, we observed a decrease in HDAC activity in the spinal cords of morphine-treated mice while overall HAT activity was unchanged, suggesting a shift toward a state of enhanced histone acetylation. The current study indicates that epigenetic mechanisms play a crucial role in opioid-induced long-lasting neuroplasticity. These results provide new sight into understanding the mechanisms of opioid-induced neuroplasticity and suggest new strategies to limit opioid abuse potential and increase the value of these drugs as analgesics. Copyright © 2013 American Pain Society. All rights reserved.

Intraoperative use of remifentanil and opioid induced hyperalgesia/acute opioid tolerance: systematic review.

PubMed

Kim, Sang Hun; Stoicea, Nicoleta; Soghomonyan, Suren; Bergese, Sergio D

2014-01-01

The use of opioids has been increasing in operating room and intensive care unit to provide perioperative analgesia as well as stable hemodynamics. However, many authors have suggested that the use of opioids is associated with the expression of acute opioid tolerance (AOT) and opioid-induced hyperalgesia (OIH) in experimental studies and clinical observations in dose and/or time dependent exposure even when used within the clinically accepted doses. Recently, remifentanil has been used for pain management during anesthesia as well as in the intensive care units because of its rapid onset and offset. Search of the available literature to assess remifentanil AOT and OIH based on available published data. We reviewed articles analyzing remifentanil AOT and OIH, and focused our literature search on evidence based information. Experimental and clinical studies were identified using electronic searches of Medline (PubMed, Ovid, Springer, and Elsevier, ClinicalKey). Our results showed that the development of remifentanil AOT and OIH is a clinically significant phenomenon requiring further research. AOT - defined as an increase in the required opioid dose to maintain adequate analgesia, and OIH - defined as decreased pain threshold after chronic opioid treatment, should be suspected with any unexplained pain report unassociated with the disease progression. The clinical significance of these findings was evaluated taking into account multiple methodological issues including the dose and duration of opioids administration, the different infusion mode, the co-administrated anesthetic drug's effect, method assessing pain sensitivity, and the repetitive and potentially tissue damaging nature of the stimuli used to determine the threshold during opioid infusion. Future studies need to investigate the contribution of remifentanil induced hyperalgesia to chronic pain and the role of pharmacological modulation to reverse this process.

Immunoneutralization of Agmatine Sensitizes Mice to μ-Opioid Receptor Tolerance

PubMed Central

Wade, Carrie L.; Eskridge, Lori L.; Nguyen, H. Oanh X.; Kitto, Kelley F.; Stone, Laura S.; Wilcox, George

2009-01-01

Systemically or centrally administered agmatine (decarboxylated arginine) prevents, moderates, or reverses opioid-induced tolerance and self-administration, inflammatory and neuropathic pain, and sequelae associated with ischemia and spinal cord injury in rodents. These behavioral models invoke the N-methyl-d-aspartate (NMDA) receptor/nitric-oxide synthase cascade. Agmatine (AG) antagonizes the NMDA receptor and inhibits nitric-oxide synthase in vitro and in vivo, which may explain its effect in models of neural plasticity. Agmatine has been detected biochemically and immunohistochemically in the central nervous system. Consequently, it is conceivable that agmatine operates in an anti-glutamatergic manner in vivo; the role of endogenous agmatine in the central nervous system remains minimally defined. The current study used an immunoneutralization strategy to evaluate the effect of sequestration of endogenous agmatine in acute opioid analgesic tolerance in mice. First, intrathecal pretreatment with an anti-AG IgG (but not normal IgG) reversed an established pharmacological effect of intrathecal agmatine: antagonism of NMDA-evoked behavior. This result justified the use of anti-AG IgG to sequester endogenous agmatine in vivo. Second, intrathecal pretreatment with the anti-AG IgG sensitized mice to induction of acute spinal tolerance of two μ-opioid receptor-selective agonists, [d-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin and endomorphin-2. A lower dose of either agonist that, under normal conditions, produces moderate or no tolerance was tolerance-inducing after intrathecal pretreatment of anti-AG IgG (but not normal IgG). The effect of the anti-AG IgG lasted for at least 24 h in both NMDA-evoked behavior and the acute opioid tolerance. These results suggest that endogenous spinal agmatine may moderate glutamate-dependent neuroplasticity. PMID:19684255

Immunoneutralization of agmatine sensitizes mice to micro-opioid receptor tolerance.

PubMed

Wade, Carrie L; Eskridge, Lori L; Nguyen, H Oanh X; Kitto, Kelley F; Stone, Laura S; Wilcox, George; Fairbanks, Carolyn A

2009-11-01

Systemically or centrally administered agmatine (decarboxylated arginine) prevents, moderates, or reverses opioid-induced tolerance and self-administration, inflammatory and neuropathic pain, and sequelae associated with ischemia and spinal cord injury in rodents. These behavioral models invoke the N-methyl-D-aspartate (NMDA) receptor/nitric-oxide synthase cascade. Agmatine (AG) antagonizes the NMDA receptor and inhibits nitric-oxide synthase in vitro and in vivo, which may explain its effect in models of neural plasticity. Agmatine has been detected biochemically and immunohistochemically in the central nervous system. Consequently, it is conceivable that agmatine operates in an anti-glutamatergic manner in vivo; the role of endogenous agmatine in the central nervous system remains minimally defined. The current study used an immunoneutralization strategy to evaluate the effect of sequestration of endogenous agmatine in acute opioid analgesic tolerance in mice. First, intrathecal pretreatment with an anti-AG IgG (but not normal IgG) reversed an established pharmacological effect of intrathecal agmatine: antagonism of NMDA-evoked behavior. This result justified the use of anti-AG IgG to sequester endogenous agmatine in vivo. Second, intrathecal pretreatment with the anti-AG IgG sensitized mice to induction of acute spinal tolerance of two micro-opioid receptor-selective agonists, [D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin and endomorphin-2. A lower dose of either agonist that, under normal conditions, produces moderate or no tolerance was tolerance-inducing after intrathecal pretreatment of anti-AG IgG (but not normal IgG). The effect of the anti-AG IgG lasted for at least 24 h in both NMDA-evoked behavior and the acute opioid tolerance. These results suggest that endogenous spinal agmatine may moderate glutamate-dependent neuroplasticity.

Effectiveness of ketamine as an adjuvant to opioid-based therapy in decreasing pain associated with opioid tolerance in adults undergoing orthopedic surgery: a systematic review protocol.

PubMed

Bennett, Marsha; Bonanno, Laura; Kuhn, William

2016-10-01

The objective of this systematic review is to examine the best available evidence on the clinical effectiveness of ketamine as an adjuvant to opioid-based therapy versus opioid-based therapy alone in decreasing perioperative pain associated with opioid tolerance in adult patients, aged 18-70 years, undergoing orthopedic surgical procedures.The following question guides the systematic review: does the administration of ketamine as an adjuvant to opioid-based therapy, compared to opioid-based therapy alone, improve perioperative pain relief in opioid-tolerant adult patients undergoing orthopedic surgical procedures?

Evaluation of Emergency Department Management of Opioid-Tolerant Cancer Patients With Acute Pain.

PubMed

Patel, Pina M; Goodman, Lauren F; Knepel, Sheri A; Miller, Charles C; Azimi, Asma; Phillips, Gary; Gustin, Jillian L; Hartman, Amber

2017-10-01

There are no previously published studies examining opioid doses administered to opioid-tolerant cancer patients during emergency department (ED) encounters. To determine if opioid-tolerant cancer patients presenting with acute pain exacerbations receive adequate initial doses of as needed (PRN) opioids during ED encounters based on home oral morphine equivalent (OME) use. We performed a retrospective cohort study of opioid-tolerant cancer patients who received opioids in our ED over a two-year period. The percentage of patients who received an adequate initial dose of PRN opioid (defined as ≥10% of total 24-hour ambulatory OME) was evaluated. Logistic regression was used to establish the relationship between 24-hour ambulatory OME and initial ED OME to assess whether higher home usage was associated with higher likelihood of being undertreated. Out of 216 patients, 61.1% of patients received an adequate initial PRN dose of opioids in the ED. Of patients taking <200 OMEs per day at home, 77.4% received an adequate initial dose; however, only 3.2% of patients taking >400 OMEs per day at home received an adequate dose. Patients with ambulatory 24-hour OME greater than 400 had 99% lower odds of receiving an adequate initial dose of PRN opioid in the ED compared to patients with ambulatory 24-hour OME less than 100 (OR <0.01, CI 0.00-0.02, P < 0.001). Patients with daily home use less than 200 OMEs generally received adequate initial PRN opioid doses during their ED visit. However, patients with higher home opioid usage were at increased likelihood of being undertreated. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Spinal interaction between the highly selective μ agonist DAMGO and several δ opioid receptor ligands in naive and morphine-tolerant mice.

PubMed

Szentirmay, A K; Király, K P; Lenkey, N; Lackó, E; Al-Khrasani, M; Friedmann, T; Timár, J; Gyarmati, S; Tóth, G; Fürst, S; Riba, P

2013-01-01

Since the discovery of opioid receptor dimers their possible roles in opioid actions were intensively investigated. Here we suggest a mechanism that may involve the μ-δ opioid heterodimers. The exact role of δ opioid receptors in antinociception and in the development of opioid tolerance is still unclear. While receptor up-regulation can be observed during the development of opioid tolerance no μ receptor down-regulation could be detected within five days. In our present work we investigated how the selective δ opioid receptor agonists and antagonists influence the antinociceptive effect of the selective μ receptor agonist DAMGO in naïve and morphine-tolerant mice. We treated male NMRI mice with 200 μmol/kg subcutaneous (s.c.) morphine twice daily for three days. On the fourth day we measured the antinociceptive effect of DAMGO alone and combined with delta ligands: DPDPE, deltorphin II (agonists), TIPP and TICPψ (antagonists), respectively, administered intrathecally (i.t.) in mouse tail-flick test. In naive control mice none of the δ ligands caused significant changes in the antinociceptive action of DAMGO. The treatment with s.c. morphine resulted in approximately four-fold tolerance to i.t. DAMGO, i.e. the ED₅₀ value of DAMGO was four times as high as in naive mice. 500 and 1000 pmol/mouse of the δ₁ selective agonist DPDPE enhanced the tolerance to DAMGO while 1000 pmol/mouse of the δ₂ selective agonist deltorphin II did not influence the degree of tolerance. However, both δ antagonists TIPP and TICPψ potentiated the antinociceptive effect of i.t. DAMGO, thus they restored the potency of DAMGO to the control level. The inhibitory action of DPDPE against the antinociceptive effect of DAMGO could be antagonized by TIPP and TICPψ. We hypothesize that during the development of morphine tolerance the formation of μδ heterodimers may contribute to the spinal opioid tolerance. δ ligands may affect the dimer formation differently. Those, like

Comparative effects of cyclo-oxygenase and nitric oxide synthase inhibition on the development and reversal of spinal opioid tolerance

PubMed Central

Powell, Kelly J; Hosokawa, Akiko; Bell, Andrew; Sutak, Maaja; Milne, Brian; Quirion, Remi; Jhamandas, Khem

1999-01-01

This study examined the effects of the COX inhibitors, ketorolac and ibuprofen, and the NOS inhibitor L-NAME for their potential to both inhibit the development and reverse tolerance to the antinociceptive action of morphine. Repeated administration of intrathecal morphine (15 μg), once daily, resulted in a progressive decline of antinociceptive effect and an increase in the ED50 value in the tailflick and paw pressure tests. Co-administration of ketorolac (30 and 45 μg) or S(+) ibuprofen (10 μg) with morphine (15 μg) prevented the decline of antinociceptive effect and increase in ED50 value. Similar treatment with L-NAME (100 μg) exerted weaker effects. Administration of S(+) but not R(−) ibuprofen (10 mg kg−1) had similar effects on systemic administration of morphine (15 mg kg−1). Intrathecal or systemic administration of the COX or NOS inhibitors did not alter the baseline responses in either tests. Acute keterolac or S(+) ibuprofen also did not potentiate the acute actions of spinal or systemic morphine, but chronic intrathecal administration of these agents increased the potency of acute morphine. In animals already tolerant to intrathecal morphine, subsequent administration of ketorolac (30 μg) with morphine (15 μg) partially restored the antinociceptive effect and ED50 value of acute morphine, reflecting the reversal of tolerance. Intrathecal L-NAME (100 μg) exerted a weaker effect. These data suggest that spinal COX activity, and to a lesser extent NOS activity, contributes to the development and expression of opioid tolerance. Inhibition of COX may represent a useful approach for the prevention as well as reversal of opioid tolerance. PMID:10401553

Buprenorphine dose induction in non-opioid-tolerant pre-release prisoners.

PubMed

Vocci, Frank J; Schwartz, Robert P; Wilson, Monique E; Gordon, Michael S; Kinlock, Timothy W; Fitzgerald, Terrence T; O'Grady, Kevin E; Jaffe, Jerome H

2015-11-01

In a previously reported randomized controlled trial, formerly opioid-dependent prisoners were more likely to enter community drug abuse treatment when they were inducted in prison onto buprenorphine/naloxone (hereafter called buprenorphine) than when they received counseling without buprenorphine in prison (47.5% vs. 33.7%, p=0.012) (Gordon et al., 2014). In this communication we report on the results of the induction schedule and the adverse event profile seen in pre-release prisoners inducted onto buprenorphine. This paper examines the dose induction procedure, a comparison of the proposed versus actual doses given per week, and side effects reported for 104 adult participants who were randomized to buprenorphine treatment in prison. Self-reported side effects were analyzed using generalized estimated equations to determine changes over time in side effects. Study participants were inducted onto buprenorphine at a rate faster than the induction schedule. Of the 104 (72 males, 32 females) buprenorphine recipients, 64 (37 males, 27 females) remained on medication at release from prison. Nine participants (8.6%) discontinued buprenorphine because of unpleasant opioid side effects. There were no serious adverse events reported during the in-prison phase of the study. Constipation was the most frequent symptom reported (69 percent). Our findings suggest that buprenorphine administered to non-opioid-tolerant adults should be started at a lower, individualized dose than customarily used for adults actively using opioids, and that non-opioid-tolerant pre-release prisoners can be successfully inducted onto therapeutic doses prior to release. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Epigenetic regulation of spinal cord gene expression contributes to enhanced postoperative pain and analgesic tolerance subsequent to continuous opioid exposure

PubMed Central

Liang, De-Yong; Shi, Xiao-You; Sun, Yuan; Clark, J David

2016-01-01

Background Opioids have become the mainstay for treatment of moderate to severe pain and are commonly used to treat surgical pain. While opioid administration has been shown to cause opioid-induced hyperalgesia and tolerance, interactions between opioid administration and surgery with respect to these problematic adaptations have scarcely been addressed. Accumulating evidence suggests opioids and nociceptive signaling may converge on epigenetic mechanisms in spinal cord to enhance or prolong neuroplastic changes. Epigenetic regulation of Bdnf (brain-derived neurotrophic factor) and Pdyn (prodynorphin) genes may be involved. Results Four days of ascending doses of morphine treatment caused opioid-induced hyperalgesia and reduced opioid analgesic efficacy in mice. Both opioid-induced hyperalgesia and the reduced opioid analgesic efficacy were enhanced in mice that received hindpaw incisions. The expression of Bdnf and Pdyn (qPCR) was increased after morphine treatment and incision. Chromatin immunoprecipitation assays demonstrated that the Pdyn and Bdnf promoters were more strongly associated with acetylated H3K9 after morphine plus incision than in the morphine or incision alone groups. Selective tropomyosin-related kinase B (ANA-12) and κ-opioid receptor (nor-binaltorphimine) antagonists were administered intrathecally, both reduced hyperalgesia one or three days after surgery. Administration of ANA-12 or nor-binaltorphimine attenuated the decreased morphine analgesic efficacy on day 1, but only nor-binaltorphimine was effective on day 3 after incision in opioid-exposed group. Coadministration of histone acetyltransferase inhibitor anacardic acid daily with morphine blocked the development of opioid-induced hyperalgesia and attenuated incision-enhanced hyperalgesia in morphine-treated mice. Anacardic acid had similar effects on analgesic tolerance, showing the involvement of histone acetylation in the interactions detected. Conclusions Spinal epigenetic changes

Epigenetic regulation of spinal cord gene expression contributes to enhanced postoperative pain and analgesic tolerance subsequent to continuous opioid exposure.

PubMed

Sahbaie, Peyman; Liang, De-Yong; Shi, Xiao-You; Sun, Yuan; Clark, J David

2016-01-01

Opioids have become the mainstay for treatment of moderate to severe pain and are commonly used to treat surgical pain. While opioid administration has been shown to cause opioid-induced hyperalgesia and tolerance, interactions between opioid administration and surgery with respect to these problematic adaptations have scarcely been addressed. Accumulating evidence suggests opioids and nociceptive signaling may converge on epigenetic mechanisms in spinal cord to enhance or prolong neuroplastic changes. Epigenetic regulation of Bdnf (brain-derived neurotrophic factor) and Pdyn (prodynorphin) genes may be involved. Four days of ascending doses of morphine treatment caused opioid-induced hyperalgesia and reduced opioid analgesic efficacy in mice. Both opioid-induced hyperalgesia and the reduced opioid analgesic efficacy were enhanced in mice that received hindpaw incisions. The expression of Bdnf and Pdyn (qPCR) was increased after morphine treatment and incision. Chromatin immunoprecipitation assays demonstrated that the Pdyn and Bdnf promoters were more strongly associated with acetylated H3K9 after morphine plus incision than in the morphine or incision alone groups. Selective tropomyosin-related kinase B (ANA-12) and κ-opioid receptor (nor-binaltorphimine) antagonists were administered intrathecally, both reduced hyperalgesia one or three days after surgery. Administration of ANA-12 or nor-binaltorphimine attenuated the decreased morphine analgesic efficacy on day 1, but only nor-binaltorphimine was effective on day 3 after incision in opioid-exposed group. Coadministration of histone acetyltransferase inhibitor anacardic acid daily with morphine blocked the development of opioid-induced hyperalgesia and attenuated incision-enhanced hyperalgesia in morphine-treated mice. Anacardic acid had similar effects on analgesic tolerance, showing the involvement of histone acetylation in the interactions detected. Spinal epigenetic changes involving Bdnf and Pdyn may

Opioid adjuvant strategy: improving opioid effectiveness.

PubMed

Bihel, Frédéric

2016-01-01

Opioid analgesics continue to be the mainstay of pharmacologic treatment of moderate to severe pain. Many patients, particularly those suffering from chronic pain, require chronic high-dose analgesic therapy. Achieving clinical efficacy and tolerability of such treatment regimens is hampered by the appearance of opioid-induced side effects such as tolerance, hyperalgesia and withdrawal syndrome. Among the therapeutic options to improve the opioid effectiveness, this current review focuses on strategies combining opioids to other drugs that can modulate opioid-mediated effects. We will discuss about experimental evidences reported for several potential opioid adjuvants, including N-methyl-D-aspartate receptor antagonists, 5-HT7 agonists, sigma-1 antagonists, I2-R ligands, cholecystokinin antagonists, neuropeptide FF-R antagonists and toll-like receptor 4 antagonists.

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

Effect of Tamoxifen and Brain-Penetrant Protein Kinase C and c-Jun N-Terminal Kinase Inhibitors on Tolerance to Opioid-Induced Respiratory Depression in Mice.

PubMed

Withey, Sarah L; Hill, Rob; Lyndon, Abigail; Dewey, William L; Kelly, Eamonn; Henderson, Graeme

2017-04-01

Respiratory depression is the major cause of death in opioid overdose. We have previously shown that prolonged treatment of mice with morphine induces profound tolerance to the respiratory-depressant effects of the drug (Hill et al., 2016). The aim of the present study was to investigate whether tolerance to opioid-induced respiratory depression is mediated by protein kinase C (PKC) and/or c-Jun N-terminal kinase (JNK). We found that although mice treated for up to 6 days with morphine developed tolerance, as measured by the reduced responsiveness to an acute challenge dose of morphine, administration of the brain-penetrant PKC inhibitors tamoxifen and calphostin C restored the ability of acute morphine to produce respiratory depression in morphine-treated mice. Importantly, reversal of opioid tolerance was dependent on the nature of the opioid ligand used to induce tolerance, as these PKC inhibitors did not reverse tolerance induced by prolonged treatment of mice with methadone nor did they reverse the protection to acute morphine-induced respiratory depression afforded by prolonged treatment with buprenorphine. We found no evidence for the involvement of JNK in morphine-induced tolerance to respiratory depression. These results indicate that PKC represents a major mechanism underlying morphine tolerance, that the mechanism of opioid tolerance to respiratory depression is ligand-dependent, and that coadministration of drugs with PKC-inhibitory activity and morphine (as well as heroin, largely metabolized to morphine in the body) may render individuals more susceptible to overdose death by reversing tolerance to the effects of morphine. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Effect of Tamoxifen and Brain-Penetrant Protein Kinase C and c-Jun N-Terminal Kinase Inhibitors on Tolerance to Opioid-Induced Respiratory Depression in Mice

PubMed Central

Withey, Sarah L.; Hill, Rob; Lyndon, Abigail; Dewey, William L.; Kelly, Eamonn

2017-01-01

Respiratory depression is the major cause of death in opioid overdose. We have previously shown that prolonged treatment of mice with morphine induces profound tolerance to the respiratory-depressant effects of the drug (Hill et al., 2016). The aim of the present study was to investigate whether tolerance to opioid-induced respiratory depression is mediated by protein kinase C (PKC) and/or c-Jun N-terminal kinase (JNK). We found that although mice treated for up to 6 days with morphine developed tolerance, as measured by the reduced responsiveness to an acute challenge dose of morphine, administration of the brain-penetrant PKC inhibitors tamoxifen and calphostin C restored the ability of acute morphine to produce respiratory depression in morphine-treated mice. Importantly, reversal of opioid tolerance was dependent on the nature of the opioid ligand used to induce tolerance, as these PKC inhibitors did not reverse tolerance induced by prolonged treatment of mice with methadone nor did they reverse the protection to acute morphine-induced respiratory depression afforded by prolonged treatment with buprenorphine. We found no evidence for the involvement of JNK in morphine-induced tolerance to respiratory depression. These results indicate that PKC represents a major mechanism underlying morphine tolerance, that the mechanism of opioid tolerance to respiratory depression is ligand-dependent, and that coadministration of drugs with PKC-inhibitory activity and morphine (as well as heroin, largely metabolized to morphine in the body) may render individuals more susceptible to overdose death by reversing tolerance to the effects of morphine. PMID:28130265

Co-morbid pain and opioid addiction: Long term effect of opioid maintenance on acute pain

PubMed Central

Wachholtz, Amy; Gonzalez, Gerardo

2014-01-01

Introduction Medication assisted treatment for opioid dependence alters the pain experience. This study will evaluate changes pain sensitivity and tolerance with opioid treatments; and duration of this effect after treatment cessation. Method 120 individuals with chronic pain were recruited in 4 groups (n=30): 1-methadone for opioid addiction; 2-buprenorphine for opioid addiction; 3-history of opioid maintenance treatment for opioid addiction but with prolonged abstinence (M=121 weeks; SD=23.3); and 4-opioid naïve controls. Participants completed a psychological assessment and a cold water task including, time to first pain (sensitivity) and time to stopping the pain task (tolerance). Data analysis used survival analyses. Results A Kaplan-Meier-Cox survival analysis showed group differences for both pain sensitivity (Log rank=15.50; p<.001) and tolerance (Log rank=20.11; p<.001). Current or historical use of opioid maintenance resulted in differing pain sensitivity compared to opioid naïve (p’s<.01). However, tolerance to pain was better among those with a history of opioid maintenance compared to active methadone patients (p<.05), with the highest tolerance found among opioid naïve control group participants (p’s<.001). Correlations within the prolonged abstinent group indicated pain tolerance was significantly improved as length of opioid abstinence increased (R=.37; p<.05); but duration of abstinence did not alter sensitivity (ns). Conclusion Among individuals with a history of prolonged opioid maintenance, there appears to be long-term differences in pain sensitivity that do not resolve with discontinuation of opioid maintenance. Although pain sensitivity does not change, pain tolerance does improve after opioid maintenance cessation. Implications for treating co-morbid opioid addiction and pain (acute and chronic) are discussed. PMID:25456326

Co-morbid pain and opioid addiction: long term effect of opioid maintenance on acute pain.

PubMed

Wachholtz, Amy; Gonzalez, Gerardo

2014-12-01

Medication assisted treatment for opioid dependence alters the pain experience. This study will evaluate changes pain sensitivity and tolerance with opioid treatments; and duration of this effect after treatment cessation. 120 Individuals with chronic pain were recruited in 4 groups (N = 30): 1-methadone for opioid addiction; 2-buprenorphine for opioid addiction; 3-history of opioid maintenance treatment for opioid addiction but with prolonged abstinence (M = 121 weeks; SD = 23.3); and 4-opioid naïve controls. Participants completed a psychological assessment and a cold water task including, time to first pain (sensitivity) and time to stopping the pain task (tolerance). Data analysis used survival analyses. A Kaplan-Meier-Cox survival analysis showed group differences for both pain sensitivity (log rank = 15.50; p < .001) and tolerance (log rank = 20.11; p < .001). Current or historical use of opioid maintenance resulted in differing pain sensitivity compared to opioid naïve (p's < .01). However, tolerance to pain was better among those with a history of opioid maintenance compared to active methadone patients (p < .05), with the highest tolerance found among opioid naïve control group participants (p's < .001). Correlations within the prolonged abstinent group indicated pain tolerance was significantly improved as length of opioid abstinence increased (R = .37; p < .05); but duration of abstinence did not alter sensitivity (ns). Among individuals with a history of prolonged opioid maintenance, there appears to be long-term differences in pain sensitivity that do not resolve with discontinuation of opioid maintenance. Although pain sensitivity does not change, pain tolerance does improve after opioid maintenance cessation. Implications for treating co-morbid opioid addiction and pain (acute and chronic) are discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Continuous delivery of naltrexone and nalmefene leads to tolerance in reducing alcohol drinking and to supersensitivity of brain opioid receptors.

PubMed

Korpi, Esa R; Linden, Anni-Maija; Hytönen, Heidi R; Paasikoski, Nelli; Vashchinkina, Elena; Dudek, Mateusz; Herr, Deron R; Hyytiä, Petri

2017-07-01

Opioid antagonist treatments reduce alcohol drinking in rodent models and in alcohol-dependent patients, with variable efficacy across different studies. These treatments may suffer from the development of tolerance and opioid receptor supersensitivity, as suggested by preclinical models showing activation of these processes during and after subchronic high-dose administration of the short-acting opioid antagonist naloxone. In the present study, we compared equipotent low and moderate daily doses of naltrexone and nalmefene, two opioid antagonists in the clinical practice for treatment of alcoholism. The antagonists were given here subcutaneously for 7 days either as daily injections or continuous osmotic minipump-driven infusions to alcohol-preferring AA rats having trained to drink 10% alcohol in a limited access protocol. One day after stopping the antagonist treatment, [ 35 S]GTPγS autoradiography on brain cryostat sections was carried out to examine the coupling of receptors to G protein activation. The results prove the efficacy of repeated injections over infused opioid antagonists in reducing alcohol drinking. Tolerance to the reducing effect on alcohol drinking and to the enhancement of G protein coupling to μ-opioid receptors in various brain regions were consistently detected only after infused antagonists. Supersensitivity of κ-opioid receptors was seen in the ventral and dorsal striatal regions especially by infused nalmefene. Nalmefene showed no clear agonistic activity in rat brain sections or at human recombinant κ-opioid receptors. The findings support the as-needed dosing practice, rather than the standard continual dosing, in the treatment of alcoholism with opioid receptor antagonists. © 2016 Society for the Study of Addiction.

Opioid receptor trafficking and interaction in nociceptors

PubMed Central

Zhang, X; Bao, L; Li, S

2015-01-01

Opiate analgesics such as morphine are often used for pain therapy. However, antinociceptive tolerance and dependence may develop with long-term use of these drugs. It was found that μ-opioid receptors can interact with δ-opioid receptors, and morphine antinociceptive tolerance can be reduced by blocking δ-opioid receptors. Recent studies have shown that μ- and δ-opioid receptors are co-expressed in a considerable number of small neurons in the dorsal root ganglion. The interaction of μ-opioid receptors with δ-opioid receptors in the nociceptive afferents is facilitated by the stimulus-induced cell-surface expression of δ-opioid receptors, and contributes to morphine tolerance. Further analysis of the molecular, cellular and neural circuit mechanisms that regulate the trafficking and interaction of opioid receptors and related signalling molecules in the pain pathway would help to elucidate the mechanism of opiate analgesia and improve pain therapy. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2 PMID:24611685

The plasticity of the association between mu-opioid receptor and glutamate ionotropic receptor N in opioid analgesic tolerance and neuropathic pain.

PubMed

Sánchez-Blázquez, Pilar; Rodríguez-Muñoz, Maria; Berrocoso, Esther; Garzón, Javier

2013-09-15

Multiple groups have reported the functional cross-regulation between mu-opioid (MOP) receptor and glutamate ionotropic receptor N (GluN), and the post-synaptic association of these receptors has been implicated in the transmission and modulation of nociceptive signals. Opioids, such as morphine, disrupt the MOP receptor-GluN receptor complex to stimulate the activity of GluN receptors via protein kinase C (PKC)/Src. This increased GluN receptor activity opposes MOP receptor signalling, and via neural nitric oxide synthase (nNOS) and calcium and calmodulin regulated kinase II (CaMKII) induces the phosphorylation and uncoupling of the opioid receptor, which results in the development of morphine analgesic tolerance. Both experimental in vivo activation of GluN receptors and neuropathic pain separate the MOP receptor-GluN receptor complex via protein kinase A (PKA) and reduce the analgesic capacity of morphine. The histidine triad nucleotide-binding protein 1 (HINT1) associates with the MOP receptor C-terminus and connects the activities of MOP receptor and GluN receptor. In HINT1⁻/⁻ mice, morphine promotes enhanced analgesia and produces tolerance that is not related to GluN receptor activity. In these mice, the GluN receptor agonist N-methyl-D-aspartate acid (NMDA) does not antagonise the analgesic effects of morphine. Treatments that rescue morphine from analgesic tolerance, such as GluN receptor antagonism or PKC, nNOS and CaMKII inhibitors, all induce MOP receptor-GluN receptor re-association and reduce GluN receptor/CaMKII activity. In mice treated with NMDA or suffering from neuropathic pain (induced by chronic constriction injury, CCI), GluN receptor antagonists, PKA inhibitors or certain antidepressants also diminish CaMKII activity and restore the MOP receptor-GluN receptor association. Thus, the HINT1 protein stabilises the association between MOP receptor and GluN receptor, necessary for the analgesic efficacy of morphine, and this coupling is reduced

Reversal of oxycodone and hydrocodone tolerance by diazepam.

PubMed

Gonek, Maciej; Akbarali, Hamid I; Henderson, Graeme; Dewey, William L

2017-11-01

The Centers for Disease Control has declared opioid abuse to be an epidemic. Overdose deaths are largely assumed to be the result of excessive opioid consumption. In many of these cases, however, opioid abusers are often polydrug abusers. Benzodiazepines are one of the most commonly co-abused substances and pose a significant risk to opioid users. In 2016, the FDA required boxed warnings - the FDA's strongest warning - for prescription opioid analgesics and benzodiazepines about the serious risks associated with using these medications at the same time. The point of our studies was to evaluate the interactions between these two classes of drugs. We investigated whether diazepam adds to the depressant effects of opioids or do they alter the levels of tolerance to opioids. In the present study, we have found that the antinociceptive tolerance that developed to repeated administration of oxycodone was reversed by an acute dose of diazepam. Antinociceptive tolerance to hydrocodone was also reversed by acute injection of diazepam; however, a fourfold higher dose of diazepam was required when compared to reversal of oxycodone-induced tolerance. These doses of diazepam did not potentiate the acute antinociceptive effect of either opioid. The same dose of diazepam that reversed oxycodone antinociceptive tolerance also reversed oxycodone locomotor tolerance while having no potentiating effects. These studies show that diazepam does not potentiate the acute effect of prescription opioids but reverses the tolerance developed after chronic administration of the drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficacy, Tolerability, and Dose-Dependent Effects of Opioid Analgesics for Low Back Pain: A Systematic Review and Meta-analysis.

PubMed

Abdel Shaheed, Christina; Maher, Chris G; Williams, Kylie A; Day, Richard; McLachlan, Andrew J

2016-07-01

Opioid analgesics are commonly used for low back pain, however, to our knowledge there has been no systematic evaluation of the effect of opioid dose and use of enrichment study design on estimates of treatment effect. To evaluate efficacy and tolerability of opioids in the management of back pain; and investigate the effect of opioid dose and use of an enrichment study design on treatment effect. Medline, EMBASE, CENTRAL, CINAHL, and PsycINFO (inception to September 2015) with citation tracking from eligible randomized clinical trials (RCTs). Placebo-controlled RCTs in any language. Two authors independently extracted data and assessed risk of bias. Data were pooled using a random effects model with strength of evidence assessed using the grading of recommendations assessment, development, and evaluation (GRADE). The primary outcome measure was pain. Pain and disability outcomes were converted to a common 0 to 100 scale, with effects greater than 20 points considered clinically important. Of 20 included RCTs of opioid analgesics (with a total of 7925 participants), 13 trials (3419 participants) evaluated short-term effects on chronic low back pain, and no placebo-controlled trials enrolled patients with acute low back pain. In half of these 13 trials, at least 50% of participants withdrew owing to adverse events or lack of efficacy. There was moderate-quality evidence that opioid analgesics reduce pain in the short term; mean difference (MD), -10.1 (95% CI, -12.8 to -7.4). Meta-regression revealed a 12.0 point greater pain relief for every 1 log unit increase in morphine equivalent dose (P = .046). Clinically important pain relief was not observed within the dose range evaluated (40.0-240.0-mg morphine equivalents per day). There was no significant effect of enrichment study design. For people with chronic low back pain who tolerate the medicine, opioid analgesics provide modest short-term pain relief but the effect is not likely to be clinically important

Attenuation of tolerance to opioid-induced antinociception and protection against morphine-induced decrease of neurofilament proteins by idazoxan and other I2-imidazoline ligands.

PubMed

Boronat, M A; Olmos, G; García-Sevilla, J A

1998-09-01

. Similarly, the concurrent chronic treatment of moxonidine (1 mg kg(-1), i.p.), a mixed I(1)-imidazoline receptor and alpha2-adrenoceptor agonist, and morphine (10 mg kg(-1), i.p.), did not alter the development of tolerance to the opiate. These results discounted the involvement of alpha2-adrenoceptors and I(1)-imidazoline receptors in the modulatory effect of idazoxan on opioid tolerance. 5. Idazoxan and other imidazol(ine) drugs fully inhibited [3H]-(+)-MK-801 binding to N-methyl-D-aspartate (NMDA) receptors in the rat cerebral cortex with low potencies (Ki: 37-190 microM). The potencies of the imidazolines idazoxan, RX821002 and moxonidine were similar, indicating a lack of relationship between potency on NMDA receptors and ability to attenuate opioid tolerance. These results suggested that modulation of opioid tolerance by idazoxan is not related to NMDA receptors blockade. 6. Chronic treatment (13 days) with morphine (10 mg kg(-1), i.p.) was associated with a marked decrease (49%) in immunolabelled neurofilament proteins (NF-L) in the frontal cortex of morphine-tolerant rats, suggesting the induction of neuronal damage. Chronic treatment (13 days) with idazoxan (10 mg kg(-1)) and LSL 60101 (10 mg kg(-1)) did not modify the levels of NF-L proteins in brain. Interestingly, the concurrent chronic treatment (13 days) of idazoxan or LSL 60101 and morphine, completely reversed the morphine-induced decrease in NF-L immunoreactivity, suggesting a neuroprotective role for these drugs. 7. Together, the results indicate that chronic treatment with I2-imidazoline ligands attenuates the development of tolerance to opiate drugs and may induce neuroprotective effects on chronic opiate treatment. Moreover, these findings offer the I2-imidazoline ligands as promising therapeutic coadjuvants in the management of chronic pain with opiate drugs.

Exploring the Neuroimmunopharmacology of Opioids: An Integrative Review of Mechanisms of Central Immune Signaling and Their Implications for Opioid Analgesia

PubMed Central

Shavit, Yehuda; Grace, Peter M.; Rice, Kenner C.; Maier, Steven F.; Watkins, Linda R.

2011-01-01

Vastly stimulated by the discovery of opioid receptors in the early 1970s, preclinical and clinical research was directed at the study of stereoselective neuronal actions of opioids, especially those played in their crucial analgesic role. However, during the past decade, a new appreciation of the non-neuronal actions of opioids has emerged from preclinical research, with specific appreciation for the nonclassic and nonstereoselective sites of action. Opioid activity at Toll-like receptors, newly recognized innate immune pattern recognition receptors, adds substantially to this unfolding story. It is now apparent from molecular and rodent data that these newly identified signaling events significantly modify the pharmacodynamics of opioids by eliciting proinflammatory reactivity from glia, the immunocompetent cells of the central nervous system. These central immune signaling events, including the release of cytokines and chemokines and the associated disruption of glutamate homeostasis, cause elevated neuronal excitability, which subsequently decreases opioid analgesic efficacy and leads to heightened pain states. This review will examine the current preclinical literature of opioid-induced central immune signaling mediated by classic and nonclassic opioid receptors. A unification of the preclinical pharmacology, neuroscience, and immunology of opioids now provides new insights into common mechanisms of chronic pain, naive tolerance, analgesic tolerance, opioid-induced hyperalgesia, and allodynia. Novel pharmacological targets for future drug development are discussed in the hope that disease-modifying chronic pain treatments arising from the appreciation of opioid-induced central immune signaling may become practical. PMID:21752874

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. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Modulation of opioid analgesia by agmatine.

PubMed

Kolesnikov, Y; Jain, S; Pasternak, G W

1996-01-18

Administered alone, agmatine at doses of 0.1 or 10 mg/kg is without effect in the mouse tailflick assay. However, agmatine enhances morphine analgesia in a dose-dependent manner, shifting morphine's ED50 over 5-fold. A far greater effect is observed when morphine is given intrathecally (9-fold shift) than after intracerebroventricular administration (2-fold). In contrast to the potentiation of morphine analgesia, agmatine (10 mg/kg) has no effect on morphine's inhibition of gastrointestinal transit. delta-Opioid receptor-mediated analgesia also is potentiated by agmatine, but kappa1-receptor-mediated (U50,488H; trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl] benzeneacetemide) and kappa3-opioid receptor-mediated (naloxone benzoylhydrazone) analgesia is not significantly enhanced by any dose of agmatine tested in this acute model. In chronic studies, agmatine at a low dose (0.1 mg/kg) which does not affect morphine analgesia acutely prevents tolerance following chronic morphine dosing for 10 days. A higher agmatine dose (10 mg/kg) has a similar effect. Agmatine also blocks tolerance to the delta-opioid receptor ligand [D-Pen2,D-Pen5]enkephalin given intrathecally, but not to the kappa3-opioid receptor agonist naloxone benzoylhydrazone. Despite its inactivity on kappa1-opioid analgesia in the acute model, agmatine prevents kappa1-opioid receptor-mediated tolerance. These studies demonstrate the dramatic interactions between agmatine and opioid analgesia and tolerance.

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

The challenge of international consensus: defining an opioid essential prescription package.

PubMed

Vignaroli, Ernesto; Wenk, Roberto

2012-09-01

To describe a new strategy that aimed to facilitate opioid prescription for better pain management. The International Association of Hospice and Palliative Care recently develop a single prescription package (drugs and dosing) with one opioid, one laxative, and one antiemetic for the initiation of opioid treatment in cancer pain and other life-threatening conditions, with the intention to facilitate opioid use, improve patient compliance, and reduce adverse effects. The opioid essential prescription package was an international project designed to ensure that opioids are better tolerated by reducing the adverse effects of opioids, which could lead to more sustained improvements in pain management.

Tolerance to the anticonvulsant effect of morphine in mice: blockage by ultra-low dose naltrexone.

PubMed

Roshanpour, Maryam; Ghasemi, Mehdi; Riazi, Kiarash; Rafiei-Tabatabaei, Neda; Ghahremani, Mohammad Hossein; Dehpour, Ahmad Reza

2009-02-01

The present study evaluated the development of tolerance to the anticonvulsant effect of morphine in a mouse model of clonic seizures induced by pentylenetetrazole, and whether ultra-low doses of the opioid receptor antagonist naltrexone which selectively block G(s) opioid receptors were capable of preventing the observed tolerance. The results showed that the morphine anticonvulsant effect could be subject to tolerance after repeated administration. Both the development and expression of tolerance were inhibited by ultra-low doses of naltrexone, suggesting the possible involvement of G(s)-coupled opioid receptors in the development of tolerance to the anticonvulsant effect of morphine.

The novel μ-opioid receptor agonist PZM21 depresses respiration and induces tolerance to antinociception.

PubMed

Hill, Rob; Disney, Alex; Conibear, Alex; Sutcliffe, Katy; Dewey, William; Husbands, Stephen; Bailey, Chris; Kelly, Eamonn; Henderson, Graeme

2018-07-01

PZM21 is a novel μ-opioid receptor ligand that has been reported to induce minimal arrestin recruitment and be devoid of the respiratory depressant effects characteristic of classical μ receptor ligands such as morphine. We have re-examined the signalling profile of PZM21 and its ability to depress respiration. G protein (G i ) activation and arrestin-3 translocation were measured in vitro, using BRET assays, in HEK 293 cells expressing μ receptors. Respiration (rate and tidal volume) was measured in awake, freely moving mice by whole-body plethysmography, and antinociception was measured by the hot plate test. PZM21 (10 -9 - 3 × 10 -5  M) produced concentration-dependent G i activation and arrestin-3 translocation. Comparison with responses evoked by morphine and DAMGO revealed that PZM21 was a low efficacy agonist in both signalling assays. PZM21 (10-80 mg·kg -1 ) depressed respiration in a dose-dependent manner. The respiratory depression was due to a decrease in the rate of breathing not a decrease in tidal volume. On repeated daily administration of PZM21 (twice daily doses of 40 mg·kg -1 ), complete tolerance developed to the antinociceptive effect of PZM21 over 3 days but no tolerance developed to its respiratory depressant effect. These data demonstrate that PZM21 is a low efficacy μ receptor agonist for both G protein and arrestin signalling. Contrary to a previous report, PZM21 depresses respiration in a manner similar to morphine, the classical opioid receptor agonist. © 2018 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Ethanol Reversal of Tolerance to the Respiratory Depressant Effects of Morphine

PubMed Central

Hill, Rob; Lyndon, Abi; Withey, Sarah; Roberts, Joanne; Kershaw, Yvonne; MacLachlan, John; Lingford-Hughes, Anne; Kelly, Eamonn; Bailey, Chris; Hickman, Matthew; Henderson, Graeme

2016-01-01

Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO2 in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths. PMID:26171718

Methadone Reverses Analgesic Tolerance Induced by Morphine Pretreatment

PubMed Central

Posa, Luca; Accarie, Alison; Marie, Nicolas

2016-01-01

Background: Opiates such as morphine are the most powerful analgesics, but their protracted use is restrained by the development of tolerance to analgesic effects. Recent works suggest that tolerance to morphine might be due to its inability to promote mu opioid receptor endocytosis, and the co-injection of morphine with a mu opioid receptor internalizing agonist like [D-Ala2,N-Me-Phe4,Gly-ol5]enkephalin reduces tolerance to morphine. So far, no studies have been conducted to evaluate the ability of methadone to reduce morphine tolerance in morphine-pretreated animals, a treatment sequence that could be encountered in opiate rotation protocol. We investigated the ability of methadone (a mu opioid receptor internalizing agonist used in therapy) to reverse morphine tolerance and the associated cellular mechanisms in the periaqueductal gray matter, a region involved in pain control. Methods: We measured analgesic response following a challenge dose of morphine in the hot plate test and investigated regulation of mu opioid receptor (coupling and endocytosis) and some cellular mechanisms involved in tolerance such as adenylate cyclase superactivation and changes in N-methyl-d-aspartate receptor subunits expression and phosphorylation state. Results: A chronic treatment with morphine promoted tolerance to its analgesic effects and was associated with a lack of mu opioid receptor endocytosis, adenylate cyclase overshoot, NR2A and NR2B downregulation, and phosphorylation of NR1. We reported that a methadone treatment in morphine-treated mice reversed morphine tolerance to analgesia by promoting mu opioid receptor endocytosis and blocking cellular mechanisms of tolerance. Conclusions: Our data might lead to rational strategies to tackle opiate tolerance in the frame of opiate rotation. PMID:26390873

AMPA receptor positive allosteric modulators attenuate morphine tolerance and dependence.

PubMed

Hu, Xiaoyu; Tian, Xuebi; Guo, Xiao; He, Ying; Chen, Haijun; Zhou, Jia; Wang, Zaijie Jim

2018-04-25

Development of opioid tolerance and dependence hinders the use of opioids for the treatment of chronic pain. In searching for the mechanism and potential intervention for opioid tolerance and dependence, we studied the action of two positive allosteric modulators of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR PAMs). In mice treated with morphine (100 mg/kg, s.c.), acute morphine tolerance and dependence developed in 4-6 h. Treatment with aniracetam, a well-established AMPAR PAM, was able to completely prevent and reverse the development of acute antinociceptive tolerance to morphine. Partial, but significant, effects of aniracetam on acute morphine induced-physical dependence were also observed. Moreover, aniracetam significantly reversed the established morphine tolerance and dependence in a chronic model of morphine tolerance and dependence produced by intermittent morphine (10 mg/kg, s.c. for 5d). In addition, HJC0122, a new AMPAR PAM was found to have similar effects as aniracetam but with a higher potency. These previously undisclosed actions of AMPAR PAMs are intriguing and may shed lights on understanding the APMA signaling pathway in opioid addiction. Moreover, these data suggest that AMPAR PAMs may have utility in preventing and treating morphine tolerance and dependence. Copyright © 2018. Published by Elsevier Ltd.

Low-Dose Cannabinoid Type 2 Receptor Agonist Attenuates Tolerance to Repeated Morphine Administration via Regulating μ-Opioid Receptor Expression in Walker 256 Tumor-Bearing Rats.

PubMed

Zhang, Mingyue; Wang, Kun; Ma, Min; Tian, Songyu; Wei, Na; Wang, Guonian

2016-04-01

Morphine is widely used in patients with moderate and severe cancer pain, whereas the development of drug tolerance remains a major problem associated with opioid use. Previous studies have shown that cannabinoid type 2 (CB2) receptor agonists induce morphine analgesia, attenuate morphine tolerance in normal and neuropathic pain animals, induce transcription of the μ-opioid receptor (MOR) gene in Jurkat T cells, and increase morphine analgesia in cancer pain animals. However, no studies of the effects of CB2 receptor agonists on morphine tolerance in cancer pain have been performed. Therefore, we investigated the effect of repeated intrathecal (IT) injection of the low-dose CB2 receptor agonist AM1241 on the development of morphine tolerance in walker 256 tumor-bearing rats. We also tested the influence of the CB2 receptor agonist AM1241 on MOR protein and messenger ribonucleic acid (mRNA) expression in the rat spinal cord and dorsal root ganglia (DRG). Walker 256 cells were implanted into the plantar region of each rat's right hindpaw. Tumor-bearing rats received IT injection of the CB2 receptor agonist AM1241 or antagonist AM630 with or without morphine subcutaneously twice daily for 8 days. Rats receiving drug vehicle only served as the control group. Mechanical paw withdrawal threshold and thermal paw withdrawal latency were assessed by a von Frey test and hot plate test 30 minutes after drug administration every day. MOR protein and mRNA expression in the spinal cord and DRG were detected after the last day (day 8) of drug administration via Western blot and real-time reverse transcription polymerase chain reaction. The data were analyzed via analysis of variance followed by Student t test with Bonferroni correction for multiple comparisons. Repeated morphine treatments reduced the mechanical withdrawal threshold and thermal latency. Coadministration of a nonanalgetic dose of the CB2 receptor agonist AM1241 with morphine significantly inhibited the

NPYFa, A Chimeric Peptide of Met-Enkephalin, and NPFF Induces Tolerance-Free Analgesia.

PubMed

Mudgal, Annu; Kumar, Krishan; Mollereau, Catherine; Pasha, Santosh

2016-06-01

Methionine-enkephalin-Arg-Phe is an endogenous amphiactive analgesic peptide. Neuropeptide FF, on the other hand, is reported for its role in opioid modulation and tolerance development. Based on these reports, in the present study we designed a chimeric peptide NPYFa (YGGFMKKKPQRFamide), having the Met-enkephalin (opioid) and PQRFamide sequence of neuropeptide FF, which can then target both the opioid and neuropeptide FF receptors. We hypothesized that the chimeric peptide so designed would have both analgesic properties and further aid in understanding of the role of neuropeptide FF in the development of opiate tolerance. Our studies indicated that NPYFa induced an early onset, potent, dose-dependent and prolonged antinociception. Additionally, antagonists (MOR, KOR, and DOR) pretreatment studies determined a KOR-mediated antinociception activity of the ligand. Further, in vitro binding studies using the Eu-GTP-γS binding assay on cell lines expressing opioid and NPFF receptors showed binding to both the opioid and neuropeptide FF receptors suggesting a multiple receptor binding character of NPYFa. Moreover, chronic (6 days) treatment with NPYFa exhibited an absence of tolerance development subsequent to its analgesia. The current study proposes NPYFa as a potent, long-acting antinociceptor lacking tolerance development as well as a probe to study opioid analgesia and the associated complex mechanisms of tolerance development. © 2016 John Wiley & Sons A/S.

Evidence that opioids may have toll-like receptor 4 and MD-2 effects.

PubMed

Hutchinson, Mark R; Zhang, Yingning; Shridhar, Mitesh; Evans, John H; Buchanan, Madison M; Zhao, Tina X; Slivka, Peter F; Coats, Benjamen D; Rezvani, Niloofar; Wieseler, Julie; Hughes, Travis S; Landgraf, Kyle E; Chan, Stefanie; Fong, Stephanie; Phipps, Simon; Falke, Joseph J; Leinwand, Leslie A; Maier, Steven F; Yin, Hang; Rice, Kenner C; Watkins, Linda R

2010-01-01

Opioid-induced proinflammatory glial activation modulates wide-ranging aspects of opioid pharmacology including: opposition of acute and chronic opioid analgesia, opioid analgesic tolerance, opioid-induced hyperalgesia, development of opioid dependence, opioid reward, and opioid respiratory depression. However, the mechanism(s) contributing to opioid-induced proinflammatory actions remains unresolved. The potential involvement of toll-like receptor 4 (TLR4) was examined using in vitro, in vivo, and in silico techniques. Morphine non-stereoselectively induced TLR4 signaling in vitro, blocked by a classical TLR4 antagonist and non-stereoselectively by naloxone. Pharmacological blockade of TLR4 signaling in vivo potentiated acute intrathecal morphine analgesia, attenuated development of analgesic tolerance, hyperalgesia, and opioid withdrawal behaviors. TLR4 opposition to opioid actions was supported by morphine treatment of TLR4 knockout mice, which revealed a significant threefold leftward shift in the analgesia dose response function, versus wildtype mice. A range of structurally diverse clinically-employed opioid analgesics was found to be capable of activating TLR4 signaling in vitro. Selectivity in the response was identified since morphine-3-glucuronide, a morphine metabolite with no opioid receptor activity, displayed significant TLR4 activity, whilst the opioid receptor active metabolite, morphine-6-glucuronide, was devoid of such properties. In silico docking simulations revealed ligands bound preferentially to the LPS binding pocket of MD-2 rather than TLR4. An in silico to in vitro prediction model was built and tested with substantial accuracy. These data provide evidence that select opioids may non-stereoselectively influence TLR4 signaling and have behavioral consequences resulting, in part, via TLR4 signaling.

Molecular Pharmacology of δ-Opioid Receptors

PubMed Central

Gendron, Louis; Cahill, Catherine M.; von Zastrow, Mark; Schiller, Peter W.

2016-01-01

Opioids are among the most effective analgesics available and are the first choice in the treatment of acute severe pain. However, partial efficacy, a tendency to produce tolerance, and a host of ill-tolerated side effects make clinically available opioids less effective in the management of chronic pain syndromes. Given that most therapeutic opioids produce their actions via µ-opioid receptors (MOPrs), other targets are constantly being explored, among which δ-opioid receptors (DOPrs) are being increasingly considered as promising alternatives. This review addresses DOPrs from the perspective of cellular and molecular determinants of their pharmacological diversity. Thus, DOPr ligands are examined in terms of structural and functional variety, DOPrs’ capacity to engage a multiplicity of canonical and noncanonical G protein–dependent responses is surveyed, and evidence supporting ligand-specific signaling and regulation is analyzed. Pharmacological DOPr subtypes are examined in light of the ability of DOPr to organize into multimeric arrays and to adopt multiple active conformations as well as differences in ligand kinetics. Current knowledge on DOPr targeting to the membrane is examined as a means of understanding how these receptors are especially active in chronic pain management. Insight into cellular and molecular mechanisms of pharmacological diversity should guide the rational design of more effective, longer-lasting, and better-tolerated opioid analgesics for chronic pain management. PMID:27343248

Analgesic tolerance to morphine is regulated by PPARγ

PubMed Central

de Guglielmo, Giordano; Kallupi, Marsida; Scuppa, Giulia; Stopponi, Serena; Demopulos, Gregory; Gaitanaris, George; Ciccocioppo, Roberto

2014-01-01

Background and Purpose Opioid drugs are potent analgesics. However, their chronic use leads to the rapid development of tolerance to their analgesic effects and subsequent increase of significant side effects, including drug dependence and addiction. Here, we investigated the role of PPARγ in the development of analgesic tolerance to morphine in mice. Experimental Approach We monitored analgesia on alternate days using the tail immersion test. Key Results Daily administration of morphine (30 mg·kg−1, bid) resulted in the rapid development of tolerance to thermal analgesia. Co-administration of pioglitazone (10 and 30 mg·kg−1, bid) significantly attenuated the development and expression of tolerance. However, pretreatment with GW-9662 (5 mg·kg−1, bid), a selective PPARγ antagonist, completely abolished this effect. Injection of GW-9662 and a lower dose of morphine (15 mg·kg−1, bid) accelerated the development of tolerance to its antinociceptive effect. Subsequently, we found that conditional neuronal PPARγ knockout (KO) mice develop a more rapid and pronounced tolerance to morphine antinociception compared with wild-type (WT) controls. Moreover, in PPARγ KO mice, pioglitazone was no longer able to prevent the development of morphine tolerance. Conclusions and Implications Overall, our results demonstrate that PPARγ plays a tonic role in the modulation of morphine tolerance, and its pharmacological activation may help to reduce its development. These findings provide new information about the role of neuronal PPARγ and suggest that combining PPARγ agonists with opioid analgesics may reduce the development of tolerance and possibly attenuate the potential for opioid abuse. PMID:25048682

Molecular Mechanisms of Opioid Receptor-Dependent Signaling and Behavior

PubMed Central

Al-Hasani, Ream; Bruchas, Michael R.

2013-01-01

Opioid receptors have been targeted for the treatment of pain and related disorders for thousands of years, and remain the most widely used analgesics in the clinic. Mu (μ), kappa (κ), and delta (δ) opioid receptors represent the originally classified receptor subtypes, with opioid receptor like-1 (ORL1) being the least characterized. All four receptors are G-protein coupled, and activate inhibitory G-proteins. These receptors form homo- and hetereodimeric complexes, signal to kinase cascades, and scaffold a variety of proteins. In this review, we discuss classical mechanisms and developments in understanding opioid tolerance, opioid receptor signaling, and highlight advances in opioid molecular pharmacology, behavioral pharmacology, and human genetics. We put into context how opioid receptor signaling leads to the modulation of behavior with the potential for therapeutic intervention. Finally, we conclude that there is a continued need for more translational work on opioid receptors in vivo. PMID:22020140

Evidence that opioids may have toll like receptor 4 and MD-2 effects

PubMed Central

Hutchinson, Mark R.; Zhang, Yingning; Shridhar, Mitesh; Evans, John H.; Buchanan, Madison M.; Zhao, Tina X.; Slivka, Peter F.; Coats, Benjamen D.; Rezvani, Niloofar; Wieseler, Julie; Hughes, Travis S.; Landgraf, Kyle E.; Chan, Stefanie; Fong, Stephanie; Phipps, Simon; Falke, Joseph J.; Leinwand, Leslie A.; Maier, Steven F.; Yin, Hang; Rice, Kenner C.; Watkins, Linda R.

2009-01-01

Opioid-induced proinflammatory glial activation modulates wide-ranging aspects of opioid pharmacology including: opposition of acute and chronic opioid analgesia, opioid analgesic tolerance, opioid-induced hyperalgesia, development of opioid dependence, opioid reward, and opioid respiratory depression. However, the mechanism(s) contributing to opioid-induced proinflammatory actions remains unresolved. The potential involvement of toll like receptor 4 (TLR4) was examined using in vitro, in vivo, and in silico techniques. Morphine non-stereoselectively induced TLR4 signaling in vitro, blocked by a classical TLR4 antagonist and non-stereoselectively by naloxone. Pharmacological blockade of TLR4 signaling in vivo potentiated acute intrathecal morphine analgesia, attenuated development of analgesic tolerance, hyperalgesia, and opioid withdrawal behaviors. TLR4 opposition to opioid actions was supported by morphine treatment of TLR4 knockout mice, which revealed a significant threefold leftward shift in the analgesia dose response function, versus wildtype mice. A range of structurally diverse clinically employed opioid analgesics was found to be capable of activating TLR4 signaling in vitro. Selectivity in the response was identified since morphine-3-glucuronide, a morphine metabolite with no opioid receptor activity, displayed significant TLR4 activity, whilst the opioid receptor active metabolite, morphine-6-glucuronide, was devoid of such properties. In silico docking simulations revealed ligands bound preferentially to the LPS binding pocket of MD-2 rather than TLR4. An in silico to in vitro prediction model was built and tested with substantial accuracy. These data provide evidence that select opioids may non-stereoselectively influence TLR4 signaling and have behavioral consequences resulting, in part, via TLR4 signaling. PMID:19679181

Nociceptin/Orphanin FQ Receptor Structure, Signaling, Ligands, Functions, and Interactions with Opioid Systems

PubMed Central

Bruchas, Michael R.; Calo', Girolamo; Cox, Brian M.; Zaveri, Nurulain T.

2016-01-01

The NOP receptor (nociceptin/orphanin FQ opioid peptide receptor) is the most recently discovered member of the opioid receptor family and, together with its endogenous ligand, N/OFQ, make up the fourth members of the opioid receptor and opioid peptide family. Because of its more recent discovery, an understanding of the cellular and behavioral actions induced by NOP receptor activation are less well developed than for the other members of the opioid receptor family. All of these factors are important because NOP receptor activation has a clear modulatory role on mu opioid receptor-mediated actions and thereby affects opioid analgesia, tolerance development, and reward. In addition to opioid modulatory actions, NOP receptor activation has important effects on motor function and other physiologic processes. This review discusses how NOP pharmacology intersects, contrasts, and interacts with the mu opioid receptor in terms of tertiary structure and mechanism of receptor activation; location of receptors in the central nervous system; mechanisms of desensitization and downregulation; cellular actions; intracellular signal transduction pathways; and behavioral actions with respect to analgesia, tolerance, dependence, and reward. This is followed by a discussion of the agonists and antagonists that have most contributed to our current knowledge. Because NOP receptors are highly expressed in brain and spinal cord and NOP receptor activation sometimes synergizes with mu receptor-mediated actions and sometimes opposes them, an understanding of NOP receptor pharmacology in the context of these interactions with the opioid receptors will be crucial to the development of novel therapeutics that engage the NOP receptor. PMID:26956246

Opioid analgesia in mechanically ventilated children: results from the multicenter Measuring Opioid Tolerance Induced by Fentanyl study.

PubMed

Anand, Kanwaljeet J S; Clark, Amy E; Willson, Douglas F; Berger, John; Meert, Kathleen L; Zimmerman, Jerry J; Harrison, Rick; Carcillo, Joseph A; Newth, Christopher J L; Bisping, Stephanie; Holubkov, Richard; Dean, J Michael; Nicholson, Carol E

2013-01-01

To examine the clinical factors associated with increased opioid dose among mechanically ventilated children in the pediatric intensive care unit. Prospective, observational study with 100% accrual of eligible patients. Seven pediatric intensive care units from tertiary-care children's hospitals in the Collaborative Pediatric Critical Care Research Network. Four hundred nineteen children treated with morphine or fentanyl infusions. None. Data on opioid use, concomitant therapy, demographic and explanatory variables were collected. Significant variability occurred in clinical practices, with up to 100-fold differences in baseline opioid doses, average daily or total doses, or peak infusion rates. Opioid exposure for 7 or 14 days required doubling of the daily opioid dose in 16% patients (95% confidence interval 12%-19%) and 20% patients (95% confidence interval 16%-24%), respectively. Among patients receiving opioids for longer than 3 days (n = 225), this occurred in 28% (95% confidence interval 22%-33%) and 35% (95% confidence interval 29%-41%) by 7 or 14 days, respectively. Doubling of the opioid dose was more likely to occur following opioid infusions for 7 days or longer (odds ratio 7.9, 95% confidence interval 4.3-14.3; p < 0.001) or co-therapy with midazolam (odds ratio 5.6, 95% confidence interval 2.4-12.9; p < 0.001), and it was less likely to occur if morphine was used as the primary opioid (vs. fentanyl) (odds ratio 0.48, 95% confidence interval 0.25-0.92; p = 0.03), for patients receiving higher initial doses (odds ratio 0.96, 95% confidence interval 0.95-0.98; p < 0.001), or if patients had prior pediatric intensive care unit admissions (odds ratio 0.37, 95% confidence interval 0.15-0.89; p = 0.03). Mechanically ventilated children require increasing opioid doses, often associated with prolonged opioid exposure or the need for additional sedation. Efforts to reduce prolonged opioid exposure and clinical practice variation may prevent the complications of

A substance P-opioid chimeric peptide as a unique nontolerance-forming analgesic

PubMed Central

Foran, Stacy E.; Carr, Daniel B.; Lipkowski, Andrzej W.; Maszczynska, Iwona; Marchand, James E.; Misicka, Aleksandra; Beinborn, Martin; Kopin, Alan S.; Kream, Richard M.

2000-01-01

To elucidate mechanisms of acute and chronic pain, it is important to understand how spinal excitatory systems influence opioid analgesia. The tachykinin substance P (SP) represents the prototypic spinal excitatory peptide neurotransmitter/neuromodulator, acting in concert with endogenous opioid systems to regulate analgesic responses to nociceptive stimuli. We have synthesized and pharmacologically characterized a chimeric peptide containing overlapping NH2- and COOH-terminal functional domains of the endogenous opioid endomorphin-2 (EM-2) and the tachykinin SP, respectively. Repeated administration of the chimeric molecule YPFFGLM-NH2, designated ESP7, into the rat spinal cord produces opioid-dependent analgesia without loss of potency over 5 days. In contrast, repeated administration of ESP7 with concurrent SP receptor (SPR) blockade results in a progressive loss of analgesic potency, consistent with the development of tolerance. Furthermore, tolerant animals completely regain opioid sensitivity after post hoc administration of ESP7 alone, suggesting that coactivation of SPRs is essential to maintaining opioid responsiveness. Radioligand binding and signaling assays, using recombinant receptors, confirm that ESP7 can coactivate μ-opioid receptors (MOR) and SPRs in vitro. We hypothesize that coincidental activation of the MOR- and SPR-expressing systems in the spinal cord mimics an ongoing state of reciprocal excitation and inhibition, which is normally encountered in nociceptive processing. Due to the ability of ESP7 to interact with both MOR and SPRs, it represents a unique prototypic, anti-tolerance-forming analgesic with future therapeutic potential. PMID:10852965

Opioid use among same-day surgery patients: Prevalence, management and outcomes

PubMed Central

Wilson, Jennifer LC; Poulin, Patricia A; Sikorski, Robert; Nathan, Howard J; Taljaard, Monica; Smyth, Catherine

2015-01-01

OBJECTIVES: To determine whether the prevalence of opioid use among patients requiring elective same-day admission (SDA) surgery is greater than the 2.5% prevalence found in the general population. Secondary objectives were to assess compliance with expert recommendations on acute pain management in opioid-tolerant patients and to examine clinical outcomes. METHODS: A retrospective review of 812 systematically sampled adult SDA surgical cases between April 1, 2008 and March 31, 2009 was conducted. RESULTS: Among 798 eligible patients, 148 (18.5% [95% CI 15.9% to 21.2%]) were prescribed opioids, with 4.4% prescribed long-acting opioids (95% CI 3.0% to 5.8%). Use of opioids was most prevalent among orthopedic and neurosurgery patients. Among the 35 patients on long-acting opioids who had a high likelihood of being tolerant, anesthesiologists correctly identified 33, but only 13 (37%) took their usual opioid preoperatively while 22 (63%) had opioids continued postoperatively. Acetaminophen, nonsteroidal anti-inflammatory drugs and pregabalin were ordered preoperatively in 18 (51%), 15 (43%) and 18 (51%) cases, respectively, while ketamine was used in 15 (43%) patients intraoperatively. Acetaminophen, nonsteroidal anti-inflammatory drugs and pregabalin were ordered postoperatively in 31 (89%), 15 (43%) and 17 (49%) of the cases, respectively. No differences in length of stay, readmissions and emergency room visits were found between opioid-tolerant and opioid-naïve patients. CONCLUSION: Opioid use is more common in SDA surgical patients than in the general population and is most prevalent within orthopedic and neurosurgery patients. Uptake of expert opinion on the management of acute pain in the opioid tolerant patient population is lacking. PMID:26357683

Targinact--opioid pain relief without constipation?

PubMed

2010-12-01

Targinact (Napp Pharmaceuticals Ltd) is a modified-release combination product containing the strong opioid oxycodone plus the opioid antagonist naloxone. It is licensed for "severe pain, which can be adequately managed only with opioid analgesics".1 The summary of product characteristics (SPC) states that "naloxone is added to counteract opioid-induced constipation by blocking the action of oxycodone at opioid receptors locally in the gut". Advertising for the product claims "better pain relief", "superior GI [gastrointestinal] tolerability" and "improved quality of life" "compared to previous treatment in a clinical practice study (n=7836)". Here we consider whether Targinact offers advantages over using strong opioids plus laxatives where required.

Opioid receptor-mediated hyperalgesia and antinociceptive tolerance induced by sustained opiate delivery.

PubMed

Gardell, Luis R; King, Tamara; Ossipov, Michael H; Rice, Kenner C; Lai, Josephine; Vanderah, Todd W; Porreca, Frank

2006-03-20

Opiates are commonly used to treat moderate to severe pain and can be used over prolonged periods in states of chronic pain such as those associated with cancer. In addition, to analgesic actions, studies show that opiate administration can paradoxically induce hyperalgesia. At the pre-clinical level, such hyperalgesia is associated with numerous pronociceptive neuroplastic changes within the primary afferent fibers and the spinal cord. In rodents, sustained opiate administration also induces antinociceptive tolerance. The mechanisms by which prolonged opiate exposure induces hyperalgesia and the relationship of this state to antinociceptive tolerance remain unclear. The present study was aimed at determining whether sustained opiate-induced hyperalgesia, associated neuroplasticity and antinociceptive tolerance are the result of specific opiate interaction at opiate receptors. Enantiomers of oxymorphone, a mu opioid receptor agonist, were administered to rats by spinal infusion across 7 days. Sustained spinal administration of (-)-oxymorphone, but not its inactive enantiomer (+)-oxymorphone or vehicle, upregulated spinal dynorphin content, produced thermal and tactile hypersensitivity, and produced antinociceptive tolerance. These results indicate that these pronociceptive actions of sustained opiate administration require specific interaction with opiate receptors and are unlikely to be the result of accumulation of potentially excitatory metabolic products. While the precise mechanisms, which may account for these pronociceptive changes remain to be unraveled, the present data point to plasticity initiated by opiate receptor interaction.

Individual variability in clinical effect and tolerability of opioid analgesics - Importance of drug interactions and pharmacogenetics.

PubMed

Solhaug, Vigdis; Molden, Espen

2017-10-01

As pain is often a comorbid condition, many patients use opioid analgesics in combination with several other drugs. This implies a generally increased risk of drug interactions, which along with inherent pharmacogenetic variability and other factors may cause differences in therapeutic response of opioids. To provide an overview of interactions and pharmacogenetic variability of relevance for individual differences in effect and tolerability of opioid analgesics, which physicians and other healthcare professionals should be aware of in clinical practice. The article was based on unsystematic searches in PubMed to identify literature highlighting the clinical impact of drug interactions and pharmacogenetics as sources of variable response of opioid analgesics. Cytochrome P450 (CYP)-mediated metabolism is an important process for both clinically relevant interactions and pharmacogenetic variability of several opioids. Concomitant use of CYP inhibitors (e.g. paroxetine, fluoxetine and bupropion) or inducers (e.g. carbamazepine, phenobarbital and phenytoin) could counteract the clinical effect or trigger side effects of analgesics in the same manner as genetically determined differences in CYP2D6-mediated metabolism of many opioids. Moreover, combination treatment with drugs that inhibit or induce P-glycoprotein (ABCB1), a blood-brain barrier efflux transporter, may alter the amount ('dose') of opioids distributed to the brain. At the pharmacodynamic level, it is crucial to be aware of the potential risk of interaction causing serotonergic syndrome when combining opioids and serotonergic drugs, in particular antidepressants inhibiting serotonin reuptake (SSRIs and SNRIs). Regarding pharmacogenetics at the receptor level of pain treatment, the knowledge is currently scarce, but an allelic variant of the μ1 opioid receptor (OPRM1) gene has been associated with higher dosage requirement to achieve analgesia. Drug interactions and pharmacogenetic differences may lead to

Blockade of NMDA receptors prevents analgesic tolerance to repeated transcutaneous electrical nerve stimulation (TENS) in rats

PubMed Central

Hingne, Priyanka M.; Sluka, Kathleen A.

2008-01-01

Repeated daily application transcutaneous electrical nerve stimulation (TENS) results in tolerance, at spinal opioid receptors, to the anti-hyperalgesia produced by TENS. Since N-Methyl-D-Aspartate (NMDA) receptor antagonists prevent analgesic tolerance to opioid agonists we hypothesized that blockade of NMDA receptors will prevent tolerance to TENS. In rats with knee joint inflammation, TENS was applied for 20 minute daily at high frequency (100 Hz), low frequency (4 Hz), or sham TENS. Rats were treated with the NMDA antagonist MK-801 (0.01 mg/kg-0.1 mg/kg) or vehicle daily before TENS. Paw withdrawal thresholds were tested before and after inflammation, and before and after TENS treatment for 4 days. On day 1 TENS reversed the decreased mechanical withdrawal threshold induced by joint inflammation. On day 4 TENS had no effect on the decreased withdrawal threshold in the group treated with vehicle demonstrating development of tolerance. However, in the group treated with 0.1 mg/kg MK-801, TENS significantly reversed the mechanical withdrawal thresholds on day 4 demonstrating that tolerance did not develop. Vehicle treated animals developed cross-tolerance at spinal opioid receptors. Treatment with MK-801 reversed this cross-tolerance at spinal opioid receptors. In summary, blockade of NMDA receptors prevents analgesic tolerance to daily TENS by preventing tolerance at spinal opioid receptors. Perspective Tolerance observed to the clinical treatment of TENS could be prevented by administration of pharmaceutical agents with NMDA receptors activity such as ketamine or dextromethorphan. PMID:18061543

Increased glutamate synaptic transmission in the nucleus raphe magnus neurons from morphine-tolerant rats.

PubMed

Bie, Bihua; Pan, Zhizhong Z

2005-02-09

Currently, opioid-based drugs are the most effective pain relievers that are widely used in the treatment of pain. However, the analgesic efficacy of opioids is significantly limited by the development of tolerance after repeated opioid administration. Glutamate receptors have been reported to critically participate in the development and maintenance of opioid tolerance, but the underlying mechanisms remain unclear. Using whole-cell voltage-clamp recordings in brainstem slices, the present study investigated chronic morphine-induced adaptations in glutamatergic synaptic transmission in neurons of the nucleus raphe magnus (NRM), a key supraspinal relay for pain modulation and opioid analgesia. Chronic morphine significantly increased glutamate synaptic transmission exclusively in one class of NRM cells that contains mu-opioid receptors in a morphine-tolerant state. The adenylyl cyclase activator forskolin and the cAMP analog 8-bromo-cAMP mimicked the chronic morphine effect in control neurons and their potency in enhancing the glutamate synaptic current was significantly increased in neurons from morphine-tolerant rats. MDL12330a, an adenylyl cyclase inhibitor, and H89, a protein kinase A (PKA) inhibitor, reversed the increase in glutamate synaptic transmission induced by chronic morphine. In addition, PMA, a phorbol ester activator of protein kinase C (PKC), also showed an increased potency in enhancing the glutamate synaptic current in these morphine-tolerant cells. The PKC inhibitor GF109203X attenuated the chronic morphine effect. Taken together, these results suggest that chronic morphine increases presynaptic glutamate release in mu receptor-containing NRM neurons in a morphine-tolerant state, and that the increased glutamate synaptic transmission appears to involve an upregulation of both the cAMP/PKA pathway and the PKC pathway. This glutamate-mediated activation of these NRM neurons that are thought to facilitate spinal pain transmission may contribute to

Opioid tolerance in periaqueductal gray neurons isolated from mice chronically treated with morphine

PubMed Central

Bagley, Elena E; Chieng, Billy C H; Christie, MacDonald J; Connor, Mark

2005-01-01

The midbrain periaqueductal gray (PAG) is a major site of opioid analgesic action, and a significant site of cellular adaptations to chronic morphine treatment (CMT). We examined μ-opioid receptor (MOP) regulation of voltage-gated calcium channel currents (ICa) and G-protein-activated K channel currents (GIRK) in PAG neurons from CMT mice. Mice were injected s.c. with 300 mg kg−1 of morphine base in a slow release emulsion three times over 5 days, or with emulsion alone (vehicles). This protocol produced significant tolerance to the antinociceptive effects of morphine in a test of thermal nociception. Voltage clamp recordings were made of ICa in acutely isolated PAG neurons and GIRK in PAG slices. The MOP agonist DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin) inhibited ICa in neurons from CMT mice (230 nM) with a similar potency to vehicle (150 nM), but with a reduced maximal effectiveness (37% inhibition in vehicle neurons, 27% in CMT neurons). Inhibition of ICa by the GABAB agonist baclofen was not altered by CMT. Met-enkephalin-activated GIRK currents recorded in PAG slices were significantly smaller in neurons from CMT mice than vehicles, while GIRK currents activated by baclofen were unaltered. These data demonstrate that CMT-induced antinociceptive tolerance is accompanied by homologous reduction in the effectiveness of MOP agonists to inhibit ICa and activate GIRK. Thus, a reduction in MOP number and/or functional coupling to G proteins accompanies the characteristic cellular adaptations to CMT previously described in PAG neurons. PMID:15980868

Opioid tolerance in periaqueductal gray neurons isolated from mice chronically treated with morphine.

PubMed

Bagley, Elena E; Chieng, Billy C H; Christie, MacDonald J; Connor, Mark

2005-09-01

The midbrain periaqueductal gray (PAG) is a major site of opioid analgesic action, and a significant site of cellular adaptations to chronic morphine treatment (CMT). We examined mu-opioid receptor (MOP) regulation of voltage-gated calcium channel currents (I(Ca)) and G-protein-activated K channel currents (GIRK) in PAG neurons from CMT mice. Mice were injected s.c. with 300 mg kg(-1) of morphine base in a slow release emulsion three times over 5 days, or with emulsion alone (vehicles). This protocol produced significant tolerance to the antinociceptive effects of morphine in a test of thermal nociception. Voltage clamp recordings were made of I(Ca) in acutely isolated PAG neurons and GIRK in PAG slices. The MOP agonist DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin) inhibited I(Ca) in neurons from CMT mice (230 nM) with a similar potency to vehicle (150 nM), but with a reduced maximal effectiveness (37% inhibition in vehicle neurons, 27% in CMT neurons). Inhibition of I(Ca) by the GABA(B) agonist baclofen was not altered by CMT. Met-enkephalin-activated GIRK currents recorded in PAG slices were significantly smaller in neurons from CMT mice than vehicles, while GIRK currents activated by baclofen were unaltered. These data demonstrate that CMT-induced antinociceptive tolerance is accompanied by homologous reduction in the effectiveness of MOP agonists to inhibit I(Ca) and activate GIRK. Thus, a reduction in MOP number and/or functional coupling to G proteins accompanies the characteristic cellular adaptations to CMT previously described in PAG neurons.

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.

Proinflammatory cytokines oppose opioid induced acute and chronic analgesia

PubMed Central

Hutchinson, Mark R.; Coats, Benjamen D.; Lewis, Susannah S.; Zhang, Yingning; Sprunger, David B.; Rezvani, Niloofar; Baker, Eric M.; Jekich, Brian M.; Wieseler, Julie L.; Somogyi, Andrew A.; Martin, David; Poole, Stephen; Judd, Charles M.; Maier, Steven F.; Watkins, Linda R.

2008-01-01

Spinal proinflammatory cytokines are powerful pain-enhancing signals that contribute to pain following peripheral nerve injury (neuropathic pain). Recently, one proinflammatory cytokine, interleukin-1, was also implicated in the loss of analgesia upon repeated morphine exposure (tolerance). In contrast to prior literature, we demonstrate that the action of several spinal proinflammatory cytokines oppose systemic and intrathecal opioid analgesia, causing reduced pain suppression. In vitro morphine exposure of lumbar dorsal spinal cord caused significant increases in proinflammatory cytokine and chemokine release. Opposition of analgesia by proinflammatory cytokines is rapid, occurring ≤5 minutes after intrathecal (perispinal) opioid administration. We document that opposition of analgesia by proinflammatory cytokines cannot be accounted for by an alteration in spinal morphine concentrations. The acute anti-analgesic effects of proinflammatory cytokines occur in a p38 mitogen-activated protein kinase and nitric oxide dependent fashion. Chronic intrathecal morphine or methadone significantly increased spinal glial activation (toll-like receptor 4 mRNA and protein) and the expression of multiple chemokines and cytokines, combined with development of analgesic tolerance and pain enhancement (hyperalgesia, allodynia). Statistical analysis demonstrated that a cluster of cytokines and chemokines was linked with pain-related behavioral changes. Moreover, blockade of spinal proinflammatory cytokines during a stringent morphine regimen previously associated with altered neuronal function also attenuated enhanced pain, supportive that proinflammatory cytokines are importantly involved in tolerance induced by such regimens. These data implicate multiple opioid-induced spinal proinflammatory cytokines in opposing both acute and chronic opioid analgesia, and provide a novel mechanism for the opposition of acute opioid analgesia. PMID:18599265

The human mu opioid receptor: modulation of functional desensitization by calcium/calmodulin-dependent protein kinase and protein kinase C.

PubMed

Mestek, A; Hurley, J H; Bye, L S; Campbell, A D; Chen, Y; Tian, M; Liu, J; Schulman, H; Yu, L

1995-03-01

Opioids are some of the most efficacious analgesics used in humans. Prolonged administration of opioids, however, often causes the development of drug tolerance, thus limiting their effectiveness. To explore the molecular basis of those mechanisms that may contribute to opioid tolerance, we have isolated a cDNA for the human mu opioid receptor, the target of such opioid narcotics as morphine, codeine, methadone, and fentanyl. The receptor encoded by this cDNA is 400 amino acids long with 94% sequence similarity to the rat mu opioid receptor. Transient expression of this cDNA in COS-7 cells produced high-affinity binding sites to mu-selective agonists and antagonists. This receptor displays functional coupling to a recently cloned G-protein-activated K+ channel. When both proteins were expressed in Xenopus oocytes, functional desensitization developed upon repeated stimulation of the mu opioid receptor, as observed by a reduction in K+ current induced by the second mu receptor activation relative to that induced by the first. The extent of desensitization was potentiated by both the multifunctional calcium/calmodulin-dependent protein kinase and protein kinase C. These results demonstrate that kinase modulation is a molecular mechanism by which the desensitization of mu receptor signaling may be regulated at the cellular level, suggesting that this cellular mechanism may contribute to opioid tolerance in humans.

Clinically Employed Opioid Analgesics Produce Antinociception via μ-δ Opioid Receptor Heteromers in Rhesus Monkeys

PubMed Central

2012-01-01

Morphine and related drugs are widely employed as analgesics despite the side effects associated with their use. Although morphine is thought to mediate analgesia through mu opioid receptors, delta opioid receptors have been implicated in mediating some side effects such as tolerance and dependence. Here we present evidence in rhesus monkeys that morphine, fentanyl, and possibly methadone selectively activate mu-delta heteromers to produce antinociception that is potently antagonized by the delta opioid receptor antagonist, naltrindole (NTI). Studies with HEK293 cells expressing mu-delta heteromeric opioid receptors exhibit a similar antagonism profile of receptor activation in the presence of NTI. In mice, morphine was potently inhibited by naltrindole when administered intrathecally, but not intracerebroventricularly, suggesting the possible involvement of mu-delta heteromers in the spinal cord of rodents. Taken together, these results strongly suggest that, in primates, mu-delta heteromers are allosterically coupled and mediate the antinociceptive effects of three clinically employed opioid analgesics that have been traditionally viewed as mu-selective. Given the known involvement of delta receptors in morphine tolerance and dependence, our results implicate mu-delta heteromers in mediating both antinociception and these side effects in primates. These results open the door for further investigation in humans. PMID:23019498

Clinically employed opioid analgesics produce antinociception via μ-δ opioid receptor heteromers in Rhesus monkeys.

PubMed

Yekkirala, Ajay S; Banks, Matthew L; Lunzer, Mary M; Negus, Stevens S; Rice, Kenner C; Portoghese, Philip S

2012-09-19

Morphine and related drugs are widely employed as analgesics despite the side effects associated with their use. Although morphine is thought to mediate analgesia through mu opioid receptors, delta opioid receptors have been implicated in mediating some side effects such as tolerance and dependence. Here we present evidence in rhesus monkeys that morphine, fentanyl, and possibly methadone selectively activate mu-delta heteromers to produce antinociception that is potently antagonized by the delta opioid receptor antagonist, naltrindole (NTI). Studies with HEK293 cells expressing mu-delta heteromeric opioid receptors exhibit a similar antagonism profile of receptor activation in the presence of NTI. In mice, morphine was potently inhibited by naltrindole when administered intrathecally, but not intracerebroventricularly, suggesting the possible involvement of mu-delta heteromers in the spinal cord of rodents. Taken together, these results strongly suggest that, in primates, mu-delta heteromers are allosterically coupled and mediate the antinociceptive effects of three clinically employed opioid analgesics that have been traditionally viewed as mu-selective. Given the known involvement of delta receptors in morphine tolerance and dependence, our results implicate mu-delta heteromers in mediating both antinociception and these side effects in primates. These results open the door for further investigation in humans.

Delta-opioid receptors as targets for migraine therapy.

PubMed

Charles, Andrew; Pradhan, Amynah A

2016-06-01

The purpose of this review is to contrast the properties of the δ-opioid receptor with those of the μ-opioid receptor, which is the primary target of most currently available opioid analgesics. We also discuss preclinical evidence that indicates the potential efficacy of δ-opioid receptor agonists as migraine therapy. The use of currently available opioid analgesics is highly problematic for patients with migraine. Delta-opioid receptors have key differences from μ receptors; these differences make the δ receptor an attractive therapeutic target for migraine. Delta-opioid receptors are expressed in both the peripheral and central nervous system in anatomical regions and cell types that are believed to play a role in migraine. Delta-receptor agonists have also shown promising effects in multiple migraine models, including nitroglycerin evoked hyperalgesia and conditioned place aversion, and cortical spreading depression. Evidence from animal models indicates that activation of δ receptors is less likely to cause tolerance and dependence, and less likely to cause hyperalgesia. In addition, δ receptors may have antidepressant and anxiolytic properties that are distinct from those of μ receptors. In human studies investigating other conditions, δ-receptor agonists have been generally safe and well tolerated. Delta-opioid receptor agonists have promising potential as acute and/or preventive migraine therapies, without the problems associated with currently used opioid analgesics.

Disruption of δ-opioid receptor phosphorylation at threonine 161 attenuates morphine tolerance in rats with CFA-induced inflammatory hypersensitivity.

PubMed

Chen, Hai-Jing; Xie, Wei-Yan; Hu, Fang; Zhang, Ying; Wang, Jun; Wang, Yun

2012-04-01

Our previous study identified Threonine 161 (Thr-161), located in the second intracellular loop of the δ-opioid receptor (DOR), as the only consensus phosphorylation site for cyclin-dependent kinase 5 (Cdk5). The aim of this study was to assess the function of DOR phosphorylation by Cdk5 in complete Freund's adjuvant (CFA)-induced inflammatory pain and morphine tolerance. Dorsal root ganglion (DRG) neurons of rats with CFA-induced inflammatory pain were acutely dissociated and the biotinylation method was used to explore the membrane localization of phosphorylated DOR at Thr-161 (pThr-161-DOR), and paw withdrawal latency was measured after intrathecal delivery of drugs or Tat-peptide, using a radiant heat stimulator in rats with CFA-induced inflammatory pain. Both the total amount and the surface localization of pThr-161-DOR were significantly enhanced in the ipsilateral DRG following CFA injection. Intrathecal delivery of the engineered Tat fusion-interefering peptide corresponding to the second intracellular loop of DOR (Tat-DOR-2L) increased inflammatory hypersensitivity, and inhibited DOR- but not µ-opioid receptor-mediated spinal analgesia in CFA-treated rats. However, intrathecal delivery of Tat-DOR-2L postponed morphine antinociceptive tolerance in rats with CFA-induced inflammatory pain. Phosphorylation of DOR at Thr-161 by Cdk5 attenuates hypersensitivity and potentiates morphine tolerance in rats with CFA-induced inflammatory pain, while disruption of the phosphorylation of DOR at Thr-161 attenuates morphine tolerance.

[Opioids in chronic noncancer pain-are opioids superior to nonopioid analgesics? A systematic review and meta-analysis of efficacy, tolerability and safety in randomized head-to-head comparisons of opioids versus nonopioid analgesics of at least four week's duration].

PubMed

Welsch, P; Sommer, C; Schiltenwolf, M; Häuser, W

2015-02-01

Some leading German pain medicine experts postulate that there is a type of chronic non-cancer pain (CNCP) with an opioid requirement. We tested whether opioids are superior to nonopioid analgesics in the management of CNCP in studies of at least 4 week's duration. We screened MEDLINE, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) up until October 2013, as well as the reference sections of original studies and systematic reviews of randomised controlled trials (RCTs) of opioids in CNCP. We included double-blind RTCs comparing opioids to nonopioid analgesics of at least 4 week's duration. Relative risks differences (RD) of categorical data and standardized mean differences (SMD) of continuous variables were calculated using a random effects model. We included 10 RCTs with 3046 participants. Median study duration was 6 weeks (range 4-12 weeks). Five studies compared tramadol with nonsteroidal anti-inflammatory drugs (NSAIDs) in osteoarthritis pain and one trial compared tramadol to flupirtine in low back pain. Morphine was compared to antidepressants (two studies), an anticonvulsant (one study) and an antiarrhythmic (one study) in different neuropathic pain syndromes. There was no significant difference between opioids and nonopioid analgesics in pain reduction (SMD 0.03 [95 % confidence interval, CI - 0.18, 0.24]; p = 0.76). Nonopioid analgesics were superior to opioids in improving physical function (SMD 0.17 [95 % CI 0.02, 0.32]; p = 0.03). Patients dropped out due to adverse events more frequently with opioids than with nonopioid analgesics (RD 0.09 [95 % CI 0.06, 0.13]; p < 0.0001). There was no significant difference between opioids and nonopioid analgesics in terms of serious adverse events or dropout rates due to lack of efficacy. Nonopioid analgesics are superior to opioids in terms of improvement of physical function and tolerability in short-term (4-12 weeks) therapy of neuropathic, low back

Comparison of tizanidine and morphine with regard to tolerance-developing ability to antinociceptive action.

PubMed

Nabeshima, T; Yamada, S; Sugimoto, A; Matsuno, K; Kameyama, T

1986-10-01

The antinociceptive, tolerance-developing and anti-withdrawal activities of tizanidine [5-chloro-4-(2-imidazolin-2-yl-amino)-2,1,3-benzo-thiadiazole] were investigated by comparing its effects with those of morphine and clonidine in tail-flick-, hot plate-, acetic acid-induced writhing-, and naloxone-precipitated withdrawal jumping-tests. The antinociceptive action of tizanidine was not altered by naloxone, while that of morphine was antagonized. Tolerance to the tizanidine-induced antinociceptive action and to motor incoordination was developed by successive administration of tizanidine. In the tizanidine-tolerant mice, the antinociceptive action of morphine was significantly decreased, but not sleeping time induced by pentobarbital. The action of tizanidine was not modified in the morphine-tolerant mice. Tizanidine failed to induce morphine-withdrawal jumping and to inhibit naloxone-precipitated withdrawal jumping in the morphine-dependent mice. Cross tolerance to the antinociceptive action induced by tizanidine and clonidine was developed. These results suggest that alpha 2-adrenoreceptors may be involved in the action mechanism of tizanidine, but not opioid receptors. Functional tolerance to tizanidine action may be developed by successive administration of tizanidine.

The Neurobiology of Opioid Dependence: Implications for Treatment

PubMed Central

Kosten, Thomas R.; George, Tony P.

2002-01-01

Opioid tolerance, dependence, and addiction are all manifestations of brain changes resulting from chronic opioid abuse. The opioid abuser’s struggle for recovery is in great part a struggle to overcome the effects of these changes. Medications such as methadone, LAAM, buprenorphine, and naltrexone act on the same brain structures and processes as addictive opioids, but with protective or normalizing effects. Despite the effectiveness of medications, they must be used in conjunction with appropriate psychosocial treatments. PMID:18567959

Low-Dose Ketamine Infusions for Highly Opioid-Tolerant Adults Following Spinal Surgery: A Retrospective Before-and-after Study.

PubMed

Vaid, Patrycja; Green, Theresa; Shinkaruk, Kelly; King-Shier, Kathryn

2016-04-01

Managing acute-on-chronic pain in opioid-tolerant individuals is complex and challenging; exploring new analgesia regimens for this population is essential. Ketamine is an N-methyl D-aspartate antagonist that blocks transmission of painful stimuli and could be a useful medication for this patient population. A new low-dose ketamine protocol as an adjunct to conventional pain therapy was implemented in a major urban Level 1 trauma center in Canada. A retrospective before-and-after chart review was conducted to explore the research question, "What is the effect of low-dose ketamine continuous intravenous infusions on pain of highly opioid-tolerant adults following spinal surgery?". All patients had spine surgery, used a minimum of 100 mg daily oral morphine equivalent preoperatively and were followed postoperatively by the hospital's Acute Pain Service. Data from individuals treated with conventional therapy during the year prior to protocol implementation were compared with data from patients who received conventional therapy plus ketamine post implementation. Outcome measures included pain scores and daily opioid consumption on postoperative days 0 through 5, time to ambulation, time to discharge, and adverse effects. There were no statistically significant differences between conventional therapy and conventional therapy plus ketamine. Ketamine may still be of benefit to patients with acute-on-chronic pain, although this was not evident in this study. Future research using more robust assessment tools to determine effectiveness of ketamine is required. Copyright © 2016 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Differential development of antinociceptive tolerance to morphine and fentanyl is not linked to efficacy in the ventrolateral periaqueductal gray of the rat

PubMed Central

Bobeck, Erin N.; Haseman, Rachel A.; Hong, Dana; Ingram, Susan L.; Morgan, Michael M.

2012-01-01

Systemic administration of morphine typically produces greater tolerance than higher efficacy mu-opioid receptor (MOPr) agonists, such as fentanyl. The objective of the present study was to test this relationship by measuring antinociceptive efficacy and tolerance to morphine and fentanyl microinjected into the ventrolateral periaqueductal gray (vlPAG). MOPr agonist efficacy was evaluated by microinjecting the irreversible opioid receptor antagonist β-funaltrexamine hydrochloride (β-FNA) into the vlPAG prior to a dose-response analysis of morphine and fentanyl antinociception. In contrast to systemic administration of morphine and fentanyl, microinjection of these drugs into the vlPAG had similar efficacy as measured by similar reductions in maximal antinociception following β-FNA administration. Analysis of tolerance revealed a rightward shift in the dose-response curve to a single pretreatment with morphine, but not fentanyl. Moreover, the magnitude of tolerance to morphine was comparable following one, four, or eight pretreatments. Tolerance to fentanyl also was evident following four or eight microinjections. These data are surprising in that antinociceptive efficacy appears to vary depending on the site of administration. Moreover, the similar efficacy following microinjection of morphine and fentanyl into the vlPAG was associated with comparable tolerance, with the one exception of no tolerance to acute administration of fentanyl. Perspective These data reveal that antinociceptive tolerance following vlPAG administration of opioids develops rapidly, is evident with both morphine and fentanyl, and the magnitude is relatively consistent regardless of the number of pretreatments. PMID:22766006

Recent developments in the study of opioid receptors.

PubMed

Cox, Brian M

2013-04-01

It is now about 40 years since Avram Goldstein proposed the use of the stereoselectivity of opioid receptors to identify these receptors in neural membranes. In 2012, the crystal structures of the four members of the opioid receptor family were reported, providing a structural basis for understanding of critical features affecting the actions of opiate drugs. This minireview summarizes these recent developments in our understanding of opiate receptors. Receptor function is also influenced by amino acid substitutions in the protein sequence. Among opioid receptor genes, one polymorphism is much more frequent in human populations than the many others that have been found, but the functional significance of this single nucleotide polymorphism (SNP) has been unclear. Recent studies have shed new light on how this SNP might influence opioid receptor function. In this minireview, the functional significance of the most prevalent genetic polymorphism among the opioid receptor genes is also considered.

Imaging opioid analgesia in the human brain and its potential relevance for understanding opioid use in chronic pain

PubMed Central

Lee, Michael C.; Wanigasekera, Vishvarani; Tracey, Irene

2014-01-01

Opioids play an important role for the management of acute pain and in palliative care. The role of long-term opioid therapy in chronic non-malignant pain remains unclear and is the focus of much clinical research. There are concerns regarding analgesic tolerance, paradoxical pain and issues with dependence that can occur with chronic opioid use in the susceptible patient. In this review, we discuss how far human neuroimaging research has come in providing a mechanistic understanding of pain relief provided by opioids, and suggest avenues for further studies that are relevant to the management of chronic pain with opioids. This article is part of the Special Issue Section entitled ‘Neuroimaging in Neuropharmacology’. PMID:23891639

Ethanol Reversal of Oxycodone Tolerance in Dorsal Root Ganglia Neurons.

PubMed

Jacob, Joanna C; Sakakibara, Kensuke; Mischel, Ryan A; Henderson, Graeme; Dewey, William L; Akbarali, Hamid I

2018-05-01

Oxycodone is a semisynthetic opioid compound that is widely prescribed, used, and abused today, and has a well-established role in shaping the current opioid epidemic. Previously, we have shown that tolerance develops to the antinociceptive and respiratory depressive effects of oxycodone in mice, and that a moderate dose of acute ethanol or a protein kinase C (PKC) inhibitor reversed that tolerance. To investigate further if tolerance was occurring through neuronal mechanisms, our aims for this study were to assess the effects of acute and prolonged oxycodone in isolated dorsal root ganglia (DRG) neurons and to determine if this tolerance was reversed by either ethanol or a PKC inhibitor. We found that an acute exposure to 3 μ M oxycodone reduced neuronal excitability, as measured by increased threshold potentials and reduced action potential amplitude, without eliciting measurable changes in resting membrane potential. Exposure to 10 μ M oxycodone for 18-24 hours prevented oxycodone's effect on neuronal excitability, indicative of tolerance development. The development of opioid tolerance was mitigated in DRG neurons from β -arrestin 2 knockout mice. Oxycodone tolerance was reversed in isolated DRG neurons by the acute application of either ethanol (20 mM) or the PKC inhibitor, bisindolylmaleimide XI hydrochloride (Bis XI), when a challenge of 3 µ M oxycodone significantly reduced neuronal excitability following prolonged exposure. Through these studies, we concluded that oxycodone acutely reduced neuronal excitability, tolerance developed to this effect, and reversal of that tolerance occurred at the level of a single neuron, suggesting that reversal of oxycodone tolerance by either ethanol or Bis XI involves cellular mechanisms. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

Increased use of heroin as an initiating opioid of abuse.

PubMed

Cicero, Theodore J; Ellis, Matthew S; Kasper, Zachary A

2017-11-01

Given the relatively recent growth in access to heroin and a more permissive atmosphere surrounding its use, we hypothesized that an increasing number of persons with limited experience and tolerance to opioids would experiment with heroin as their first opioid rather than more common prescription opioid analgesics. Individuals entering substance abuse treatment for an opioid use disorder in the period 2010-2016 (N=5885) were asked about the specific opioid they first regularly used to get high. To limit long-term recall and survival bias, analyses was restricted to opioid initiation that occurred in the past ten years (2005-2015). In 2005, only 8.7% of opioid initiators started with heroin, but this sharply increased to 33.3% (p<0.001) in 2015, with no evidence of stabilization. The use of commonly prescribed opioids, oxycodone and hydrocodone, dropped from 42.4% and 42.3% of opioid initiators, respectively, to 24.1% and 27.8% in 2015, such that heroin as an initiating opioid was now more frequently endorsed than prescription opioid analgesics. Our data document that, as the most commonly prescribed opioids - hydrocodone and oxycodone - became less accessible due to supply-side interventions, the use of heroin as an initiating opioid has grown at an alarming rate. Given that opioid novices have limited tolerance to opioids, a slight imprecision in dosing inherent in heroin use is likely to be an important factor contributing to the growth in heroin-related over dose fatalities in recent years. Copyright © 2017. Published by Elsevier Ltd.

Naloxegol: A Novel Therapy in the Management of Opioid-Induced Constipation.

PubMed

Jones, Rachel; Prommer, Eric; Backstedt, David

2016-11-01

Opioid-related bowel dysfunction is a common and potentially severe adverse effect from treatment with opioid analgesics. Its development is not dose related, nor do patients develop tolerance. Opioid-induced constipation (OIC) can lead to fecal impaction, bowel obstruction, and bowel perforation as well as noncompliance with opioid analgesics and poor quality of life. Routine administration of laxatives is necessary to maintain bowel function, and, in refractory cases, other modalities must be pursued. Available options are limited but include peripherally acting μ-opioid receptor antagonists (PAMORAs), including methylnaltrexone. Naloxegol is a newly developed PAMORA that is available through the oral route. At the therapeutic dose of 25 mg daily, naloxegol is effective and safe, with a limited side effect profile and is associated with preservation of centrally mediated analgesia. In this article, we discuss the pharmacokinetics, pharmacodynamics, adverse effects, clinical trials, and cost considerations of naloxegol. Finally, we discuss its potential role as a novel key treatment for OIC in palliative medicine patients. © The Author(s) 2015.

Dual-opioid therapy: changing the paradigm. Introduction.

PubMed

Nicholson, Bruce D

2012-03-01

Morphine sulfate and oxycodone hydrochloride are commonly used for pain management because of their pharmacologic profile, pharmacokinetics, and analgesic potency. However, opioids are associated with a significant adverse event (AE) burden that limits their use in both the acute and the chronic pain settings. Co-administration of opioids demonstrated synergistic analgesia and reduced side effects. Thus, dual-opioid therapy has the potential to enhance the positive analgesic benefits of opioids, while limiting the burden of opioid-related AEs. This symposium proceedings was based on presentations at the 13th World Congress on Pain in August 2010. This program will review the rationale for dual-opioid therapy based on preclinical findings and data from clinical studies showing the efficacy and tolerability profile of a dual-opioid formulation when used to treat acute postoperative pain. Wiley Periodicals, Inc.

Sustained ligand-activated preconditioning via δ-opioid receptors.

PubMed

Peart, Jason N; Hoe, Louise E See; Gross, Garrett J; Headrick, John P

2011-01-01

We have previously described novel cardioprotection in response to sustained morphine exposure, efficacious in young to aged myocardium and mechanistically distinct from conventional opioid or preconditioning (PC) responses. We further investigate opioid-dependent sustained ligand-activated preconditioning (SLP), assessing duration of protection, opioid receptor involvement, additivity with conventional responses, and signaling underlying preischemic induction of the phenotype. Male C57BL/6 mice were treated with morphine (75-mg subcutaneous pellet) for 5 days followed by morphine-free periods (0, 3, 5, or 7 days) before ex vivo assessment of myocardial tolerance to 25-min ischemia/45-min reperfusion. SLP substantially reduced infarction (by ∼50%) and postischemic contractile dysfunction (eliminating contracture, doubling force development). Cardioprotection persisted for 5 to 7 days after treatment. SLP was induced specifically by δ-receptor and not κ- or μ-opioid receptor agonism, was eliminated by δ-receptor and nonselective antagonism, and was additive with adenosinergic but not acute morphine- or PC-triggered protection. Cotreatment during preischemic morphine exposure with the phosphoinositide-3 kinase (PI3K) inhibitor wortmannin, but not the protein kinase A (PKA) inhibitor myristoylated PKI-(14-22)-amide, prevented induction of SLP. This was consistent with shifts in total and phospho-Akt during the induction period. In summary, data reveal that SLP triggers sustained protection from ischemia for up to 7 days after stimulus, is δ-opioid receptor mediated, is induced in a PI3K-dependent/PKA-independent manner, and augments adenosinergic protection. Mechanisms underlying SLP may be useful targets for manipulation of ischemic tolerance in young or aged myocardium.

The present and future of opioid analgesics in small animal practice.

PubMed

Simon, B T; Steagall, P V

2017-08-01

Opioids are the cornerstone for the treatment of acute pain in small animal patients. This is primarily because of their remarkable safety profile, high efficacy, and benefit of reversibility. There have been some significant advances in our knowledge on opioid pharmacology and clinical usage in companion animal medicine. This review discusses the progression of opioid use in small animal practice providing current misconceptions and controversies in light of routes of administration. Potential targets for research and drug development and novel therapies are discussed in addition to the concepts of glial cell modulators, individual variability, and opioid tolerance and hyperalgesia. The future brings an interesting perspective with the application of pharmacogenetics and individualized pain management in canine and feline practice. © 2016 John Wiley & Sons Ltd.

Dextromethorphan attenuated inflammation and combined opioid use in humans undergoing methadone maintenance treatment.

PubMed

Chen, Shiou-Lan; Lee, Sheng-Yu; Tao, Pao-Luh; Chang, Yun-Hsuan; Chen, Shih-Heng; Chu, Chun-Hsien; Chen, Po See; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang; Hong, Jau-Shyong; Lu, Ru-Band

2012-12-01

Recent studies show that proinflammatory cytokines might be related to the development of opioid dependence (physiological, psychological, or both). In a double-blind, randomly stratified clinical trial investigating whether add-on dextromethorphan (60-120 mg/day) attenuated inflammation and the combined use of opioids in heroin-dependent patients undergoing methadone maintenance treatment, we evaluated whether inflammation is related to the progression of opioid dependence. All participants (107 heroin-dependent patients and 84 nondependent healthy controls) were recruited from National Cheng Kung University Hospital. Their plasma cytokine levels were measured to evaluate the effect of add-on dextromethorphan. Plasma TNF-α and IL-8 levels were significantly higher in long-term heroin-dependent patients than in healthy controls (p < 0.001). Chronic heroin-use-induced TNF-α and IL-8 levels were significantly (p < 0.05) attenuated in patients treated for 12 weeks with add-on dextromethorphan. Moreover, both tolerance to methadone and the combined use of opioids were significantly (p < 0.05) attenuated in patients taking dextromethorphan. We conclude that dextromethorphan might be a feasible adjuvant therapeutic for attenuating inflammation and inhibiting methadone tolerance and combined opioid use in heroin-dependent patients.

Structure-Activity Relationships of Bifunctional Cyclic Disulfide Peptides Based on Overlapping Pharmacophores at Opioid and Cholecystokinin Receptors

PubMed Central

Agnes, Richard S.; Ying, Jinfa; Kövér, Katalin E.; Lee, Yeon Sun; Davis, Peg; Ma, Shou-wu; Badghisi, Hamid; Porreca, Frank; Lai, Josephine; Hruby, Victor J.

2008-01-01

Prolonged opioid exposure increases the expression of cholecystokinin (CCK) and its receptors in the central nervous system, where CCK may attenuate the antinociceptive effects of opioids. The complex interactions between opioid and CCK may play a role in the development of opioid tolerance. We designed and synthesized cyclic disulfide peptides and determined their agonist properties at opioid receptors and antagonist properties at CCK receptors. Compound 1 (Tyr-c[D-Cys-Gly-Trp-Cys]-Asp-Phe-NH2) showed potent binding and agonist activities at δ and µ opioid receptors while displaying some binding to CCK receptors. The NMR structure of the lead compound displayed similar conformational features of opioid and CCK ligands. PMID:18502541

Delayed Ego Strength Development in Opioid Dependent Adolescents and Young Adults.

PubMed

Abramoff, Benjamin A; Lange, Hannah L H; Matson, Steven C; Cottrill, Casey B; Bridge, Jeffrey A; Abdel-Rasoul, Mahmoud; Bonny, Andrea E

2015-01-01

Objective. To evaluate ego strengths, in the context of Erikson's framework, among adolescents and young adults diagnosed with opioid dependence as compared to non-drug using youth. Methods. Opioid dependent (n = 51) and non-drug using control (n = 31) youth completed the self-administered Psychosocial Inventory of Ego Strengths (PIES). The PIES assesses development in the framework of Erikson's ego strength stages. Multivariate linear regression modeling assessed the independent association of the primary covariate (opioid dependent versus control) as well as potential confounding variables (e.g., psychiatric comorbidities, intelligence) with total PIES score. Results. Mean total PIES score was significantly lower in opioid dependent youth (231.65 ± 30.39 opioid dependent versus 270.67 ± 30.06 control; p < 0.01). Evaluation of the PIES subscores found significant (p < 0.05) delays in all ego strength areas (hope, will, purpose, competence, fidelity, love, care, and wisdom). When adjusting for potential confounders, opioid dependence remained a significant (p < 0.001) independent predictor of total PIES score. Conclusion. Adolescents with opioid dependence demonstrated significant delays in ego strength development. A treatment approach acknowledging this delay may be needed in the counseling and treatment of adolescents with opioid dependence.

Delayed Ego Strength Development in Opioid Dependent Adolescents and Young Adults

PubMed Central

Abramoff, Benjamin A.; Lange, Hannah L. H.; Matson, Steven C.; Cottrill, Casey B.; Bridge, Jeffrey A.; Abdel-Rasoul, Mahmoud; Bonny, Andrea E.

2015-01-01

Objective. To evaluate ego strengths, in the context of Erikson's framework, among adolescents and young adults diagnosed with opioid dependence as compared to non-drug using youth. Methods. Opioid dependent (n = 51) and non-drug using control (n = 31) youth completed the self-administered Psychosocial Inventory of Ego Strengths (PIES). The PIES assesses development in the framework of Erikson's ego strength stages. Multivariate linear regression modeling assessed the independent association of the primary covariate (opioid dependent versus control) as well as potential confounding variables (e.g., psychiatric comorbidities, intelligence) with total PIES score. Results. Mean total PIES score was significantly lower in opioid dependent youth (231.65 ± 30.39 opioid dependent versus 270.67 ± 30.06 control; p < 0.01). Evaluation of the PIES subscores found significant (p < 0.05) delays in all ego strength areas (hope, will, purpose, competence, fidelity, love, care, and wisdom). When adjusting for potential confounders, opioid dependence remained a significant (p < 0.001) independent predictor of total PIES score. Conclusion. Adolescents with opioid dependence demonstrated significant delays in ego strength development. A treatment approach acknowledging this delay may be needed in the counseling and treatment of adolescents with opioid dependence. PMID:26664819

The role of orexin type-1 receptors in the development of morphine tolerance in locus coeruleus neurons: An electrophysiological perspective.

PubMed

Abdollahi, Hakime; Ghaemi-Jandabi, Masoumeh; Azizi, Hossein; Semnanian, Saeed

2016-09-01

Long-term exposure to opioid agonists results in tolerance to their analgesic effects, so the effectiveness of opioid agonists in the management of pain becomes limited. The locus coeruleus (LC) nucleus has been involved in the development of tolerance to opiates. Orexin type-1 receptors (OX1Rs) are highly expressed in LC nucleus. Orexin plays a noteworthy role in the occurrence of morphine tolerance. The purpose of the present study is to investigate the role of orexin type-1 receptors in the development of morphine tolerance in LC neurons. In this study, adult male Wistar rats weighing 250-300g were utilized. Induction of morphine tolerance was obtained by single injection of morphine per day for 6 successive days. An orexin type-1 receptor antagonist (SB-334867) was injected into the lateral ventricle instantly prior to morphine injection. On day 7, the effect of morphine on the electrical activity of LC neurons was studied using in vivo extracellular single unit recording. The results demonstrate that morphine injection for 6 consecutive days led to the development of morphine-induced tolerance in LC neurons. In other words, there was a significant decrease in LC neuronal responsiveness to morphine injection. Inhibitory responses of LC neurons to intraperitoneally applied morphine can be observed with the treatment of the SB-334867 prior to morphine injection. This study showed that OX1R blockade by SB-334867 prevents the development of morphine tolerance in LC neurons. We hope that further studies will lead to considerable progress in understanding the molecular adaptations that contribute to morphine tolerance. Copyright © 2016 Elsevier B.V. All rights reserved.

Case report: efficacy and tolerability of ketamine in opioid-refractory cancer pain.

PubMed

Amin, Priya; Roeland, Eric; Atayee, Rabia

2014-09-01

A 36-year-old female with metastatic breast cancer involving bones, liver, lung, and pleura/chest wall with worsening back pain received weight-based intravenous (IV) ketamine and was transitioned to oral ketamine for cancer-related neuropathic pain. She had responded poorly to outpatient pain regimen of oxycodone sustained and immediate release, hydromorphone, gabapentin, and duloxetine (approximate 480 mg total oral morphine equivalents [OME]), reporting an initial pain score of 10/10. She was started on hydromorphone parenteral patient-controlled analgesia (PCA) bolus dose in addition to her outpatient regimen. Despite escalating doses of opioids and the addition of a lidocaine 5% patch, the patient's pain remained uncontrolled 6 days after admission. On hospital day 7, utilizing a hospital weight-based ketamine protocol, the patient was started on subanesthetic doses of ketamine at 0.2 mg/kg/h (288 mg/24 h) and titrated over 2 days to 0.4 mg/kg/h (576 mg/24 h). Then, a 3-day rotation from intravenous to oral ketamine was initiated, and the patient was discharged on ketamine oral solution, 75 mg every 8 hours. When the patient's dose was increased to 0.4 mg/kg/h, adequate pain relief was charted by the nurse within 120 minutes, "patient pain free and resting comfortably." Her pain continued to be well managed, with an average pain score of 5/10 with the ketamine continuous infusion and sustained with conversion to oral ketamine without any report of side effects. This was a 37% reduction in pain scores. With the patient's stabilized dose of ketamine, opioid requirements decreased by 61.4% (1017.5 mg reduction in total OME). The use of weight-based dosing of IV continuous infusion and transition to oral ketamine was effective and tolerable in the management of opioid-refractory, neuropathic cancer pain. It is hoped that this case report promotes a discussion regarding ketamine dosing in refractory neuropathic cancer pain.

Effectiveness and gastrointestinal tolerability during conversion and titration with once-daily OROS® hydromorphone extended release in opioid-tolerant patients with chronic low back pain

PubMed Central

Hale, Martin E; Nalamachu, Srinivas R; Khan, Arif; Kutch, Michael

2013-01-01

Purpose To describe the efficacy and safety of hydromorphone extended-release tablets (OROS hydromorphone ER) during dose conversion and titration. Patients and methods A total of 459 opioid-tolerant adults with chronic moderate to severe low back pain participated in an open-label, 2- to 4-week conversion/titration phase of a double-blind, placebo-controlled, randomized withdrawal trial, conducted at 70 centers in the United States. Patients were converted to once-daily OROS hydromorphone ER at 75% of the equianalgesic dose of their prior total daily opioid dose (5:1 conversion ratio), and titrated as frequently as every 3 days to a maximum dose of 64 mg/day. The primary outcome measure was change in pain intensity numeric rating scale; additional assessments included the Patient Global Assessment and the Roland–Morris Disability Questionnaire scores. Safety assessments were performed at each visit and consisted of recording and monitoring all adverse events (AEs) and serious AEs. Results Mean (standard deviation) final daily dose of OROS hydromorphone ER was 37.5 (17.8) mg. Mean (standard error of the mean [SEM]) numeric rating scale scores decreased from 6.6 (0.1) at screening to 4.3 (0.1) at the final titration visit (mean [SEM] change, −2.3 [0.1], representing a 34.8% reduction). Mean (SEM) change in Patient Global Assessment was −0.6 (0.1), and mean change (SEM) in the Roland–Morris Disability Questionnaire was −2.8 (0.3). Patients achieving a stable dose showed greater improvement than patients who discontinued during titration for each of these measures (P < 0.001). Almost 80% of patients achieving a stable dose (213/268) had a ≥30% reduction in pain. Commonly reported AEs were constipation (15.4%), nausea (11.9%), somnolence (8.7%), headache (7.8%), and vomiting (6.5%); 13.0% discontinued from the study due to AEs. Conclusion The majority of opioid-tolerant patients with chronic low back pain were successfully converted to effective doses of

Targeting multiple opioid receptors - improved analgesics with reduced side effects?

PubMed

Günther, Thomas; Dasgupta, Pooja; Mann, Anika; Miess, Elke; Kliewer, Andrea; Fritzwanker, Sebastian; Steinborn, Ralph; Schulz, Stefan

2017-04-05

Classical opioid analgesics, including morphine, mediate all of their desired and undesired effects by specific activation of the μ-opioid receptor (μ receptor). The use of morphine for treating chronic pain, however, is limited by the development of constipation, respiratory depression, tolerance and dependence. Analgesic effects can also be mediated through other members of the opioid receptor family such as the κ-opioid receptor (κ receptor), δ-opioid receptor (δ receptor) and the nociceptin/orphanin FQ peptide receptor (NOP receptor). Currently, a new generation of opioid analgesics is being developed that can simultaneously bind with high affinity to multiple opioid receptors. With this new action profile, it is hoped that additional analgesic effects and fewer side effects can be achieved. Recent research is mainly focused on the development of bifunctional μ/NOP receptor agonists, which has already led to novel lead structures such as the spiroindole-based cebranopadol and a compound class with a piperidin-4-yl-1,3-dihydroindol-2-one backbone (SR16835/AT-202 and SR14150/AT-200). In addition, the ornivol BU08028 is an analogue of the clinically well-established buprenorphine. Moreover, the morphinan-based nalfurafine exerts its effect with a dominant κ receptor-component and is therefore utilized in the treatment of pruritus. The very potent dihydroetorphine is a true multi-receptor opioid ligand in that it binds to μ, κ and δ receptors. The main focus of this review is to assess the paradigm of opioid ligands targeting multiple receptors with a single chemical entity. We reflect on this rationale by discussing the biological actions of particular multi-opioid receptor ligands, but not on their medicinal chemistry and design. © 2017 The British Pharmacological Society.

Functionally Selective Signaling for Morphine and Fentanyl Antinociception and Tolerance Mediated by the Rat Periaqueductal Gray

PubMed Central

Morgan, Michael M.; Reid, Rachel A.; Saville, Kimber A.

2014-01-01

Functionally selective signaling appears to contribute to the variability in mechanisms that underlie tolerance to the antinociceptive effects of opioids. The present study tested this hypothesis by examining the contribution of G protein-coupled receptor kinase (GRK)/Protein kinase C (PKC) and C-Jun N-terminal kinase (JNK) activation on both the expression and development of tolerance to morphine and fentanyl microinjected into the ventrolateral periaqueductal gray of the rat. Microinjection of morphine or fentanyl into the periaqueductal gray produced a dose-dependent increase in hot plate latency. Microinjection of the non-specific GRK/PKC inhibitor Ro 32-0432 into the periaqueductal gray to block mu-opioid receptor phosphorylation enhanced the antinociceptive effect of morphine but had no effect on fentanyl antinociception. Microinjection of the JNK inhibitor SP600125 had no effect on morphine or fentanyl antinociception, but blocked the expression of tolerance to repeated morphine microinjections. In contrast, a microinjection of Ro 32-0432 blocked the expression of fentanyl, but not morphine tolerance. Repeated microinjections of Ro 32-0432 blocked the development of morphine tolerance and inhibited fentanyl antinociception whether rats were tolerant or not. Repeated microinjections of SP600125 into the periaqueductal gray blocked the development of tolerance to both morphine and fentanyl microinjections. These data demonstrate that the signaling molecules that contribute to tolerance vary depending on the opioid and methodology used to assess tolerance (expression vs. development of tolerance). This signaling difference is especially clear for the expression of tolerance in which JNK contributes to morphine tolerance and GRK/PKC contributes to fentanyl tolerance. PMID:25503060

14-Alkoxy- and 14-acyloxypyridomorphinans: μ agonist/δ antagonist opioid analgesics with diminished tolerance and dependence side effects.

PubMed

Ananthan, Subramaniam; Saini, Surendra K; Dersch, Christina M; Xu, Heng; McGlinchey, Nicholas; Giuvelis, Denise; Bilsky, Edward J; Rothman, Richard B

2012-10-11

In the search for opioid ligands with mixed functional activity, a series of 5'-(4-chlorophenyl)-4,5α-epoxypyridomorphinans possessing alkoxy or acyloxy groups at C-14 was synthesized and evaluated. In this series, the affinity and functional activity of the ligands were found to be influenced by the nature of the substituent at C-14 as well as by the substituent at N-17. Whereas the incorporation of a 3-phenylpropoxy group at C-14 on N-methylpyridomorhinan gave a dual MOR agonist/DOR agonist 17h, its incorporation on N-cyclopropylmethylpyridomorphinan gave a MOR agonist/DOR antagonist 17d. Interestingly, 17d, in contrast to 17h, did not produce tolerance or dependence effects upon prolonged treatment in cells expressing MOR and DOR. Moreover, 17d displayed greatly diminished analgesic tolerance as compared to morphine upon repeated administration, thus supporting the hypothesis that ligands with MOR agonist/DOR antagonist functional activity could emerge as novel analgesics devoid of tolerance, dependence, and related side effects.

Hot Topics in Primary Care: Management of Opioid-induced Constipation.

PubMed

Johnson, David A; Argoff, Charles E

2015-12-01

Constipation is a common complication of opioid therapy that contributes to substantial patient morbidity, decreased productivity, and opioid nonadherence. Other causes of constipation may occur concomitantly and should be investigated. Although evidence supporting their use is limited, the use of fiber, water, laxatives, and/or exercise is recommended in current guidelines as initial management. Peripherally acting μ-opioid receptor antagonists are important treatment options, are well-tolerated, and improve many signs and symptoms of OIC in patients taking an opioid for chronic noncancer pain.

Olea Europea-derived phenolic products attenuate antinociceptive morphine tolerance: an innovative strategic approach to treat cancer pain.

PubMed

Muscoli, C; Lauro, F; Dagostino, C; D'Agostino, C; Ilari, S; Giancotti, L A; Gliozzi, M; Costa, N; Carresi, C; Musolino, V; Casale, F; Ventrice, D; Oliverio, M; Oliverio, E; Palma, E; Nisticò, S; Nistico', S; Procopio, A; Rizzo, M; Mollace, V

2014-01-01

Morphine and related opioid drugs are currently the major drugs for severe pain. Their clinical utility is limited in the management of severe cancer pain due to the rapid development of tolerance. Restoring opioid efficacy is therefore of great clinical importance. A great body of evidence suggests the key role of free radicals and posttranslational modulation in the development of tolerance to the analgesic activity of morphine. Epidemiological studies have shown a relationship between the Mediterranean diet and a reduced incidence of pathologies such as coronary heart disease and cancer. A central hallmark of this diet is the high consumption of virgin olive oil as the main source of fat which contains antioxidant components in the non-saponifiable fraction, including phenolic compounds absent in seed oils. Here, we show that in a rodent model of opiate tolerance, removal of the free radicals with phenolic compounds of olive oil such as hydroxytyrosol and oleuropein reinstates the analgesic action of morphine. Chronic injection of morphine in mice led to the development of tolerance and this was associated with increased nitrotyrosin and malondialdehyde (MDA) formation together with nitration and deactivation of MnSOD in the spinal cord. Removal of free radicals by hydroxytyrosol and oleuropein blocked morphine tolerance by inhibiting nitration and MDA formation and replacing the MnSOD activity. The phenolic fraction of virgin olive oil exerts antioxidant activities in vivo and free radicals generation occurring during chronic morphine administration play a crucial role in the development of opioid tolerance. Our data suggest novel therapeutic approach in the management of chronic cancer pain, in particular for those patients who require long-term opioid treatment for pain relief without development of tolerance.

Development of concepts on the interaction of drugs with opioid receptors

NASA Astrophysics Data System (ADS)

Kuzmina, N. E.; Kuzmin, V. S.

2011-02-01

The development of concepts on the molecular mechanisms of the action of medicinal drugs on the opioid receptors is briefly surveyed. The modern point of view on the mechanism of activation of opioid receptors is given based on the data from chimeric and site-directed mutagenesis of the cloned opioid receptors and the computer-aided simulations of the reception zone and ligand-receptor complexes. Three-dimensional models of the opioid pharmacophore derived by both conventional methods and a comparative analysis of molecular fields are described in detail.

Methylnaltrexone mechanisms of action and effects on opioid bowel dysfunction and other opioid adverse effects.

PubMed

Yuan, Chun-Su

2007-06-01

To review the mechanisms of action of methylnaltrexone and its effects on opioid bowel dysfunction, as well as its effects on other opioid-induced adverse effects (ADEs), and its potential roles in clinical practice. A literature search using the MEDLINE and Cochrane Collaboration databases for articles published between 1966 and March 2007 was performed. Additional data sources were obtained from manual searches of recent journal articles, book chapters, and monographs. An updated literature search showed no additional publications. Abstracts and original preclinical and clinical research reports published in the English language were identified for review. Review articles, commentaries, and news reports of this compound were excluded. Literature related to opioids, opioid receptors, opioid antagonists, methylnaltrexone, opioid-induced bowel dysfunction, constipation, nausea, and vomiting was evaluated and selected based on consideration of the support shown for the proof of concept, mechanistic findings, and timeliness. Fifty-eight original articles from preclinical studies and clinical trials using methylnaltrexone were identified. Pharmacologic action, benefits, and ADEs of methylnaltrexone were reviewed, with a focus on its effects on bowel dysfunction after opioids. Emphases were placed on its receptor binding activities and therapeutically relevant sites of action (peripheral vs central), in which peripheral opioid receptors in the body contribute to physiological and drug-induced effects. Morphine and related opioids are associated with a number of limiting ADEs, including opioid-induced bowel dysfunction. Methylnaltrexone, a quaternary derivative of naltrexone, blocks peripheral effects of opioids while sparing central analgesic effects. It is currently under late-stage clinical investigation for the treatment of opioid-induced constipation in patients with advanced illness. Reported results showed the drug to be generally well-tolerated. The rapid

Recent Advances in the Realm of Allosteric Modulators for Opioid Receptors for Future Therapeutics.

PubMed

Remesic, Michael; Hruby, Victor J; Porreca, Frank; Lee, Yeon Sun

2017-06-21

Opioids, and more specifically μ-opioid receptor (MOR) agonists such as morphine, have long been clinically used as therapeutics for severe pain states but often come with serious side effects such as addiction and tolerance. Many studies have focused on bringing about analgesia from the MOR with attenuated side effects, but its underlying mechanism is not fully understood. Recently, focus has been geared toward the design and elucidation of the orthosteric site with ligands of various biological profiles and mixed subtype opioid activities and selectivities, but targeting the allosteric site is an area of increasing interest. It has been shown that allosteric modulators play key roles in influencing receptor function such as its tolerance to a ligand and affect downstream pathways. There has been a high variance of chemical structures that provide allosteric modulation at a given receptor, but recent studies and reviews tend to focus on the altered cellular mechanisms instead of providing a more rigorous description of the allosteric ligand's structure-function relationship. In this review, we aim to explore recent developments in the structural motifs that potentiate orthosteric binding and their influences on cellular pathways in an effort to present novel approaches to opioid therapeutic design.

Exploring the latent trait of Opioid Use Disorder criteria among frequent nonmedical prescription opioid users

PubMed Central

Castaldelli-Maia, João Mauricio; Andrade, Laura H.; Keyes, Katherine M.; Cerdá, Magdalena; Pilowsky, Daniel J.; Martins, Silvia S.

2016-01-01

Background There is a need to explore the dimensional and categorical phenotypes of criteria of opioid use disorder among frequent nonmedical users of prescription opioids (NMUPO) users. Methods We used pooled data of 2011–2012 National Survey on Drug Use and Health to examine reliability and phenotypic variability in the diagnosis of OUD secondary to NMUPO in a nationally-representative sample of 18+ years-old frequent past-year NMUPO users (120+ days, n=806). Through exploratory factor analysis (EFA) and latent class analysis (LCA), we examined 10 past-year OUD criteria. We examined associations between the latent classes and sociodemographic/psychiatric/NMUPO correlates. Results OUD criteria were unidimensional, and a three-class model was the overall best fitting solution for characterizing individuals into phenotypes along this unidimensional continuum: a “non-symptomatic class” (40.7%), “Tolerance-Time spent class” (29.0%) with high probability of endorsing Tolerance/Time Spent criteria, and a “High-moderate symptomatic class” (30.1%). The last class was significantly associated with being male, having insurance and obtaining prescription opioids (PO) nonmedically via “doctor shopping” as compared to the non-symptomatic class. “Tolerance-Time spent class” was significantly associated with being younger (18–25 years) and obtaining PO nonmedically from family/friends as compared to the non-symptomatic class. Conclusion This study revealed the different characteristics and routes of access to PO of different classes of frequent NMUPO users. It is possible that these groups may respond to different interventions, however such conclusions would require a clinical study. PMID:27302873

Acute stimulation of brain mu opioid receptors inhibits glucose-stimulated insulin secretion via sympathetic innervation.

PubMed

Tudurí, Eva; Beiroa, Daniel; Stegbauer, Johannes; Fernø, Johan; López, Miguel; Diéguez, Carlos; Nogueiras, Rubén

2016-11-01

Pancreatic insulin-secreting β-cells express opioid receptors, whose activation by opioid peptides modulates hormone secretion. Opioid receptors are also expressed in multiple brain regions including the hypothalamus, where they play a role in feeding behavior and energy homeostasis, but their potential role in central regulation of glucose metabolism is unknown. Here, we investigate whether central opioid receptors participate in the regulation of insulin secretion and glucose homeostasis in vivo. C57BL/6J mice were acutely treated by intracerebroventricular (i.c.v.) injection with specific agonists for the three main opioid receptors, kappa (KOR), delta (DOR) and mu (MOR) opioid receptors: activation of KOR and DOR did not alter glucose tolerance, whereas activation of brain MOR with the specific agonist DAMGO blunted glucose-stimulated insulin secretion (GSIS), reduced insulin sensitivity, increased the expression of gluconeogenic genes in the liver and, consequently, impaired glucose tolerance. Pharmacological blockade of α2A-adrenergic receptors prevented DAMGO-induced glucose intolerance and gluconeogenesis. Accordingly, DAMGO failed to inhibit GSIS and to impair glucose tolerance in α2A-adrenoceptor knockout mice, indicating that the effects of central MOR activation on β-cells are mediated via sympathetic innervation. Our results show for the first time a new role of the central opioid system, specifically the MOR, in the regulation of insulin secretion and glucose metabolism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Current Research on Opioid Receptor Function

PubMed Central

Feng, Yuan; He, Xiaozhou; Yang, Yilin; Chao, Dongman; Lazarus, Lawrence H.; Xia, Ying

2012-01-01

The use of opioid analgesics has a long history in clinical settings, although the comprehensive action of opioid receptors is still less understood. Nonetheless, recent studies have generated fresh insights into opioid receptor-mediated functions and their underlying mechanisms. Three major opioid receptors (μ-opioid receptor, MOR; δ-opioid receptor, DOR; and κ-opioid receptor, KOR) have been cloned in many species. Each opioid receptor is functionally sub-classified into several pharmacological subtypes, although, specific gene corresponding each of these receptor subtypes is still unidentified as only a single gene has been isolated for each opioid receptor. In addition to pain modulation and addiction, opioid receptors are widely involved in various physiological and pathophysiological activities, including the regulation of membrane ionic homeostasis, cell proliferation, emotional response, epileptic seizures, immune function, feeding, obesity, respiratory and cardiovascular control as well as some neurodegenerative disorders. In some species, they play an essential role in hibernation. One of the most exciting findings of the past decade is the opioid-receptor, especially DOR, mediated neuroprotection and cardioprotection. The up-regulation of DOR expression and DOR activation increase the neuronal tolerance to hypoxic/ischemic stress. The DOR signal triggers (depending on stress duration and severity) different mechanisms at multiple levels to preserve neuronal survival, including the stabilization of homeostasis and increased pro-survival signaling (e.g., PKC-ERK-Bcl 2) and anti-oxidative capacity. In the heart, PKC and KATP channels are involved in the opioid receptor-mediated cardioprotection. The DOR-mediated neuroprotection and cardioprotection have the potential to significantly alter the clinical pharmacology in terms of prevention and treatment of life-threatening conditions like stroke and myocardial infarction. The main purpose of this article

14-Alkoxy- and 14-Acyloxypyridomorphinans: Mu Agonist/Delta Antagonist Opioid Analgesics with Diminished Tolerance and Dependence Side Effects

PubMed Central

Ananthan, Subramaniam; Saini, Surendra K.; Dersch, Christina M.; Xu, Heng; McGlinchey, Nicholas; Giuvelis, Denise; Bilsky, Edward J.; Rothman, Richard B.

2012-01-01

In the search for opioid ligands with mixed functional activity, a series of 5′-(4-chlorophenyl)-4,5α-epoxypyridomorphinans possessing alkoxy or acyloxy groups at C-14 was synthesized and evaluated. In this series, the affinity and functional activity of the ligands were found to be influenced by the nature of the substituent at C-14 as well as by the substituent at N-17. Whereas the incorporation of a 3-phenylpropoxy group at C-14 on N-methylpyridomorhinan gave a dual MOR agonist/DOR agonist 17h its incorporation on N-cyclopropylmethylpyridomorphinan gave a MOR agonist/DOR antagonist 17d. Interestingly, 17d, in contrast to 17h, did not produce tolerance or dependence effects on prolonged treatment in cells expressing MOR and DOR. Moreover, 17d displayed greatly diminished analgesic tolerance as compared to morphine on repeated administration, thus supporting the hypothesis that ligands with MOR agonist/DOR antagonist functional activity could emerge as novel analgesics devoid of tolerance, dependence and related side effects. PMID:23016952

Development and validation of an Opioid Attractiveness Scale: a novel measure of the attractiveness of opioid products to potential abusers

PubMed Central

Butler, Stephen F; Benoit, Christine; Budman, Simon H; Fernandez, Kathrine C; McCormick, Cynthia; Venuti, Synne Wing; Katz, Nathaniel

2006-01-01

Background The growing trends in opioid abuse, assessment of the abuse liability of prescription opioid products, and growing efforts by the pharmaceutical industry to develop 'abuse-resistant' formulations highlight a need to understand the features that make one product more 'attractive' than another to potential abusers. We developed a scale to measure the 'attractiveness' of prescription opioids to potential abusers, and used the scale to measure the relative attractiveness of 14 opioid analgesic products. Methods First, the concept of attractiveness was empirically defined with a group of prescription opioid abusers and experts in opioid abuse using a process called Concept Mapping. Abuse liability consisted of two components: factors intrinsic to the drug formulation (e.g., speed of onset, duration) and factors extrinsic to drug formulation (e.g., availability, availability of alternatives, cost). A 17-item Opioid Attractiveness Scale (OAS) was constructed, focusing on factors intrinsic to the drug product. Results A total of 144 individuals participated in tests of validity and reliability. Internal consistency was excellent (Cronbach's α = 0.85–0.94). Drug rankings based on OAS scores achieved good inter-rater agreement (Kendall's W 0.37, p < 0.001). Agreement on drug OAS scores between the developmental sample and a confirmation sample was good (IntraClass Correlations [ICC] of 0.65–0.69). Global ratings of overall attractiveness of the 14 selected opioid products by substance abuse counselors corresponded with the rankings based on OAS ratings of the abuser group. Finally, substance abuse counselors completed the OAS, yielding a high level of correspondence with ratings by the abuser group (ICC = 0.83, p = 0.002). The OAS differentiated attractiveness among 14 selected pharmaceutical opioid products. OxyContin, Dilaudid, and Percocet were ranked highest (most attractive); Talwin NX and Duragesic were ranked lowest (least attractive). Conclusion An

Development and validation of an Opioid Attractiveness Scale: a novel measure of the attractiveness of opioid products to potential abusers.

PubMed

Butler, Stephen F; Benoit, Christine; Budman, Simon H; Fernandez, Kathrine C; McCormick, Cynthia; Venuti, Synne Wing; Katz, Nathaniel

2006-02-02

The growing trends in opioid abuse, assessment of the abuse liability of prescription opioid products, and growing efforts by the pharmaceutical industry to develop 'abuse-resistant' formulations highlight a need to understand the features that make one product more 'attractive' than another to potential abusers. We developed a scale to measure the 'attractiveness' of prescription opioids to potential abusers, and used the scale to measure the relative attractiveness of 14 opioid analgesic products. First, the concept of attractiveness was empirically defined with a group of prescription opioid abusers and experts in opioid abuse using a process called Concept Mapping. Abuse liability consisted of two components: factors intrinsic to the drug formulation (e.g., speed of onset, duration) and factors extrinsic to drug formulation (e.g., availability, availability of alternatives, cost). A 17-item Opioid Attractiveness Scale (OAS) was constructed, focusing on factors intrinsic to the drug product. A total of 144 individuals participated in tests of validity and reliability. Internal consistency was excellent (Cronbach's alpha = 0.85-0.94). Drug rankings based on OAS scores achieved good inter-rater agreement (Kendall's W 0.37, p < 0.001). Agreement on drug OAS scores between the developmental sample and a confirmation sample was good (IntraClass Correlations [ICC] of 0.65-0.69). Global ratings of overall attractiveness of the 14 selected opioid products by substance abuse counselors corresponded with the rankings based on OAS ratings of the abuser group. Finally, substance abuse counselors completed the OAS, yielding a high level of correspondence with ratings by the abuser group (ICC = 0.83, p = 0.002). The OAS differentiated attractiveness among 14 selected pharmaceutical opioid products. OxyContin, Dilaudid, and Percocet were ranked highest (most attractive); Talwin NX and Duragesic were ranked lowest (least attractive). An initial examination of the psychometric

Pregabalin role in inhibition of morphine analgesic tolerance and physical dependency in rats.

PubMed

Hasanein, Parisa; Shakeri, Saeed

2014-11-05

Pregabalin is recently proposed as analgesic or adjuvant in pain management. While previous preclinical investigations have evaluated pregabalin-opioid interactions, the effect of pregabalin on opioid tolerance and dependency has not yet been studied. Here we evaluated the effects of different doses of pregabalin (50, 100 and 200mg/kg, s.c.) on morphine-induced tolerance and dependency in rats. Adult male Wistar rats were rendered tolerant to analgesic effect of morphine by injection of morphine (10mg/kg, s.c.) twice daily for 7 days. To develop morphine dependence, rats were given escalating doses of morphine. To determine the effect of pregabalin on the development of morphine tolerance and dependence, different doses of pregabalin were administrated before morphine. The tail-flick and naloxone precipitation withdrawal tests were used to evaluate the degree of tolerance and dependence, respectively. Chronic morphine-injected rats showed significant decrements in the percentage maximum possible effect (%MPE) of morphine on the days 5 and 7 (32.5%±3.5, 21.5%±4, respectively) compared to the first day (100%) which showed morphine tolerance. Pregabalin 200mg/kg completely prevented the development of morphine tolerance. In addition, concomitant treatment of morphine with pregabalin attenuated almost all of the naloxone-induced withdrawal signs which include weight loss, jumping, penis licking, teeth chattering, wet dog shakes, rearing, standing, sniffing, face grooming and paw tremor. These data show that pregabaline has a potential anti-tolerant/anti-dependence property against chronic usage of morphine. Therefore, pregabalin appears to be a promising candidate for the treatment of opioid addiction after confirming by future clinical studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Rational use of opioids.

PubMed

Mastronardi, P; Cafiero, T

2001-04-01

The role of analgesia and sedation in intensive care units (ICU) is ancillary to other intensive care strategies, nevertheless they permit that every other diagnostic and therapeutic procedure is safely performed by keeping the patient pain-free, anxiety-free and cooperative. Commonly used opioids in ICU include morphine, fentanyl, sufentanil and remifentanil. The choice among opioid drugs relies on their pharmacokinetics and their pharmacodynamic effects. Cardiovascular stability observed with fentanyl and sufentanil indicates their use in hemodynamically compromised patients. Short-acting remifentanil offers several advantages in patients requiring prolonged infusions. The organ-independent metabolism of this newer molecule may be valuable in patients with multiple organ failure. The main indications for opioid analgesia and sedation in ICU include: 1) Anxiety, pain and agitation: in turn, they can increase cardiac workload, myocardial oxygen consumption and rate of dysarrhythmias; 2) immediate postoperative period after major surgery; 3) short-term invasive procedures. Potential advantages offered by opioids in the ICU setting also include: a) Cardiac protection: in animal models, it has been observed that delta-opiate receptor stimulation confers a preconditioning-like protective effects against myocardial ischemia; b) Neuroprotection: recent studies suggest that mu- and kappa-opiate receptors are involved in ischemic preconditioning against seizures in the brain. During opioid therapy in the ICU, drug tolerance and withdrawal symptoms should be anticipated and the dose adjusted accordingly.

Cancer pain in the opioid-addicted patient: can we treat it right?

PubMed

Modesto-Lowe, Vania; Girard, Lisa; Chaplin, Margaret

2012-01-01

Although cancer elicits an array of physical and emotional symptoms, pain is often identified as the most distressing. Cancer pain may result from the primary tumor, metastasis, surgery, radiation, chemotherapy, or medical comorbidities. Although treatment with opioid analgesics is accepted as appropriate therapy for cancer-related pain, under treatment may persist among certain patients. Opioid-addicted individuals represent a challenging and heterogeneous population to treat. Addiction is linked to psychopathology and antisocial behaviors (eg, lying) which often complicate evaluation. Chronic exposure to opioids may lead to physiologic dependence and its correlates, tolerance and hyperalgesia. Given the variability and subjectivity of the cancer pain experience, there are no objective measures which capture the adequacy of pain control. Thus, when faced with complaints of uncontrolled pain, clinicians must consider a differential diagnosis of tolerance, disease progression, addiction, pseudoaddiction, chemical coping, or even criminal behavior. This article explores the cognitive, behavioral, and physiological correlates of opioid addiction that may impact cancer pain management. It also discusses risk reduction strategies for opioid misuse and research directions that may lead to improved clinical outcomes in these patients.

Simultaneous determination of 18 abused opioids and metabolites in human hair using LC-MS/MS and illegal opioids abuse proven by hair analysis.

PubMed

Kim, Jihyun; Ji, Dajeong; Kang, Soyoung; Park, Meejung; Yang, Wonkyung; Kim, Eunmi; Choi, Hwakyung; Lee, Sooyeun

2014-02-01

Natural and synthetic opioids have efficient analgesic activity but can also be addictive. Thus, the determination of opioids and their metabolites in biological specimens is of interest in clinical and forensic toxicology laboratories. The analysis of drugs in hair provides valuable information on previous chronic drug use and has been successfully applied to the diagnosis of drug abuse, tolerance, compliance and gestational drug exposure. Despite the abuse of prescription opioids along with heroin and other illegal opiates, few studies have been conducted on the simultaneous determination of the broad range of opioids covering those drugs in hair. In the present study, an analytical method for the simultaneous detection in hair of 18 opioids and metabolites considered to have a high abuse risk based on the results of urine drug screening was established and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the purpose of clinical and forensic applications. The drugs and metabolites were extracted from hair using methanol and analyzed using LC-MS/MS. The validation results proved that the method was selective, accurate and precise with acceptable linearity within calibration ranges. No significant variation was observed by different sources of matrices. The limits of detection and the limits of quantification ranged from 0.05 to 0.25ng/10mg hair and from 0.05 to 0.5ng/10mg hair, respectively. The developed method was successfully applied to 15 hair samples from opioids users. This method will be very useful for monitoring the inappropriate use of opioid drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

Novel Molecular Strategies and Targets for Opioid Drug Discovery for the Treatment of Chronic Pain

PubMed Central

Olson, Keith M.; Lei, Wei; Keresztes, Attila; LaVigne, Justin; Streicher, John M.

2017-01-01

Opioid drugs like morphine and fentanyl are the gold standard for treating moderate to severe acute and chronic pain. However, opioid drug use can be limited by serious side effects, including constipation, tolerance, respiratory suppression, and addiction. For more than 100 years, we have tried to develop opioids that decrease or eliminate these liabilities, with little success. Recent advances in understanding opioid receptor signal transduction have suggested new possibilities to activate the opioid receptors to cause analgesia, while reducing or eliminating unwanted side effects. These new approaches include designing functionally selective ligands, which activate desired signaling cascades while avoiding signaling cascades that are thought to provoke side effects. It may also be possible to directly modulate downstream signaling through the use of selective activators and inhibitors. Separate from downstream signal transduction, it has also been found that when the opioid system is stimulated, various negative feedback systems are upregulated to compensate, which can drive side effects. This has led to the development of multi-functional molecules that simultaneously activate the opioid receptor while blocking various negative feedback receptor systems including cholecystokinin and neurokinin-1. Other novel approaches include targeting heterodimers of the opioid and other receptor systems which may drive side effects, and making endogenous opioid peptides druggable, which may also reduce opioid mediated side effects. Taken together, these advances in our molecular understanding provide a path forward to break the barrier in producing an opioid with reduced or eliminated side effects, especially addiction, which may provide relief for millions of patients. PMID:28356897

Development and validation of the Current Opioid Misuse Measure.

PubMed

Butler, Stephen F; Budman, Simon H; Fernandez, Kathrine C; Houle, Brian; Benoit, Christine; Katz, Nathaniel; Jamison, Robert N

2007-07-01

Clinicians recognize the importance of monitoring aberrant medication-related behaviors of chronic pain patients while being prescribed opioid therapy. The purpose of this study was to develop and validate the Current Opioid Misuse Measure (COMM) for those pain patients already on long-term opioid therapy. An initial pool of 177 items was developed with input from 26 pain management and addiction specialists. Concept mapping identified six primary concepts underlying medication misuse, which were used to develop an initial item pool. Twenty-two pain and addiction specialists rated the items on importance and relevance, resulting in selection of a 40-item alpha COMM. Final item selection was based on empirical evaluation of items with patients taking opioids for chronic, noncancer pain (N=227). One-week test-retest reliability was examined with 55 participants. All participants were administered the alpha version of the COMM, the Prescription Drug Use Questionnaire (PDUQ) interview, and submitted a urine sample for toxicology screening. Physician ratings of patient aberrant behaviors were also obtained. Of the 40 items, 17 items appeared to adequately measure aberrant behavior, demonstrating excellent internal consistency and test-retest reliability. Cutoff scores were examined using ROC curve analysis and reasonable sensitivity and specificity were established. To evaluate the COMM's ability to capture change in patient status, it was tested on a subset of patients (N=86) that were followed and reassessed three months later. The COMM was found to have promise as a brief, self-report measure of current aberrant drug-related behavior. Further cross-validation and replication of these preliminary results is pending.

Synthesis and evaluation of 4-substituted piperidines and piperazines as balanced affinity μ opioid receptor (MOR) agonist/δ opioid receptor (DOR) antagonist ligands.

PubMed

Bender, Aaron M; Clark, Mary J; Agius, Michael P; Traynor, John R; Mosberg, Henry I

2014-01-15

In this letter, we describe a series of 4-substituted piperidine and piperazine compounds based on tetrahydroquinoline 1, a compound that shows balanced, low nanomolar binding affinity for the mu opioid receptor (MOR) and the delta opioid receptor (DOR). We have shown that by changing the length and flexibility profile of the side chain in this position, binding affinity is improved at both receptors by a significant degree. Furthermore, several of the compounds described herein display good efficacy at MOR, while simultaneously displaying DOR antagonism. The MOR agonist/DOR antagonist has shown promise in the reduction of negative side effects displayed by selective MOR agonists, namely the development of dependence and tolerance. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Magnesium enhances opioid-induced analgesia - What we have learnt in the past decades?

PubMed

Bujalska-Zadrożny, Magdalena; Tatarkiewicz, Jan; Kulik, Kamila; Filip, Małgorzata; Naruszewicz, Marek

2017-03-01

Opioids are increasingly used in alleviating pain, including cancer-related pain and postoperative pain. Unfortunately, the development of tolerance, the resistance of neuropathic pain on opioid analgesia or other undesirable effects may limit their utility. In order to reduce opioid doses, and thereby to avoid the risk of side effects and sudden deaths due to overdosing, attempts have been made to introduce co-analgesics. Due to an increasing amount of data concerning a potential enhance of opioid analgesia by the physiological antagonist of N-methyl-d-aspartate receptors, magnesium ions (Mg 2+ ), a concomitant use of such a combination seems to be interesting from a clinical point of view. Therefore, the aim of this review is to provide an analysis of existing preclinical and clinical studies in the context of the benefits of using this combination in clinical practice. A potential mechanism of magnesium - opioid interaction is also suggested. The potential influence of Mg on opioid adverse/side effects as well as conclusions on the safety of combined administration of magnesium and opioid drugs were also summarized. Data from animal studies indicate that magnesium increases opioid analgesia in chronic (e.g., neuropathic, inflammatory) as well as acute pain. In clinical trials, most authors confirmed that magnesium reduces opioid consumption and alleviates postoperative pain scores while not increasing the risk of side effects after opioids. However, more clinical studies are needed concerning an influence of Mg on opioid activity in other difficult to treat types of pain, especially neuropathic and inflammatory. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent advances in the development of 14-alkoxy substituted morphinans as potent and safer opioid analgesics.

PubMed

Spetea, M; Schmidhammer, H

2012-01-01

Morphine and other opioid morphinans produce analgesia primarily through μ opioid receptors (MORs), which mediate beneficial but also non-beneficial actions. There is a continued search for efficacious opioid analgesics with reduced complications. The cornerstone in the development of 14-alkoxymorphinans as novel analgesic drugs was the synthesis of the highly potent MOR agonist 14-O-methyloxymorphone. This opioid showed high antinociceptive potency but also the adverse effects associated with morphine type compounds. Further developments represent the introduction of a methyl and benzyl group at position 5 of 14-O-methyloxymorphone leading to the strong opioid analgesics 14-methoxymetopon and its 5-benzyl analogue, which exhibited less pronounced side effects than morphine although interacting selectively with MORs. Introduction of arylalkyl substituents such as phenylpropoxy in position 14 led to a series of extremely potent antinociceptive agents with enhanced affinities at all three opioid receptor types. During the past years, medicinal chemistry and opioid research focused increasingly on exploring the therapeutic potential of peripheral opioid receptors by peripheralization of opioids in order to minimize the occurrence of centrally-mediated side effects. Strategies to reduce penetration to the central nervous system (CNS) include chemical modifications that increase hydrophilicity. Zwitterionic 6-amino acid conjugates of 14-Oalkyloxymorphones were developed in an effort to obtain opioid agonists that have limited access to the CNS. These compounds show high antinociceptive potency by interacting with peripheral MORs. Opioid drugs with peripheral site of action represent an important target for the treatment of severe and chronic pain without the adverse actions of centrally acting opioids.

Prospects for Creation of Cardioprotective and Antiarrhythmic Drugs Based on Opioid Receptor Agonists

PubMed Central

Maslov, Leonid N; Oeltgen, Peter R.; Naryzhnaya, Natalia V.; Pei, Jian‐Ming; Brown, Stephen A.; Lishmanov, Yury B.; Downey, James M.

2016-01-01

Abstract It has now been demonstrated that the μ, δ1, δ2, and κ1 opioid receptor (OR) agonists represent the most promising group of opioids for the creation of drugs enhancing cardiac tolerance to the detrimental effects of ischemia/reperfusion (I/R). Opioids are able to prevent necrosis and apoptosis of cardiomyocytes during I/R and improve cardiac contractility in the reperfusion period. The OR agonists exert an infarct‐reducing effect with prophylactic administration and prevent reperfusion‐induced cardiomyocyte death when ischemic injury of heart has already occurred; that is, opioids can mimic preconditioning and postconditioning phenomena. Furthermore, opioids are also effective in preventing ischemia‐induced arrhythmias. PMID:27197922

Reduction of opioid withdrawal and potentiation of acute opioid analgesia by systemic AV411 (ibudilast)

PubMed Central

Hutchinson, Mark R.; Lewis, Susannah S.; Coats, Benjamen D.; Skyba, David A.; Crysdale, Nicole Y.; Berkelhammer, Debra L.; Brzeski, Anita; Northcutt, Alexis; Vietz, Christine M.; Judd, Charles M.; Maier, Steven F.; Watkins, Linda R.; Johnson, Kirk W.

2009-01-01

Morphine-induced glial proinflammatory responses have been documented to contribute to tolerance to opioid analgesia. Here, we examined whether drugs previously shown to suppress glial proinflammatory responses can alter other clinically relevant opioid effects; namely, withdrawal or acute analgesia. AV411 (ibudilast) and minocycline, drugs with distinct mechanisms of action that result in attenuation of glial proinflammatory responses, each reduced naloxone-precipitated withdrawal. Analysis of brain nuclei associated with opioid withdrawal revealed that morphine altered expression of glial activation markers, cytokines, chemokines, and a neurotrophic factor. AV411 attenuated many of these morphine-induced effects. AV411 also protected against spontaneous withdrawal-induced hyperactivity and weight loss recorded across a 12-day timecourse. Notably, in the spontaneous withdrawal study, AV411 treatment was delayed relative to the start of the morphine regimen so to also test whether AV411 could still be effective in the face of established morphine dependence, which it was. AV411 did not simply attenuate all opioid effects, as co-administering AV411 with morphine or oxycodone caused 3-to-5-fold increases in acute analgesic potency, as revealed by leftward shifts in the analgesic dose response curves. Timecourse analyses revealed that plasma morphine levels were not altered by AV411, suggestive that potentiated analgesia was not simply due to prolongation of morphine exposure or increased plasma concentrations. These data support and extend similar potentiation of acute opioid analgesia by minocycline, again providing converging lines of evidence of glial involvement. Hence, suppression of glial proinflammatory responses can significantly reduce opioid withdrawal, whilst improving analgesia. PMID:18938237

Combined Interactions with I1-, I2-Imidazoline Binding Sites and α2-Adrenoceptors To Manage Opioid Addiction

PubMed Central

2016-01-01

Tolerance and dependence associated with chronic opioid exposure result from molecular, cellular, and neural network adaptations. Such adaptations concern opioid and nonopioid systems, including α2-adrenoceptors (α2-ARs) and I1- and I2-imidazoline binding sites (IBS). Agmatine, one of the hypothesized endogenous ligands of IBS, targeting several systems including α2-ARs and IBS, proved to be able to regulate opioid-induced analgesia and to attenuate the development of tolerance and dependence. Interested in the complex pharmacological profile of agmatine and considering the nature of its targets, we evaluated two series of imidazolines, rationally designed to simultaneously interact with I1-/I2-IBS or I1-/I2-IBS/α2-ARs. The compounds showing the highest affinities for I1-/I2-IBS or I1-/I2-IBS/α2-ARs have been selected for their in vivo evaluation on opiate withdrawal syndrome. Interestingly, 9, displaying I1-/I2-IBS/α2-ARs interaction profile, appears more effective in reducing expression and acquisition of morphine dependence and, therefore, might be considered a promising tool in managing opioid addiction. PMID:27774136

Opioids and Opioid Maintenance Therapies: Their Impact on Monocyte-Mediated HIV Neuropathogenesis

PubMed Central

Jaureguiberry-Bravo, Matias; Wilson, Rebecca; Carvallo, Loreto; Berman, Joan W.

2017-01-01

Background HIV-1 enters the CNS within two weeks after peripheral infection and results in chronic neuroinflammation that leads to HIV associated neurocognitive disorders (HAND) in more than 50% of infected people. HIV enters the CNS by transmigration of infected monocytes across the blood brain barrier. Intravenous drug abuse is a major risk factor for HIV-1 infection, and opioids have been shown to alter the progression and severity of HAND. Methadone and buprenorphine are opioid derivates that are used as opioid maintenance therapies. They are commonly used to treat opioid dependency in HIV infected substance abusers, but their effects on monocyte migration relevant to the development of cognitive impairment are not well characterized. Conclusion Here, we will discuss the effects of opioids and opioid maintenance therapies on the inflammatory functions of monocytes and macrophages that are related to the development of neuroinflammation in the context of HIV infection. PMID:27009099

Fast Modulation of μ-Opioid Receptor (MOR) Recycling Is Mediated by Receptor Agonists*

PubMed Central

Roman-Vendrell, Cristina; Yu, Y. Joy; Yudowski, Guillermo Ariel

2012-01-01

The μ-opioid receptor (MOR) is a member of the G protein-coupled receptor family and the main target of endogenous opioid neuropeptides and morphine. Upon activation by ligands, MORs are rapidly internalized via clathrin-coated pits in heterologous cells and dissociated striatal neurons. After initial endocytosis, resensitized receptors recycle back to the cell surface by vesicular delivery for subsequent cycles of activation. MOR trafficking has been linked to opioid tolerance after acute exposure to agonist, but it is also involved in the resensitization process. Several studies describe the regulation and mechanism of MOR endocytosis, but little is known about the recycling of resensitized receptors to the cell surface. To study this process, we induced internalization of MOR with [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO) and morphine and imaged in real time single vesicles recycling receptors to the cell surface. We determined single vesicle recycling kinetics and the number of receptors contained in them. Then we demonstrated that rapid vesicular delivery of recycling MORs to the cell surface was mediated by the actin-microtubule cytoskeleton. Recycling was also dependent on Rab4, Rab11, and the Ca2+-sensitive motor protein myosin Vb. Finally, we showed that recycling is acutely modulated by the presence of agonists and the levels of cAMP. Our work identifies a novel trafficking mechanism that increases the number of cell surface MORs during acute agonist exposure, effectively reducing the development of opioid tolerance. PMID:22378794

Effect of Bacopasides on acquisition and expression of morphine tolerance.

PubMed

Rauf, Khalid; Subhan, Fazal; Abbas, Muzaffar; Badshah, Amir; Ullah, Ihsan; Ullah, Sami

2011-07-15

Opioids are extensively used for the management of both chronic malignant and non malignant pains. One major serious limitation associated with chronic use of opioids is the development of tolerance to its analgesic effect. The effect of Bacopa monnieri, a renowned ayurvedic medicine for acquisition and expression of morphine tolerance in mice, was investigated. Bacopa monnieri, n-Butanol fraction was analyzed on High performance liquid chromatography (HPLC), for Bacopaside A major components i.e. Bacoside A(3), Bacopaside ll and Bacosaponin C. Antinociceptive effect of n-Butanol extract of Bacopa monnieri (n Bt-ext BM) (5, 10 and 15 mg/kg) was assessed on hot plate. Effect of different doses of n Bt-ext BM on morphine antinociception was also assessed. n Bt-ext BM was also screened for development of tolerance to antinociceptive effect of Bacopa monnieri by administering 15 mg/kg n Bt-ext BM for seven days. Tolerance to morphine analgesia was induced in mice by administering intraperitoneally (I.P.) 20 mg/kg morphine twice daily for five days. Acute and Chronic administration of 5, 10 and 15 mg/kg n Bt-ext BM significantly reduced both expression and development of tolerance to morphine analgesia in mice. Additionally, Bacopa monnieri was found to enhance antinociceptive effect of morphine in intolerant animals. However, no tolerance to Bacopa monnieri antinociceptive effect was observed in seven days treatment schedule. These findings indicate effectiveness of Bacopa monnieri for management of morphine tolerance. Copyright © 2011 Elsevier GmbH. All rights reserved.

Morphine induces endocytosis of neuronal μ-opioid receptors through the sustained transfer of Gα subunits to RGSZ2 proteins

PubMed Central

Rodríguez-Muñoz, María; de la Torre-Madrid, Elena; Sánchez-Blázquez, Pilar; Garzón, Javier

2007-01-01

long-term sequestering of morphine-activated Gα subunits by certain RGS proteins reduces the responses to this opioid in neurons. This phenomenon probably increases free Gβγ dimers in the receptor environment and leads to GRK phosphorylation and internalization of the MORs. Although, the internalization of the MORs permits the transfer of opioid-activated Gα subunits to the RGSZ2 proteins, it interferes with the stabilization of this regulatory process and recycled MORs recover the control on these Gα subunits and opioid tolerance develops slowly. PMID:17634133

Opioid Challenge Evaluation of Blockade by Extended-Release Naltrexone in Opioid-Abusing Adults: Dose-Effects and Time-Course

PubMed Central

Bigelow, George E.; Preston, Kenzie L.; Schmittner, John; Dong, Qunming; Gastfriend, David R.

2013-01-01

Background Oral naltrexone's effectiveness as an opioid antagonist has been limited due to poor patient adherence. A long-acting naltrexone formulation may be beneficial. This study evaluated the effects of extended-release injectable naltrexone (XR-NTX), targeted for a one-month duration of action, in blocking opioid agonist challenge effects in humans. Methods Outpatient non-dependent opioid abusers (N=27) were randomly assigned to a single double-blind IM administration of 75, 150, or 300 mg XR-NTX. To assess the extent of opioid blockade, hydromorphone challenges (0, 3, 4.5, 6 mg IM in ascending order at 1-hr intervals [up to 13.5 mg total]) were given at pretreatment baseline and on days 7, 14, 21, 28, 42, and 56. Opioid blockade was assessed via (1) tolerability of the ascending hydromorphone doses; (2) Visual Analog Scale (VAS) ratings of subjective opioid effects and (3) pupil diameter. Effects on the VAS and pupils were assessed via the slope of the time-action function over ascending hydromorphone doses, with zero slope indicating complete blockade. Results Blockade of the VAS “any drug effect” response to 3 mg hydromorphone was complete for 14, 21, and 28 days, respectively, for the XR-NTX doses of 75, 150 and 300 mg. Subjective effects were more readily blocked than was pupil constriction. Higher hydromorphone doses produced only modest increases in agonist effects. With the 300 mg XR-NTX dose the slope of VAS responses remained at or near zero for one month even with maximal cumulative hydromorphone dosing. Conclusions These data quantify the month-long opioid blockade underlying XR-NTX's efficacy in opioid dependence treatment. PMID:22079773

Supraspinally administered agmatine prevents the development of supraspinal morphine analgesic tolerance.

PubMed

Kitto, Kelley F; Fairbanks, Carolyn A

2006-04-24

We have determined the effect of intracerebroventricularly (i.c.v.) administered decarboxylated arginine (agmatine) on supraspinally induced chronic morphine analgesic tolerance. Mice pre-treated with a schedule of chronic i.c.v administration of morphine (10 nmol, b.i.d. 3 days) show a 12-fold reduction in the potency of acutely administered i.c.v morphine compared to saline injected controls. Co-administration of agmatine (10 nmol) with one of the two daily morphine injections completely prevents the reduction in i.c.v morphine analgesia. Mice injected with agmatine once daily (but no morphine) do not show a increase in morphine analgesic potency relative to saline controls, indicating that a mere potentiation of acute morphine analgesia cannot account for the agmatine-mediated anti-tolerance effect in those mice subjected to the morphine tolerance induction schedule. These observations agree with previous reports that systemically and intrathecally administered agmatine prevent opioid tolerance, and extend these results to include a supraspinal site of action.

The convulsive and electroencephalographic changes produced by nonpeptidic delta-opioid agonists in rats: comparison with pentylenetetrazol.

PubMed

Jutkiewicz, Emily M; Baladi, Michelle G; Folk, John E; Rice, Kenner C; Woods, James H

2006-06-01

delta-Opioid agonists produce convulsions and antidepressant-like effects in rats. It has been suggested that the antidepressant-like effects are produced through a convulsant mechanism of action either through overt convulsions or nonconvulsive seizures. This study evaluated the convulsive and seizurogenic effects of nonpeptidic delta-opioid agonists at doses that previously were reported to produce antidepressant-like effects. In addition, delta-opioid agonist-induced electroencephalographic (EEG) and behavioral changes were compared with those produced by the chemical convulsant pentylenetetrazol (PTZ). For these studies, EEG changes were recorded using a telemetry system before and after injections of the delta-opioid agonists [(+)-4-[(alphaR)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-methoxyphenyl)methyl]-N,N-diethylbenz (SNC80) and [(+)-4-[alpha(R)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-hydroxyphenyl)methyl]-N,N-diethylbenzamide [(+)-BW373U86]. Acute administration of nonpeptidic delta-opioid agonists produced bilateral ictal and paroxysmal spike and/or sharp wave discharges. delta-Opioid agonists produced brief changes in EEG recordings, and tolerance rapidly developed to these effects; however, PTZ produced longer-lasting EEG changes that were exacerbated after repeated administration. Studies with antiepileptic drugs demonstrated that compounds used to treat absence epilepsy blocked the convulsive effects of nonpeptidic delta-opioid agonists. Overall, these data suggest that delta-opioid agonist-induced EEG changes are not required for the antidepressant-like effects of these compounds and that neural circuitry involved in absence epilepsy may be related to delta-opioid agonist-induced convulsions. In terms of therapeutic development, these data suggest that it may be possible to develop delta-opioid agonists devoid of convulsive properties.

Tolerance to the Diuretic Effects of Cannabinoids and Cross-Tolerance to a κ-Opioid Agonist in THC-Treated Mice.

PubMed

Chopda, Girish R; Parge, Viraj; Thakur, Ganesh A; Gatley, S John; Makriyannis, Alexandros; Paronis, Carol A

2016-08-01

Daily treatment with cannabinoids results in tolerance to many, but not all, of their behavioral and physiologic effects. The present studies investigated the effects of 7-day exposure to 10 mg/kg daily of Δ(9)-tetrahydrocannabinol (THC) on the diuretic and antinociceptive effects of THC and the synthetic cannabinoid AM4054. Comparison studies determined diuretic responses to the κ-opioid agonist U50,488 and furosemide. After determination of control dose-response functions, mice received 10 mg/kg daily of THC for 7 days, and dose-response functions were re-determined 24 hours, 7 days, or 14 days later. THC and AM4054 had biphasic diuretic effects under control conditions with maximum effects of 30 and 35 ml/kg of urine, respectively. In contrast, antinociceptive effects of both drugs increased monotonically with dose to >90% of maximal possible effect. Treatment with THC produced 9- and 7-fold rightward shifts of the diuresis and antinociception dose-response curves for THC and, respectively, 7- and 3-fold rightward shifts in the AM4054 dose-response functions. U50,488 and furosemide increased urine output to >35 ml/kg under control conditions. The effects of U50,488 were attenuated after 7-day treatment with THC, whereas the effects of furosemide were unaltered. Diuretic effects of THC and AM4054 recovered to near-baseline levels within 14 days after stopping daily THC injections, whereas tolerance to the antinociceptive effects persisted longer than 14 days. The tolerance induced by 7-day treatment with THC was accompanied by a 55% decrease in the Bmax value for cannabinoid receptors (CB1). These data indicate that repeated exposure to THC produces similar rightward shifts in the ascending and descending limbs of cannabinoid diuresis dose-effect curves and to antinociceptive effects while resulting in a flattening of the U50,488 diuresis dose-effect function. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Agonist-Specific Recruitment of Arrestin Isoforms Differentially Modify Delta Opioid Receptor Function

PubMed Central

Perroy, Julie; Walwyn, Wendy M.; Smith, Monique L.; Vicente-Sanchez, Ana; Segura, Laura; Bana, Alia; Kieffer, Brigitte L.; Evans, Christopher J.

2016-01-01

Ligand-specific recruitment of arrestins facilitates functional selectivity of G-protein-coupled receptor signaling. Here, we describe agonist-selective recruitment of different arrestin isoforms to the delta opioid receptor in mice. A high-internalizing delta opioid receptor agonist (SNC80) preferentially recruited arrestin 2 and, in arrestin 2 knock-outs (KOs), we observed a significant increase in the potency of SNC80 to inhibit mechanical hyperalgesia and decreased acute tolerance. In contrast, the low-internalizing delta agonists (ARM390, JNJ20788560) preferentially recruited arrestin 3 with unaltered behavioral effects in arrestin 2 KOs. Surprisingly, arrestin 3 KO revealed an acute tolerance to these low-internalizing agonists, an effect never observed in wild-type animals. Furthermore, we examined delta opioid receptor–Ca2+ channel coupling in dorsal root ganglia desensitized by ARM390 and the rate of resensitization was correspondingly decreased in arrestin 3 KOs. Live-cell imaging in HEK293 cells revealed that delta opioid receptors are in pre-engaged complexes with arrestin 3 at the cell membrane and that ARM390 strengthens this membrane interaction. The disruption of these complexes in arrestin 3 KOs likely accounts for the altered responses to low-internalizing agonists. Together, our results show agonist-selective recruitment of arrestin isoforms and reveal a novel endogenous role of arrestin 3 as a facilitator of resensitization and an inhibitor of tolerance mechanisms. SIGNIFICANCE STATEMENT Agonists that bind to the same receptor can produce highly distinct signaling events and arrestins are a major mediator of this ligand bias. Here, we demonstrate that delta opioid receptor agonists differentially recruit arrestin isoforms. We found that the high-internalizing agonist SNC80 preferentially recruits arrestin 2 and knock-out (KO) of this protein results in increased efficacy of SNC80. In contrast, low-internalizing agonists (ARM390 and JNJ20788560

Mitragynine/Corynantheidine Pseudoindoxyls As Opioid Analgesics with Mu Agonism and Delta Antagonism, Which Do Not Recruit β-Arrestin-2.

PubMed

Váradi, András; Marrone, Gina F; Palmer, Travis C; Narayan, Ankita; Szabó, Márton R; Le Rouzic, Valerie; Grinnell, Steven G; Subrath, Joan J; Warner, Evelyn; Kalra, Sanjay; Hunkele, Amanda; Pagirsky, Jeremy; Eans, Shainnel O; Medina, Jessica M; Xu, Jin; Pan, Ying-Xian; Borics, Attila; Pasternak, Gavril W; McLaughlin, Jay P; Majumdar, Susruta

2016-09-22

Natural products found in Mitragyna speciosa, commonly known as kratom, represent diverse scaffolds (indole, indolenine, and spiro pseudoindoxyl) with opioid activity, providing opportunities to better understand opioid pharmacology. Herein, we report the pharmacology and SAR studies both in vitro and in vivo of mitragynine pseudoindoxyl (3), an oxidative rearrangement product of the corynanthe alkaloid mitragynine. 3 and its corresponding corynantheidine analogs show promise as potent analgesics with a mechanism of action that includes mu opioid receptor agonism/delta opioid receptor antagonism. In vitro, 3 and its analogs were potent agonists in [(35)S]GTPγS assays at the mu opioid receptor but failed to recruit β-arrestin-2, which is associated with opioid side effects. Additionally, 3 developed analgesic tolerance more slowly than morphine, showed limited physical dependence, respiratory depression, constipation, and displayed no reward or aversion in CPP/CPA assays, suggesting that analogs might represent a promising new generation of novel pain relievers.

Opioids in Preclinical and Clinical Trials

NASA Astrophysics Data System (ADS)

Nagase, Hiroshi; Fujii, Hideaki

Since 1952, when Gates determined the stereo structure of morphine, numerous groups have focused on discovering a nonnarcotic opioid drug [1]. Although several natural, semisynthetic, and synthetic opioid ligands (alkaloids and peptides) have been developed in clinical studies, very few were nonnarcotic opioid drugs [2]. One of the most important studies in the opioid field appeared in 1976, when Martin and colleagues [3] established types of opioid receptors (these are now classified into μ, δ, and κ types). Later, Portoghese discovered a highly selective μ type opioid receptor antagonist, β-funaltrexamine [4]. This led to the finding that the μ type opioid receptor was correlated to drug dependence [5]. Consequently, δ, and particularly κ, opioid agonists were expected to lead to ideal opioid drugs. Moreover, opioid antagonists were evaluated for the treatment of symptoms related to undesirable opioid system activation. In this chapter, we provide a short survey of opioid ligands in development and describe the discovery of the two most promising drugs, TRK-851 [6] and TRK-820 (nalfurafine hydrochloride) [7].

Dextromethorphan differentially affects opioid antinociception in rats

PubMed Central

Chen, Shiou-Lan; Huang, Eagle Yi-Kung; Chow, Lok-Hi; Tao, Pao-Luh

2005-01-01

Opioid drugs such as morphine and meperidine are widely used in clinical pain management, although they can cause some adverse effects. A number of studies indicate that N-methyl-D-aspartate (NMDA) receptors may play a role in the mechanism of morphine analgesia, tolerance and dependence. Being an antitussive with NMDA antagonist properties, dextromethorphan (DM) may have some therapeutic benefits when coadministered with morphine. In the present study, we investigated the effects of DM on the antinociceptive effects of different opioids. We also investigated the possible pharmacokinetic mechanisms involved. The antinociceptive effects of the μ-opioid receptor agonists morphine (5 mg kg−1, s.c.), meperidine (25 mg kg−1, s.c.) and codeine (25 mg kg−1, s.c.), and the κ-opioid agonists nalbuphine (8 mg kg−1, s.c.) and U-50,488H (20 mg kg−1, s.c.) were studied using the tail-flick test in male Sprague–Dawley rats. Coadministration of DM (20 mg kg−1, i.p.) with these opioids was also performed and investigated. The pharmacokinetic effects of DM on morphine and codeine were examined, and the free concentration of morphine or codeine in serum was determined by HPLC. It was found that DM potentiated the antinociceptive effects of some μ-opioid agonists but not codeine or κ-opioid agonists in rats. DM potentiated morphine's antinociceptive effect, and acutely increased the serum concentration of morphine. In contrast, DM attenuated the antinociceptive effect of codeine and decreased the serum concentration of its active metabolite (morphine). The pharmacokinetic interactions between DM and opioids may partially explain the differential effects of DM on the antinociception caused by opioids. PMID:15655510

Pain Intensity and Opioid Utilization in Response to CPAP Therapy in Veterans with Obstructive Sleep Apnea on Chronic Opioid Treatment.

PubMed

Jaoude, Philippe; Lal, Ashima; Vermont, Leah; Porhomayon, Jahan; El-Solh, Ali A

2016-08-15

Sleep fragmentation has been linked to poor pain tolerance and lowered pain threshold. Little evidence exists on whether continuous positive airway pressure (CPAP) adherence in veterans with obstructive sleep apnea (OSA) who are taking opioids for non-malignant pain would ameliorate pain and reduce consumption of opioids. A retrospective case-control study was performed at a VA sleep center. Pain intensity was assessed using the Numerical Categorical Scale prior to CPAP treatment and 12-mo follow-up. Opioids intake was assessed using the morphine equivalent daily dose (MEDD). Adherence to CPAP was evaluated with the built-in meter. We reviewed 113 patients with OSA (apnea-hypopnea index [AHI] 35.9 ± 29.5) using a MEDD of 61.6 mg (range 5-980 mg) and a control group of 113 veterans with OSA (AHI 33.4 ± 27.3) on no opioids treatment. CPAP adherence was significantly lower at 12 mo in opioid-treated patients compared to controls (37% versus 55%; p = 0.01). Greater pain intensity was the only independent variable associated with CPAP non-adherence at 12-mo follow-up (p = 0.03). Compared to baseline, no significant difference was observed in pain intensity or consumption of opioids in CPAP adherent patients. CPAP treatment did not reduce pain intensity or consumption of opioids in veterans with chronic pain who have coexisting OSA. CPAP adherence was lower in opioid-treated veterans with OSA compared to opioid-free veterans with OSA. Pain intensity was the only determinant of CPAP adherence. Future studies are needed to evaluate pain management program on adherence to CPAP. © 2016 American Academy of Sleep Medicine.

Putative kappa opioid heteromers as targets for developing analgesics free of adverse effects.

PubMed

Le Naour, Morgan; Lunzer, Mary M; Powers, Michael D; Kalyuzhny, Alexander E; Benneyworth, Michael A; Thomas, Mark J; Portoghese, Philip S

2014-08-14

It is now generally recognized that upon activation by an agonist, β-arrestin associates with G protein-coupled receptors and acts as a scaffold in creating a diverse signaling network that could lead to adverse effects. As an approach to reducing side effects associated with κ opioid agonists, a series of β-naltrexamides 3-10 was synthesized in an effort to selectively target putative κ opioid heteromers without recruiting β-arrestin upon activation. The most potent derivative 3 (INTA) strongly activated KOR-DOR and KOR-MOR heteromers in HEK293 cells. In vivo studies revealed 3 to produce potent antinociception, which, when taken together with antagonism data, was consistent with the activation of both heteromers. 3 was devoid of tolerance, dependence, and showed no aversive effect in the conditioned place preference assay. As immunofluorescence studies indicated no recruitment of β-arrestin2 to membranes in coexpressed KOR-DOR cells, this study suggests that targeting of specific putative heteromers has the potential to identify leads for analgesics devoid of adverse effects.

Personality as a risk factor for illicit opioid use and a protective factor for illicit opioid dependence.

PubMed

Zaaijer, Eline R; Bruijel, Jessica; Blanken, Peter; Hendriks, Vincent; Koeter, Maarten W J; Kreek, Mary Jeanne; Booij, Jan; Goudriaan, Anna E; van Ree, Jan M; van den Brink, Wim

2014-12-01

Most studies investigating the role of personality as a risk factor for the development of opioid dependence compare dependent opioid users with healthy controls who never used heroin. In order to understand the potential protective role of personality, it is crucial to compare illicit opioid users who never became dependent with dependent opioid users. This study aims to examine the role of personality as a risk factor for opioid use and as a protective factor for the development of opioid dependence. Comparing personality factors between three groups: (1) 161 never-dependent illicit opioid users who have been using illicit opioids but never became opioid dependent; (2) 402 dependent opioid users in methadone maintenance treatment or heroin-assisted treatment; and (3) 135 healthy controls who never used heroin. Personality was assessed with a short version of Cloninger's Temperament and Character Inventory. Never-dependent opioid users reported more Novelty Seeking and Harm Avoidance and less Self-Directedness and Cooperativeness than healthy controls and more Reward Dependence and Self-Directedness, and less Harm Avoidance than dependent opioid users. Furthermore, never-dependent opioid users reported more Self-Transcendence than both dependent opioid users and healthy controls. Never-dependent opioid users may have started to use opioids partly due to their tendency to seek novel and/or spiritual experiences (high Novelty Seeking, high Self-Transcendence) and their tendency to avoid aversive stimuli (high Harm Avoidance), whereas they may have been protected against the development of dependence by their need for social approval (high Reward Dependence) and their self-efficacy (high Self-Directedness). Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Biphalin preferentially recruits peripheral opioid receptors to facilitate analgesia in a mouse model of cancer pain - A comparison with morphine.

PubMed

Lesniak, Anna; Bochynska-Czyz, Marta; Sacharczuk, Mariusz; Benhye, Sandor; Misicka, Aleksandra; Bujalska-Zadrozny, Magdalena; Lipkowski, Andrzej W

2016-06-30

The search for new drugs for cancer pain management has been a long-standing goal in basic and clinical research. Classical opioid drugs exert their primary antinociceptive effect upon activating opioid receptors located in the central nervous system. A substantial body of evidence points to the relevance of peripheral opioid receptors as potential targets for cancer pain treatment. Peptides showing limited blood-brain-barrier permeability promote peripheral analgesia in many pain models. In the present study we examined the peripheral and central analgesic effect of intravenously administered biphalin - a dimeric opioid peptide in a mouse skin cancer pain model, developed by an intraplantar inoculation of B16F0 melanoma cells. The effect of biphalin was compared with morphine - a golden standard in cancer pain management. Biphalin produced profound, dose-dependent and naloxone sensitive spinal analgesia. Additionally, the effect in the tumor-bearing paw was largely mediated by peripheral opioid receptors, as it was readily attenuated by the blood-brain-barrier-restricted opioid receptor antagonist - naloxone methiodide. On the contrary, morphine facilitated its analgesic effect primarily by activating spinal opioid receptors. Both drugs induced tolerance in B16F0 - implanted paws after chronic treatment, however biphalin as opposed to morphine, showed little decrease in its activity at the spinal level. Our results indicate that biphalin may be considered a future alternative drug in cancer pain treatment due to an enhanced local analgesic activity as well as lower tolerance liability compared with morphine. Copyright © 2016 Elsevier B.V. All rights reserved.

On subclasses of opioid analgesics.

PubMed

Raffa, Robert B

2014-12-01

The history of discovery of analgesic drugs has followed a trajectory from original serendipitous discovery of plant-derived substances to laboratory creation of customized molecules that are intentionally designed to interact with specific receptors of neurotransmitters involved in either the transmission of the pain signal or the attenuation of such a signal. The drugs most recently developed have been designed to provide incremental greater separation between pain relief and adverse effects. The result has been drugs that have individualized pharmacodynamic and pharmacokinetic characteristics that represent specific advances in basic science and translate into unique clinical profiles. Several of the drugs include non-opioid components. They retain some of the features of opioids, but have distinct clinical characteristics that differentiate them from traditional opioids. Thus they defy simple classification as opioids. A summary is provided of the development of the modern view of multi-mechanistic pain and its treatment using analgesics that have multi-mechanisms of action (consisting of both opioid and non-opioid components). Descriptions of examples of such current analgesics and of those that have pharmacokinetic characteristics that result in atypical opioid clinical profiles are given. By serendipity or design, several current strong analgesics have opioid components of action, but have an additional non-opioid mechanism of action or some pharmacokinetic feature that gives them an atypical opioid clinical profile and renders them not easily classified as classical opioids. An appreciation that there are now opioid analgesics that differentiate from classical opioids in ways that defy their simplistic classification as opioids suggests that recognition of subclasses of opioid analgesics would be more accurate scientifically and would be more informative for healthcare providers and regulators. This would likely lead to positive outcomes for the clinical

[Interindividual variation of pharmacokinetic disposition of and clinical responses to opioid analgesics in cancer pain patients].

PubMed

Naito, Takafumi; Kawakami, Junichi

2015-01-01

Use of prescription opioids for cancer pain according to the World Health Organization analgesic ladder has been accepted in Japan. Although oxycodone and fentanyl are commonly used as first-line analgesics, a few clinical reports have been published on interindividual variations in their pharmacokinetics and clinical responses in cancer patients. (1) Some factors relating to CYP2D6, CYP3A, ATP-binding cassette sub-family B member 1 (ABCB1), and opioid receptor mu 1 (OPRM1) involve oxycodone pharmacokinetics and sensitivity in humans. The relations between their genetic variations and clinical responses to oxycodone are being revealed in limited groups. In our study, the impact of genetic variants and pharmacokinetics on clinical responses to oxycodone were evaluated in Japanese populations. (2) Opioid switching improves the opioid tolerance related to the balance between analgesia and adverse effects. Some patients have difficulty in obtaining better opioid tolerance in recommended conversion ratios. The activities of CYP3A, ABCB1, and OPRM1 contribute to the interindividual variations in clinical responses to fentanyl in cancer patients. However, the variations in opioid switching remain to be clarified in clinical settings. In our study, genetic factors related to interindividual variations in clinical responses in opioid switching to fentanyl were revealed in Japanese populations. In this symposium review, the possibility of approaches to personalized palliative care using opioids based on genetic variants of CYP2D6, CYP3A5, ABCB1, and OPRM1 is discussed.

Basic/Translational Development of Forthcoming Opioid- and Nonopioid-Targeted Pain Therapeutics.

PubMed

Knezevic, Nebojsa Nick; Yekkirala, Ajay; Yaksh, Tony L

2017-11-01

Opioids represent an efficacious therapeutic modality for some, but not all pain states. Singular reliance on opioid therapy for pain management has limitations, and abuse potential has deleterious consequences for patient and society. Our understanding of pain biology has yielded insights and opportunities for alternatives to conventional opioid agonists. The aim is to have efficacious therapies, with acceptable side effect profiles and minimal abuse potential, which is to say an absence of reinforcing activity in the absence of a pain state. The present work provides a nonexclusive overview of current drug targets and potential future directions of research and development. We discuss channel activators and blockers, including sodium channel blockers, potassium channel activators, and calcium channel blockers; glutamate receptor-targeted agents, including N-methyl-D-aspartate, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid, and metabotropic receptors. Furthermore, we discuss therapeutics targeted at γ-aminobutyric acid, α2-adrenergic, and opioid receptors. We also considered antagonists of angiotensin 2 and Toll receptors and agonists/antagonists of adenosine, purine receptors, and cannabinoids. Novel targets considered are those focusing on lipid mediators and anti-inflammatory cytokines. Of interest is development of novel targeting strategies, which produce long-term alterations in pain signaling, including viral transfection and toxins. We consider issues in the development of druggable molecules, including preclinical screening. While there are examples of successful translation, mechanistically promising preclinical candidates may unexpectedly fail during clinical trials because the preclinical models may not recapitulate the particular human pain condition being addressed. Molecular target characterization can diminish the disconnect between preclinical and humans' targets, which should assist in developing nonaddictive analgesics.

Single-dose evaluation of safety, tolerability and pharmacokinetics of newly formulated hydromorphone immediate-release and hydrophilic matrix extended-release tablets in healthy Japanese subjects without co-administration of an opioid antagonist.

PubMed

Toyama, Kaoru; Uchida, Naoki; Ishizuka, Hitoshi; Sambe, Takehiko; Kobayashi, Shinichi

2015-09-01

This single dose, open-label study investigated the safety, tolerability and pharmacokinetics of single oral doses of newly formulated immediate-release (IR) and hydrophilic matrix extended-release (ER) hydromorphone tablets in healthy Japanese subjects without co-administration of an opioid antagonist under fasting and fed conditions. Plasma and urinary concentrations of hydromorphone and metabolites were measured by liquid-chromatography tandem mass-spectroscopy. Following administration of the ER tablet, plasma concentrations of hydromorphone slowly increased with a median tmax of 5.0 h and the Cmax decreased to 37% of the IR tablet, while the AUC0-inf was comparable with that of the IR tablet when administered at the same dose. The degree of fluctuation in the plasma concentration for the ER tablet was much lower than that of the IR tablet and certain levels of plasma concentrations were maintained after 24 h of ER dosing. The AUC0-inf and Cmax increased with food for both IR and ER tablets. The AUC0-inf of hydromorphone-3-glucoside was one-tenth of that of hydromorphone-3-glucuronide. A single oral administration of the hydromorphone tablets would be well-tolerated in healthy Japanese subjects despite a lack of co-administration of an opioid antagonist and the newly developed ER hydromorphone tablets may have the appropriate PK characteristics for once-daily dosing. © 2015, The American College of Clinical Pharmacology.

Distress Intolerance and Prescription Opioid Misuse among Patients with Chronic Pain

PubMed Central

McHugh, R. Kathryn; Weiss, Roger D.; Cornelius, Marise; Martel, Marc O.; Jamison, Robert N.; Edwards, Robert R.

2016-01-01

The risk for misuse of opioid medications is a significant challenge in the management of chronic pain. The identification of those who may be at greater risk for misusing opioids is needed to facilitate closer monitoring of high-risk subgroups, and may help to identify therapeutic targets for mitigating this risk. The aim of this study was to examine whether distress intolerance--the perceived or actual inability to manage negative emotional and somatic states--was associated with opioid misuse in those with chronic pain. A sample of 51 participants prescribed opioid analgesics for chronic back or neck pain were recruited for a one-time laboratory study. Participants completed measures of distress intolerance and opioid misuse, and a quantitative sensory testing battery. Results suggested that distress intolerance was associated with opioid misuse, even controlling for pain severity and negative affect. Distress intolerance was not associated with pain severity, threshold or tolerance, but was associated with self-reported anxiety and stress following noxious stimuli. This study found robust differences in distress intolerance between adults with chronic pain with and without opioid medication misuse. Distress intolerance may be a relevant marker of risk for opioid misuse among those with chronic pain. PMID:27058161

Bivalent ligands that target μ opioid (MOP) and cannabinoid1 (CB1) receptors are potent analgesics devoid of tolerance.

PubMed

Le Naour, Morgan; Akgün, Eyup; Yekkirala, Ajay; Lunzer, Mary M; Powers, Mike D; Kalyuzhny, Alexander E; Portoghese, Philip S

2013-07-11

Given that μ opioid (MOP) and canabinoid (CB1) receptors are colocalized in various regions of the central nervous system and have been reported to associate as heteromer (MOP-CB1) in cultured cells, the possibility of functional, endogenous MOP-CB1 in nociception and other pharmacologic effects has been raised. As a first step in investigating this possibility, we have synthesized a series of bivalent ligands 1-5 that contain both μ agonist and CB1 antagonist pharmacophores for use as tools to study the functional interaction between MOP and CB1 receptors in vivo. Immunofluorescent studies on HEK293 cells coexpressing both receptors suggested 5 (20-atom spacer) to be the only member of the series that bridges the protomers of the heteromer. Antinociceptive testing in mice revealed 5 to be the most potent member of the series. As neither a mixture of monovalent ligands 9 + 10 nor bivalents 2-5 produced tolerance in mice, MOR-CB1 apparently is not an important target for reducing tolerance.

Altered quantitative sensory testing outcome in subjects with opioid therapy.

PubMed

Chen, Lucy; Malarick, Charlene; Seefeld, Lindsey; Wang, Shuxing; Houghton, Mary; Mao, Jianren

2009-05-01

Preclinical studies have suggested that opioid exposure may induce a paradoxical decrease in the nociceptive threshold, commonly referred as opioid-induced hyperalgesia (OIH). While OIH may have implications in acute and chronic pain management, its clinical features remain unclear. Using an office-based quantitative sensory testing (QST) method, we compared pain threshold, pain tolerance, and the degree of temporal summation of the second pain in response to thermal stimulation among three groups of subjects: those with neither pain nor opioid therapy (group 1), with chronic pain but without opioid therapy (group 2), and with both chronic pain and opioid therapy (group 3). We also examined the possible correlation between QST responses to thermal stimulation and opioid dose, opioid treatment duration, opioid analgesic type, pain duration, or gender in group 3 subjects. As compared with both group 1 (n=41) and group 2 (n=41) subjects, group 3 subjects (n=58) displayed a decreased heat pain threshold and exacerbated temporal summation of the second pain to thermal stimulation. In contrast, there were no differences in cold or warm sensation among three groups. Among clinical factors, daily opioid dose consistently correlated with the decreased heat pain threshold and exacerbated temporal summation of the second pain in group 3 subjects. These results indicate that decreased heat pain threshold and exacerbated temporal summation of the second pain may be characteristic QST changes in subjects with opioid therapy. The data suggest that QST may be a useful tool in the clinical assessment of OIH.

Pain and Poppies: The Good, the Bad, and the Ugly of Opioid Analgesics.

PubMed

Trang, Tuan; Al-Hasani, Ream; Salvemini, Daniela; Salter, Michael W; Gutstein, Howard; Cahill, Catherine M

2015-10-14

Treating pain is one of the most difficult challenges in medicine and a key facet of disease management. The isolation of morphine by Friedrich Sertürner in 1804 added an essential pharmacological tool in the treatment of pain and spawned the discovery of a new class of drugs known collectively as opioid analgesics. Revered for their potent pain-relieving effects, even Morpheus the god of dreams could not have dreamt that his opium tincture would be both a gift and a burden to humankind. To date, morphine and other opioids remain essential analgesics for alleviating pain. However, their use is plagued by major side effects, such as analgesic tolerance (diminished pain-relieving effects), hyperalgesia (increased pain sensitivity), and drug dependence. This review highlights recent advances in understanding the key causes of these adverse effects and explores the effect of chronic pain on opioid reward. Chronic pain is pervasive and afflicts >100 million Americans. Treating pain in these individuals is notoriously difficult and often requires opioids, one of the most powerful and effective classes of drugs used for controlling pain. However, their use is plagued by major side effects, such as a loss of pain-relieving effects (analgesic tolerance), paradoxical pain (hyperalgesia), and addiction. Despite the potential side effects, opioids remain the pharmacological cornerstone of modern pain therapy. This review highlights recent breakthroughs in understanding the key causes of these adverse effects and explores the cellular control of opioid systems in reward and aversion. The findings will challenge traditional views of the good, the bad, and the ugly of opioids. Copyright © 2015 the authors 0270-6474/15/3513879-10$15.00/0.

Pain and Poppies: The Good, the Bad, and the Ugly of Opioid Analgesics

PubMed Central

Al-Hasani, Ream; Salvemini, Daniela; Salter, Michael W.; Gutstein, Howard

2015-01-01

Treating pain is one of the most difficult challenges in medicine and a key facet of disease management. The isolation of morphine by Friedrich Sertürner in 1804 added an essential pharmacological tool in the treatment of pain and spawned the discovery of a new class of drugs known collectively as opioid analgesics. Revered for their potent pain-relieving effects, even Morpheus the god of dreams could not have dreamt that his opium tincture would be both a gift and a burden to humankind. To date, morphine and other opioids remain essential analgesics for alleviating pain. However, their use is plagued by major side effects, such as analgesic tolerance (diminished pain-relieving effects), hyperalgesia (increased pain sensitivity), and drug dependence. This review highlights recent advances in understanding the key causes of these adverse effects and explores the effect of chronic pain on opioid reward. SIGNIFICANCE STATEMENT Chronic pain is pervasive and afflicts >100 million Americans. Treating pain in these individuals is notoriously difficult and often requires opioids, one of the most powerful and effective classes of drugs used for controlling pain. However, their use is plagued by major side effects, such as a loss of pain-relieving effects (analgesic tolerance), paradoxical pain (hyperalgesia), and addiction. Despite the potential side effects, opioids remain the pharmacological cornerstone of modern pain therapy. This review highlights recent breakthroughs in understanding the key causes of these adverse effects and explores the cellular control of opioid systems in reward and aversion. The findings will challenge traditional views of the good, the bad, and the ugly of opioids. PMID:26468188

Oral cryotherapy reduces mucositis and opioid use after myeloablative therapy--a randomized controlled trial.

PubMed

Svanberg, Anncarin; Birgegård, Gunnar; Ohrn, Kerstin

2007-10-01

Mucositis is a major complication in myeloablative therapy, which often necessitates advanced pharmacological pain treatment, including i.v. opioids. Attempts to prevent oral mucositis have included oral cryotherapy, which has been shown to reduce mucositis, but there is a lack of knowledge concerning the effect of oral cryotherapy on opioid use by reducing the mucositis for patients treated with myeloablative therapy before bone marrow transplantation (BMT). The aim of the present study was to evaluate if oral cryotherapy could delay or alleviate the development of mucositis and thereby reduce the number of days with i.v. opioids among patients who receive myeloablative therapy before BMT. Eighty patients 18 years and older, scheduled for BMT, were included consecutively and randomised to oral cryotherapy or standard oral care. A stratified randomisation was used with regard to type of transplantation. Intensity of pain, severity of mucositis and use of opioids were recorded using pain visual analogue scale (VAS) scores, mucositis index scores and medical and nursing charts. This study showed that patients receiving oral cryotherapy had less pronounced mucositis and significantly fewer days with i.v. opioids than the control group. In the autologous setting, cryotherapy patients also needed significantly lower total dose of opioids. Oral cryotherapy is an effective and well-tolerated therapy to alleviate mucositis and consequently reduce the number of days with i.v. opioids among patients treated with myeloablative therapy before BMT.

Long-term efficacy, safety and tolerability of Remoxy for the management of chronic pain.

PubMed

Pergolizzi, Joseph V; Zampogna, Gianpietro; Taylor, Robert; Raffa, Robert B

2015-03-01

Historically, chronic pain generally went under-treated for a variety of objective and subjective reasons, including difficulty to objectively diagnose and manage over a long period of time, potential serious adverse effects of commonly available medications, and patient, healthcare and societal concerns over opioid medications. More recently, in an effort to redress the under-treatment of pain, the number of prescriptions of opioid analgesics has risen dramatically. However, paralleling the increased legitimate use has been a concomitant increase in opioid abuse, misuse and diversion. Pharmaceutical companies have responded by developing a variety of opioid formulations designed to deter abuse by making the products more difficult to tamper with. One such product is Remoxy(®), an extended-release formulation of the strong opioid oxycodone. We review the efficacy, safety and tolerability of this formulation based on the available published literature.

[Management of opioid maintenance treatments when analgesic treatments are required].

PubMed

Laprevote, Vincent; Geoffroy, Pierre A; Rolland, Benjamin; Leheup, Benoît F; Di Patrizio, Paolo; Cottencin, Olivier; Schwan, Raymund

2013-01-01

Opioid maintenance treatments (OMT) reduce illicit opiate use and its associated risks. They are often prescribed on a long-term basis. Physiological changes induced by long-term OMT may cause hyperalgesia and cross-tolerance to opioid agonists, which suggests that the dosage of analgesic treatment should be modified in cases of acute pain, especially when an opioid-based analgesia is required. When treatment with analgesics is necessary, OMT must be maintained, except in exceptional cases. If a split-dosing schedule is temporarily employed during OMT, the daily dosage should not be increased for analgesic purposes. Analgesic treatment must be managed differently in case of treatment with buprenorphine or methadone. With buprenorphine, non-opioid analgesics should be introduced first, if possible. If this strategy is inefficient or contraindicated, a temporary or definitive switch to methadone should be considered. In the case of methadone-based OMT, opioid analgesics should be added directly and the dosage should be adapted according to the level of pain reported by the patient. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Brief Opioid Overdose Knowledge (BOOK): A Questionnaire to Assess Overdose Knowledge in Individuals Who Use Illicit or Prescribed Opioids.

PubMed

Dunn, Kelly E; Barrett, Frederick S; Yepez-Laubach, Claudia; Meyer, Andrew C; Hruska, Bryce J; Sigmon, Stacey C; Fingerhood, Michael; Bigelow, George E

2016-01-01

Opioid overdose is a public health crisis. This study describes efforts to develop and validate the Brief Opioid Overdose Knowledge (BOOK) questionnaire to assess patient knowledge gaps related to opioid overdose risks. Two samples of illicit opioid users and a third sample of patients receiving an opioid for the treatment of chronic pain (total N = 848) completed self-report items pertaining to opioid overdose risks. A 3-factor scale was established, representing Opioid Knowledge (4 items), Opioid Overdose Knowledge (4 items), and Opioid Overdose Response Knowledge (4 items). The scale had strong internal and face validity. Patients with chronic pain performed worse than illicit drug users in almost all items assessed, highlighting the need to increase knowledge of opioid overdose risk to this population. This study sought to develop a brief, internally valid method for quickly assessing deficits in opioid overdose risk areas within users of illicit and prescribed opioids, to provide an efficient metric for assessing and comparing educational interventions, facilitate conversations between physicians and patients about overdose risks, and help formally identify knowledge deficits in other patient populations.

Development of an opioid-related Overdose Risk Behavior Scale (ORBS).

PubMed

Pouget, Enrique R; Bennett, Alex S; Elliott, Luther; Wolfson-Stofko, Brett; Almeñana, Ramona; Britton, Peter C; Rosenblum, Andrew

2017-01-01

Drug overdose has emerged as the leading cause of injury-related death in the United States, driven by prescription opioid (PO) misuse, polysubstance use, and use of heroin. To better understand opioid-related overdose risks that may change over time and across populations, there is a need for a more comprehensive assessment of related risk behaviors. Drawing on existing research, formative interviews, and discussions with community and scientific advisors an opioid-related Overdose Risk Behavior Scale (ORBS) was developed. Military veterans reporting any use of heroin or POs in the past month were enrolled using venue-based and chain referral recruitment. The final scale consisted of 25 items grouped into 5 subscales eliciting the number of days in the past 30 during which the participant engaged in each behavior. Internal reliability, test-retest reliability and criterion validity were assessed using Cronbach's alpha, intraclass correlations (ICC) and Pearson's correlations with indicators of having overdosed during the past 30 days, respectivelyInternal reliability, test-retest reliability and criterion validity were assessed using Cronbach's alpha, intraclass correlations (ICC) and Pearson's correlations with indicators of having overdosed during the past 30 days, respectively. Data for 220 veterans were analyzed. The 5 subscales-(A) Adherence to Opioid Dosage and Therapeutic Purposes; (B) Alternative Methods of Opioid Administration; (C) Solitary Opioid Use; (D) Use of Nonprescribed Overdose-associated Drugs; and (E) Concurrent Use of POs, Other Psychoactive Drugs and Alcohol-generally showed good internal reliability (alpha range = 0.61 to 0.88), test-retest reliability (ICC range = 0.81 to 0.90), and criterion validity (r range = 0.22 to 0.66). The subscales were internally consistent with each other (alpha = 0.84). The scale mean had an ICC value of 0.99, and correlations with validators ranged from 0.44 to 0.56. These results constitute preliminary

Ethanol Reversal of Tolerance to the Antinociceptive Effects of Oxycodone and Hydrocodone.

PubMed

Jacob, Joanna C; Poklis, Justin L; Akbarali, Hamid I; Henderson, Graeme; Dewey, William L

2017-07-01

This study compared the development of tolerance to two orally bioavailable prescription opioids, oxycodone and hydrocodone, to that of morphine, and the reversal of this tolerance by ethanol. Oxycodone (s.c.) was significantly more potent in the mouse tail-withdrawal assay than either morphine or hydrocodone. Oxycodone was also significantly more potent in this assay than hydrocodone when administered orally. Tolerance was seen following chronic subcutaneous administration of each of the three drugs and by the chronic administration of oral oxycodone, but not following the chronic oral administration of hydrocodone. Ethanol (1 g/kg i.p.) significantly reversed the tolerance to the subcutaneous administration of each of the three opioids that developed when given 30 minutes prior to challenge doses. It took twice as much ethanol, when given orally, to reverse the tolerance to oxycodone. We investigated whether the observed tolerance to oxycodone and its reversal by ethanol were due to biodispositional changes or reflected a true neuronal tolerance. As expected, a relationship between brain oxycodone concentrations and activity in the tail-immersion test existed following administration of acute oral oxycodone. Following chronic treatment, brain oxycodone concentrations were significantly lower than acute concentrations. Oral ethanol (2 g/kg) reversed the tolerance to chronic oxycodone, but did not alter brain concentrations of either acute or chronic oxycodone. These studies show that there is a metabolic component of tolerance to oxycodone; however, the reversal of that tolerance by ethanol is not due to an alteration of the biodisposition of oxycodone, but rather is neuronal in nature. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Development of an integrated cognitive behavioral therapy for anxiety and opioid use disorder: Study protocol and methods.

PubMed

McHugh, R Kathryn; Votaw, Victoria R; Barlow, David H; Fitzmaurice, Garrett M; Greenfield, Shelly F; Weiss, Roger D

2017-09-01

Opioid use disorder is a highly disabling psychiatric disorder, and is associated with both significant functional disruption and risk for negative health outcomes such as infectious disease and fatal overdose. Even among those who receive evidence-based pharmacotherapy for opioid use disorder, many drop out of treatment or relapse, highlighting the importance of novel treatment strategies for this population. Over 60% of those with opioid use disorder also meet diagnostic criteria for an anxiety disorder; however, efficacious treatments for this common co-occurrence have not be established. This manuscript describes the rationale and methods for a behavioral treatment development study designed to develop and test an integrated cognitive-behavioral therapy for those with co-occurring opioid use disorder and anxiety disorders. The aims of the study are (1) to develop and pilot test a new manualized cognitive behavioral therapy for co-occurring opioid use disorder and anxiety disorders, (2) to test the efficacy of this treatment relative to an active comparison treatment that targets opioid use disorder alone, and (3) to investigate the role of stress reactivity in both prognosis and recovery from opioid use disorder and anxiety disorders. Our overarching aim is to investigate whether this new treatment improves both anxiety and opioid use disorder outcomes relative to standard treatment. Identifying optimal treatment strategies for this population are needed to improve outcomes among those with this highly disabling and life-threatening disorder. Copyright © 2017 Elsevier Inc. All rights reserved.

Distress Intolerance and Prescription Opioid Misuse Among Patients With Chronic Pain.

PubMed

McHugh, R Kathryn; Weiss, Roger D; Cornelius, Marise; Martel, Marc O; Jamison, Robert N; Edwards, Robert R

2016-07-01

The risk for misuse of opioid medications is a significant challenge in the management of chronic pain. The identification of those who may be at greater risk for misusing opioids is needed to facilitate closer monitoring of high-risk subgroups, and may help to identify therapeutic targets for mitigating this risk. The aim of this study was to examine whether distress intolerance-the perceived or actual inability to manage negative emotional and somatic states-was associated with opioid misuse in those with chronic pain. A sample of 51 participants prescribed opioid analgesics for chronic back or neck pain were recruited for a 1-time laboratory study. Participants completed measures of distress intolerance and opioid misuse, and a quantitative sensory testing battery. Results suggested that distress intolerance was associated with opioid misuse, even controlling for pain severity and negative affect. Distress intolerance was not associated with pain severity, threshold, or tolerance, but was associated with self-reported anxiety and stress after noxious stimuli. This study found robust differences in distress intolerance between adults with chronic pain with and without opioid medication misuse. Distress intolerance may be a relevant marker of risk for opioid misuse among those with chronic pain. This study demonstrated that distress intolerance was associated with opioid misuse in adults with chronic pain who were prescribed opioids. Distress intolerance can be modified with treatment, and thus may be relevant not only for identification of risk for opioid misuse, but also for mitigation of this risk. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Spinal Ceramide and Neuronal Apoptosis in Morphine Antinociceptive Tolerance

PubMed Central

Bryant, Leesa; Doyle, Tim; Chen, Zhoumo; Cuzzocrea, Salvatore; Masini, Emanuela; Vinci, M. Cristina; Esposito, Emanuela; Mazzon, Emanuela; Petrusca, Daniela Nicoleta; Petrache, Irina; Salvemini, Daniela

2009-01-01

Opiates, like morphine, are the most effective analgesics for treating acute and chronic severe pain, but their use is limited by the development of analgesic tolerance and hypersensitivity to innocuous and noxious stimuli. Because opioids are a mainstay of pain management, restoring their efficacy has great clinical importance. We have recently demonstrated that spinal ceramide, a sphingolipid signaling molecule plays a central role in the development of morphine antinociceptive tolerance. We now report that ceramide up-regulation in dorsal horn tissues in response to chronic morphine administration is associated with significant neuronal apoptosis. Inhibition of ceramide biosynthesis attenuated both the increase in neuronal apoptosis and the development of antinociceptive tolerance. These findings indicate that spinal ceramide upregulation is a key pro-apoptotic event that occurs upstream of the development of morphine antinociceptive tolerance and support the rationale for development of inhibitors of ceramide biosynthesis as adjuncts to opiates for the management of chronic pain. PMID:19631718

Distance traveled and frequency of interstate opioid dispensing in opioid shoppers and nonshoppers.

PubMed

Cepeda, M Soledad; Fife, Daniel; Yuan, Yingli; Mastrogiovanni, Greg

2013-10-01

Little is known about how far opioid shoppers travel or how often they cross state lines to fill their opioid prescriptions. This retrospective cohort study evaluated these measures for opioid shoppers and nonshoppers using a large U.S. prescription database. Patients with ≥3 opioid dispensings were followed for 18 months. A subject was considered a shopper when he or she filled overlapping opioid prescriptions written by >1 prescriber at ≥3 pharmacies. A heavy shopper had ≥5 shopping episodes. Outcomes assessed were distance traveled among pharmacies and number of states visited to fill opioid prescriptions. A total of 10,910,451 subjects were included; .7% developed any shopping behavior and their prescriptions accounted for 8.6% of all opioid dispensings. Shoppers and heavy shoppers were younger than the nonshoppers. Shoppers traveled a median of 83.8 miles, heavy shoppers 199.5 miles, and nonshoppers 0 miles. Almost 20% of shoppers or heavy shoppers, but only 4% of nonshoppers, visited >1 state. Shoppers traveled greater distances and more often crossed state borders to fill opioid prescriptions than nonshoppers, and their dispensings accounted for a disproportionate number of opioid dispensings. Sharing of data among prescription-monitoring programs will likely strengthen those programs and may decrease shopping behavior. This study shows that opioid shoppers travel greater distances and more often cross state borders to fill opioid prescriptions than nonshoppers, and their dispensings accounted for a disproportionate number of opioid dispensings. The findings support the need for data sharing among prescription-monitoring programs to deter opioid shopping behavior. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Opiate Drugs with Abuse Liability Hijack the Endogenous Opioid System to Disrupt Neuronal and Glial Maturation in the Central Nervous System.

PubMed

Hauser, Kurt F; Knapp, Pamela E

2017-01-01

The endogenous opioid system, comprised of multiple opioid neuropeptide and receptor gene families, is highly expressed by developing neural cells and can significantly influence neuronal and glial maturation. In many central nervous system (CNS) regions, the expression of opioid peptides and receptors occurs only transiently during development, effectively disappearing with subsequent maturation only to reemerge under pathologic conditions, such as with inflammation or injury. Opiate drugs with abuse liability act to modify growth and development by mimicking the actions of endogenous opioids. Although typically mediated by μ-opioid receptors, opiate drugs can also act through δ- and κ-opioid receptors to modulate growth in a cell-type, region-specific, and developmentally regulated manner. Opioids act as biological response modifiers and their actions are highly contextual, plastic, modifiable, and influenced by other physiological processes or pathophysiological conditions, such as neuro-acquired immunodeficiency syndrome. To date, most studies have considered the acute effects of opiates on cellular maturation. For example, activating opioid receptors typically results in acute growth inhibition in both neurons and glia. However, with sustained opioid exposure, compensatory factors become operative, a concept that has been largely overlooked during CNS maturation. Accordingly, this article surveys prior studies on the effects of opiates on CNS maturation, and also suggests new directions for future research in this area. Identifying the cellular and molecular mechanisms underlying the adaptive responses to chronic opiate exposure (e.g., tolerance) during maturation is crucial toward understanding the consequences of perinatal opiate exposure on the CNS.

Definition Development and Prevalence of New Persistent Opioid Use Following Hysterectomy.

PubMed

Swenson, Carolyn W; Kamdar, Neil S; Seiler, Kristian; Morgan, Daniel M; Lin, Paul; As-Sanie, Sawsan

2018-06-18

Opioids used for postoperative pain control after surgery have been associated with an increased risk of chronic opioid use. Hysterectomy is the most common major gynecologic procedure in the United States; however, we lack a data-driven definition of new persistent opioid use specific to hysterectomy. 1) Determine a data-driven definition of new persistent opioid use among opioid naïve women undergoing hysterectomy; 2) Determine the prevalence of and risk factors for new persistent opioid use. We used data from Optum Clinformatics that includes both medical and pharmacy data from a single national private health insurer. Hysterectomies performed from January 1, 2011 to December 31, 2014 were identified using Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes. Inclusion criteria included: age ≤ 63 years at hysterectomy, no opioid fills for eight months preceding (excluding the 30 days immediately prior), and no additional surgical procedures within six months post-hysterectomy. The perioperative period was defined as 30 days prior to 14 days after hysterectomy. Number of opioid prescription fills, days supplied, and total oral morphine equivalents were analyzed to determine the distribution of opioid use in the perioperative and postoperative periods. We obtained demographics including age, race, educational level, and division of the country according to the U.S. Census Bureau and used International Classification of Diseases, Ninth Revision diagnosis codes to identify hysterectomy indications, surgical route, chronic pain disorders, depression/anxiety, and substance abuse. Bivariate analyses were used to compare persistent to non-persistent opioid users. A hierarchical logistic regression model controlling for regional variation was used to determine factors associated with new persistent opioid use following hysterectomy. 24,331 women were included in the analysis. "New persistent opioid use" was defined as: �

Anti-nociceptive interactions between opioids and a cannabinoid receptor 2 agonist in inflammatory pain

PubMed Central

Hale, David E; Guindon, Josée; Morgan, Daniel J

2017-01-01

The cannabinoid 1 receptor and cannabinoid 2 receptor can both be targeted in the treatment of pain; yet, they have some important differences. Cannabinoid 1 receptor is expressed at high levels in the central nervous system, whereas cannabinoid 2 receptor is found predominantly, although not exclusively, outside the central nervous system. The objective of this study was to investigate potential interactions between cannabinoid 2 receptor and the mu-opioid receptor in pathological pain. The low level of adverse side effects and lack of tolerance for cannabinoid 2 receptor agonists are attractive pharmacotherapeutic traits. This study assessed the anti-nociceptive effects of a selective cannabinoid 2 receptor agonist (JWH-133) in pathological pain using mice subjected to inflammatory pain using the formalin test. Furthermore, we examined several ways in which JWH-133 may interact with morphine. JWH-133 produces dose-dependent anti-nociception during both the acute and inflammatory phases of the formalin test. This was observed in both male and female mice. However, a maximally efficacious dose of JWH-133 (1 mg/kg) was not associated with somatic withdrawal symptoms, motor impairment, or hypothermia. After eleven once-daily injections of 1 mg/JWH-133, no tolerance was observed in the formalin test. Cross-tolerance for the anti-nociceptive effects of JWH-133 and morphine were assessed to gain insight into physiologically relevant cannabinoid 2 receptor and mu-opioid receptor interaction. Mice made tolerant to the effects of morphine exhibited a lower JWH-133 response in both phases of the formalin test compared to vehicle-treated morphine-naïve animals. However, repeated daily JWH-133 administration did not cause cross-tolerance for morphine, suggesting opioid and cannabinoid 2 receptor cross-tolerance is unidirectional. However, preliminary data suggest co-administration of JWH-133 with morphine modestly attenuates morphine tolerance. Isobolographic analysis

Low efficacy of non-opioid drugs in opioid withdrawal symptoms.

PubMed

Hermann, Derik; Klages, Eckard; Welzel, Helga; Mann, Karl; Croissant, Bernhard

2005-06-01

Opioid withdrawal, stress or cues associated with opioid consumption can induce opioid craving. If opioids are not available, opioid-dependent patients usually search for alternative drugs. Because several non-opioid drugs stimulate the endogenous opioidergic system, this concept may explain their frequent use by opioid-dependent patients. We hypothesized that non-opioid drugs alleviate opioid withdrawal symptoms and are therefore consumed by opioid addicts. We asked 89 opioid-dependent patients participating in an out-patient opioid maintenance program to estimate the potential of several non-opioid drugs in being able to alleviate opioid withdrawal. We applied a five-point Lickert scale (1 = very good reduction of opioid withdrawal; 5 = no reduction of opioid withdrawal). Patients could also indicate a worsening of opioid withdrawal. Values (mean +/- SD) were: for benzodiazepines, 3.2 +/- 1.1; tricyclic antidepressants, 3.6 +/- 1.1; cannabis, 3.6 +/- 1.0; alcohol, 4.1 +/- 1.1; cocaine, 4.2 +/- 1.1; amphetamine, 4.4 +/- 0.9; nicotine, 4.7 +/- 0.7; and caffeine, 4.9 +/- 0.5. A worsening of opioid withdrawal was reported by 62% of the patients for cocaine, 62% for amphetamine, 50% for caffeine, 37.5% for cannabis, 27% for nicotine, 26% for alcohol, 8% for tricyclic antidepressants and 3% for benzodiazepines. Our study shows a low efficacy of non-opioid drugs in alleviating opioid withdrawal symptoms. The data basis of this study was good and the sample was suitable to be asked for estimations of drug-drug interactions. Of the patients, 26 - 62% even reported a worsening of opioid withdrawal for cannabis, alcohol, cocaine and amphetamine. Only benzodiazepines and tricyclic antidepressants were reported to have a moderate positive effect on opioid withdrawal.

Endogenous opioid systems: physiological role in the self-limitation of seizures.

PubMed

Tortella, F C; Long, J B; Holaday, J W

1985-04-15

Immediately following a seizure, the severity of subsequent seizures is significantly reduced. The involvement of endogenous opioid systems as a physiological regulator of this postseizure inhibition was studied in rats using repeated maximal electroshock (MES) seizures. Both the opiate antagonist (-)-naloxone and morphine tolerance abolished the progressive seizure protection associated with repeated MES. We propose that endogenous opioids, activated by a prior seizure, provide a central homeostatic inhibitory mechanism which may be responsible for the initiation of a postictal refractory state in the epileptic.

The Influence of Prescription Opioid Use Duration and Dose on Development of Treatment Resistant Depression

PubMed Central

Scherrer, Jeffrey F.; Salas, Joanne; Sullivan, Mark D.; Schneider, F. David; Bucholz, Kathleen K.; Burroughs, Thomas; Copeland, Laurel; Ahmedani, Brian; Lustman, Patrick J.

2016-01-01

Long-term prescription opioid use is associated both with new-onset and recurrence of depression. Whether chronic opioid use interferes with depression management has not been reported, therefore we determined whether patients’ longer duration of opioid use and higher opioid dose are associated with new-onset treatment resistant depression (TRD) after controlling for confounding from pain and other variables. Data was obtained from Veteran Health Administration (VHA) de-identified patient medical records. We used a retrospective cohort design from 2000–2012. Eligible subjects (n=6,169) were 18–80 years of age, free of cancer and HIV, diagnosed with depression and opioid-free for the 24-month interval prior to the observation period. Duration of a new prescription for opioid analgesic was categorized as 1–30 days, 31–90 days and >90 days. Morphine-equivalent dose (MED) during follow-up categorized as ≤50 mg versus >50 mg per day. Pain and other sources of confounding were controlled by propensity scores and inverse probability of treatment weighting. Cox proportional hazard models were computed to estimate the association between duration and dose of opioid and onset of TRD. After removing confounding by weighting data, opioid use for 31–90 days and for >90 days, compared to 1–30 days, was significantly associated with new onset TRD (HR=1.25; 95%CI: 1.09–1.45 and HR=1.52; 95%CI: 1.32–1.74, respectively). MED was not associated with new onset TRD. The risk of developing TRD increased as time spent on opioid analgesics increased. Long-term opioid treatment of chronic pain may interfere with treatment of depression. PMID:27497660

Non-analgesic effects of opioids: opioids and the endocrine system.

PubMed

Elliott, Jennifer A; Opper, Susan E; Agarwal, Sonali; Fibuch, Eugene E

2012-01-01

Opioids are among the oldest known and most widely used analgesics. The application of opioids has expanded over the last few decades, especially in the treatment of chronic non-malignant pain. This upsurge in opioid use has been accompanied by the increasingly recognized occurrence of opioid-associated endocrinopathy. This may arise after exposure to enteral, parenteral, or neuraxial opioids. Opioid-associated endocrinopathy consists primarily of hypothalamic-pituitary-gonadal axis or hypothalamic-pituitary-adrenal axis dysfunction and may manifest with symptoms of hypogonadism, adrenal dysfunction, and other hormonal disturbances. Additionally, opioid related endocrine dysfunction may be coupled with such disorders as osteoporosis and mood disturbances including depression. Undesirable changes in pain sensitivity such as opioid-induced hyperalgesia, and reduced potency of opioid analgesia may also be potential consequences of chronic opioid consumption. Few studies to date have been able to establish what degree of opioid exposure, in terms of dose or duration of therapy, may predispose patients to opioid-associated endocrinopathy. This article will review the currently available literature concerning opioid-associated endocrinopathy and will provide recommendations for the evaluation, monitoring, and management of opioid-associated endocrinopathy and its other accompanying undesired effects.

Investigational opioid antagonists for treating opioid-induced bowel dysfunction.

PubMed

Mozaffari, Shilan; Nikfar, Shekoufeh; Abdollahi, Mohammad

2018-03-01

Opioids have been highlighted for their role in pain relief among cancer and non-cancer patients. Novel agents have been investigated to reduce opioid-induced constipation (OIC) as the main adverse effect that may lead to treatment discontinuation. Development of peripherally acting mu-opioid receptor antagonists (PAMORA) has resulted in a novel approach to preserve the efficacy of pain control along with less OIC. Areas covered: Clinical evidence for investigational PAMORAs was reviewed and clinical trials on investigational agents to reduce OIC were included. TD-1211 is currently being evaluated in Phase II clinical trial. Oxycodone-naltrexone and ADL-5945 went through Phase III clinical trials, but have been discontinued. Expert opinion: There is a substantial need to develop agents with specific pharmacokinetic properties to meet the needs of patients with underlying diseases. Holding the efficacy of a medicine with the highest selectivity on targeted receptors and the least adverse effects is the main approach in upcoming investigations to improve patients' quality of life (QoL). Novel agents to reduce opioid-induced bowel dysfunction (OIBD) that do not reverse peripherally mediated pain analgesia are of great interest. Direct comparison of available agents in this field is lacking in the literature.

Opioid-use disorder among patients on long-term opioid therapy: impact of final DSM-5 diagnostic criteria on prevalence and correlates.

PubMed

Boscarino, Joseph A; Hoffman, Stuart N; Han, John J

2015-01-01

Previously, we estimated the prevalence and risk factors for prescription opioid-use disorder among outpatients on opioid therapy using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 and DSM-4 criteria. However, at the time, the DSM-5 criteria were not finalized. In the current study, we analyzed these data using the final DSM-5 criteria and compared these results. Using electronic records from a large US health care system, we identified outpatients receiving five or more prescription orders for opioid therapy in the past 12 months for noncancer pain (mean prescription orders =10.72; standard deviation =4.96). In 2008, we completed diagnostic interviews with 705 of these patients using the DSM-4 criteria. In the current study, we reassessed these results using the final DSM-5 criteria. The lifetime prevalence of DSM-5 opioid-use disorders using the final DSM-5 criteria was 58.7% for no or few symptoms (<2), 28.1% for mild symptoms (2-3), 9.7% for moderate symptoms (4-5), and 3.5% for severe symptoms (six or more). Thus, the lifetime prevalence of "any" prescription opioid-use disorder in this cohort was 41.3% (95% confidence interval [CI] =37.6-45.0). A comparison to the DSM-4 criteria indicated that the majority of patients with lifetime DSM-4 opioid dependence were now classified as having mild opioid-use disorder, based on the DSM-5 criteria (53.6%; 95% CI =44.1-62.8). In ordinal logistic regression predicting no/few, mild, moderate, and severe opioid-use disorder, the best predictors were age <65 years, current pain impairment, trouble sleeping, suicidal thoughts, anxiety disorders, illicit drug use, and history of substance abuse treatment. Given the final DSM-5 criteria, including the elimination of tolerance and withdrawal, inclusion of craving and abuse symptoms, and introduction of a new graded severity classification, the prevalence of opioid-use disorders has changed, while many of the DSM-4 risk factors for opioid dependence were

Opioid-use disorder among patients on long-term opioid therapy: impact of final DSM-5 diagnostic criteria on prevalence and correlates

PubMed Central

Boscarino, Joseph A; Hoffman, Stuart N; Han, John J

2015-01-01

Aims Previously, we estimated the prevalence and risk factors for prescription opioid-use disorder among outpatients on opioid therapy using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 and DSM-4 criteria. However, at the time, the DSM-5 criteria were not finalized. In the current study, we analyzed these data using the final DSM-5 criteria and compared these results. Methods Using electronic records from a large US health care system, we identified outpatients receiving five or more prescription orders for opioid therapy in the past 12 months for noncancer pain (mean prescription orders =10.72; standard deviation =4.96). In 2008, we completed diagnostic interviews with 705 of these patients using the DSM-4 criteria. In the current study, we reassessed these results using the final DSM-5 criteria. Results The lifetime prevalence of DSM-5 opioid-use disorders using the final DSM-5 criteria was 58.7% for no or few symptoms (<2), 28.1% for mild symptoms (2–3), 9.7% for moderate symptoms (4–5), and 3.5% for severe symptoms (six or more). Thus, the lifetime prevalence of “any” prescription opioid-use disorder in this cohort was 41.3% (95% confidence interval [CI] =37.6–45.0). A comparison to the DSM-4 criteria indicated that the majority of patients with lifetime DSM-4 opioid dependence were now classified as having mild opioid-use disorder, based on the DSM-5 criteria (53.6%; 95% CI =44.1–62.8). In ordinal logistic regression predicting no/few, mild, moderate, and severe opioid-use disorder, the best predictors were age <65 years, current pain impairment, trouble sleeping, suicidal thoughts, anxiety disorders, illicit drug use, and history of substance abuse treatment. Conclusion Given the final DSM-5 criteria, including the elimination of tolerance and withdrawal, inclusion of craving and abuse symptoms, and introduction of a new graded severity classification, the prevalence of opioid-use disorders has changed, while many of the DSM-4

Probing ligand recognition of the opioid pan antagonist AT-076 at nociceptin, kappa, mu, and delta opioid receptors through structure-activity relationships.

PubMed

Journigan, V Blair; Polgar, Willma E; Tuan, Edward W; Lu, James; Daga, Pankaj R; Zaveri, Nurulain T

2017-10-16

Few opioid ligands binding to the three classic opioid receptor subtypes, mu, kappa and delta, have high affinity at the fourth opioid receptor, the nociceptin/orphanin FQ receptor (NOP). We recently reported the discovery of AT-076 (1), (R)-7-hydroxy-N-((S)-1-(4-(3-hydroxyphenyl)piperidin-1-yl)-3-methylbutan-2-yl)-1,2,3,4-tetrahydroisoquinoline-3-carboxamide, a pan antagonist with nanomolar affinity for all four subtypes. Since AT-076 binds with high affinity at all four subtypes, we conducted a structure-activity relationship (SAR) study to probe ligand recognition features important for pan opioid receptor activity, using chemical modifications of key pharmacophoric groups. SAR analysis of the resulting analogs suggests that for the NOP receptor, the entire AT-076 scaffold is crucial for high binding affinity, but the binding mode is likely different from that of NOP antagonists C-24 and SB-612111 bound in the NOP crystal structure. On the other hand, modifications of the 3-hydroxyphenyl pharmacophore, but not the 7-hydroxy Tic pharmacophore, are better tolerated at kappa and mu receptors and yield very high affinity multifunctional (e.g. 12) or highly selective (e.g. 16) kappa ligands. With the availability of the opioid receptor crystal structures, our SAR analysis of the common chemotype of AT-076 suggests rational approaches to modulate binding selectivity, enabling the design of multifunctional or selective opioid ligands from such scaffolds.

Comparison of the risks of shopping behavior and opioid abuse between tapentadol and oxycodone and association of shopping behavior and opioid abuse.

PubMed

Cepeda, M Soledad; Fife, Daniel; Kihm, Mary A; Mastrogiovanni, Greg; Yuan, Yingli

2014-12-01

This study compared the risks of opioid shopping behavior and opioid abuse between tapentadol immediate release and oxycodone immediate release and, to validate the definition of shopping, examined the association between opioid shopping and opioid abuse further. This retrospective cohort study using linked dispensing and diagnosis databases followed opioid-naive patients for development of shopping behavior and/or opioid abuse during 1 year after initial exposure to tapentadol or oxycodone. Shopping was defined by having overlapping opioid prescriptions from >1 prescriber filled at ≥3 pharmacies; abuse by having International Classification of Diseases, 9th revision diagnoses reflecting opioid abuse, addiction, or dependence. To determine their association, we cross-tabulated shopping and opioid abuse and calculated odds ratios. Risks of developing each outcome were estimated using logistic regression. Among 277,401 participants initiating opioid use with tapentadol (39,524) or oxycodone (237,877), 0.6% developed shopping behavior, 0.75% developed abuse. Higher proportions of patients in the oxycodone group developed shopping behavior and abuse than in the tapentadol group (shopping: adjusted odds ratio [95% confidence interval], 0.45 [0.36-0.55]; abuse: 0.44 [0.37-0.54]). Shopping behavior and abuse were associated; of those with shopping behavior, 6.5% had abuse. Age (18 to 64 y), sex (male), prior benzodiazepine use, paying cash, and history (mood disorders, abuse of nonopioid medications, and back pain) were risk factors for developing either outcome. Shopping behavior and abuse measure complementary, but associated, constructs, which further validates the current definition of shopping. The risk of developing either is lower among patients who initiate opioid use with tapentadol than those who initiate opioid use with oxycodone.

Development of dependence following treatment with opioid analgesics for pain relief: a systematic review.

PubMed

Minozzi, Silvia; Amato, Laura; Davoli, Marina

2013-04-01

To assess the incidence or prevalence of opioid dependence syndrome in adults (with and without previous history of substance abuse) following treatment with opioid analgesics for pain relief. Medline, Embase, CINHAL and the Cochrane Library were searched up to January 2011. Systematic reviews and primary studies were included if they reported data about incidence or prevalence of opioid dependence syndrome (as defined by DSM-IV or ICD-10) in patients receiving strong opioids (or opioid-type analgesics) for treatment of acute or chronic pain due to any physical condition. The data were abstracted, and the methodological quality was assessed using validated checklists. Data were extracted from 17 studies involving a total of 88 235 participants. The studies included three systematic reviews, one randomized controlled trial, eight cross-sectional studies and four uncontrolled case series. Most studies included adult patients with chronic non-malignant pain; two also included patients with cancer pain; only one included patients with a previous history of dependence. Incidence ranged from 0 to 24% (median 0.5%); prevalence ranged from 0 to 31% (median 4.5%). The available evidence suggests that opioid analgesics for chronic pain conditions are not associated with a major risk for developing dependence. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

Endomorphin-2 analogs with C-terminal esterification produce potent systemic antinociception with reduced tolerance and gastrointestinal side effects.

PubMed

Wang, Chang-Lin; Qiu, Ting-Ting; Yang, Dai-Jun; Yuan, Bi-Yu; Han, Feng-Tong; Li, Li; Gu, Ning

2017-04-01

C-terminal esterification of opioid peptides may change their opioid activities due to the modified physicochemical properties. In the present study, the pharmacological activities of C-terminal esterified endomorphin-2 (EM-2) analogs 1-3 were characterized by in vitro metabolic stability and octanol/buffer distribution assays. Also, the antinociceptive profiles in the radiant heat paw withdrawal test and related side effects of these analogs were determined. Our results showed that all three analogs significantly increased the metabolic stability and lipophilicity. Moreover, analogs 1-3 displayed potent antinociceptive activities after intracerebroventricular (i.c.v.) administration. Analogs 1 and 3 exhibited about 2-fold higher antinociception than EM-2, and differential opioid mechanisms were involved. In addition, EM-2 at 50 μmol/kg failed to produce any significant antinociceptive activity after subcutaneous (s.c.) administration, whereas equimolar dose of analogs 1-3 produced significant analgesic effects. Analog 3 showed the highest antinociceptive activity after systemic administration, which was consistent with its in vitro stability and lipophilicity. We further evaluated the antinociceptive tolerance of analogs 1-3. In acute tolerance test, analogs 1-3 shifted the dose-response curves rightward by only 1.4-3.2 fold as determined by tolerance ratio, whereas EM-2 by 5.6-fold, demonstrating reduced antinociceptive tolerance. Also, analogs 1 and 2 decreased chronic antinociceptive tolerance by central and peripheral administration of drugs. In particular, analogs 3 displayed insignificant chronic antinociceptive tolerance. Furthermore, analogs 1-3 were less prone to induce gastrointestinal side effects at analgesic doses. The present investigation gave the evidence that C-terminal esterified modifications of EM-2 will facilitate the development of novel opioid analgesics with reduced side effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Opioid-Induced Bowel Dysfunction

PubMed Central

Cheng, Vivian; Lembo, Anthony

2013-01-01

Opioid-induced bowel dysfunction (OIBD) is a potentially debilitating side effect of chronic opioid use. It refers to a collection of primarily gastrointestinal motility disorders induced by opioids, of which opioid-induced constipation (OIC) is the most common. Management of OIBD is difficult, and affected patients will often limit their opioid intake at the expense of experiencing more pain, to reduce the negative impact of OIBD on their quality of life. Effective pharmacologic therapy for OIC is considered an unmet need and several agents have recently been given priority review and approval for OIC. Furthermore, multiple agents currently in development show promise in treating OIC without significant impact on analgesia or precipitation of withdrawal symptoms. The approval and availability of such medications would represent a significant improvement in the management of OIC and OIBD in patients with chronic pain. PMID:23900996

Opioid Use Disorders

PubMed Central

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

2016-01-01

Opioid use and addiction in adolescents and young adults, including heroin and non-medical use of prescription opioids, is a serious and growing health problem of epidemic proportions. Opioid use has devastating consequences for youth and their families, including: progression to full addiction, severe psychosocial impairment, HCV and HIV transmission with injection use, exacerbation of co-occurring psychiatric disorders, overdose, and death. This chapter will provide an overview of opioid use disorders (OUDs) in youth, including: etiologic factors, epidemiology, consequences, clinical presentation and course, assessment and diagnosis, overdose, detoxification, and treatment. Opioid overdose is a life-threatening emergency. Respiratory depression should be treated with naloxone, and respiratory support if necessary. Overdose should always be utilized as an opportunity to initiate addiction treatment. Opioid withdrawal management (detoxification) is often a necessary, but never sufficient, component of treatment for OUDs. Medications used in the treatment of withdrawal may include buprenorphine, clonidine and others for relief of symptoms. Treatment for OUDs is effective but treatment capacity is alarmingly limited and under-developed. Although there is a limited evidence base for youth specific treatment, 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

Are Prescription Opioids Driving the Opioid Crisis? Assumptions vs Facts.

PubMed

Rose, Mark Edmund

2018-04-01

Sharp increases in opioid prescriptions, and associated increases in overdose deaths in the 2000s, evoked widespread calls to change perceptions of opioid analgesics. Medical literature discussions of opioid analgesics began emphasizing patient and public health hazards. Repetitive exposure to this information may influence physician assumptions. While highly consequential to patients with pain whose function and quality of life may benefit from opioid analgesics, current assumptions about prescription opioid analgesics, including their role in the ongoing opioid overdose epidemic, have not been scrutinized. Information was obtained by searching PubMed, governmental agency websites, and conference proceedings. Opioid analgesic prescribing and associated overdose deaths both peaked around 2011 and are in long-term decline; the sharp overdose increase recorded in 2014 was driven by illicit fentanyl and heroin. Nonmethadone prescription opioid analgesic deaths, in the absence of co-ingested benzodiazepines, alcohol, or other central nervous system/respiratory depressants, are infrequent. Within five years of initial prescription opioid misuse, 3.6% initiate heroin use. The United States consumes 80% of the world opioid supply, but opioid access is nonexistent for 80% and severely restricted for 4.1% of the global population. Many current assumptions about opioid analgesics are ill-founded. Illicit fentanyl and heroin, not opioid prescribing, now fuel the current opioid overdose epidemic. National discussion has often neglected the potentially devastating effects of uncontrolled chronic pain. Opioid analgesic prescribing and related overdoses are in decline, at great cost to patients with pain who have benefited or may benefit from, but cannot access, opioid analgesic therapy.

[Functional selectivity of opioid receptors ligands].

PubMed

Audet, Nicolas; Archer-Lahlou, Elodie; Richard-Lalonde, Mélissa; Piñeyro-Filpo, Graciela

2010-01-01

Opiates are the most effective analgesics available for the treatment of severe pain. However, their clinical use is restricted by unwanted side effects such as tolerance, physical dependence and respiratory depression. The strategy to develop new opiates with reduced side effects has mainly focused on the study and production of ligands that specifically bind to different opiate receptors subtypes. However, this strategy has not allowed the production of novel therapeutic ligands with a better side effects profile. Thus, other research strategies need to be explored. One which is receiving increasing attention is the possibility of exploiting ligand ability to stabilize different receptor conformations with distinct signalling profiles. This newly described property, termed functional selectivity, provides a potential means of directing the stimulus generated by an activated receptor towards a specific cellular response. Here we summarize evidence supporting the existence of ligand-specific active conformations for two opioid receptors subtypes (delta and mu), and analyze how functional selectivity may contribute in the production of longer lasting, better tolerated opiate analgesics. double dagger.

Comparison of the Risks of Shopping Behavior and Opioid Abuse Between Tapentadol and Oxycodone and Association of Shopping Behavior and Opioid Abuse

PubMed Central

Fife, Daniel; Kihm, Mary A.; Mastrogiovanni, Greg; Yuan, Yingli

2014-01-01

Objectives: This study compared the risks of opioid shopping behavior and opioid abuse between tapentadol immediate release and oxycodone immediate release and, to validate the definition of shopping, examined the association between opioid shopping and opioid abuse further. Materials and Methods: This retrospective cohort study using linked dispensing and diagnosis databases followed opioid-naive patients for development of shopping behavior and/or opioid abuse during 1 year after initial exposure to tapentadol or oxycodone. Shopping was defined by having overlapping opioid prescriptions from >1 prescriber filled at ≥3 pharmacies; abuse by having International Classification of Diseases, 9th revision diagnoses reflecting opioid abuse, addiction, or dependence. To determine their association, we cross-tabulated shopping and opioid abuse and calculated odds ratios. Risks of developing each outcome were estimated using logistic regression. Results: Among 277,401 participants initiating opioid use with tapentadol (39,524) or oxycodone (237,877), 0.6% developed shopping behavior, 0.75% developed abuse. Higher proportions of patients in the oxycodone group developed shopping behavior and abuse than in the tapentadol group (shopping: adjusted odds ratio [95% confidence interval], 0.45 [0.36-0.55]; abuse: 0.44 [0.37-0.54]). Shopping behavior and abuse were associated; of those with shopping behavior, 6.5% had abuse. Age (18 to 64 y), sex (male), prior benzodiazepine use, paying cash, and history (mood disorders, abuse of nonopioid medications, and back pain) were risk factors for developing either outcome. Discussion: Shopping behavior and abuse measure complementary, but associated, constructs, which further validates the current definition of shopping. The risk of developing either is lower among patients who initiate opioid use with tapentadol than those who initiate opioid use with oxycodone. PMID:24370606

Very low dose naltrexone addition in opioid detoxification: a randomized, controlled trial.

PubMed

Mannelli, Paolo; Patkar, Ashwin A; Peindl, Kathi; Gorelick, David A; Wu, Li-Tzy; Gottheil, Edward

2009-04-01

Although current treatments for opioid detoxification are not always effective, medical detoxification remains a required step before long-term interventions. The use of opioid antagonist medications to improve detoxification has produced inconsistent results. Very low dose naltrexone (VLNTX) was recently found to reduce opioid tolerance and dependence in animal and clinical studies. We decided to evaluate safety and efficacy of VLNTX adjunct to methadone in reducing withdrawal during detoxification. In a multi-center, double-blind, randomized study at community treatment programs, where most detoxifications are performed, 174 opioid-dependent subjects received NTX 0.125 mg, 0.250 mg or placebo daily for 6 days, together with methadone in tapering doses. VLNTX-treated individuals reported attenuated withdrawal symptoms [F = 7.24 (2,170); P = 0.001] and reduced craving [F = 3.73 (2,107); P = 0.03]. Treatment effects were more pronounced at discharge and were not accompanied by a significantly higher retention rate. There were no group differences in use of adjuvant medications and no treatment-related adverse events. Further studies should explore the use of VLNTX, combined with full and partial opioid agonist medications, in detoxification and long-term treatment of opioid dependence.

Psychophysiology of pain and opioid use: implications for managing pain in patients with an opioid use disorder.

PubMed

Wachholtz, Amy; Foster, Simmie; Cheatle, Martin

2015-01-01

Opioid therapy is one component of an effective pain management regimen for patients with chronic pain and the majority of these patients use their medications responsibly. However, there are a growing number of these patients who develop an opioid use disorder and in some cases require opioid replacement therapy. Managing these patients is complex and the underlying mechanisms of pain and addiction are not well understood. Developing an effective interdisciplinary treatment program for the individual with pain and an opioid use disorder will depend on enhancing our knowledge of the psychophysiology of pain and addiction. Authors gathered key empirical and theoretical papers examining the psychophysiology of comorbid pain and opioid misuse disorders. This article reviews the current theory of the effect of pain on patients with pain and concomitant addiction, the psychophysiology of pain, opioid use and addiction, and future research in this area. Individuals with a history of opioid misuse have greater levels of hyperalgesia which may be due to alterations in psychophysiological pathways. More research is needed into the psychophysiological biomarkers among individuals with comorbid pain and addiction in order to develop better treatment approaches and improve outcomes among this difficult to treat population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Role of protein kinase C and μ-opioid receptor (MOPr) desensitization in tolerance to morphine in rat locus coeruleus neurons

PubMed Central

Bailey, C P; Llorente, J; Gabra, B H; Smith, F L; Dewey, W L; Kelly, E; Henderson, G

2009-01-01

In morphine tolerance a key question that remains to be answered is whether μ-opioid receptor (MOPr) desensitization contributes to morphine tolerance, and if so by what cellular mechanisms. Here we demonstrate that MOPr desensitization can be observed in single rat brainstem locus coeruleus (LC) neurons following either prolonged (> 4 h) exposure to morphine in vitro or following treatment of animals with morphine in vivo for 3 days. Analysis of receptor function by an operational model indicated that with either treatment morphine could induce a profound degree (70–80%) of loss of receptor function. Ongoing PKC activity in the MOPr-expressing neurons themselves, primarily by PKCα, was required to maintain morphine-induced MOPr desensitization, because exposure to PKC inhibitors for only the last 30–50 min of exposure to morphine reduced the MOPr desensitization that was induced both in vitro and in vivo. The presence of morphine was also required for maintenance of desensitization, as washout of morphine for > 2 h reversed MOPr desensitization. MOPr desensitization was homologous, as there was no change in α2-adrenoceptor or ORL1 receptor function. These results demonstrate that prolonged morphine treatment induces extensive homologous desensitization of MOPrs in mature neurons, that this desensitization has a significant PKC-dependent component and that this desensitization underlies the maintenance of morphine tolerance. PMID:19200236

Tolerance to the antinociceptive effect of morphine in the absence of short-term presynaptic desensitization in rat periaqueductal gray neurons.

PubMed

Fyfe, Leon W; Cleary, Daniel R; Macey, Tara A; Morgan, Michael M; Ingram, Susan L

2010-12-01

Opioids activate the descending antinociceptive pathway from the ventrolateral periaqueductal gray (vlPAG) by both pre- and postsynaptic inhibition of tonically active GABAergic neurons (i.e., disinhibition). Previous research has shown that short-term desensitization of postsynaptic μ-opioid receptors (MOPrs) in the vlPAG is increased with the development of opioid tolerance. Given that pre- and postsynaptic MOPrs are coupled to different signaling mechanisms, the present study tested the hypothesis that short-term desensitization of presynaptic MOPrs also contributes to opioid tolerance. Twice-daily injections of morphine (5 mg/kg s.c.) for 2 days caused a rightward shift in the morphine dose-response curve on the hot plate test (D(50) = 9.9 mg/kg) compared with saline-pretreated (5.3 mg/kg) male Sprague-Dawley rats. In vitro whole-cell patch-clamp recordings from vlPAG slices revealed that inhibition of evoked inhibitory postsynaptic currents (eIPSCs) by the MOPr-selective agonist [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin was decreased in morphine-tolerant (EC(50) = 708 nM) compared with saline-pretreated rats (EC(50) = 163 nM). However, short-term desensitization of MOPr inhibition of eIPSCs was not observed in either saline- or morphine-pretreated rats. Reducing the number of available MOPrs with the irreversible opioid receptor antagonist, β-chlornaltrexamine decreased maximal MOPr inhibition with no evidence of desensitization, indicating that the lack of observed desensitization is not caused by receptor reserve. These results demonstrate that tolerance to the antinociceptive effect of morphine is associated with a decrease in presynaptic MOPr sensitivity or coupling to effectors, but this change is independent of short-term MOPr desensitization.

Tolerance to the Antinociceptive Effect of Morphine in the Absence of Short-Term Presynaptic Desensitization in Rat Periaqueductal Gray Neurons

PubMed Central

Fyfe, Leon W.; Cleary, Daniel R.; Macey, Tara A.; Morgan, Michael M.

2010-01-01

Opioids activate the descending antinociceptive pathway from the ventrolateral periaqueductal gray (vlPAG) by both pre- and postsynaptic inhibition of tonically active GABAergic neurons (i.e., disinhibition). Previous research has shown that short-term desensitization of postsynaptic μ-opioid receptors (MOPrs) in the vlPAG is increased with the development of opioid tolerance. Given that pre- and postsynaptic MOPrs are coupled to different signaling mechanisms, the present study tested the hypothesis that short-term desensitization of presynaptic MOPrs also contributes to opioid tolerance. Twice-daily injections of morphine (5 mg/kg s.c.) for 2 days caused a rightward shift in the morphine dose-response curve on the hot plate test (D50 = 9.9 mg/kg) compared with saline-pretreated (5.3 mg/kg) male Sprague-Dawley rats. In vitro whole-cell patch-clamp recordings from vlPAG slices revealed that inhibition of evoked inhibitory postsynaptic currents (eIPSCs) by the MOPr-selective agonist [d-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin was decreased in morphine-tolerant (EC50 = 708 nM) compared with saline-pretreated rats (EC50 = 163 nM). However, short-term desensitization of MOPr inhibition of eIPSCs was not observed in either saline- or morphine-pretreated rats. Reducing the number of available MOPrs with the irreversible opioid receptor antagonist, β-chlornaltrexamine decreased maximal MOPr inhibition with no evidence of desensitization, indicating that the lack of observed desensitization is not caused by receptor reserve. These results demonstrate that tolerance to the antinociceptive effect of morphine is associated with a decrease in presynaptic MOPr sensitivity or coupling to effectors, but this change is independent of short-term MOPr desensitization. PMID:20739455

Analysis of opioid-mediated analgesia in Phase III studies of methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain

PubMed Central

Webster, Lynn R; Brenner, Darren M; Barrett, Andrew C; Paterson, Craig; Bortey, Enoch; Forbes, William P

2015-01-01

Background Subcutaneous methylnaltrexone is efficacious and well tolerated for opioid-induced constipation (OIC) but may theoretically disrupt opioid-mediated analgesia. Methods Opioid use, pain intensity, and opioid withdrawal (Objective Opioid Withdrawal Scale [OOWS] and Subjective Opiate Withdrawal Scale [SOWS] scores) were reported in a randomized, double-blind trial with an open-label extension (RCT) and an open-label trial (OLT) evaluating safety in adults with chronic noncancer pain. In the RCT, patients taking ≥50 mg of oral morphine equivalents daily with <3 rescue-free bowel movements weekly received methyl naltrexone 12 mg once daily (n=150), every other day (n=148), or placebo (n=162) for 4 weeks, followed by open-label methylnaltrexone 12 mg (as needed [prn]; n=364) for 8 weeks. In the OLT, patients (n=1,034) on stable opioid doses with OIC received methylnaltrexone 12 mg prn for up to 48 weeks. Results Minimal fluctuations of median morphine equivalent dose from baseline (BL) were observed in the RCT double-blind period (BL, 154.8–161.0 mg/d; range, 137.1–168.0 mg/d), RCT open-label period (BL, 156.3–174.6; range, 144.0–180.0) and OLT (BL, 120 mg/d; range, 117.3–121.1 mg/d). No significant change from BL in pain intensity score occurred in any group at weeks 2 or 4 (both P≥0.1) of the RCT double-blind period, and scores remained stable during the open-label period and in the OLT (mean change, −0.2 to 0.1). Changes from BL in OOWS and SOWS scores during the double-blind period were not significantly impacted by methylnaltrexone exposure at weeks 2 or 4 (P>0.05 for all). Conclusion Methylnaltrexone did not affect opioid-mediated analgesia in patients with chronic noncancer pain and OIC. PMID:26586963

Development of a brief tool for monitoring aberrant behaviours among patients receiving long-term opioid therapy: The Opioid-Related Behaviours In Treatment (ORBIT) scale.

PubMed

Larance, Briony; Bruno, Raimondo; Lintzeris, Nicholas; Degenhardt, Louisa; Black, Emma; Brown, Amanda; Nielsen, Suzanne; Dunlop, Adrian; Holland, Rohan; Cohen, Milton; Mattick, Richard P

2016-02-01

Early identification of problems is essential in minimising the unintended consequences of opioid therapy. This study aimed to develop a brief scale that identifies and quantifies recent aberrant behaviour among diverse patient populations receiving long-term opioid treatment. 40 scale items were generated via literature review and expert panel (N=19) and tested in surveys of: (i) N=41 key experts, and (ii) N=426 patients prescribed opioids >3 months (222 pain patients and 204 opioid substitution therapy (OST) patients). We employed item and scale psychometrics (exploratory factor analyses, confirmatory factor analyses and item-response theory statistics) to refine items to a brief scale. Following removal of problematic items (poor retest-reliability or wording, semantic redundancy, differential item functioning, collinearity or rarity) iterative factor analytic procedures identified a 10-item unifactorial scale with good model fit in the total sample (N=426; CFI=0.981, TLI=0.975, RMSEA=0.057), and among pain (CFI=0.969, TLI=0.960, RMSEA=0.062) and OST subgroups (CFI=0.989, TFI=0.986, RMSEA=0.051). The 10 items provided good discrimination between groups, demonstrated acceptable test-retest reliability (ICC 0.80, 95% CI 0.60-0.89; Cronbach's alpha=0.89), were moderately correlated with related constructs, including opioid dependence (SDS), depression and stress (DASS subscales) and Social Relationships and Environment domains of the WHO-QoL, and had strong face validity among advising clinicians. The Opioid-Related Behaviours In Treatment (ORBIT) scale is brief, reliable and validated for use in diverse patient groups receiving opioids. The ORBIT has potential applications as a checklist to prompt clinical discussions and as a tool to quantify aberrant behaviour and assess change over time. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

Attentional bias for prescription opioid cues among opioid dependent chronic pain patients.

PubMed

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

2013-12-01

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 opioid-related 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. vs. 2,000 ms.) interaction, such that opioid-dependent individuals evidenced a significant AB towards opioid cues presented for 200 ms but not for cues presented for 2,000 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.

WITHDRAWN: Opioids for the palliation of breathlessness in advanced disease and terminal illness.

PubMed

Jennings, Anne Louise; Davies, Andrew N; Higgins, Julian P T; Anzures-Cabrera, Judith; Broadley, Karen E

2012-07-11

Breathlessness is a common symptom in people with advanced disease. The most effective treatments are aimed at treating the underlying cause of the breathlessness but this may not be possible and symptomatic treatment is often necessary. Strategies for the symptomatic treatment of breathlessness have never been systematically evaluated. Opioids are commonly used to treat breathlessness: the mechanisms underlying their effectiveness are not completely clear and there have been few good-sized trials in this area. To determine the effectiveness of opioid drugs given by any route in relieving the symptom of breathlessness in patients who are being treated palliatively. An electronic search was carried out of Medline, Embase, CINAHL, T he Cochrane L ibrary, Dissertation Abstracts, Cancercd and SIGLE. Review articles and reference lists of retrieved articles were hand searched. Date of most recent search: May 1999. Randomised double-blind, controlled trials comparing the use of any opioid drug against placebo for the relief of breathlessness were included. Patients with any illness suffering from breathlessness were included and the intervention was any opioid, given by any route, in any dose. Studies identified by the search were imported into a reference manager database. The full texts of the relevant studies were retrieved and data were independently extracted by two review authors. Studies were quality scored according to the Oxford Quality scale. The primary outcome measure used was breathlessness and the secondary outcome measure was exercise tolerance. Studies were divided into non-nebulised and nebulised and were analysed both separately and together. A qualitative analysis was carried out of adverse effects of opioids. Where appropriate, meta-analysis was carried out. Eighteen studies were identified of which nine involved the non-nebulised route of administration and nine the nebulised route. A small but statistically significant positive effect of opioids was

Extended-release intramuscular naltrexone (VIVITROL®): a review of its use in the prevention of relapse to opioid dependence in detoxified patients.

PubMed

Syed, Yahiya Y; Keating, Gillian M

2013-10-01

Naltrexone is a μ-opioid receptor antagonist that blocks the euphoric effects of heroin and prescription opioids. In order to improve treatment adherence, a once-monthly, intramuscular, extended-release formulation of naltrexone (XR-NTX) [VIVITROL(®)] has been developed, and approved in the USA and Russia for the prevention of relapse to opioid dependence, after opioid detoxification. The clinical efficacy of this formulation in patients with opioid dependence was demonstrated in a 24-week, randomized, double-blind, placebo-controlled, multicentre, phase III trial (ALK21-013; n = 250). In this trial, opioid-detoxified patients receiving XR-NTX 380 mg once every 4 weeks, in combination with psychosocial support, had a significantly higher median proportion of weeks of confirmed opioid abstinence during weeks 5-24, compared with those receiving placebo (primary endpoint). A significantly higher proportion of patients receiving XR-NTX achieved total confirmed abstinence during this period than those receiving placebo. XR-NTX was also associated with a significantly greater reduction in opioid craving and a significantly longer treatment retention period than placebo. XR-NTX was generally well tolerated in the phase III trial. The most common (incidence ≥5 %) treatment-emergent adverse events that also occurred more frequently with XR-NTX than with placebo were hepatic enzyme abnormalities, nasopharyngitis, insomnia, hypertension, influenza and injection-site pain. Thus, XR-NTX is a useful treatment option for the prevention of relapse to opioid dependence, following opioid detoxification.

Treatment options for chronic pain management: opioids revisited.

PubMed

Lipman, Arthur G

2007-02-01

Pain is a public health disaster. Although it remains largely undertreated, pharmacists and pharmacy managers can do much to correct the problem. Change will require the education of patients and health care professionals on the facts pertaining to addiction, drug dependence, and drug tolerance. Evidence-based resources, including guidelines published by the APS, should be consulted. A variety of short- and long-acting drugs are available, not the least of which are the opioids. Fears regarding addiction and uncertainty about tolerance have precluded the comprehensive use of these drugs, and varying dose requirements complicate the picture. What is known, however, is that dose titration must be performed with the goal of preventing breakthrough pain. Fortunately, sufficient drug formulae have been developed to accommodate this need. Pain is the primary reason why people come into the health care system, and it is incumbent upon health care professionals to eliminate insufficient pain control, using the drugs available to the patient's best advantage.

From morphine clinics to buprenorphine: regulating opioid agonist treatment of addiction in the United States.

PubMed

Jaffe, Jerome H; O'Keeffe, Charles

2003-05-21

The practice of prescribing opioid drugs for opioid dependent patients in the U.S. has been subjected to special government scrutiny for almost 100 years. From 1920 until 1964, doctors who used opioids to treat addicts risked federal and/or state criminal prosecution. Although that period ended when oral methadone maintenance was established as legitimate medical practice, public concern about methadone diversion and accidental overdose fatalities, combined with political pressure from both hostile bureaucracies and groups committed to drug-free treatments, led to the development of unprecedented and detailed Food and Drug Administration (FDA) regulations that specified the manner in which methadone (and later, levo-alpha-acetyl methadol, or levomethadyl acetate, (LAAM)) could be provided. In 1974, Congress gave the Drug Enforcement Administration (DEA) additional oversight of methadone treatment programs. Efforts to liberalize the FDA regulations over the past 30 years have been resisted by both the DEA and existing treatment providers. Additional flexibility for clinicians may evolve from the most recent effort to create an accreditation system to replace some of the FDA regulations. The development of buprenorphine, a partial opioid agonist, as an effective treatment for opioid addiction reopened the possibility for having a less burdensome oversight process, especially because of its reduced toxicity if ingested by non-tolerant individuals. New legislation, the Drug Addiction Treatment Act (DATA) of 2000, created an opportunity for clinicians with special training to be exempted from both federal methadone regulations and the requirement to obtain a special DEA license when using buprenorphine to treat addicts. Some details of how the DATA was developed, moved through Congress, and signed into law are described.

The development and feasibility of a pharmacy-delivered opioid intervention in the emergency department

PubMed Central

Winstanley, Erin L.; Mashni, Rebecca; Schnee, Sydney; Miller, Nate; Mashni, Susan M.

2017-01-01

Objectives To develop a brief intervention and to assess the feasibility of pharmacy-delivered education on opioid safety and overdose prevention in the emergency department. Methods A convenience sample of patients (n = 102) approached between May and June 2016 at a single community-based suburban emergency department located in the Midwest. Results The intervention included scripted counseling to be delivered in person and 2 educational brochures. The counseling took approximately 5 minutes, and only 2 patients refused the counseling. All the patients were satisfied with the intervention, and 97.4% of them reported that the counseling improved their knowledge of opioid side effects. The majority of patients thought that their own risk of addiction was significantly less than the general public’s risk of addiction when taking opioids. Conclusion This study provides preliminary evidence that student pharmacists or pharmacists are able to deliver opioid safety and overdose education in the emergency department. PMID:28292506

Parent and Metabolite Opioid Drug Concentrations in Unintentional Deaths Involving Opioid and Benzodiazepine Combinations*†‡

PubMed Central

Fields, Marcia D.; Abate, Marie A.; Hu, Lan; Long, D. Leann; Blommel, Matthew L.; Haikal, Nabila A.; Kraner, James C.

2016-01-01

Effects of benzodiazepines on postmortem opioid parent and parent/metabolite blood concentration ratios were determined for fentanyl-, hydrocodone-, methadone-, or oxycodone-related accidental deaths. These opioids are partially metabolized by the CYP3A4 enzyme system, which is also affected by diazepam and alprazolam. Opioid/metabolite combinations examined were as follows: fentanyl/norfentanyl, hydrocodone/dihydrocodeine, methadone/EDDP, and oxycodone/oxymorphone. Parent opioid concentrations were analyzed for 877 deaths. Parent/metabolite concentration ratios were analyzed for 349 deaths, excluding cases with co-intoxicants present known to interfere with opioid elimination. Alprazolam in combination with diazepam significantly decreased median hydrocodone concentrations by 48% (p = 0.01) compared to hydrocodone alone. The methadone parent/metabolite concentration ratio was reduced by 35% in the presence of diazepam compared to methadone alone (p = 0.03). Benzodiazepines did not statistically significantly affect fentanyl or oxycodone concentrations. Possible factors affecting opioid concentrations and possible toxicity development, including any differential effects on specific opioids, should continue to be explored. PMID:26223761

Differentiation of δ, μ, and κ opioid receptor agonists based on pharmacophore development and computed physicochemical properties

NASA Astrophysics Data System (ADS)

Filizola, Marta; Villar, Hugo O.; Loew, Gilda H.

2001-04-01

Compounds that bind with significant affinity to the opioid receptor types, δ, μ, and κ, with different combinations of activation and inhibition at these three receptors could be promising behaviorally selective agents. Working on this hypothesis, the chemical moieties common to three different sets of opioid receptor agonists with significant affinity for each of the three receptor types δ, μ, or κ were identified. Using a distance analysis approach, common geometric arrangements of these chemical moieties were found for selected δ, μ, or κ opioid agonists. The chemical and geometric commonalities among agonists at each opioid receptor type were then compared with a non-specific opioid recognition pharmacophore recently developed. The comparison provided identification of the additional requirements for activation of δ, μ, and κ opioid receptors. The distance analysis approach was able to clearly discriminate κ-agonists, while global molecular properties for all compounds were calculated to identify additional requirements for activation of δ and μ receptors. Comparisons of the combined geometric and physicochemical properties calculated for each of the three sets of agonists allowed the determination of unique requirements for activation of each of the three opioid receptors. These results can be used to improve the activation selectivity of known opioid agonists and as a guide for the identification of novel selective opioid ligands with potential therapeutic usefulness.

Neonatal opioid withdrawal and antenatal opioid prescribing

PubMed Central

Gomes, Tara; Camacho, Ximena; Yao, Zhan; Guttmann, Astrid; Mamdani, Muhammad M.; Juurlink, David N.; Dhalla, Irfan A.

2015-01-01

Background The incidence of neonatal opioid withdrawal is increasing in both Canada and the United States. However, the degree to which the treatment of pain with opioids, rather than the misuse of prescription opioids or heroin, contributes to the prevalence of neonatal opioid withdrawal remains unknown. Methods We conducted a retrospective, population-based, cross-sectional study between 1992 and 2011 in Ontario with 2 objectives. First, we determined the annual incidence of neonatal abstinence syndrome. Second, using data from a subset of women eligible for publicly funded prescription drugs, we determined what proportion of women who deliver an infant with neonatal abstinence syndrome were given a prescription for an opioid before and during pregnancy. Results The incidence of neonatal abstinence syndrome in Ontario increased 15-fold during the study period, from 0.28 per 1000 live births in 1992 to 4.29 per 1000 live births in 2011. During the final 5 years of the study, we identified 927 deliveries of infants with neonatal abstinence syndrome to mothers who were public drug plan beneficiaries. Of these mothers, 67% had received an opioid prescription in the 100 days preceding delivery, including 53.3% who received methadone, an increase from 28.6% in the interval spanning 1 to 2 years before delivery (p < 0.001). Prescription for nonmethadone opioids decreased from 38% to 17% (p < 0.001). Interpretation The incidence of neonatal opioid withdrawal in Ontario has increased substantially over the last 20 years. Most of the women in this cohort who delivered an infant with neonatal abstinence syndrome had received a prescription for an opioid both before and during their pregnancy. PMID:25844370

Role of opioid receptors in the reinstatement of opioid-seeking behavior: an overview.

PubMed

Fattore, Liana; Fadda, Paola; Antinori, Silvia; Fratta, Walter

2015-01-01

Opioid abuse in humans is characterized by discontinuous periods of drug use and abstinence. With time, the probability of falling into renewed drug consumption becomes particularly high and constitutes a considerable problem in the management of heroin addicts. The major problem in the treatment of opioid dependence still remains the occurrence of relapse, to which stressful life events, renewed use of heroin, and exposure to drug-associated environmental cues are all positively correlated. To study the neurobiology of relapse, many research groups currently use the reinstatement animal model, which greatly contributed to disentangle the mechanisms underlying relapse to drug-seeking in laboratory animals. The use of this model is becoming increasingly popular worldwide, and new versions have been recently developed to better appreciate the differential contribution of each opioid receptor subtype to the relapse phenomenon. In this chapter we review the state of the art of our knowledge on the specific role of the opioid receptors as unrevealed by the reinstatement animal model of opioid-seeking behavior.

Oxycodone-induced tolerance to respiratory depression: reversal by ethanol, pregabalin and protein kinase C inhibition.

PubMed

Hill, Rob; Dewey, William L; Kelly, Eamonn; Henderson, Graeme

2018-06-01

Oxycodone, a prescription opioid, is a major drug of abuse, especially in the USA, and contributes significantly to opioid overdose deaths each year. Overdose deaths result primarily from respiratory depression. We have studied respiratory depression by oxycodone and have characterized how tolerance develops on prolonged exposure to the drug. We have investigated the role of PKC in maintaining tolerance and have examined whether ethanol or pregabalin reverses oxycodone-induced tolerance. Respiration was measured in male CD-1 mice by whole-body plethysmography. Mice were preinjected with oxycodone then implanted with mini-pumps (s.c.) delivering 20, 45 or 120 mg·kg -1 ·day -1 oxycodone for 6 days and subsequently challenged with oxycodone (3 mg·kg -1 , i.p.) or morphine (10 mg·kg -1 , i.p.) to assess the level of tolerance. Oxycodone-treated mice developed tolerance to oxycodone and cross tolerance to morphine-induced respiratory depression. Tolerance was less with 20 mg·kg -1 ·day -1 than with 45 or 120 mg·kg -1 ·day -1 oxycodone treatment. At doses that do not depress respiration, ethanol (0.3 g·kg -1 ), pregabalin (20 mg·kg -1 ) and calphostin C (45 μg·kg -1 ) all reversed oxycodone-induced tolerance resulting in significant respiratory depression. Reversal of tolerance was less in mice treated with oxycodone (120 mg·kg -1 ·day -1 ). In mice receiving ethanol and calphostin C or ethanol and pregabalin, there was no greater reversal of tolerance than seen with either drug alone. These data suggest that oxycodone-induced tolerance is mediated by PKC and that reversal of tolerance by ethanol or pregabalin may be a contributory factor in oxycodone overdose deaths. © 2018 The British Pharmacological Society.

A comprehensive review of opioid-induced hyperalgesia.

PubMed

Lee, Marion; Silverman, Sanford M; Hansen, Hans; Patel, Vikram B; Manchikanti, Laxmaiah

2011-01-01

talk of neural mechanisms of pain and tolerance. Clinicians should suspect OIH when opioid treatment's effect seems to wane in the absence of disease progression, particularly if found in the context of unexplained pain reports or diffuse allodynia unassociated with the original pain, and increased levels of pain with increasing dosages. The treatment involves reducing the opioid dosage, tapering them off, or supplementation with NMDA receptor modulators. This comprehensive review addresses terminology and definition, prevalence, the evidence for mechanism and physiology with analysis of various factors leading to OIH, and effective strategies for preventing, reversing, or managing OIH.

Will abuse-deterrent formulations of opioid analgesics be successful in achieving their purpose?

PubMed

Bannwarth, Bernard

2012-09-10

During the last 2 decades, there has been a dramatic increase in the use of strong opioids for chronic non-cancer pain. This increase has been accompanied by a steep increase in abuse, misuse, and both fatal and non-fatal overdoses involving prescription opioids. The situation is already alarming in the US. Prescription opioid-related harm is a complex, multifactorial issue that requires a multifaceted solution. In this respect, formulations of opioid analgesics designed to resist or deter abuse may be a useful component of a comprehensive opioid risk minimization programme. Such formulations have or are being developed. Abuse-resistant opioids include those that use some kind of physical barrier to prevent tampering with the formulation. Abuse-deterrent opioids are not necessarily resistant to tampering, but contain substances that are designed to make the formulation less attractive to abusers. This article focuses on two products intended to deter abuse that were reviewed by the US Food and Drug Administration (FDA). The first (Embeda®) consists of extended-release morphine with sequestered naltrexone, an opioid antagonist that is released if the tablet is compromised by chewing or crushing. Although Embeda® exhibited abuse-deterrent features, its label warns that it can be abused in a manner similar to other opioid agonists. Furthermore, tampering with Embeda® will result in the release of naltrexone, which may precipitate withdrawal in opioid-tolerant individuals. In March 2011, all dosage forms of Embeda® were recalled because the product failed to meet routine stability standards, and its return date to the market is currently unknown. The second product (Acurox®) was intended to be both tamper resistant and abuse deterrent. It consisted of an immediate-release oxycodone tablet with subtherapeutic niacin as an aversive agent and used a gel-forming ingredient designed to inhibit inhalation and prevent extraction of the drug for injection. The new drug

Pain, opioids, and sleep: implications for restless legs syndrome treatment.

PubMed

Trenkwalder, Claudia; Zieglgänsberger, Walter; Ahmedzai, Sam H; Högl, Birgit

2017-03-01

Opioid receptor agonists are known to relieve restless legs syndrome (RLS) symptoms, including both sensory and motor events, as well as improving sleep. The mechanisms of action of opioids in RLS are still a matter of speculation. The mechanisms by which endogenous opioids contribute to the pathophysiology of this polygenetic disorder, in which there are a number of variants, including developmental factors, remains unknown. A summary of the cellular mode of action of morphine and its (partial) antagonist naloxone via α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and the involvement of dendritic spine activation is described. By targeting pain and its consequences, opioids are the first-line treatment in many diseases and conditions with both acute and chronic pain and have thus been used in both acute and chronic pain conditions over the last 40 years. Addiction, dependence, and tolerability of opioids show a wide variability interindividually, as the response to opioids is influenced by a complex combination of genetic, molecular, and phenotypic factors. Although several trials have now addressed opioid treatment in RLS, hyperalgesia as a complication of long-term opioid treatment, or opioid-opioid interaction have not received much attention so far. Therapeutic opioids may act not only on opioid receptors but also via histamine or N-methyl-d-aspartate (NMDA) receptors. In patients with RLS, one of the few studies investigating opioid bindings found that possible brain regions involved in the severity of RLS symptoms are similar to those known to be involved in chronic pain, such as the medial pain system (medial thalamus, amygdala, caudate nucleus, anterior cingulate gyrus, insular cortex, and orbitofrontal cortex). The results of this diprenorphine positron emission tomography study suggested that the more severe the RLS, the greater the release of endogenous opioids. Since 1993, when the first small controlled study was performed with

Chronic Opioid Use After Surgery: Implications for Perioperative Management in the Face of the Opioid Epidemic.

PubMed

Hah, Jennifer M; Bateman, Brian T; Ratliff, John; Curtin, Catherine; Sun, Eric

2017-11-01

Physicians, policymakers, and researchers are increasingly focused on finding ways to decrease opioid use and overdose in the United States both of which have sharply increased over the past decade. While many efforts are focused on the management of chronic pain, the use of opioids in surgical patients presents a particularly challenging problem requiring clinicians to balance 2 competing interests: managing acute pain in the immediate postoperative period and minimizing the risks of persistent opioid use after the surgery. Finding ways to minimize this risk is particularly salient in light of a growing literature suggesting that postsurgical patients are at increased risk for chronic opioid use. The perioperative care team, including surgeons and anesthesiologists, is poised to develop clinical- and systems-based interventions aimed at providing pain relief in the immediate postoperative period while also reducing the risks of opioid use longer term. In this paper, we discuss the consequences of chronic opioid use after surgery and present an analysis of the extent to which surgery has been associated with chronic opioid use. We follow with a discussion of the risk factors that are associated with chronic opioid use after surgery and proceed with an analysis of the extent to which opioid-sparing perioperative interventions (eg, nerve blockade) have been shown to reduce the risk of chronic opioid use after surgery. We then conclude with a discussion of future research directions.

Variants of opioid system genes are associated with non-dependent opioid use and heroin dependence.

PubMed

Randesi, Matthew; van den Brink, Wim; Levran, Orna; Blanken, Peter; Butelman, Eduardo R; Yuferov, Vadim; da Rosa, Joel Correa; Ott, Jurg; van Ree, Jan M; Kreek, Mary Jeanne

2016-11-01

Heroin addiction is a chronic, relapsing brain disease. Genetic factors are involved in the development of drug addiction. The aim of this study was to determine whether specific variants in genes of the opioid system are associated with non-dependent opioid use and heroin dependence. Genetic information from four subject groups was collected: non-dependent opioid users (NOD) [n=163]; opioid-dependent (OD) patients in methadone maintenance treatment (MMT) [n=143]; opioid-dependent MMT-resistant patients in heroin-assisted treatment (HAT) [n=138]; and healthy controls with no history of opioid use (HC) [n=153]. Eighty-two variants in eight opioid system genes were studied. To establish the role of these genes in (a) non-dependent opioid use, and (b) heroin dependence, the following groups were compared: HC vs. NOD; HC vs. OD (MMT+HAT); and NOD vs. OD (MMT+HAT). Five unique SNPs in four genes showed nominally significant associations with non-dependent opioid use and heroin dependence. The association of the delta opioid receptor (OPRD1) intronic SNP rs2236861 with non-dependent opioid use (HC vs. NOD) remained significant after correction for multiple testing (OR=0.032; p corrected =0.015). This SNP exhibited a significant gene-gene interaction with prepronociceptin (PNOC) SNP rs2722897 (OR=5.24; p corrected =0.041) (HC vs. NOD). This study identifies several new and some previously reported associations of variants with heroin dependence and with non-dependent opioid use, an important and difficult to obtain group not extensively studied previously. Further studies are warranted to confirm and elucidate the potential roles of these variants in the vulnerability to illicit drug use and drug addiction. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development and applications of the Veterans Health Administration's Stratification Tool for Opioid Risk Mitigation (STORM) to improve opioid safety and prevent overdose and suicide.

PubMed

Oliva, Elizabeth M; Bowe, Thomas; Tavakoli, Sara; Martins, Susana; Lewis, Eleanor T; Paik, Meenah; Wiechers, Ilse; Henderson, Patricia; Harvey, Michael; Avoundjian, Tigran; Medhanie, Amanuel; Trafton, Jodie A

2017-02-01

Concerns about opioid-related adverse events, including overdose, prompted the Veterans Health Administration (VHA) to launch an Opioid Safety Initiative and Overdose Education and Naloxone Distribution program. To mitigate risks associated with opioid prescribing, a holistic approach that takes into consideration both risk factors (e.g., dose, substance use disorders) and risk mitigation interventions (e.g., urine drug screening, psychosocial treatment) is needed. This article describes the Stratification Tool for Opioid Risk Mitigation (STORM), a tool developed in VHA that reflects this holistic approach and facilitates patient identification and monitoring. STORM prioritizes patients for review and intervention according to their modeled risk for overdose/suicide-related events and displays risk factors and risk mitigation interventions obtained from VHA electronic medical record (EMR)-data extracts. Patients' estimated risk is based on a predictive risk model developed using fiscal year 2010 (FY2010: 10/1/2009-9/30/2010) EMR-data extracts and mortality data among 1,135,601 VHA patients prescribed opioid analgesics to predict risk for an overdose/suicide-related event in FY2011 (2.1% experienced an event). Cross-validation was used to validate the model, with receiver operating characteristic curves for the training and test data sets performing well (>.80 area under the curve). The predictive risk model distinguished patients based on risk for overdose/suicide-related adverse events, allowing for identification of high-risk patients and enrichment of target populations of patients with greater safety concerns for proactive monitoring and application of risk mitigation interventions. Results suggest that clinical informatics can leverage EMR-extracted data to identify patients at-risk for overdose/suicide-related events and provide clinicians with actionable information to mitigate risk. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effect of Iboga Alkaloids on µ-Opioid Receptor-Coupled G Protein Activation

PubMed Central

Antonio, Tamara; Childers, Steven R.; Rothman, Richard B.; Dersch, Christina M.; King, Christine; Kuehne, Martin; Bornmann, William G.; Eshleman, Amy J.; Janowsky, Aaron; Simon, Eric R.; Reith, Maarten E. A.; Alper, Kenneth

2013-01-01

Objective The iboga alkaloids are a class of small molecules defined structurally on the basis of a common ibogamine skeleton, some of which modify opioid withdrawal and drug self-administration in humans and preclinical models. These compounds may represent an innovative approach to neurobiological investigation and development of addiction pharmacotherapy. In particular, the use of the prototypic iboga alkaloid ibogaine for opioid detoxification in humans raises the question of whether its effect is mediated by an opioid agonist action, or if it represents alternative and possibly novel mechanism of action. The aim of this study was to independently replicate and extend evidence regarding the activation of μ-opioid receptor (MOR)-related G proteins by iboga alkaloids. Methods Ibogaine, its major metabolite noribogaine, and 18-methoxycoronaridine (18-MC), a synthetic congener, were evaluated by agonist-stimulated guanosine-5´-O-(γ-thio)-triphosphate ([35S]GTPγS) binding in cells overexpressing the recombinant MOR, in rat thalamic membranes, and autoradiography in rat brain slices. Results And Significance In rat thalamic membranes ibogaine, noribogaine and 18-MC were MOR antagonists with functional Ke values ranging from 3 uM (ibogaine) to 13 uM (noribogaine and 18MC). Noribogaine and 18-MC did not stimulate [35S]GTPγS binding in Chinese hamster ovary cells expressing human or rat MORs, and had only limited partial agonist effects in human embryonic kidney cells expressing mouse MORs. Ibogaine did not did not stimulate [35S]GTPγS binding in any MOR expressing cells. Noribogaine did not stimulate [35S]GTPγS binding in brain slices using autoradiography. An MOR agonist action does not appear to account for the effect of these iboga alkaloids on opioid withdrawal. Taken together with existing evidence that their mechanism of action also differs from that of other non-opioids with clinical effects on opioid tolerance and withdrawal, these findings suggest a

Effect of Iboga alkaloids on µ-opioid receptor-coupled G protein activation.

PubMed

Antonio, Tamara; Childers, Steven R; Rothman, Richard B; Dersch, Christina M; King, Christine; Kuehne, Martin; Bornmann, William G; Eshleman, Amy J; Janowsky, Aaron; Simon, Eric R; Reith, Maarten E A; Alper, Kenneth

2013-01-01

The iboga alkaloids are a class of small molecules defined structurally on the basis of a common ibogamine skeleton, some of which modify opioid withdrawal and drug self-administration in humans and preclinical models. These compounds may represent an innovative approach to neurobiological investigation and development of addiction pharmacotherapy. In particular, the use of the prototypic iboga alkaloid ibogaine for opioid detoxification in humans raises the question of whether its effect is mediated by an opioid agonist action, or if it represents alternative and possibly novel mechanism of action. The aim of this study was to independently replicate and extend evidence regarding the activation of μ-opioid receptor (MOR)-related G proteins by iboga alkaloids. Ibogaine, its major metabolite noribogaine, and 18-methoxycoronaridine (18-MC), a synthetic congener, were evaluated by agonist-stimulated guanosine-5´-O-(γ-thio)-triphosphate ([(35)S]GTPγS) binding in cells overexpressing the recombinant MOR, in rat thalamic membranes, and autoradiography in rat brain slices. In rat thalamic membranes ibogaine, noribogaine and 18-MC were MOR antagonists with functional Ke values ranging from 3 uM (ibogaine) to 13 uM (noribogaine and 18MC). Noribogaine and 18-MC did not stimulate [(35)S]GTPγS binding in Chinese hamster ovary cells expressing human or rat MORs, and had only limited partial agonist effects in human embryonic kidney cells expressing mouse MORs. Ibogaine did not did not stimulate [(35)S]GTPγS binding in any MOR expressing cells. Noribogaine did not stimulate [(35)S]GTPγS binding in brain slices using autoradiography. An MOR agonist action does not appear to account for the effect of these iboga alkaloids on opioid withdrawal. Taken together with existing evidence that their mechanism of action also differs from that of other non-opioids with clinical effects on opioid tolerance and withdrawal, these findings suggest a novel mechanism of action, and further

A Clinical Study on Administration of Opioid Antagonists in Terminal Cancer Patients: 7 Patients Receiving Opioid Antagonists Following Opioids among 2443 Terminal Cancer Patients Receiving Opioids.

PubMed

Uekuzu, Yoshihiro; Higashiguchi, Takashi; Futamura, Akihiko; Ito, Akihiro; Mori, Naoharu; Murai, Miyo; Ohara, Hiroshi; Awa, Hiroko; Chihara, Takeshi

2017-03-01

There have been few detailed reports on respiratory depression due to overdoses of opioids in terminal cancer patients. We investigated the situation of treatment with opioid antagonists for respiratory depression that occurred after administration of opioid at optimal doses in terminal cancer patients, to clarify pathological changes as well as causative factors. In 2443 terminal cancer patients receiving opioids, 7 patients (0.3%) received opioid antagonists: 6, morphine (hydrochloride, 5; sulfate, 1); 1, oxycodone. The median dosage of opioids was 13.3 mg/d, as converted to morphine injection. Respiratory depression occurred on this daily dose in 4 patients and after changed dose and route in 3 patients. Opioids were given through the vein in 6 patients and by the enteral route in 1 patient. Concomitant drugs included nonsteroidal anti-inflammatory drugs in 3 patients and zoledronic acid in 2 patients. In morphine-receiving patients, renal functions were significantly worsened at the time of administration of an opioid antagonist than the day before the start of opioid administration. These findings indicate that the proper use of opioids was safe and acceptable in almost all terminal cancer patients. In rare cases, however, a risk toward respiratory depression onset is indicated because morphine and morphine-6-glucuronide become relatively excessive owing to systemic debility due to disease progression, especially respiratory and renal dysfunctions. At the onset of respiratory depression, appropriate administration of an opioid antagonist mitigated the symptoms. Thereafter, opioid switching or continuous administration at reduced dosages of the same opioids prevented the occurrence of serious adverse events.

Intraoperative ketamine reduces immediate postoperative opioid consumption after spinal fusion surgery in chronic pain patients with opioid dependency: a randomized, blinded trial.

PubMed

Nielsen, Rikke Vibeke; Fomsgaard, Jonna Storm; Siegel, Hanna; Martusevicius, Robertas; Nikolajsen, Lone; Dahl, Jørgen Berg; Mathiesen, Ole

2017-03-01

Perioperative handling of surgical patients with opioid dependency represents an important clinical problem. Animal studies suggest that ketamine attenuates central sensitization and hyperalgesia and thereby reduces postoperative opioid tolerance. We hypothesized that intraoperative ketamine would reduce immediate postoperative opioid consumption compared with placebo in chronic pain patients with opioid dependency undergoing lumbar spinal fusion surgery. Primary outcome was morphine consumption 0 to 24 hours postoperatively. Secondary outcomes were acute pain at rest and during mobilization 2 to 24 hours postoperatively (visual analogue scale), adverse events, and persistent pain 6 months postoperatively. One hundred fifty patients were randomly assigned to intraoperative S-ketamine bolus 0.5 mg/kg and infusion 0.25 mg·kg·h or placebo. Postoperatively, patients received their usual opioids, paracetamol and IV patient-controlled analgesia with morphine. In the final analyses, 147 patients were included. Patient-controlled analgesia IV morphine consumption 0 to 24 hours postoperatively was significantly reduced in the ketamine group compared with the placebo group: 79 (47) vs 121 (53) mg IV, mean difference 42 mg (95% confidence interval -59 to -25), P < 0.001. Sedation was significantly reduced in the ketamine group 6 and 24 hours postoperatively. There were no significant differences regarding acute pain, nausea, vomiting, hallucinations, or nightmares. Back pain at 6 months postoperatively compared with preoperative pain was significantly more improved in the ketamine group compared with the placebo group, P = 0.005. In conclusion, intraoperative ketamine significantly reduced morphine consumption 0 to 24 hours after lumbar fusion surgery in opioid-dependent patients. The trend regarding less persistent pain 6 months postoperatively needs further investigation.

Opioid Analgesics for Chronic Non-Cancer Pain: A Guideline on Opioid Prescribing.

PubMed

Van Demark, Robert; Chang, Peter; Heinemann, Daniel

2016-01-01

Over the past decade, the use of opioid analgesics has risen dramatically both in the U.S. and South Dakota. Opioids have been increasingly used to treat chronic non-cancer pain; however, the utilization of opioids for this role has limited and questionable utility. The U.S. has also seen a rise of opioid abuse, addiction, misuse, and overdose. The various pharmacological and non-pharmacological strategies to help physicians manage chronic non-cancer pain and a guideline on appropriate opioid prescribing are presented. Before the decision is made to begin opioid therapy for chronic non-cancer pain, other pharmacological and non-pharmacological therapeutic strategies should be explored. The schema for responsible opioid prescribing can be dived into the following: the initial assessment, initiating opioid therapy, maintenance therapy, and the discontinuation of opioid treatment. These categories are explored, and a general approach to prescribing opioids for chronic non-cancer pain is presented. The Centers for Disease Control and Prevention (CDC) has declared opioid prescription abuse an "epidemic." There are a variety of methods clinicians can utilize to relieve chronic non-cancer pain. If opioid therapy is sought, clinicians should be mindful of the current state of opioid abuse and misuse. This guideline may aid clinicians in appropriate opioid prescribing.

The opioid epidemic and national guidelines for opioid therapy for chronic noncancer pain: a perspective from different continents.

PubMed

Häuser, Winfried; Schug, Stephan; Furlan, Andrea D

2017-05-01

A marked rise in opioid prescriptions for patients with chronic noncancer pain (CNCP) with a parallel increase in opioid abuse/misuse, and resulting deaths was noted in the Unites states in the past decade (opioid epidemic). In response, the US Center of Diseases Control (CDC) developed a guideline for prescribing of opioids for patients with CNCP. To assess (1) if there is an opioid epidemic in Australia, Canada, and Germany (2) to compare Australian, Canadian, German, and Center of Diseases Control guidelines recommendations for long-term opioid therapy for CNCP. National evidence-based guidelines and PubMed were searched for recommendations for opioid prescriptions for CNCP. There are signs of an opioid epidemic in Australia and Canada, but not in Germany. Guidelines in all 4 countries provide similar recommendations: opioids are not the first-line therapy for patients with CNCP; regular clinical assessments of benefits and harms are necessary; excessive doses should be avoided (recommended morphine equivalent daily doses range from 50 to 200 mg/d); stopping rules should be followed. All guidelines do not recommend the use of opioids in chronic pain conditions without an established nociceptive or neuropathic cause such as fibromyalgia and primary headache. Implementation of opioid prescribing guidelines should ensure that physicians prescribe opioids only for appropriate indications in limited doses for selected patients and advice patients on their safe use. These measures could contribute to reduce prescription opioid misuse/abuse and deaths.

Experimental Pain and Opioid Analgesia in Volunteers at High Risk for Obstructive Sleep Apnea

PubMed Central

Doufas, Anthony G.; Tian, Lu; Padrez, Kevin A.; Suwanprathes, Puntarica; Cardell, James A.; Maecker, Holden T.; Panousis, Periklis

2013-01-01

Background Obstructive sleep apnea (OSA) is characterized by recurrent nocturnal hypoxia and sleep disruption. Sleep fragmentation caused hyperalgesia in volunteers, while nocturnal hypoxemia enhanced morphine analgesic potency in children with OSA. This evidence directly relates to surgical OSA patients who are at risk for airway compromise due to postoperative use of opioids. Using accepted experimental pain models, we characterized pain processing and opioid analgesia in male volunteers recruited based on their risk for OSA. Methods After approval from the Intitutional Review Board and informed consent, we assessed heat and cold pain thresholds and tolerances in volunteers after overnight polysomnography (PSG). Three pro-inflammatory and 3 hypoxia markers were determined in the serum. Pain tests were performed at baseline, placebo, and two effect site concentrations of remifentanil (1 and 2 µg/ml), an μ-opioid agonist. Linear mixed effects regression models were employed to evaluate the association of 3 PSG descriptors [wake after sleep onset, number of sleep stage shifts, and lowest oxyhemoglobin saturation (SaO2) during sleep] and all serum markers with pain thresholds and tolerances at baseline, as well as their changes under remifentanil. Results Forty-three volunteers (12 normal and 31 with a PSG-based diagnosis of OSA) were included in the analysis. The lower nadir SaO2 and higher insulin growth factor binding protein-1 (IGFBP-1) were associated with higher analgesic sensitivity to remifentanil (SaO2, P = 0.0440; IGFBP-1, P = 0.0013). Other pro-inflammatory mediators like interleukin-1β and tumor necrosis factor-α (TNF-α) were associated with an enhanced sensitivity to the opioid analgesic effect (IL-1β, P = 0.0218; TNF-α, P = 0.0276). Conclusions Nocturnal hypoxemia in subjects at high risk for OSA was associated with an increased potency of opioid analgesia. A serum hypoxia marker (IGFBP-1) was associated with hypoalgesia and

The role of δ-opioid receptors in learning and memory underlying the development of addiction.

PubMed

Klenowski, Paul; Morgan, Michael; Bartlett, Selena E

2015-01-01

Opioids are important endogenous ligands that exist in both invertebrates and vertebrates and signal by activation of opioid receptors to produce analgesia and reward or pleasure. The μ-opioid receptor is the best known of the opioid receptors and mediates the acute analgesic effects of opiates, while the δ-opioid receptor (DOR) has been less well studied and has been linked to effects that follow from chronic use of opiates such as stress, inflammation and anxiety. Recently, DORs have been shown to play an essential role in emotions and increasing evidence points to a role in learning actions and outcomes. The process of learning and memory in addiction has been proposed to involve strengthening of specific brain circuits when a drug is paired with a context or environment. The DOR is highly expressed in the hippocampus, amygdala, striatum and other basal ganglia structures known to participate in learning and memory. In this review, we will focus on the role of the DOR and its potential role in learning and memory underlying the development of addiction. This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2. © 2014 The British Pharmacological Society.

New developments in managing opioid addiction: impact of a subdermal buprenorphine implant

PubMed Central

Itzoe, MariaLisa; Guarnieri, Michael

2017-01-01

Opioid addiction to prescription and illicit drugs is a serious and growing problem. In the US alone, >2.4 million people suffer from opioid use disorder. Government and pharmaceutical agencies have begun to address this crisis with recently released and revised task forces and medication-assisted therapies (MAT). For decades, oral or intravenous (IV) MATs have helped patients in their recovery by administration of opioid agonists (methadone, buprenorphine, oxycodone), antagonists (naltrexone, naloxone), and combinations of the two (buprenorphine/naloxone). While shown to be successful, particularly when combined with psychological counseling, oral and IV forms of treatment come with constraints and challenges. Patients can become addicted to the agonists themselves, and there is increased risk for diversion, abuse, or missed dosages. Consequently, long-acting implants have begun to be developed as a potentially preferable method of agonist delivery. To date, the newest implant approved by the US Food and Drug Administration (May 2016) is Probuphine®, which delivers steady-state levels of buprenorphine over the course of 6 months. Numerous studies have demonstrated its efficacy and safety. Yet, implants come with their own risks such as surgical site irritation, possible movement, and protrusion of implant out of skin. This review introduces the opioid abuse epidemic, examines existing medications used for therapy, and highlights Probuphine as a new treatment option. Costs associated with MATs are also discussed. PMID:28546740

New developments in managing opioid addiction: impact of a subdermal buprenorphine implant.

PubMed

Itzoe, MariaLisa; Guarnieri, Michael

2017-01-01

Opioid addiction to prescription and illicit drugs is a serious and growing problem. In the US alone, >2.4 million people suffer from opioid use disorder. Government and pharmaceutical agencies have begun to address this crisis with recently released and revised task forces and medication-assisted therapies (MAT). For decades, oral or intravenous (IV) MATs have helped patients in their recovery by administration of opioid agonists (methadone, buprenorphine, oxycodone), antagonists (naltrexone, naloxone), and combinations of the two (buprenorphine/naloxone). While shown to be successful, particularly when combined with psychological counseling, oral and IV forms of treatment come with constraints and challenges. Patients can become addicted to the agonists themselves, and there is increased risk for diversion, abuse, or missed dosages. Consequently, long-acting implants have begun to be developed as a potentially preferable method of agonist delivery. To date, the newest implant approved by the US Food and Drug Administration (May 2016) is Probuphine ® , which delivers steady-state levels of buprenorphine over the course of 6 months. Numerous studies have demonstrated its efficacy and safety. Yet, implants come with their own risks such as surgical site irritation, possible movement, and protrusion of implant out of skin. This review introduces the opioid abuse epidemic, examines existing medications used for therapy, and highlights Probuphine as a new treatment option. Costs associated with MATs are also discussed.

Characteristics of opioid-users whose death was related to opioid-toxicity: a population-based study in Ontario, Canada.

PubMed

Madadi, Parvaz; Hildebrandt, Doris; Lauwers, Albert E; Koren, Gideon

2013-01-01

The impact of the prescription opioid public health crisis has been illustrated by the dramatic increase in opioid-related deaths in North America. We aimed to identify patterns and characteristics amongst opioid-users whose cause of death was related to opioid toxicity. This was a population-based study of Ontarians between the years 2006 and 2008. All drug-related deaths which occurred during this time frame were reviewed at the Office of the Chief Coroner of Ontario, and opioid-related deaths were identified. Medical, toxicology, pathology, and police reports were comprehensively reviewed. Narratives, semi-quantitative, and quantitative variables were extracted, tabulated, and analyzed. Out of 2330 drug-related deaths in Ontario, 58% were attributed either in whole or in part, to opioids (n = 1359). Oxycodone was involved in approximately one-third of all opioid-related deaths. At least 7% of the entire cohort used opioids that were prescribed for friends and/or family, 19% inappropriately self-administered opioids (injection, inhalation, chewed patch), 3% were recently released from jail, and 5% had been switched from one opioid to another near the time of death. Accidental deaths were significantly associated with personal history of substance abuse, enrollment in methadone maintenance programs, cirrhosis, hepatitis, and cocaine use. Suicides were significantly associated with mental illness, previous suicide attempts, chronic pain, and a history of cancer. These results identify novel, susceptible groups of opioid-users whose cause of death was related to opioids in Ontario and provide the first evidence to assist in quantifying the contribution of opioid misuse and diversion amongst opioid-related mortality in Canada. Multifaceted prevention strategies need to be developed based on subpopulations of opioid users.

Effectiveness of low-dose naltrexone in the post-detoxification treatment of opioid dependence.

PubMed

Mannelli, Paolo; Patkar, Ashwin A; Peindl, Kathleen; Murray, Heather W; Wu, Li-Tzy; Hubbard, Robert

2007-10-01

The clinical use of naltrexone (NTX) in the treatment of opioid dependence has been limited because of poor compliance and inconsistent outcomes. In particular, the therapeutic benefit of extended treatment with NTX after opioid detoxification is unclear. The present study evaluated whether the augmentation with low-dose NTX during the post-detoxification treatment of opioid dependence would improve outcomes. In an open-label naturalistic design, 435 opioid-dependent patients who had completed inpatient detoxification were offered the choice of entering 1 of the 2 outpatient treatment arms: clonidine extended treatment (CET) (clonidine + psychosocial treatment), or enhanced extended treatment (EET) (oral NTX [1-10 mg/d] + CET) for 21 days. The primary outcome measure was retention in treatment. Secondary outcomes included abstinence from opioids, dropouts, and adherence to postdischarge care. One hundred sixty-two patients (37.2%) accepted EET. Subjects receiving EET stayed longer in the program (F = 64.4; P = 0.000), were less likely to drop out, used less opioids, and followed through with referral to long-term outpatient treatment in a higher number, compared with patients in the CET arm (P = 0.000 in each case). The NTX + clonidine combination was safe and well tolerated. This preliminary study indicates the potential benefit of augmentation with low-dose NTX to improve outcomes after opioid detoxification for a preferred group of patients. Randomized controlled trials are necessary to further evaluate the role of low-dose NTX in the outpatient treatment of opioid dependence.

Intolerance of uncertainty in opioid dependency - Relationship with trait anxiety and impulsivity.

PubMed

Garami, Julia; Haber, Paul; Myers, Catherine E; Allen, Michael T; Misiak, Blazej; Frydecka, Dorota; Moustafa, Ahmed A

2017-01-01

Intolerance of uncertainty (IU) is the tendency to interpret ambiguous situations as threatening and having negative consequences, resulting in feelings of distress and anxiety. IU has been linked to a number of anxiety disorders, and anxiety felt in the face of uncertainty may result in maladaptive behaviors such as impulsive decision making. Although there is strong evidence that anxiety and impulsivity are risk factors for addiction, there is a paucity of research examining the role of IU in this disorder. The rate of opioid addiction, in particular, has been rising steadily in recent years, which necessitates deeper understanding of risk factors in order to develop effective prevention and treatment methods. The current study tested for the first time whether opioid-dependent adults are less tolerant of uncertainty compared to a healthy comparison group. Opioid dependent patients undergoing methadone maintenance therapy (n = 114) and healthy comparisons (n = 69) completed the following scales: Intolerance of Uncertainty Scale, the Barrett Impulsivity Scale, and the State Trait Anxiety Inventory. Analysis revealed that these measures were positively correlated with each other and that opioid-dependent patients had significantly higher IU scores. Regression analysis revealed that anxiety mediated the relationship between IU and impulsivity. Hierarchical moderation regression found an interaction between addiction status and impulsivity on IU scores in that the relationship between these variables was only observed in the patient group. Findings suggest that IU is a feature of addiction but does not necessarily play a unique role. Further research is needed to explore the complex relationship between traits and how they may contribute to the development and maintenance of addiction.

Will peripherally restricted kappa-opioid receptor agonists (pKORAs) relieve pain with less opioid adverse effects and abuse potential?

PubMed

Albert-Vartanian, A; Boyd, M R; Hall, A L; Morgado, S J; Nguyen, E; Nguyen, V P H; Patel, S P; Russo, L J; Shao, A J; Raffa, R B

2016-08-01

Optimal utilization of opioid analgesics is significantly limited by the central nervous system adverse effects and misuse/abuse potential of currently available drugs. It has been postulated that opioid-associated adverse effects and abuse potential would be greatly reduced if opioids could be excluded from reaching the brain. We review the basic science and clinical evidence of one such approach - peripherally restricted kappa-opioid receptor (KOR) agonists (pKORAs). Published and unpublished literature, websites and other sources were searched for basic science and clinical information related to the potential benefits and development of peripherally restricted kappa-opioid receptor agonists. Each source was summarized, reviewed and assessed. The historical development of pKORAs can be traced from the design of increasingly KOR-selective agonists, elucidation of the pharmacologic attributes of such compounds and strategies to restrict passage across the blood-brain barrier. Novel compounds are under development and have progressed to clinical trials. The results from recent clinical trials suggest that peripherally restricted opioids can be successfully designed and that they can retain analgesic efficacy with a more favourable adverse effect profile. © 2016 John Wiley & Sons Ltd.

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

PubMed

Desantana, Josimari M; Santana-Filho, Valter J; Sluka, Kathleen A

2008-04-01

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%). Laboratory. Adult male Sprague-Dawley rats (N=36). Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100micros pulse duration. Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.

Using behavioral economics to predict opioid use during prescription opioid dependence treatment.

PubMed

Worley, Matthew J; Shoptaw, Steven J; Bickel, Warren K; Ling, Walter

2015-03-01

Research grounded in behavioral economics has previously linked addictive behavior to disrupted decision-making and reward-processing, but these principles have not been examined in prescription opioid addiction, which is currently a major public health problem. This study examined whether pre-treatment drug reinforcement value predicted opioid use during outpatient treatment of prescription opioid addiction. Secondary analyses examined participants with prescription opioid dependence who received 12 weeks of buprenorphine-naloxone and counseling in a multi-site clinical trial (N=353). Baseline measures assessed opioid source and indices of drug reinforcement value, including the total amount and proportion of income spent on drugs. Weekly urine drug screens measured opioid use. Obtaining opioids from doctors was associated with lower pre-treatment drug spending, while obtaining opioids from dealers/patients was associated with greater spending. Controlling for demographics, opioid use history, and opioid source frequency, patients who spent a greater total amount (OR=1.30, p<.001) and a greater proportion of their income on drugs (OR=1.31, p<.001) were more likely to use opioids during treatment. Individual differences in drug reinforcement value, as indicated by pre-treatment allocation of economic resources to drugs, reflects propensity for continued opioid use during treatment among individuals with prescription opioid addiction. Future studies should examine disrupted decision-making and reward-processing in prescription opioid users more directly and test whether reinforcer pathology can be remediated in this population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Using behavioral economics to predict opioid use during prescription opioid dependence treatment

PubMed Central

Worley, Matthew J.; Shoptaw, Steven J.; Bickel, Warren K.; Ling, Walter

2015-01-01

Background Research grounded in behavioral economics has previously linked addictive behavior to disrupted decision-making and reward-processing, but these principles have not been examined in prescription opioid addiction, which is currently a major public health problem. This study examined whether pre-treatment drug reinforcement value predicted opioid use during outpatient treatment of prescription opioid addiction. Methods Secondary analyses examined participants with prescription opioid dependence who received 12 weeks of buprenorphine-naloxone and counseling in a multi-site clinical trial (N = 353). Baseline measures assessed opioid source and indices of drug reinforcement value, including the total amount and proportion of income spent on drugs. Weekly urine drug screens measured opioid use. Results Obtaining opioids from doctors was associated with lower pre-treatment drug spending, while obtaining opioids from dealers/patients was associated with greater spending. Controlling for demographics, opioid use history, and opioid source frequency, patients who spent a greater total amount (OR = 1.30, p < .001) and a greater proportion of their income on drugs (OR = 1.31, p < .001) were more likely to use opioids during treatment. Conclusions Individual differences in drug reinforcement value, as indicated by pre-treatment allocation of economic resources to drugs, reflects propensity for continued opioid use during treatment among individuals with prescription opioid addiction. Future studies should examine disrupted decision-making and reward-processing in prescription opioid users more directly and test whether reinforcer pathology can be remediated in this population. PMID:25622776

Characteristics of Opioid-Users Whose Death Was Related to Opioid-Toxicity: A Population-Based Study in Ontario, Canada

PubMed Central

Madadi, Parvaz; Hildebrandt, Doris; Lauwers, Albert E.; Koren, Gideon

2013-01-01

Background The impact of the prescription opioid public health crisis has been illustrated by the dramatic increase in opioid-related deaths in North America. We aimed to identify patterns and characteristics amongst opioid-users whose cause of death was related to opioid toxicity. Methods This was a population-based study of Ontarians between the years 2006 and 2008. All drug-related deaths which occurred during this time frame were reviewed at the Office of the Chief Coroner of Ontario, and opioid-related deaths were identified. Medical, toxicology, pathology, and police reports were comprehensively reviewed. Narratives, semi-quantitative, and quantitative variables were extracted, tabulated, and analyzed. Results Out of 2330 drug-related deaths in Ontario, 58% were attributed either in whole or in part, to opioids (n = 1359). Oxycodone was involved in approximately one-third of all opioid-related deaths. At least 7% of the entire cohort used opioids that were prescribed for friends and/or family, 19% inappropriately self-administered opioids (injection, inhalation, chewed patch), 3% were recently released from jail, and 5% had been switched from one opioid to another near the time of death. Accidental deaths were significantly associated with personal history of substance abuse, enrollment in methadone maintenance programs, cirrhosis, hepatitis, and cocaine use. Suicides were significantly associated with mental illness, previous suicide attempts, chronic pain, and a history of cancer. Significance/Conclusion These results identify novel, susceptible groups of opioid-users whose cause of death was related to opioids in Ontario and provide the first evidence to assist in quantifying the contribution of opioid misuse and diversion amongst opioid-related mortality in Canada. Multifaceted prevention strategies need to be developed based on subpopulations of opioid users. PMID:23577131

Inhibition of Spinal Oxidative Stress by Bergamot Polyphenolic Fraction Attenuates the Development of Morphine Induced Tolerance and Hyperalgesia in Mice.

PubMed

Lauro, Filomena; Giancotti, Luigino Antonio; Ilari, Sara; Dagostino, Concetta; Gliozzi, Micaela; Morabito, Chiara; Malafoglia, Valentina; Raffaeli, William; Muraca, Maurizio; Goffredo, Bianca M; Mollace, Vincenzo; Muscoli, Carolina

2016-01-01

Citrus Bergamia Risso, commonly known as Bergamot, is a fruit whose Essential Oil and Bergamot Polyphenolic Fraction have numerous medicinal properties. It is also an excellent antioxidant and in this study, for the first time, its potential effect on morphine induced tolerance in mice has been investigated. Our studies revealed that development of antinociceptive tolerance to repeated doses of morphine in mice is consistently associated with increased formation of superoxide, malondialdehyde and tyrosine-nitrated proteins in the dorsal horn of the spinal cord such as the enzyme glutamine synthase. Nitration of this protein is intimately linked to inactivation of its biological function and resulting increase of glutamate levels in the spinal cord. Administration of Bergamot Polyphenolic Fraction (5-50 mg/kg) attenuated tolerance development. This effect was accompanied by reduction of superoxide and malondialdehyde production, prevention of GS nitration, re-establishment of its activity and of glutamate levels. Our studies confirmed the main role of free radicals during the cascade of events induced by prolonged morphine treatment and the co-administration of natural derivatives antioxidant such as Bergamot Polyphenolic Fraction can be an important therapeutic approach to restore opioids analgesic efficacy.

Inhibition of Spinal Oxidative Stress by Bergamot Polyphenolic Fraction Attenuates the Development of Morphine Induced Tolerance and Hyperalgesia in Mice

PubMed Central

Lauro, Filomena; Giancotti, Luigino Antonio; Ilari, Sara; Dagostino, Concetta; Gliozzi, Micaela; Morabito, Chiara; Malafoglia, Valentina; Raffaeli, William; Muraca, Maurizio; Goffredo, Bianca M.; Mollace, Vincenzo; Muscoli, Carolina

2016-01-01

Citrus Bergamia Risso, commonly known as Bergamot, is a fruit whose Essential Oil and Bergamot Polyphenolic Fraction have numerous medicinal properties. It is also an excellent antioxidant and in this study, for the first time, its potential effect on morphine induced tolerance in mice has been investigated. Our studies revealed that development of antinociceptive tolerance to repeated doses of morphine in mice is consistently associated with increased formation of superoxide, malondialdehyde and tyrosine-nitrated proteins in the dorsal horn of the spinal cord such as the enzyme glutamine synthase. Nitration of this protein is intimately linked to inactivation of its biological function and resulting increase of glutamate levels in the spinal cord. Administration of Bergamot Polyphenolic Fraction (5–50 mg/kg) attenuated tolerance development. This effect was accompanied by reduction of superoxide and malondialdehyde production, prevention of GS nitration, re-establishment of its activity and of glutamate levels. Our studies confirmed the main role of free radicals during the cascade of events induced by prolonged morphine treatment and the co-administration of natural derivatives antioxidant such as Bergamot Polyphenolic Fraction can be an important therapeutic approach to restore opioids analgesic efficacy. PMID:27227548

Low-dose hydrocortisone replacement improves wellbeing and pain tolerance in chronic pain patients with opioid-induced hypocortisolemic responses. A pilot randomized, placebo-controlled trial.

PubMed

Nenke, Marni A; Haylock, Clare L; Rankin, Wayne; Inder, Warrick J; Gagliardi, Lucia; Eldridge, Crystal; Rolan, Paul; Torpy, David J

2015-06-01

Long-term opioid therapy has been associated with low cortisol levels due to central suppression of the hypothalamic-pituitary-adrenal axis. The implications of hypocortisolism on wellbeing have not been established. Our aim was to determine whether intervention with physiologic glucocorticoid replacement therapy improves wellbeing and analgesic responses in patients with chronic non-cancer pain on long-term opioid therapy with mild cortisol deficiency. We performed a pilot randomized, double-blind, placebo-controlled crossover study of oral hydrocortisone replacement therapy in 17 patients recruited from a Pain Clinic at a single tertiary center in Adelaide, Australia. Patients were receiving long-term opioid therapy (≥ 20 mg morphine equivalents per day for ≥ 4 weeks) for chronic non-cancer pain with mild hypocortisolism, as defined by a plasma cortisol response ≤ 350 nmol/L at 60 min following a cold pressor test. The crossover intervention included 28-day treatment with either 10mg/m(2)/day of oral hydrocortisone in three divided doses or placebo. Improvement in wellbeing was assessed using Version 2 of the Short Form-36 (SF-36v2), Brief Pain Inventory-Short Form, and Addison's disease quality of life questionnaires; improvement in analgesic response was assessed using cold pressor threshold and tolerance times. Following treatment with hydrocortisone, the bodily pain (P=0.042) and vitality (P=0.013) subscales of the SF-36v2 were significantly better than scores following treatment with placebo. There was also an improvement in pain interference on general activity (P=0.035), mood (P=0.03) and work (P=0.04) following hydrocortisone compared with placebo. This is the first randomized, double-blind placebo-controlled trial of glucocorticoid replacement in opioid users with chronic non-cancer pain and mild hypocortisolism. Our data suggest that physiologic hydrocortisone replacement produces improvements in vitality and pain experiences in this cohort

Roadside opioid testing of drivers using oral fluid: the case of a country with a zero tolerance law, Spain.

PubMed

Fierro, Inmaculada; Colás, Mónica; González-Luque, Juan Carlos; Álvarez, F Javier

2017-05-10

Opioids can impair psychomotor performance, and driving under the influence of opioids is associated with an increased risk of accidents. The goals of this study were i) to determine the prevalence of opioids (heroin, morphine, codeine, methadone and tramadol) in Spanish drivers and ii) to explore the presence of opioids, more specifically whether they are used alone or in combination with other drugs. The 2008/9 DRUID database regarding Spain was used, which provided information on 3302 drivers. All drivers included in the study provided a saliva sample and mass-chromatographic analyses were carried out in all cases. To determine the prevalence, the sample was weighted according to traffic intensity. In the case of opioid use combinations, the sample was not weighted. The detection limit for each substance was considered a positive result. The prevalence of opioids in Spanish drivers was 1.8% (95% CI, 1.4-2.3). Polydrug detection was common (56.2%): of these, in two out of three cases, two opioids were detected and cocaine was also detected in 86% of the cases. The concentration (median [Q1-Q3] ng/ml) of the substances was low: methadone 1.71 [0.10-15.30], codeine 40.55 [2.10-120.77], 6-acetylmorphine 5.71 [1.53-84.05], and morphine 37.40 [2.84-200.00]. Morphine was always detected with 6-acetylmorphine (heroin use). Driving under the influence of opioids is relatively infrequent, but polydrug use is common. Our study shows that 6 out of 10 drivers with methadone in their OF (likely in methadone maintenance programs) are using other substances. This should be taken into account by health professionals in order to properly inform patients about the added risks of mixing substances when driving.

Pain as a reward: changing the meaning of pain from negative to positive co-activates opioid and cannabinoid systems.

PubMed

Benedetti, Fabrizio; Thoen, Wilma; Blanchard, Catherine; Vighetti, Sergio; Arduino, Claudia

2013-03-01

Pain is a negative emotional experience that is modulated by a variety of psychological factors through different inhibitory systems. For example, endogenous opioids and cannabinoids have been found to be involved in stress and placebo analgesia. Here we show that when the meaning of the pain experience is changed from negative to positive through verbal suggestions, the opioid and cannabinoid systems are co-activated and these, in turn, increase pain tolerance. We induced ischemic arm pain in healthy volunteers, who had to tolerate the pain as long as possible. One group was informed about the aversive nature of the task, as done in any pain study. Conversely, a second group was told that the ischemia would be beneficial to the muscles, thus emphasizing the usefulness of the pain endurance task. We found that in the second group pain tolerance was significantly higher compared to the first one, and that this effect was partially blocked by the opioid antagonist naltrexone alone and by the cannabinoid antagonist rimonabant alone. However, the combined administration of naltrexone and rimonabant antagonized the increased tolerance completely. Our results indicate that a positive approach to pain reduces the global pain experience through the co-activation of the opioid and cannabinoid systems. These findings may have a profound impact on clinical practice. For example, postoperative pain, which means healing, can be perceived as less unpleasant than cancer pain, which means death. Therefore, the behavioral and/or pharmacological manipulation of the meaning of pain can represent an effective approach to pain management. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

New trends in the development of opioid peptide analogues as advanced remedies for pain relief.

PubMed

Gentilucci, Luca

2004-01-01

The search for new peptides to be used as analgesics in place of morphine has been mainly directed to develop peptide analogues or peptidomimetics having higher biological stability and receptor selectivity. Indeed, most of the alkaloid opioid counterindications are due to the scarce stability and the contemporary activation of different receptor types. However, the development of several extremely stable and selective peptide ligands for the different opioid receptors, and the recent discovery of the micro-receptor selective endomorphins, rendered this search less fundamental. In recent years, other opioid peptide properties have been investigated in the search for new pharmacological tools. The utility of a drug depends on its ability to reach appropriate receptors at the target tissue and to remain metabolically stable in order to produce the desired effect. This review deals with the recent investigations on peptide bioavailability, in particular barrier penetration and resistance against enzymatic degradation; with the development of peptides having activity at different receptors; with chimeric peptides, with propeptides, and with non-conventional peptides, lacking basic pharmacophoric features.

Opioids and the management of chronic severe pain in the elderly: consensus statement of an International Expert Panel with focus on the six clinically most often used World Health Organization Step III opioids (buprenorphine, fentanyl, hydromorphone, methadone, morphine, oxycodone).

PubMed

Pergolizzi, Joseph; Böger, Rainer H; Budd, Keith; Dahan, Albert; Erdine, Serdar; Hans, Guy; Kress, Hans-Georg; Langford, Richard; Likar, Rudolf; Raffa, Robert B; Sacerdote, Paola

2008-01-01

status need to be taken carefully into account when addressing pain in the elderly. World Health Organization step III opioids are the mainstay of pain treatment for cancer patients and morphine has been the most commonly used for decades. In general, high level evidence data (Ib or IIb) exist, although many studies have included only few patients. Based on these studies, all opioids are considered effective in cancer pain management (although parts of cancer pain are not or only partially opioid sensitive), but no well-designed specific studies in the elderly cancer patient are available. Of the 2 opioids that are available in transdermal formulation--fentanyl and buprenorphine--fentanyl is the most investigated, but based on the published data both seem to be effective, with low toxicity and good tolerability profiles, especially at low doses. 2. The use of opioids in noncancer-related pain: Evidence is growing that opioids are efficacious in noncancer pain (treatment data mostly level Ib or IIb), but need individual dose titration and consideration of the respective tolerability profiles. Again no specific studies in the elderly have been performed, but it can be concluded that opioids have shown efficacy in noncancer pain, which is often due to diseases typical for an elderly population. When it is not clear which drugs and which regimes are superior in terms of maintaining analgesic efficacy, the appropriate drug should be chosen based on safety and tolerability considerations. Evidence-based medicine, which has been incorporated into best clinical practice guidelines, should serve as a foundation for the decision-making processes in patient care; however, in practice, the art of medicine is realized when we individualize care to the patient. This strikes a balance between the evidence-based medicine and anecdotal experience. Factual recommendations and expert opinion both have a value when applying guidelines in clinical practice. 3. The use of opioids in

Synthesis, Modeling, and Pharmacological Evaluation of UMB 425, a Mixed μ Agonist/δ Antagonist Opioid Analgesic with Reduced Tolerance Liabilities

PubMed Central

2013-01-01

Opioid narcotics are used for the treatment of moderate-to-severe pain and primarily exert their analgesic effects through μ receptors. Although traditional μ agonists can cause undesired side effects, including tolerance, addition of δ antagonists can attenuate said side effects. Herein, we report 4a,9-dihydroxy-7a-(hydroxymethyl)-3-methyl-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one (UMB 425) a 5,14-bridged morphinan-based orvinol precursor synthesized from thebaine. Although UMB 425 lacks δ-specific motifs, conformationally sampled pharmacophore models for μ and δ receptors predict it to have efficacy similar to morphine at μ receptors and similar to naltrexone at δ receptors, due to the compound sampling conformations in which the hydroxyl moiety interacts with the receptors similar to orvinols. As predicted, UMB 425 exhibits a mixed μ agonist/δ antagonist profile as determined in receptor binding and [35S]GTPγS functional assays in CHO cells. In vivo studies in mice show that UMB 425 displays potent antinociception in the hot plate and tail-flick assays. The antinociceptive effects of UMB 425 are blocked by naloxone, but not by the κ-selective antagonist norbinaltorphimine. During a 6-day tolerance paradigm, UMB 425 maintains significantly greater antinociception compared to morphine. These studies thus indicate that, even in the absence of δ-specific motifs fused to the C-ring, UMB 425 has mixed μ agonist/δ antagonist properties in vitro that translate to reduced tolerance liabilities in vivo. PMID:23713721

Development of the Chronic Pain Coding System (CPCS) for Characterizing Patient-Clinician Discussions About Chronic Pain and Opioids.

PubMed

Henry, Stephen G; Chen, Meng; Matthias, Marianne S; Bell, Robert A; Kravitz, Richard L

2016-10-01

To describe the development and initial application of the Chronic Pain Coding System. Secondary analysis of data from a randomized clinical trial. Six primary care clinics in northern California. Forty-five primary care visits involving 33 clinicians and 45 patients on opioids for chronic noncancer pain. The authors developed a structured coding system to accurately and objectively characterize discussions about pain and opioids. Two coders applied the final system to visit transcripts. Intercoder agreement for major coding categories was moderate to substantial (kappa = 0.5-0.7). Mixed effects regression was used to test six hypotheses to assess preliminary construct validity. Greater baseline pain interference was associated with longer pain discussions (P = 0.007) and more patient requests for clinician action (P = 0.02) but not more frequent negative patient evaluations of pain (P = 0.15). Greater clinician-reported visit difficulty was associated with more frequent disagreements with clinician recommendations (P = 0.003) and longer discussions of opioid risks (P = 0.049) but not more frequent requests for clinician action (P = 0.11). Rates of agreement versus disagreement with patient requests and clinician recommendations were similar for opioid-related and non-opioid-related utterances. This coding system appears to be a reliable and valid tool for characterizing patient-clinician communication about opioids and chronic pain during clinic visits. Objective data on how patients and clinicians discuss chronic pain and opioids are necessary to identify communication patterns and strategies for improving the quality and productivity of discussions about chronic pain that may lead to more effective pain management and reduce inappropriate opioid prescribing. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Development of 5-Substituted N-Methylmorphinan-6-ones as Potent Opioid Analgesics with Improved Side-Effect Profile.

PubMed

Schmidhammer, Helmut; Spetea, Mariana

2012-01-01

One of the most important functions of the opioid system is the control of pain. Among the three main opioid receptor classes (μ, δ, κ), the μ (MOR) is the main type targeted for pharmacotherapy of pain. Opioid analgesics such as morphine, oxycodone and fentanyl are agonists at the MOR and are the mainstay for the treatment of moderate-to-severe pain. However, adverse effects related to opioid use are severe and often lead to early discontinuation and inadequate analgesia. The development of more effective and safer medications for the management of pain still remains a major direction in pharmaceutical research. Chemical approaches towards the identification of novel MOR analgesics with reduced side effects include structural modifications of 14-alkoxy-N-methylmorphinan-6-ones in key positions that are important for binding, selectivity, potency, and efficacy at opioid receptors. This paper describes a representative strategy to improve the therapeutic usefulness of opioid analgesics from the morphinan class of drugs by targeting position 5. The focus is on chemical and biological studies and structure-activity relationships of this series of ligands. We report on 14-alkoxymorphinan-6-ones having a methyl and benzyl group at position 5 as strong opioid antinociceptive agents with reduced propensity to cause undesired effects compared to morphine although interacting selectively with MORs.

Chronic Pain, Chronic Opioid Addiction: a Complex Nexus.

PubMed

Salsitz, Edwin A

2016-03-01

Over the past two decades, there has been a significant increase in the prescribing of opioids, with associated increases in opioid addiction and overdose deaths. This article reviews the evidence for the effectiveness and risk of developing an opioid use disorder (OUD) in those patients treated with chronic opioid therapy (COT) for chronic non-cancer pain (CNCP). Rates of development of OUD range from 0-50 %, and aberrant drug related behaviors (ADRBs) are reported to be 20 %. Health care providers must properly assess, screen, and carefully monitor patients on COT utilizing evidence-based tools.

Opioid Receptors: Toward Separation of Analgesic from Undesirable Effects

PubMed Central

Law, P.Y.; Reggio, Patricia H.; Loh, H.H.

2013-01-01

The use of opioid analgesics for pain has always been hampered by their many side effects; in particular, the addictive liability associated with chronic use. Recently, attempts to develop analgesic agents with reduced side effects have targeted either the putative opioid receptor splice variants or the receptor heterooligomers. This review discusses the potential for receptor splice variant- and the hetero-oligomer-based discovery of new opioid analgesics. We also examine an alternative approach of using receptor mutants for pain management. Finally, we discuss the role of the biased agonism observed and the recently reported opioid receptor crystal structures in guiding the future development of opioid analgesics PMID:23598157

Morphine-induced internalization of the L83I mutant of the rat μ-opioid receptor

PubMed Central

Cooke, A E; Oldfield, S; Krasel, C; Mundell, S J; Henderson, G; Kelly, E

2015-01-01

BACKGROUND AND PURPOSE Naturally occurring single-nucleotide polymorphisms (SNPs) within GPCRs can result in alterations in various pharmacological parameters. Understanding the regulation and function of endocytic trafficking of the μ-opioid receptor (MOP receptor) is of great importance given its implication in the development of opioid tolerance. This study has compared the agonist-dependent trafficking and signalling of L83I, the rat orthologue of a naturally occurring variant of the MOP receptor. EXPERIMENTAL APPROACH Cell surface elisa, confocal microscopy and immunoprecipitation assays were used to characterize the trafficking properties of the MOP-L83I variant in comparison with the wild-type receptor in HEK 293 cells. Functional assays were used to compare the ability of the L83I variant to signal to several downstream pathways. KEY RESULTS Morphine-induced internalization of the L83I MOP receptor was markedly increased in comparison with the wild-type receptor. The altered trafficking of this variant was found to be specific to morphine and was both G-protein receptor kinase- and dynamin-dependent. The enhanced internalization of L83I variant in response to morphine was not due to increased phosphorylation of serine 375, arrestin association or an increased ability to signal. CONCLUSIONS AND IMPLICATIONS These results suggest that morphine promotes a specific conformation of the L83I variant that makes it more liable to internalize in response to morphine, unlike the wild-type receptor that undergoes significantly less morphine-stimulated internalization, providing an example of a ligand-selective biased receptor. The presence of this SNP within an individual may consequently affect the development of tolerance and analgesic responses. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2 PMID:24697554

Morphine-induced internalization of the L83I mutant of the rat μ-opioid receptor.

PubMed

Cooke, A E; Oldfield, S; Krasel, C; Mundell, S J; Henderson, G; Kelly, E

2015-01-01

Naturally occurring single-nucleotide polymorphisms (SNPs) within GPCRs can result in alterations in various pharmacological parameters. Understanding the regulation and function of endocytic trafficking of the μ-opioid receptor (MOP receptor) is of great importance given its implication in the development of opioid tolerance. This study has compared the agonist-dependent trafficking and signalling of L83I, the rat orthologue of a naturally occurring variant of the MOP receptor. Cell surface elisa, confocal microscopy and immunoprecipitation assays were used to characterize the trafficking properties of the MOP-L83I variant in comparison with the wild-type receptor in HEK 293 cells. Functional assays were used to compare the ability of the L83I variant to signal to several downstream pathways. Morphine-induced internalization of the L83I MOP receptor was markedly increased in comparison with the wild-type receptor. The altered trafficking of this variant was found to be specific to morphine and was both G-protein receptor kinase- and dynamin-dependent. The enhanced internalization of L83I variant in response to morphine was not due to increased phosphorylation of serine 375, arrestin association or an increased ability to signal. These results suggest that morphine promotes a specific conformation of the L83I variant that makes it more liable to internalize in response to morphine, unlike the wild-type receptor that undergoes significantly less morphine-stimulated internalization, providing an example of a ligand-selective biased receptor. The presence of this SNP within an individual may consequently affect the development of tolerance and analgesic responses. This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2. © 2014 The British Pharmacological Society.

Synthetic Studies of Neoclerodane Diterpenes from Salvia divinorum: Identification of a Potent and Centrally Acting μ Opioid Analgesic with Reduced Abuse Liability.

PubMed

Crowley, Rachel Saylor; Riley, Andrew P; Sherwood, Alexander M; Groer, Chad E; Shivaperumal, Nirajmohan; Biscaia, Miguel; Paton, Kelly; Schneider, Sebastian; Provasi, Davide; Kivell, Bronwyn M; Filizola, Marta; Prisinzano, Thomas E

2016-12-22

Opioids are widely used to treat millions suffering from pain, but their analgesic utility is limited due to associated side effects. Herein we report the development and evaluation of a chemical probe exhibiting analgesia and reduced opioid-induced side effects. This compound, kurkinorin (5), is a potent and selective μ-opioid receptor (MOR) agonist (EC 50 = 1.2 nM, >8000 μ/κ selectivity). 5 is a biased activator of MOR-induced G-protein signaling over β-arrestin-2 recruitment. Metadynamics simulations of 5's binding to a MOR crystal structure suggest energetically preferred binding modes that differ from crystallographic ligands. In vivo studies with 5 demonstrate centrally mediated antinociception, significantly reduced rewarding effects, tolerance, and sedation. We propose that this novel MOR agonist may represent a valuable tool in distinguishing the pathways involved in MOR-induced analgesia from its side effects.

Intolerance of uncertainty in opioid dependency – Relationship with trait anxiety and impulsivity

PubMed Central

Haber, Paul; Myers, Catherine E.; Allen, Michael T.; Misiak, Blazej; Frydecka, Dorota; Moustafa, Ahmed A.

2017-01-01

Intolerance of uncertainty (IU) is the tendency to interpret ambiguous situations as threatening and having negative consequences, resulting in feelings of distress and anxiety. IU has been linked to a number of anxiety disorders, and anxiety felt in the face of uncertainty may result in maladaptive behaviors such as impulsive decision making. Although there is strong evidence that anxiety and impulsivity are risk factors for addiction, there is a paucity of research examining the role of IU in this disorder. The rate of opioid addiction, in particular, has been rising steadily in recent years, which necessitates deeper understanding of risk factors in order to develop effective prevention and treatment methods. The current study tested for the first time whether opioid-dependent adults are less tolerant of uncertainty compared to a healthy comparison group. Opioid dependent patients undergoing methadone maintenance therapy (n = 114) and healthy comparisons (n = 69) completed the following scales: Intolerance of Uncertainty Scale, the Barrett Impulsivity Scale, and the State Trait Anxiety Inventory. Analysis revealed that these measures were positively correlated with each other and that opioid-dependent patients had significantly higher IU scores. Regression analysis revealed that anxiety mediated the relationship between IU and impulsivity. Hierarchical moderation regression found an interaction between addiction status and impulsivity on IU scores in that the relationship between these variables was only observed in the patient group. Findings suggest that IU is a feature of addiction but does not necessarily play a unique role. Further research is needed to explore the complex relationship between traits and how they may contribute to the development and maintenance of addiction. PMID:28759635

Opioids, pain, the brain, and hyperkatifeia: a framework for the rational use of opioids for pain.

PubMed

Shurman, Joseph; Koob, George F; Gutstein, Howard B

2010-07-01

Opioids have relieved more human suffering than any other medication, but their use is still fraught with significant concerns of misuse, abuse, and addiction. This theoretical article explores the hypothesis that opioid misuse in the context of pain management produces a hypersensitivity to emotional distress, termed hyperkatifeia. In the misuse of opioids, neural substrates that mediate positive emotional states (brain reward systems) are compromised, and substrates mediating negative emotional states (brain stress systems) are enhanced. A reflection and early marker of such a nonhomeostatic state may be the development of opioid-induced hyperkatifeia, defined as the increased intensity of the constellation of negative emotional/motivational symptoms and signs observed during withdrawal from drugs of abuse (derived from the Greek "katifeia" for dejection or negative emotional state) and is most likely to occur in subjects in whom the opioid produces a break with homeostasis and less likely to occur when the opioid is restoring homeostasis, such as in effective pain treatment. When the opioid appropriately relieves pain, opponent processes are not engaged. However, if the opioid is administered in excess of need because of overdose, pharmacokinetic variables, or treating an individual without pain, then the body will react to that perturbation by engaging opponent processes in the domains of both pain (hyperalgesia) and negative emotional states (hyperkatifeia). Repeated engagement of opponent processes without time for the brain's emotional systems to reestablish homeostasis will further drive changes in emotional processes that may produce opioid abuse or addiction, particularly in individuals with genetic or environmental vulnerability.

Behavioral and electrographic effects of opioids on kindled seizures in rats.

PubMed

Caldecott-Hazard, S; Shavit, Y; Ackermann, R F; Engel, J; Frederickson, R C; Liebeskind, J C

1982-11-18

Our laboratory previously suggested that opioid peptides are released by an amygdaloid kindled seizure and may affect the elicitation of a subsequent seizure. The present study examined the effects of morphine, naloxone, enkephalin analogues, and conditions of morphine tolerance and withdrawal on the severity and duration of a series of amygdaloid kindled seizures. The results suggest two distinct opiate/opioid actions on seizures. The first is an anticonvulsant effect on the behavioral manifestations of seizures. This effect is seen following a high dose (50 mg/kg) of morphine or a low dose (6 mg/kg) of enkephalin analogue (LY146104), and is reversed by naloxone. The second is a naloxone-reversible prolonging effect of the high dose of morphine on the electrographic components of the seizures. Receptor affinities of these various opiate/opioid drugs suggest that these two actions are mediated by different receptors which appear not to include high affinity mu receptors.

Biological profile and bioavailability of imidazoline compounds on morphine tolerance modulation.

PubMed

Caprioli, Giovanni; Mammoli, Valerio; Ricciutelli, Massimo; Sagratini, Gianni; Ubaldi, Massimo; Domi, Esi; Mennuni, Laura; Sabatini, Chiara; Galimberti, Chiara; Ferrari, Flora; Milia, Chiara; Comi, Eleonora; Lanza, Marco; Giannella, Mario; Pigini, Maria; Del Bello, Fabio

2015-12-15

Tolerance to opioid administration represents a serious medical alert in different chronic conditions. This study compares the effects of the imidazoline compounds 1, 2, and 3 on morphine tolerance in an animal model of inflammatory pain in the rat. 1, 2, and 3 have been selected in that, although bearing a common scaffold, preferentially bind to α2-adrenoceptors, imidazoline I2 receptors, or both systems, respectively. Such compounds have been tested in vivo by measuring the paw withdrawal threshold to mechanical pressure after complete Freund's adjuvant injection. To determine the ligand levels in rat plasma, an HPLC-mass spectrometry method has been developed. All the compounds significantly reduced the induction of morphine tolerance, showing different potency and duration of action. Indeed, the selective imidazoline I2 receptor interaction (2) restored the analgesic response by maintaining the same time-dependent profile observed after a single morphine administration. Differently, the selective α2C-adrenoceptor activation (1) or the combination between α2C-adrenoceptor activation and imidazoline I2 receptor engagement (3) promoted a change in the temporal profile of morphine analgesia by maintaining a mild but long lasting analgesic effect. Interestingly, the kinetics of compounds in rat plasma supported the pharmacodynamic data. Therefore, this study highlights that both peculiar biological profile and bioavailability of such ligands complement each other to modulate the reduction of morphine tolerance. Based on these observations, 1-3 can be considered useful leads in the design of new drugs able to turn off the undesired tolerance induced by opioids. Copyright © 2015 Elsevier B.V. All rights reserved.

Past-year Prescription Drug Monitoring Program Opioid Prescriptions and Self-reported Opioid Use in an Emergency Department Population With Opioid Use Disorder.

PubMed

Hawk, Kathryn; D'Onofrio, Gail; Fiellin, David A; Chawarski, Marek C; O'Connor, Patrick G; Owens, Patricia H; Pantalon, Michael V; Bernstein, Steven L

2017-11-22

Despite increasing reliance on prescription drug monitoring programs (PDMPs) as a response to the opioid epidemic, the relationship between aberrant drug-related behaviors captured by the PDMP and opioid use disorder is incompletely understood. How PDMP data should guide emergency department (ED) assessment has not been studied. The objective was to evaluate a relationship between PDMP opioid prescription records and self-reported nonmedical opioid use of prescription opioids in a cohort of opioid-dependent ED patients enrolled in a treatment trial. PDMP opioid prescription records during 1 year prior to study enrollment on 329 adults meeting Diagnostic and Statistical Manual IV criteria for opioid dependence entering a randomized clinical trial in a large, urban ED were cross-tabulated with data on 30-day nonmedical prescription opioid use self-report. The association among these two types of data was assessed by the Goodman and Kruskal's gamma; a logistic regression was used to explore characteristics of participants who had PDMP record of opioid prescriptions. During 1 year prior to study enrollment, 118 of 329 (36%) patients had at least one opioid prescription (range = 1-51) in our states' PDMP. Patients who reported ≥15 of 30 days of nonmedical prescription opioid use were more likely to have at least four PDMP opioid prescriptions (20/38; 53%) than patients reporting 1 to 14 days (14/38, 37%) or zero days of nonmedical prescription opioid use (4/38, 11%; p = 0.002). Female sex and having health insurance were significantly more represented in the PDMP (p < 0.05 for both). PDMPs may be helpful in identifying patients with certain aberrant drug-related behavior, but are unable to detect many patients with opioid use disorder. The majority of ED patients with opioid use disorder were not captured by the PDMP, highlighting the importance of using additional methods such as screening and clinical history to identify opioid use disorders in ED patients and the

Dmt and opioid peptides: a potent alliance.

PubMed

Bryant, Sharon D; Jinsmaa, Yunden; Salvadori, Severo; Okada, Yoshio; Lazarus, Lawrence H

2003-01-01

The introduction of the Dmt (2',6'-dimethyl-L-tyrosine)-Tic pharmacophore into the design of opioid ligands produced an extraordinary family of potent delta-opioid receptor antagonists and heralded a new phase in opioid research. First reviewed extensively in 1998, the incorporation of Dmt into a diverse group of opioid molecules stimulated the opioid field leading to the development of unique analogues with remarkable properties. This overview will document the crucial role played by this residue in the proliferation of opioid peptides with high receptor affinity (K(i) equal to or less than 1 nM) and potent bioactivity. The discussion will include the metamorphosis between delta-opioid receptor antagonists to delta-agonists based solely on subtle structural changes at the C-terminal region of the Dmt-Tic pharmacophore as well as their behavior in vivo. Dmt may be considered promiscuous due to the acquisition of potent mu-agonism by dermorphin and endomorphin derivatives as well as by a unique class of opioidmimetics containing two Dmt residues separated by alkyl or pyrazinone linkers. Structural studies on the Dmt-Tic compounds were enhanced tremendously by x-ray diffraction data for three potent and biologically diverse Dmt-Tic opioidmimetics that led to the development of pharmacophores for both delta-opioid receptor agonists and antagonists. Molecular modeling studies of other unique Dmt opioid analogues illuminated structural differences between delta- and mu-receptor ligand interactions. The future of these compounds as therapeutic applications for various medical syndromes including the control of cancer-associated pain is only a matter of time and perseverance. Copyright 2003 Wiley Periodicals, Inc.

Development of the Chronic Pain Coding System (CPCS) for Characterizing Patient-Clinician Discussions About Chronic Pain and Opioids

PubMed Central

Chen, Meng; Matthias, Marianne S.; Bell, Robert A.; Kravitz, Richard L.

2016-01-01

Objective. To describe the development and initial application of the Chronic Pain Coding System. Design. Secondary analysis of data from a randomized clinical trial. Setting. Six primary care clinics in northern California. Subjects. Forty-five primary care visits involving 33 clinicians and 45 patients on opioids for chronic noncancer pain. Methods. The authors developed a structured coding system to accurately and objectively characterize discussions about pain and opioids. Two coders applied the final system to visit transcripts. Intercoder agreement for major coding categories was moderate to substantial (kappa = 0.5–0.7). Mixed effects regression was used to test six hypotheses to assess preliminary construct validity. Results. Greater baseline pain interference was associated with longer pain discussions (P = 0.007) and more patient requests for clinician action (P = 0.02) but not more frequent negative patient evaluations of pain (P = 0.15). Greater clinician-reported visit difficulty was associated with more frequent disagreements with clinician recommendations (P = 0.003) and longer discussions of opioid risks (P = 0.049) but not more frequent requests for clinician action (P = 0.11). Rates of agreement versus disagreement with patient requests and clinician recommendations were similar for opioid-related and non-opioid–related utterances. Conclusions. This coding system appears to be a reliable and valid tool for characterizing patient-clinician communication about opioids and chronic pain during clinic visits. Objective data on how patients and clinicians discuss chronic pain and opioids are necessary to identify communication patterns and strategies for improving the quality and productivity of discussions about chronic pain that may lead to more effective pain management and reduce inappropriate opioid prescribing. PMID:26936453

Modulation Between High- and Low-Frequency Transcutaneous Electric Nerve Stimulation Delays the Development of Analgesic Tolerance in Arthritic Rats

PubMed Central

DeSantana, Josimari M.; Santana-Filho, Valter J.; Sluka, Kathleen A.

2009-01-01

Objective To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Design Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%–2%). Setting Laboratory. Animals Adult male Sprague-Dawley rats (N=36). Intervention Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100μs pulse duration. Main Outcome Measures Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. Results The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. Conclusions These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop. PMID:18374009

Drug interactions: volatile anesthetics and opioids.

PubMed

Glass, P S; Gan, T J; Howell, S; Ginsberg, B

1997-09-01

Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

High-Dose Opioid Prescribing and Opioid-Related Hospitalization: A Population-Based Study.

PubMed

Fernandes, Kimberly; Martins, Diana; Juurlink, David; Mamdani, Muhammad; Paterson, J Michael; Spooner, Luke; Singh, Samantha; Gomes, Tara

2016-01-01

To examine the impact of national clinical practice guidelines and provincial drug policy interventions on prevalence of high-dose opioid prescribing and rates of hospitalization for opioid toxicity. Interventional time-series analysis. Ontario, Canada, from 2003 to 2014. Ontario Drug Benefit (ODB) beneficiaries aged 15 to 64 years from 2003 to 2014. Publication of Canadian clinical practice guidelines for use of opioids in chronic non-cancer pain (May 2010) and implementation of Ontario's Narcotics Safety and Awareness Act (NSAA; November 2011). Three outcomes were explored: the rate of opioid use among ODB beneficiaries, the prevalence of opioid prescriptions exceeding 200 mg and 400 mg morphine equivalents per day, and rates of opioid-related emergency department visits and hospital admissions. Over the 12 year study period, the rate of opioid use declined 15.2%, from 2764 to 2342 users per 10,000 ODB eligible persons. The rate of opioid use was significantly impacted by the Canadian clinical practice guidelines (p-value = .03) which led to a decline in use, but no impact was observed by the enactment of the NSAA (p-value = .43). Among opioid users, the prevalence of high-dose prescribing doubled (from 4.2% to 8.7%) over the study period. By 2014, 40.9% of recipients of long-acting opioids exceeded daily doses of 200 mg morphine or equivalent, including 55.8% of long-acting oxycodone users and 76.3% of transdermal fentanyl users. Moreover, in the last period, 18.7% of long-acting opioid users exceeded daily doses of 400 mg morphine or equivalent. Rates of opioid-related emergency department visits and hospital admissions increased 55.0% over the study period from 9.0 to 14.0 per 10,000 ODB beneficiaries from 2003 to 2013. This rate was not significantly impacted by the Canadian clinical practice guidelines (p-value = .68) or enactment of the NSAA (p-value = .59). Although the Canadian clinical practice guidelines for use of opioids in chronic non-cancer pain led

Opioids with abuse-deterrent properties: A regulatory and technological overview.

PubMed

Haddox, J David

Three concurrent public health problems coexist in the United States: endemic nonmedical use/misuse of opioid analgesics, epidemic overdose fatalities involving opioid analgesics, and endemic chronic pain in adults. These intertwined issues comprise an opioid crisis that has spurred the development of formulations of opioids with abuse-deterrent properties and label claims (OADP). To reduce abuse and misuse of prescription opioids, the federal Food and Drug Administration (FDA) has issued a formal Guidance to drug developers that delineates four categories of testing to generate data sufficient for a description of a product's abuse-deterrent properties, along with associated claims, in its Full Prescribing Information (FPI). This article reviews the epidemiology of the crisis as background for the development of OADP, summarizes the FDA Guidance for Industry regarding abuse-deterrent technologies, and provides an overview of some technologies that are currently employed or are under study for incorporation into OADP. Such technologies include physical and chemical barriers to abuse, combined formulations of opioid agonists and antagonists, inclusion of aversive agents, use of delivery systems that deter abuse, development of new molecular entities and prodrugs, and formulation of products that include some combination of these approaches. Opioids employing these novel technologies are one part of a comprehensive intervention strategy that can deter abuse of prescription opioid analgesics without creating barriers to the safe use of prescription opioids. The maximal public health contribution of OADP will probably occur only when all opioids have FDA-recognized abuse-deterrent properties and label claims.

Intravenous non-opioid analgesia for peri- and postoperative pain management: a scientific review of intravenous acetaminophen and ibuprofen

PubMed Central

Koh, Wonuk; Nguyen, Kimngan Pham

2015-01-01

Pain is a predictable consequence following operations, but the management of postoperative pain is another challenge for anesthesiologists and inappropriately controlled pain may lead to unwanted outcomes in the postoperative period. Opioids are indeed still at the mainstream of postoperative pain control, but solely using only opioids for postoperative pain management may be connected with risks of complications and adverse effects. As a consequence, the concept of multimodal analgesia has been proposed and is recommended whenever possible. Acetaminophen is one of the most commonly used analgesic and antipyretic drug for its good tolerance and high safety profiles. The introduction of intravenous form of acetaminophen has led to a wider flexibility of its use during peri- and postoperative periods, allowing the early initiation of multimodal analgesia. Many studies have revealed the efficacy, safety and opioid sparing effects of intravenous acetaminophen. Intravenous ibuprofen has also shown to be well tolerated and demonstrated to have significant opioid sparing effects during the postoperative period. However, the number of randomized controlled trials confirming the efficacy and safety is small and should be used in caution in certain group of patients. Intravenous acetaminophen and ibuprofen are important options for multimodal postoperative analgesia, improving pain and patient satisfaction. PMID:25664148

Intravenous non-opioid analgesia for peri- and postoperative pain management: a scientific review of intravenous acetaminophen and ibuprofen.

PubMed

Koh, Wonuk; Nguyen, Kimngan Pham; Jahr, Jonathan S

2015-02-01

Pain is a predictable consequence following operations, but the management of postoperative pain is another challenge for anesthesiologists and inappropriately controlled pain may lead to unwanted outcomes in the postoperative period. Opioids are indeed still at the mainstream of postoperative pain control, but solely using only opioids for postoperative pain management may be connected with risks of complications and adverse effects. As a consequence, the concept of multimodal analgesia has been proposed and is recommended whenever possible. Acetaminophen is one of the most commonly used analgesic and antipyretic drug for its good tolerance and high safety profiles. The introduction of intravenous form of acetaminophen has led to a wider flexibility of its use during peri- and postoperative periods, allowing the early initiation of multimodal analgesia. Many studies have revealed the efficacy, safety and opioid sparing effects of intravenous acetaminophen. Intravenous ibuprofen has also shown to be well tolerated and demonstrated to have significant opioid sparing effects during the postoperative period. However, the number of randomized controlled trials confirming the efficacy and safety is small and should be used in caution in certain group of patients. Intravenous acetaminophen and ibuprofen are important options for multimodal postoperative analgesia, improving pain and patient satisfaction.

Synthesis of conolidine, a potent non-opioid analgesic for tonic and persistent pain

NASA Astrophysics Data System (ADS)

Tarselli, Michael A.; Raehal, Kirsten M.; Brasher, Alex K.; Streicher, John M.; Groer, Chad E.; Cameron, Michael D.; Bohn, Laura M.; Micalizio, Glenn C.

2011-06-01

Management of chronic pain continues to represent an area of great unmet biomedical need. Although opioid analgesics are typically embraced as the mainstay of pharmaceutical interventions in this area, they suffer from substantial liabilities that include addiction and tolerance, as well as depression of breathing, nausea and chronic constipation. Because of their suboptimal therapeutic profile, the search for non-opioid analgesics to replace these well-established therapeutics is an important pursuit. Conolidine is a rare C5-nor stemmadenine natural product recently isolated from the stem bark of Tabernaemontana divaricata (a tropical flowering plant used in traditional Chinese, Ayurvedic and Thai medicine). Although structurally related alkaloids have been described as opioid analgesics, no therapeutically relevant properties of conolidine have previously been reported. Here, we describe the first de novo synthetic pathway to this exceptionally rare C5-nor stemmadenine natural product, the first asymmetric synthesis of any member of this natural product class, and the discovery that (±)-, (+)- and (-)-conolidine are potent and efficacious non-opioid analgesics in an in vivo model of tonic and persistent pain.

Opioid Dependence Treatment: Options In Pharmacotherapy

PubMed Central

Stotts, Angela L.; Dodrill, Carrie L.; Kosten, Thomas R.

2010-01-01

The development of effective treatments for opioid dependence is of great importance given the devastating consequences of the disease. Pharmacotherapies for opioid addiction include opioid agonists, partial agonists, opioid antagonists, and alpha-2-adrenergic agonists, which are targeted toward either detoxification or long-term agonist maintenance. Agonist maintenance therapy is currently the recommended treatment for opioid dependence due to its superior outcomes relative to detoxification. Detoxification protocols have limited long term efficacy and patient discomfort remains a significant therapy challenge. Buprenorphine’s effectiveness relative to methadone remains a controversy and may be most appropriate for patients in need of low doses of agonist treatment. Buprenorphine appears superior to alpha-2 agonists, however, and office-based treatment with buprenorphine in the US is gaining support. Studies of sustained-release formulations of naltrexone suggest improved effectiveness for retention and sustained abstinence, however, randomized clinical trials are needed. PMID:19538000

Opioid analgesics stop the development of clostridial gas gangrene.

PubMed

Chakravorty, Anjana; Awad, Milena M; Hiscox, Thomas J; Cheung, Jackie K; Choo, Jocelyn M; Lyras, Dena; Rood, Julian I

2014-08-01

Gas gangrene is a potentially fatal disease that is primarily caused by the ubiquitous, anaerobic bacteria Clostridium perfringens and Clostridium septicum. Treatment is limited to antibiotic therapy, debridement of the infected tissue, and, in severe cases, amputation. The need for new treatment approaches is compelling. Opioid-based analgesics such as buprenorphine and morphine also have immunomodulatory properties, usually leading to faster disease progression. However, here we show that mice pretreated with buprenorphine and morphine do not die from clostridial myonecrosis. Treatment with buprenorphine after the onset of infection also arrested disease development. Protection against myonecrotic disease was specific to C. perfringens-mediated myonecrosis; buprenorphine did not protect against disease caused by C. septicum infection even though infections due to both species are very similar. These data provide the first evidence of a protective role for opioids during infection and suggest that new therapeutic strategies may be possible for the treatment of C. perfringens-mediated myonecrosis. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Preventing Opioid Use Disorders among Fishing Industry Workers

PubMed Central

Morocho, Cesar; King, Lauren; Bartlett, John; Kelsey, Debra; DeSousa, Monica; Biesecker, Gretchen

2018-01-01

Fishing industry workers are at high risk for work-related musculoskeletal disorders (MSDs) and injuries. Prescription opioids used to treat pain injuries may put these workers at increased risk for developing substance disorders. Using a Community-Based Participatory Research approach, formative research was conducted to inform the eventual development of relevant interventions to prevent and reduce opioid use disorders among fishing industry workers. Qualitative interviews (n = 21) were conducted to assess: knowledge and attitudes about opioid use disorders; features of fishing work that might affect use and/or access to treatment; and community and organizational capacity for prevention and treatment. Participants reported numerous pathways connecting commercial fishing with opioid use. The combination of high stress and physically tasking job duties requires comprehensive workplace interventions to prevent chronic pain and MSDs, in addition to tailored and culturally responsive treatment options to address opioid use disorders in this population. Public health programs must integrate workplace health and safety protection along with evidence-based primary, secondary, and tertiary interventions in order to address opioid use disorders, particularly among workers in strenuous jobs. PMID:29614742

Preventing Opioid Use Disorders among Fishing Industry Workers.

PubMed

Walter, Angela Wangari; Morocho, Cesar; King, Lauren; Bartlett, John; Kelsey, Debra; DeSousa, Monica; Biesecker, Gretchen; Punnett, Laura

2018-03-31

Fishing industry workers are at high risk for work-related musculoskeletal disorders (MSDs) and injuries. Prescription opioids used to treat pain injuries may put these workers at increased risk for developing substance disorders. Using a Community-Based Participatory Research approach, formative research was conducted to inform the eventual development of relevant interventions to prevent and reduce opioid use disorders among fishing industry workers. Qualitative interviews ( n = 21) were conducted to assess: knowledge and attitudes about opioid use disorders; features of fishing work that might affect use and/or access to treatment; and community and organizational capacity for prevention and treatment. Participants reported numerous pathways connecting commercial fishing with opioid use. The combination of high stress and physically tasking job duties requires comprehensive workplace interventions to prevent chronic pain and MSDs, in addition to tailored and culturally responsive treatment options to address opioid use disorders in this population. Public health programs must integrate workplace health and safety protection along with evidence-based primary, secondary, and tertiary interventions in order to address opioid use disorders, particularly among workers in strenuous jobs.

Opioids for neuropathic pain.

PubMed

Katz, Nathaniel; Benoit, Christine

2005-06-01

Whether opioids are effective for neuropathic pain has been a matter of controversy for decades. Within limits, it is clear that opioids in general are effective for neuropathic pain. Furthermore, there is no evidence that opioids are any less effective for neuropathic pain than for non-neuropathic pain, no evidence that opioids are less effective for neuropathic pain than are other medications, and no evidence that one opioid is any more effective than another for neuropathic pain. It remains uncertain whether opioids are effective for central pain, although they may have a role. Although some patients appear to enjoy long-term benefits, most studies have been short-term. Opioids have an important role in the treatment of neuropathic pain; however, skillful opioid use balances the benefits with management of side effects and prevention and treatment of abuse and addiction.

Prevalence of prescription opioid use disorder among chronic opioid therapy patients after health plan opioid dose and risk reduction initiatives.

PubMed

Von Korff, Michael; Walker, Rod L; Saunders, Kathleen; Shortreed, Susan M; Thakral, Manu; Parchman, Michael; Hansen, Ryan N; Ludman, Evette; Sherman, Karen J; Dublin, Sascha

2017-08-01

No studies have assessed the comparative effectiveness of guideline-recommended interventions to reduce risk of prescription opioid use disorder among chronic opioid therapy (COT) patients. We compared the prevalence of prescription opioid use disorder among COT patients from intervention clinics that had implemented opioid dose and risk reduction initiatives for more than 4 years relative to control clinics that had not. After a healthcare system in Washington State implemented interventions to reduce opioid dose and risks, we surveyed 1588 adult primary care COT patients to compare the prevalence of prescription opioid use disorder among COT patients from the intervention and control clinics. Intervention clinics managed COT patients at lower COT doses and with more consistent use of risk reduction practices. Control clinics cared for similar COT patients but prescribed higher opioid doses and used COT risk reduction practices inconsistently. Prescription opioid use disorder was assessed with the Psychiatric Research Interview for Substance and Mental Disorders. The prevalence of prescription opioid use disorder was 21.5% (95% CI=18.9% to 24.4%) among COT patients in the intervention clinics and 23.9% (95% CI=20.5% to 27.6%) among COT patients in the control clinics. The adjusted relative risk of prescription opioid use disorder was 1.08 (95% CI=0.89, 1.32) among the control clinic patients relative to the intervention clinic patients. Long-term implementation of opioid dose and risk reduction initiatives was not associated with lower rates of prescription opioid use disorder among prevalent COT patients. Extreme caution should be exercised by clinicians considering COT for patients with chronic non-cancer pain until benefits of this treatment and attendant risks are clarified. Copyright © 2017 Elsevier B.V. All rights reserved.

Mindfulness-Meditation-Based Pain Relief Is Not Mediated by Endogenous Opioids

PubMed Central

Adler-Neal, Adrienne L.; Wells, Rebecca E.; Stagnaro, Emily; May, Lisa M.; Eisenach, James C.; McHaffie, John G.; Coghill, Robert C.

2016-01-01

. The results demonstrate that meditation-based pain relief does not require endogenous opioids. Therefore, the treatment of chronic pain may be more effective with meditation due to a lack of cross-tolerance with opiate-based medications. PMID:26985045

Opioid Stewardship in Otolaryngology: State of the Art Review.

PubMed

Cramer, John D; Wisler, Brad; Gouveia, Christopher J

2018-05-01

Objective The United States is facing an epidemic of opioid addiction. Deaths from opioid overdose have quadrupled in the past 15 years and now surpass annual deaths during the height of the human immunodeficiency virus epidemic. There is a link between opioid prescriptions after surgery, opioid misuse, opioid diversion, and use of other drugs of abuse. As surgeons, otolaryngologists contribute to this crisis. Our objective is to outline the risk of abuse from opioids in the management of acute postoperative pain in otolaryngology-head and neck surgery (OHNS) and strategies to avoid misuse. Data Sources PubMed/MEDLINE. Review Methods We conducted a review of the literature on the rate of opioid abuse after surgery, methods of safe opioid use, and strategies to minimize the dangers of opioids. Conclusions Otolaryngologists have a responsibility to treat pain. This begins preoperatively by discussing perioperative pain control and developing a personalized pain control plan. Patients should be aware that opioids carry significant risks of adverse events and abuse. Perioperative use of multimodal nonopioid agents enables pain control and avoidance of opioids in many otolaryngologic cases. When this approach is inadequate, opioids should be used in short duration under close surveillance. Institutional standards for opioid prescribing after common procedures can minimize misuse. Implications for Practice Otolaryngologists need to acknowledge the potential harm that opioids cause. It is essential that we evaluate our practices to ensure that opioids are used responsibly. Furthermore, opioid stewardship should become a priority in otolaryngology.

Regulation and Functional Implications of Opioid Receptor Splicing in Opioid Pharmacology and HIV Pathogenesis

PubMed Central

Regan, Patrick M.; Langford, T. Dianne; Khalili, Kamel

2015-01-01

Despite the identification and characterization of four opioid receptor subtypes and the genes from which they are encoded, pharmacological data does not conform to the predications of a four opioid receptor model. Instead, current studies of opioid pharmacology suggest the existence of additional receptor subtypes; however, no additional opioid receptor subtype has been identified to date. It is now understood that this discrepancy is due to the generation of multiple isoforms of opioid receptor subtypes. While several mechanisms are utilized to generate these isoforms, the primary mechanism involves alternative splicing of the pre-mRNA transcript. Extensive alternative splicing patterns for opioid receptors have since been identified and discrepancies in opioid pharmacology are now partially attributed to variable expression of these isoforms. Recent studies have been successful in characterizing the localization of these isoforms as well as their specificity in ligand binding; however, the regulation of opioid receptor splicing specificity is poorly characterized. Furthermore, the functional significance of individual receptor isoforms and the extent to which opioid- and/or HIV-mediated changes in the opioid receptor isoform profile contributes to altered opioid pharmacology or the well-known physiological role of opioids in the exacerbation of HIV neurocognitive dysfunction is unknown. As such, the current review details constitutive splicing mechanisms as well as the specific architecture of opioid receptor genes, transcripts, and receptors in order to highlight the current understanding of opioid receptor isoforms, potential mechanisms of their regulation and signaling, and their functional significance in both opioid pharmacology and HIV-associated neuropathology. PMID:26529364

Development and Validation of a Novel LC-MS/MS Opioid Confirmation Assay: Evaluation of β-glucuronidase Enzymes and Sample Cleanup Methods.

PubMed

Yang, He S; Wu, Alan H B; Lynch, Kara L

2016-06-01

With the rise in the use and misuse of prescription opioids, there is an increasing need for the confirmed identification of opioid analgesics in toxicology laboratories. The goals of this study were to (i) systematically evaluate the hydrolysis efficiency of four β-glucuronidase enzymes under optimized condition; (ii) evaluate compound recovery, matrix effects and precision of three protein precipitation plates and (iii) develop and validate a qualitative liquid-chromatography mass spectrometry (LC-MS/MS) assay to identify 13 opioids in urine. A recombinant β-glucuronidase exhibited the best overall hydrolysis efficiency for seven opioid glucuronide conjugates compared with β-glucuronidase from red abalone, Escherichia coli and Patella vulgata One of the protein precipitation plates tested exhibited overall better recovery of the opioids and lower ion suppression compared with the other two plates. An ESI positive mode LC-MS/MS assay for qualitative opioid analysis was developed and validated. Linearity, LOD, precision, matrix effect, recovery, carryover and interference of the method were evaluated. Sixty-two patient samples were analyzed by both a legacy GC-MS opioid method and the LC-MS/MS method, and 22 samples were analyzed by the LC-MS/MS and an LC-MS/MS reference method. The results of the comparisons showed good concordance. Overall, we described an efficient sample preparation procedure for a sensitive qualitative opioid confirmation assay in urine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Use of Opioids and Sedatives at End-of-Life

PubMed Central

Sim, Shin Wei; Ho, Shirlynn; Kumar, Radha Krishna Lalit

2014-01-01

Despite their proven efficacy and safety, opioid and sedative use for palliation in patients afflicted with cancer in Singapore have been shown to be a fraction of that in other countries. This paper explores the various psychosocial and system-related factors that appear to propagate this conservative approach to care in what is largely a western-influenced care practice. A search for publications relating to sedative and opioid usage in Asia was performed on PubMed, Google, Google Scholar, World Health Organization, and Singapore's government agency websites using search terms such as “opioids,” “sedatives,” “palliation,” “end-of-life-care,” “pain management,” “palliative care,” “cancer pain,” “Asia,” “Singapore,” and “morphine.” Findings were classified into three broad groups – system-related, physician-related, and patient-related factors. A cautious medico-legal climate, shortage of physicians trained in palliative care, and lack of instruments for symptom assessment of patients at the end of life contribute to system-related barriers. Physician-related barriers include delayed access to palliative care due to late referrals, knowledge deficits in non-palliative medicine physicians, and sub-optimal care provided by palliative physicians. Patients' under-reporting of symptoms and fear of addiction, tolerance, and side effects of opioids and sedatives may lead to conservative opioid use in palliative care as well. System-related, physician-related, and patient-related factors play crucial roles in steering the management of palliative patients. Addressing and increasing the awareness of these factors may help ensure patients receive adequate relief and control of distressing symptoms. PMID:25125876

Work Enabling Opioid Management.

PubMed

Lavin, Robert A; Kalia, Nimisha; Yuspeh, Larry; Barry, Jill A; Bernacki, Edward J; Tao, Xuguang Grant

2017-08-01

This study describes the relationship between opioid prescribing and ability to work. The opioid prescription patterns of 4994 claimants were studied. Three groups were constructed: 1) at least 3 consecutive months prescribed (chronic opioid therapy; COT); 2) less than 3 consecutive months prescribed (acute opioid therapy; AOT); and 3) no opioids prescribed. Variables included sex, age, daily morphine equivalent dose (MED), days opioids were prescribed, temporary total days (TTDs), and medical/indemnity/total costs. The COT versus AOT claimants had higher opioid costs ($8618 vs $94), longer TTD (636.2 vs 182.3), and average MED (66.8 vs 34.9). Only 2% of the COT cohort were not released to work. Fifty-seven percent of patients in the COT category (64 of 112) were released to work while still receiving opioids. COT does not preclude ability to work when prescribing within established guidelines.

Development of a Community Readiness Survey for Coalitions to Address Prescription Opioid Misuse

ERIC Educational Resources Information Center

Trudeau, Kimberlee J.

2015-01-01

A community readiness survey for coalitions to address the growing epidemic of prescription opioid misuse was developed in this four-part study. A total of 70 coalition members participated. 1) We conducted 30-minute phone interviews with coalition members (n = 30) and a literature review to develop an item list. 2) Coalition members rated these…

Pharmacological characterization of the bifunctional opioid ligand H-Dmt-Tic-Gly-NH-Bzl (UFP-505).

PubMed

Dietis, N; McDonald, J; Molinari, S; Calo, G; Guerrini, R; Rowbotham, D J; Lambert, D G

2012-02-01

While producing good-quality analgesia, µ-opioid (MOP) receptor activation produces a number of side-effects including tolerance. Simultaneous blockade of δ-opioid (DOP) receptors has been shown to reduce tolerance to morphine. Here, we characterize a prototype bifunctional opioid H-Dmt-Tic-Gly-NH-Bzl (UFP-505). We measured receptor binding affinity in Chinese hamster ovary (CHO) cells expressing recombinant human MOP, DOP, k-opioid (KOP), nociceptin/orphanin (NOP) receptors. For activation, we measured the binding of GTPγ(35)S to membranes from CHO(hMOP), CHO(hDOP), rat cerebrocortex, and rat spinal cord. In addition, we assessed 'end organ' responses in the guinea pig ileum and mouse vas deferens. UFP-505 bound to CHO(hMOP) and CHO(hDOP) with (binding affinity) pK(i) values of 7.79 and 9.82, respectively. There was a weak interaction at KOP and NOP (pK(i) 6.29 and 5.86). At CHO(hMOP), UFP-505 stimulated GTPγ(35)S binding with potency (pEC(50)) of 6.37 and in CHO(hDOP) reversed the effects of a DOP agonist with affinity (pK(b)) of 9.81 (in agreement with pK(i) at DOP). UFP-505 also stimulated GTPγ(35)S binding in rat cerebrocortex and spinal cord with pEC(50) values of 6.11-6.53. In the guinea pig ileum (MOP-rich preparation), UFP-505 inhibited contractility with pEC(50) of 7.50 and in the vas deferens (DOP-rich preparation) reversed the effects of a DOP agonist with an affinity (pA(2)) of 9.15. We have shown in a range of preparations and assays that UFP-505 behaves as a potent MOP agonist and DOP antagonist; a MOP/DOP bifunctional opioid. Further studies in dual expression systems and whole animals with this prototype are warranted.

Nonopioid substance use disorders and opioid dose predict therapeutic opioid addiction.

PubMed

Huffman, Kelly L; Shella, Elizabeth R; Sweis, Giries; Griffith, Sandra D; Scheman, Judith; Covington, Edward C

2015-02-01

Limited research examines the risk of therapeutic opioid addiction (TOA) in patients with chronic noncancer pain. This study examined TOA among 199 patients undergoing long-term opioid therapy at the time of admission to a pain rehabilitation program. It was hypothesized that nonopioid substance use disorders and opioid dosage would predict TOA. Daily mean opioid dose was 132.85 mg ± 175.39. Patients with nonopioid substance use disorders had 28 times the odds (odds ratio [OR] = 28.58; 95% confidence interval [CI] = 10.86, 75.27) of having TOA. Each 50-mg increase in opioid dose nearly doubled the odds of TOA (OR = 1.73; 95% CI = 1.29, 2.32). A 100-mg increase was associated with a 3-fold increase in odds (OR = 3.00; 95% CI = 1.67, 5.41). Receiver operating characteristic analysis revealed that opioid dose was a moderately accurate predictor (area under the curve = .75; 95% CI = .68, .82) of TOA. The sensitivity (.70) and specificity (.68) of opioid dose in predicting TOA was maximized at 76.10 mg; in addition, 46.00 mg yielded 80% sensitivity in identifying TOA. These results underscore the importance of obtaining a substance use history prior to prescribing and suggest a low screening threshold for TOA in patients who use opioids in the absence of improvement in pain or functional impairment. This article examines TOA in patients with chronic noncancer pain undergoing long-term opioid therapy. Results suggest that patients should be screened for nonopioid substance use disorders prior to prescribing. In the absence of improvement in pain or function, there is a low threshold (∼50 mg daily opioid dose) for addiction screening. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Development and Initial Testing of a Tailored Telephone Intervention Delivered by Peers to Prevent Recurring Opioid-Overdoses (TTIP-PRO)

ERIC Educational Resources Information Center

Winhusen, T.; Theobald, J.; Lewis, D.; Wilder, C. M.; Lyons, M. S.

2016-01-01

Individuals with opioid use disorder experiencing a non-fatal opioid-overdose (OOD) are at heightened risk for future OODs; there are no interventions to facilitate treatment enrollment for these patients. Our goal was to develop and initially test the "tailored telephone intervention delivered by peers to prevent recurring…

Physician Introduction to Opioids for Pain Among Patients with Opioid Dependence and Depressive Symptoms

PubMed Central

Tsui, Judith I.; Herman, Debra S.; Kettavong, Malyna; Alford, Daniel; Anderson, Bradley J.; Stein, Michael D.

2011-01-01

This study determined the frequency of reporting being introduced to opioids by a physician among opioid dependent patients. Cross-sectional analyses were performed using baseline data from a cohort of opioid addicts seeking treatment with buprenorphine. The primary outcome was response to the question: “Who introduced you to opiates?” Covariates included sociodemographics, depression, pain, current and prior substance use. Of 140 participants, 29% reported that they had been introduced to opioids by a physician. Of those who were introduced to opioids by a physician, all indicated that they had initially used opioids for pain, versus only 11% of those who did not report being introduced to opioids by a physician (p<0.01). There was no difference in current pain (78% vs. 85%, p=0.29), however participants who were introduced to opioids by a physician were more likely to have chronic pain (63% vs. 43%, p=0.04). A substantial proportion of individuals with opioid dependence seeking treatment may have been introduced to opioids by a physician. PMID:20727704

Delay discounting in opioid use disorder: Differences between heroin and prescription opioid users.

PubMed

Karakula, Sterling L; Weiss, Roger D; Griffin, Margaret L; Borges, Allison M; Bailey, Allen J; McHugh, R Kathryn

2016-12-01

Among those with opioid use disorder, heroin use is associated with poorer prognosis relative to use of prescription opioids alone. However, relatively little is known about distinguishing features between those who use heroin relative to those who use prescription opioids. In the present study we evaluated differences in delay discounting in those with opioid use disorder based on primary opioid of use. Delay discounting is associated with a range of negative outcomes and is an important therapeutic target in this population. Treatment-seeking adults with opioid dependence completed self-report measures including past-month opioid use and the Monetary Choice Questionnaire (Kirby and Marakovic, 1996; Kirby et al., 1999), a measure of delay discounting. Participants were divided into two groups based on whether they used any heroin in the past 30days or only prescription opioids, and delay discounting scores were compared between the groups. Group differences in sociodemographic or clinical variables were included in the analysis as covariates. Results from a forward stepwise linear regression indicated that heroin use was associated with significantly higher delay discounting (B=-0.99, SE B =0.34, t=-2.88, p=0.005), even when considering covariates. Adults with opioid dependence who exclusively used prescription opioids had lower delay discounting relative to those who used heroin. This finding contributes further to the literature suggesting that heroin use is associated with greater clinical severity among those with opioid use disorder. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Opioid dependence

PubMed Central

2011-01-01

Introduction Dependence on opioids is a multifactorial condition involving genetic and psychosocial factors. There are three stages to treating opioid dependence. Stabilisation is usually by opioid substitution treatments, and aims to ensure that the drug use becomes independent of mental state (such as craving and mood) and independent of circumstances (such as finance and physical location). The next stage is to withdraw (detox) from opioids. The final stage is relapse prevention. This treatment process contributes to recovery of the individual, which also includes improved overall health and wellbeing, as well as engagement in society. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for stabilisation (maintenance) in people with opioid dependence? What are the effects of drug treatments for withdrawal in people with opioid dependence? What are the effects of drug treatments for relapse prevention in people with opioid dependence? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2011 (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 26 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: buprenorphine; clonidine; lofexidine; methadone; naltrexone; and ultra-rapid withdrawal regimens. PMID:21929827

Opioid dependence.

PubMed

Praveen, K Thyarappa; Law, Fergus; O'Shea, Jacinta; Melichar, Jan

2011-09-20

Dependence on opioids is a multifactorial condition involving genetic and psychosocial factors. There are three stages to treating opioid dependence. Stabilisation is usually by opioid substitution treatments, and aims to ensure that the drug use becomes independent of mental state (such as craving and mood) and independent of circumstances (such as finance and physical location). The next stage is to withdraw (detox) from opioids. The final stage is relapse prevention. This treatment process contributes to recovery of the individual, which also includes improved overall health and wellbeing, as well as engagement in society. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for stabilisation (maintenance) in people with opioid dependence? What are the effects of drug treatments for withdrawal in people with opioid dependence? What are the effects of drug treatments for relapse prevention in people with opioid dependence? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 26 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review, we present information relating to the effectiveness and safety of the following interventions: buprenorphine; clonidine; lofexidine; methadone; naltrexone; and ultra-rapid withdrawal regimens.

"Weak" opioid analgesics. Codeine, dihydrocodeine and tramadol: no less risky than morphine.

PubMed

2016-02-01

So-called weak opioid analgesics are often used to treat severe pain, or when paracetamol or a nonsteroidal anti-inflammatory drug (NSAID) proves inadequate. But are weak opioids any more effective than paracetamol or NSAIDs on nociceptive pain, and are they better tolerated than morphine? To answer these questions, we conducted a review of literature using the standard Prescrire methodology. The potency of codeine and tramadol is strongly influenced by the cytochrome P450 isoenzyme CYP2D6 genotype, which varies widely from one person to another. This explains reports of overdosing or underdosing after administration of standard doses of the two drugs. The potency of morphine and that of buprenorphine, an opioid receptor agonist-antagonist, appears to be independent of CYP2D6 activity. All "weak" opioids can have the same dose-dependent adverse effects as morphine. There is no evidence that, at equivalent analgesic efficacy, weak opioids carry a lower risk of addiction than low-dose morphine. Respiratory depression can occur in ultrarapid metabolisers after brief exposure to standard doses of codeine or tramadol. Similar cases have been reported with dihydrocodeine in patients with renal failure. In addition, tramadol can cause a serotonin syndrome, hypoglycaemia, hyponatraemia and seizures. Several trials have compared different weak opioids in patients with post-operative pain. A single dose of a weak opioid, possibly combined with paracetamol, has greater analgesic efficacy than paracetamol alone but is not more effective than an NSAID alone. There is a dearth of evidence on weak opioids in patients with chronic pain. Available trials fail to show that a weak opioid has markedly superior analgesic efficacy to paracetamol or an NSAID. Sublingual buprenorphine at analgesic doses appears less likely to cause respiratory depression, but it seems to have weak analgesic efficacy. In practice, when opioid therapy is needed, there is no evidence that codeine

Opioid intoxication

MedlinePlus

... treat severe cough or diarrhea. The illegal drug heroin is also an opioid. When abused , opioids cause ... Abuse. What are the medical complications of chronic heroin use? National Institute on Drug Abuse Web site. ...

Positive allosteric modulators of the μ-opioid receptor: a novel approach for future pain medications

PubMed Central

Burford, N T; Traynor, J R; Alt, A

2015-01-01

Morphine and other agonists of the μ-opioid receptor are used clinically for acute and chronic pain relief and are considered to be the gold standard for pain medication. However, these opioids also have significant side effects, which are also mediated via activation of the μ-opioid receptor. Since the latter half of the twentieth century, researchers have sought to tease apart the mechanisms underlying analgesia, tolerance and dependence, with the hope of designing drugs with fewer side effects. These efforts have revolved around the design of orthosteric agonists with differing pharmacokinetic properties and/or selectivity profiles for the different opioid receptor types. Recently, μ-opioid receptor-positive allosteric modulators (μ-PAMs) were identified, which bind to a (allosteric) site on the μ-opioid receptor separate from the orthosteric site that binds an endogenous agonist. These allosteric modulators have little or no detectable functional activity when bound to the receptor in the absence of orthosteric agonist, but can potentiate the activity of bound orthosteric agonist, seen as an increase in apparent potency and/or efficacy of the orthosteric agonist. In this review, we describe the potential advantages that a μ-PAM approach might bring to the design of novel therapeutics for pain that may lack the side effects currently associated with opioid therapy. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2 PMID:24460691

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.

Parallel Synthesis of Hexahydrodiimidazodiazepines Heterocyclic Peptidomimetics and Their in Vitro and in Vivo Activities at μ (MOR), δ (DOR), and κ (KOR) Opioid Receptors.

PubMed

Eans, Shainnel O; Ganno, Michelle L; Mizrachi, Elisa; Houghten, Richard A; Dooley, Colette T; McLaughlin, Jay P; Nefzi, Adel

2015-06-25

In the development of analgesics with mixed-opioid agonist activity, peripherally selective activity is expected to decrease side effects, minimizing respiratory depression and reinforcing properties generating significantly safer analgesic therapeutics. We synthesized diazaheterocyclics from reduced tripeptides. In vitro screening with radioligand competition binding assays demonstrated variable affinity for μ (MOR), δ (DOR), and κ (KOR) opioid receptors across the series, with the diimidazodiazepine 14 (2065-14) displaying good affinity for DOR and KOR. Central (icv), intraperitoneal (ip), or oral (po) administration of 14 produced dose-dependent, opioid-receptor mediated antinociception in the mouse, as determined from a 55 °C warm-water tail-withdrawal assay. Only trace amounts of compound 14 was found in brain up to 90 min later, suggesting poor BBB penetration and possible peripherally restricted activity. Central administration of 14 did not produce locomotor effects, acute antinociceptive tolerance, or conditioned-place preference or aversion. The data suggest these diazaheterocyclic mixed activity opioid receptor agonists may hold potential as new analgesics with fewer liabilities of use.

Evaluating the abuse potential of opioids and abuse-deterrent -opioid formulations: A review of clinical study methodology.

PubMed

Setnik, Beatrice; Schoedel, Kerri A; Levy-Cooperman, Naama; Shram, Megan; Pixton, Glenn C; Roland, Carl L

With the development of opioid abuse-deterrent formulations (ADFs), there is a need to conduct well-designed human abuse potential studies to evaluate the effectiveness of their deterrent properties. Although these types of studies have been conducted for many years, largely to evaluate inherent abuse potential of a molecule and inform drug scheduling, methodological approaches have varied across studies. The focus of this review is to describe current "best practices" and methodological adaptations required to assess abuse-deterrent opioid formulations for regulatory submissions. A literature search was conducted in PubMed® to review methodological approaches (study conduct and analysis) used in opioid human abuse potential studies. Search terms included a combination of "opioid," "opiate," "abuse potential," "abuse liability," "liking," AND "pharmacodynamic," and only studies that evaluated single doses of opioids in healthy, nondependent individuals with or without prior opioid experience were included. Seventy-one human abuse potential studies meeting the prespecified criteria were identified, of which 21 studies evaluated a purported opioid ADF. Based on these studies, key methodological considerations were reviewed and summarized according to participant demographics, study prequalification, comparator and dose selection, route of administration and drug manipulation, study blinding, outcome measures and training, safety, and statistical analyses. The authors recommend careful consideration of key elements (eg, a standardized definition of a "nondependent recreational user"), as applicable, and offer key principles and "best practices" when conducting human abuse potential studies for opioid ADFs. Careful selection of appropriate study conditions is dependent on the type of ADF technology being evaluated.

Opioid withdrawal suppression efficacy of oral dronabinol in opioid dependent humans

PubMed Central

Lofwall, Michelle R.; Babalonis, Shanna; Nuzzo, Paul A.; Elayi, Samy Claude; Walsh, Sharon L.

2016-01-01

Background The cannabinoid (CB) system is a rational novel target for treating opioid dependence, a significant public health problem around the world. This proof-of-concept study examined the potential efficacy of a CB1 receptor partial agonist, dronabinol, in relieving signs and symptoms of opioid withdrawal. Methods Twelve opioid dependent adults participated in this 5-week, inpatient, double-blind, randomized, placebo-controlled study. Volunteers were maintained on double-blind oxycodone (30mg oral, four times/day) and participated in a training session followed by 7 experimental sessions, each testing a single oral test dose (placebo, oxycodone 30 and 60mg, dronabinol 5, 10, 20, and 30mg [decreased from 40mg]). Placebo was substituted for oxycodone maintenance doses for 21 hours before each session in order to produce measurable opioid withdrawal. Outcomes included observer- and participant-ratings of opioid agonist, opioid withdrawal and psychomotor/cognitive performance. Results Oxycodone produced prototypic opioid agonist effects (i.e., suppressing withdrawal and increasing subjective effects indicative of abuse liability). Dronabinol 5 and 10mg produced effects most similar to placebo, while the 20 and 30mg doses produced modest signals of withdrawal suppression that were accompanied by dose-related increases in high, sedation, bad effects, feelings of heart racing, and tachycardia. Dronabinol was not liked more than placebo, showed some impairment in cognitive performance, and was identified as marijuana with increasing dose. Conclusion CB1 receptor activation is a reasonable strategy to pursue for the treatment of opioid withdrawal; however, dronabinol is not a likely candidate given its modest withdrawal suppression effects of limited duration and previously reported tachycardia during opioid withdrawal. PMID:27234658

Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors

PubMed Central

2013-01-01

Opioids are widely used as the pain reliever and also notorious for being addictive drugs. Sex differences in the opioid analgesia and addiction have been reported and investigated in human subjects and animal models. Yet, the molecular mechanism underlying the differences between males and females is still unclear. Here, we reviewed the literature describing the sex differences in analgesic responses and addiction liabilities to clinically relevant opioids. The reported interactions among opioids, estrogens, opioid receptors, and estrogen receptors are also evaluated. We postulate that the sex differences partly originated from the crosstalk among the estrogen and opioid receptors when stimulated by the exogenous opioids, possibly through common secondary messengers and the downstream gene transcriptional regulators. PMID:24010861

International Narcotics Research Conference-35th Meeting. Current developments in medicinal chemistry in the opioid field 17-24 July 2004, Kyoto, Japan.

PubMed

Kitchen, Ian

2004-09-01

Research in the opioid field underwent a lull in the 1990's but much new research has recently been stimulated, firstly by the cloning of all of the opioid receptors and then by the development of gene knockout mice and their phenotype characterization. These developments have led to a a reappraisal of the potential utility of opioid agonists and antagonists not only for the treatment of pain but also for mood-related conditions and peripheral indications. Medicinal chemistry groups are still moving the field forward, and the pharmaceutical industry continues to keep a watching brief. Opioids are no longer exclusively the province of pain scientists, and potential for treatment of limbic disorders, itch and addiction are only now beginning to be considered seriously.

Long-Term Opioid Therapy Reconsidered

PubMed Central

Von Korff, Michael; Kolodny, Andrew; Deyo, Richard A.; Chou, Roger

2012-01-01

In the past 20 years, primary care physicians have greatly increased prescribing of long-term opioid therapy. However, the rise in opioid prescribing has outpaced the evidence regarding this practice. Increased opioid availability has been accompanied by an epidemic of opioid abuse and overdose. The rate of opioid addiction among patients receiving long-term opioid therapy remains unclear, but research suggests that opioid misuse is not rare. Recent studies report increased risks for serious adverse events, including fractures, cardiovascular events, and bowel obstruction, although further research on medical risks is needed. New data indicate that opioid-related risks may increase with dose. From a societal perspective, higher-dose regimens account for the majority of opioids dispensed, so cautious dosing may reduce both diversion potential and patient risks for adverse effects. Limiting long-term opioid therapy to patients for whom it provides decisive benefits could also reduce risks. Given the warning signs and knowledge gaps, greater caution and selectivity are needed in prescribing long-term opioid therapy. Until stronger evidence becomes available, clinicians should err on the side of caution when considering this treatment. PMID:21893626

Opioid Utilization and Opioid-Related Adverse Events in Non-Surgical Patients in U.S. Hospitals

PubMed Central

Herzig, Shoshana J.; Rothberg, Michael B.; Cheung, Michael; Ngo, Long H.; Marcantonio, Edward R.

2014-01-01

Background Recent studies in the outpatient setting have demonstrated high rates of opioid prescribing and overdose-related deaths. Prescribing practices in hospitalized patients are unexamined. Objective To investigate patterns and predictors of opioid utilization in non-surgical admissions to U.S. hospitals, variation in use, and the association between hospital-level use and rates of severe opioid-related adverse events. Design, Setting, and Patients Adult non-surgical admissions to 286 U.S. hospitals. Measurements Opioid exposure and severe opioid-related adverse events during hospitalization, defined using hospital charges and ICD-9-CM codes. Results Of 1.14 million admissions, opioids were used in 51%. The mean ± s.d. daily dose received in oral morphine equivalents (OME) was 68 ± 185 mg; 23% of exposed received a total daily dose of ≥ 100 mg OME. Opioid prescribing rates ranged from 5% in the lowest to 72% in the highest prescribing hospital (mean 51% ± 10%). After adjusting for patient characteristics, the adjusted opioid prescribing rates ranged from 33–64% (mean 50% ± s.d. 4%). Among exposed, 0.97% experienced severe opioid-related adverse events. Hospitals with higher opioid prescribing rates had higher adjusted relative risk of a severe opioid-related adverse event per patient exposed (RR 1.23 [1.14–1.33] for highest compared to lowest prescribing quartile). Conclusions The majority of hospitalized non-surgical patients were exposed to opioids, often at high doses. Hospitals that used opioids most frequently had increased adjusted risk of a severe opioid-related adverse event per patient exposed. Interventions to standardize and enhance the safety of opioid prescribing in hospitalized patients should be investigated. PMID:24227700

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline.

PubMed

Müller-Lissner, Stefan; Bassotti, Gabrio; Coffin, Benoit; Drewes, Asbjørn Mohr; Breivik, Harald; Eisenberg, Elon; Emmanuel, Anton; Laroche, Françoise; Meissner, Winfried; Morlion, Bart

2017-10-01

To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction. Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term "opioid-induced bowel dysfunction." A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system. From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction. In recent years, more insight has been gained in the pathophysiology of this "entity"; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present. © 2016 American Academy of Pain Medicine.

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline

PubMed Central

Müller-Lissner, Stefan; Bassotti, Gabrio; Coffin, Benoit; Drewes, Asbjørn Mohr; Breivik, Harald; Eisenberg, Elon; Emmanuel, Anton; Laroche, Françoise; Meissner, Winfried; Morlion, Bart

2017-01-01

Abstract Objective To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction. Setting Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term “opioid-induced bowel dysfunction.” Methods A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system. Results From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction. Conclusions In recent years, more insight has been gained in the pathophysiology of this “entity”; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present. PMID:28034973

New 2',6'-dimethyl-L-tyrosine (Dmt) opioid peptidomimetics based on the Aba-Gly scaffold. Development of unique mu-opioid receptor ligands.

PubMed

Ballet, Steven; Salvadori, Severo; Trapella, Claudio; Bryant, Sharon D; Jinsmaa, Yunden; Lazarus, Lawrence H; Negri, Lucia; Giannini, Elisa; Lattanzi, Roberta; Tourwé, Dirk; Balboni, Gianfranco

2006-06-29

The Aba-Gly scaffold, incorporated into Dmt-Tic ligands (H-Dmt-Tic-Gly-NH-CH2-Ph, H-Dmt-Tic-Gly-NH-Ph, H-Dmt-Tic-NH-CH2-Bid), exhibited mixed micro/delta or delta opioid receptor activities with micro agonism. Substitution of Tic by Aba-Gly coupled to -NH-CH2-Ph (1), -NH-Ph (2), or -Bid (Bid=1H-benzimidazole-2-yl) (3) shifted affinity (Ki(micro)=0.46, 1.48, and 19.9 nM, respectively), selectivity, and bioactivity to micro-opioid receptors. These compounds represent templates for a new class of lead opioid agonists that are easily synthesized and suitable for therapeutic pain relief.

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

inflammatory pain and opioid abuse liability, and should help to facilitate the development of novel and safer opioid-based strategies for treating chronic pain. PMID:26338332

Combination of intrathecal opioids with bupivacaine attenuates opioid dose escalation in chronic noncancer pain patients.

PubMed

Veizi, I Elias; Hayek, Salim M; Narouze, Samer; Pope, Jason E; Mekhail, Nagy

2011-10-01

The purpose of this study was to examine the effect of intrathecal (IT) coadministration of bupivacaine with opioids during the initial phase of opioid titration and up to 1 year after implantation of an IT drug delivery system (IDDS). The study was designed as a retrospective study. OUTCOMES ANALYZED: The outcomes analyzed for this study were pain relief, oral opioid consumption, IT opioid, and bupivacaine dosage. METHODS AND PATIENT POPULATION: The patient population for this study were consecutively implanted patients over a period of 6 years in a tertiary single center with multiple practitioners. In this retrospective study, 126 consecutive noncancer intractable pain patients were implanted with IDDS and initiated with an IT opioid (O) as a single medication or an IT opioid and bupivacaine (O + B). Pain intensity, amount of oral opioids, dose, rate, and concentration of IT opioids and bupivacaine, and number and type of IT medication used were recorded at preimplant, implant, and at 3, 6, and 12 months postimplant. The intervention used for the study was the IT delivery device implant. Significant reduction in pain intensity was observed in both groups at 12 months postimplant (O group: baseline 7.42 ± 2.1 to 5.85 ± 2.8 [n = 72, P < 0.001]; O + B group 7.35 ± 2 to 5.03 ± 2.4 (n = 54; P < 0.001]). The combination of opioids with bupivacaine from the start of IT infusion treatment resulted in a reduced progression of opioid dose escalation in comparison to patients started with opioids (O group). The rate of increase of IT opioids in the O group at 12 months was 535 ± 180%, whereas in the O + B, the dose increase was significantly lower at 185 ± 85% (P < 0.004). In both groups, there was a statistically significant decrease in oral opioid consumption compared with preimplant doses. Concomitant initial coadministration of IT bupivacaine with opioids blunts the rate of IT opioid dose escalation during the first year after implant of an IDDS. More studies are

Using Opioids Safely After Surgery

MedlinePlus

... Adult , Geriatric Using Opioids Safely After Surgery Using Opioids Safely After Surgery Stick to the lowest dose ... need opioid pain medicine. If your doctor says opioids aren’t necessary. If your doctor thinks you ...

Suicide by means of opioid overdose in patients with chronic pain.

PubMed

Madadi, Parvaz; Persaud, Nav

2014-11-01

Deaths from prescription opioid use continue to rise in North America. The main focus to date has been developing strategies to prevent nonintentional (accidental) fatalities, which constitute the majority of opioid deaths across all jurisdictions. Often overlooked is the complex group of individuals whose cause of death was suicide by opioid overdose. Although most opioid prescribing tools focus on identifying risk factors for potential abuse, diversion, and propensity for opioid addiction, physicians who consider prescribing opioids should also screen and optimize chronic pain treatment for patients at risk for suicide.

Opioid Abuse and Addiction

MedlinePlus

Opioids, sometimes called narcotics, are a type of drug. They include strong prescription pain relievers, such as ... tramadol. The illegal drug heroin is also an opioid. Some opioids are made from the opium plant, ...

Understanding the Opioid Epidemic

MedlinePlus

... Opioid Overdose Deaths Preventing Overdose Deaths Opioid Overdose Deaths From 1999-2016, more than 350,000 people ... counterfeit pills, and cocaine. 1,3 Preventing Overdose Deaths Combatting the Opioid Overdose Epidemic CDC is committed ...

Managing Opioid Addiction Risk in Plastic Surgery during the Perioperative Period.

PubMed

Demsey, Daniel; Carr, Nicholas J; Clarke, Hance; Vipler, Sharon

2017-10-01

Opioid addiction is a public health crisis that affects all areas of medicine. Large numbers of the population across all racial and economic demographics misuse prescription opioids and use illicit opioids. The current understanding is that opioid misuse is a disease that requires treatment, and is not an issue of choice or character. Use of opioid medication is a necessary part of postoperative analgesia, but many physicians are unsure of how to do this safely given the risk of patients developing an opioid misuse disorder. This review gives an update of the current state of the opioid crisis, explains how current surgeons' prescribing practices are contributing to it, and gives recommendations on how to use opioid medication safely in the perioperative period.

Craving and subsequent opioid use among opioid dependent patients who initiate treatment with buprenorphine

PubMed Central

Tsui, Judith I.; Anderson, Bradley J.; Strong, David R.; Stein, Michael D.

2016-01-01

Background Few studies have directly assessed associations between craving and subsequent opioid use among treated patients. Our objective was to prospectively evaluate the relative utility of two craving questionnaires to predict opioid use among opioid dependent patients in treatment. Method Opioid dependent patients (n=147) initiating buprenorphine treatment were assessed for three months. Craving was measured using: 1) the Desires for Drug Questionnaire (DDQ) and 2) the Penn Alcohol-Craving Scale adapted for opioid craving (PCS) for this study. Multi-level logistic regression models estimated the effects of craving on the likelihood of opioid use after adjusting for gender, age, ethnicity, education, opioid of choice, frequency of use, pain and depression. In these analyses craving assessed at time t was entered as a time-varying predictor of opioid use at time t+1. Results In adjusted regression models, a 1-point increase in PCS scores (on a 7-point scale) was associated with a significant increase in the odds of opioid use at the subsequent assessment (OR = 1.27, 95% CI 1.08; 1.49, p < .01). The odds of opioid use at the subsequent follow-up assessment increased significantly as DDQ desire and intention scores increased (OR = 1.25, 95%CI 1.03; 1.51, p< .05), but was not associated significantly with DDQ negative reinforcement (OR = 1.01, 95%CI 0.88; 1.17, p > .05) or DDQ control (OR = 0.97, 95%CI 0.85; 1.11, p > .05) scores. Conclusion Self-reported craving for opioids was associated with subsequent lapse to opioid use among a cohort of patients treated with buprenorphine. PMID:24521036

Mindfulness-Meditation-Based Pain Relief Is Not Mediated by Endogenous Opioids.

PubMed

Zeidan, Fadel; Adler-Neal, Adrienne L; Wells, Rebecca E; Stagnaro, Emily; May, Lisa M; Eisenach, James C; McHaffie, John G; Coghill, Robert C

2016-03-16

demonstrate that meditation-based pain relief does not require endogenous opioids. Therefore, the treatment of chronic pain may be more effective with meditation due to a lack of cross-tolerance with opiate-based medications. Copyright © 2016 the authors 0270-6474/16/363391-07$15.00/0.

Opioid dependence - management in general practice.

PubMed

Frei, Matthew

2010-08-01

Addiction to opioids, or opioid dependence, encompasses the biopsychosocial dysfunction seen in illicit heroin injectors, as well as aberrant behaviours in patients prescribed opioids for chronic nonmalignant pain. To outline the management of opioid dependence using opioid pharmacotherapy as part of a comprehensive chronic illness management strategy. The same principles and skills general practitioners employ in chronic illness management underpin the care of patients with opioid dependence. Opioid pharmacotherapy, with the substitution medications methadone and buprenorphine, is an effective management of opioid dependence. Training and regulatory requirements for prescribing opioid pharmacotherapies vary between jurisdictions, but this treatment should be within the scope of most Australian GPs.

Opioid Attentional Bias and Cue-Elicited Craving Predict Future Risk of Prescription Opioid Misuse Among Chronic Pain Patients*

PubMed Central

Garland, Eric L.; Howard, Matthew O.

2014-01-01

Background Some chronic pain patients receiving long-term opioid analgesic pharmacotherapy are at risk for misusing opioids. Like other addictive behaviors, risk of opioid misuse may be signaled by an attentional bias (AB) towards drug-related cues. The purpose of this study was to examine opioid AB as a potential predictor of opioid misuse among chronic pain patients following behavioral treatment. Methods Chronic pain patients taking long-term opioid analgesics (N = 47) completed a dot probe task designed to assess opioid AB, as well as self-report measures of opioid misuse and pain severity, and then participated in behavioral treatment. Regression analyses examined opioid AB and cue-elicited craving as predictors of opioid misuse at 3-months posttreatment follow-up. Results Patients who scored high on a measure of opioid misuse risk following treatment exhibited significantly greater opioid AB scores than patients at low risk for opioid misuse. Opioid AB for 200 ms cues and cue-elicited craving significantly predicted opioid misuse risk 20 weeks later, even after controlling for pre-treatment opioid dependence diagnosis, opioid misuse, and pain severity (Model R2 = .50). Conclusion Biased initial attentional orienting to prescription opioid cues and cue-elicited craving may reliably signal future opioid misuse risk following treatment. These measures may therefore provide potential prognostic indicators of treatment outcome. PMID:25282309

Incidence of iatrogenic opioid dependence or abuse in patients with pain who were exposed to opioid analgesic therapy: a systematic review and meta-analysis.

PubMed

Higgins, C; Smith, B H; Matthews, K

2018-06-01

The prevalence and incidence of chronic conditions, such as pain and opioid dependence, have implications for policy development, resource allocation, and healthcare delivery. The primary objective of the current review was to estimate the incidence of iatrogenic opioid dependence or abuse after treatment with opioid analgesics. Systematic electronic searches utilised six research databases (Embase, Medline, PubMed, Cinahl Plus, Web of Science, OpenGrey). A 'grey' literature search and a reference search of included articles were also undertaken. The PICOS framework was used to develop search strategies and the findings are reported in accordance with the PRISMA Statement. After eligibility reviews of 6164 articles, 12 studies (involving 310 408 participants) were retained for inclusion in the meta-analyses. A random effects model (DerSimonian-Laird method) generated a pooled incidence of opioid dependence or abuse of 4.7%. There was little within-study risk of bias and no significant publication bias; however, substantial heterogeneity was found among study effects (99.78%). Sensitivity analyses indicated that the diagnostic criteria selected for identifying opioid dependence or abuse (Diagnostic Statistical Manual (DSM-IV) vs International Classification of Diseases (ICD-9)) accounted for 20% and duration of exposure to opioid analgesics accounted for 18% of variance in study effects. Longer-term opioid analgesic exposure, and prescription of strong rather than weak opioids, were associated with a significantly lower incidence of opioid dependence or abuse. The incidence of iatrogenic opioid dependence or abuse was 4.7% of those prescribed opioids for pain. Further research is required to confirm the potential for our findings to inform prevention of this serious adverse event. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Prescription opioid abuse, pain and addiction: clinical issues and implications.

PubMed

Ling, Walter; Mooney, Larissa; Hillhouse, Maureen

2011-05-01

Prescription opioid misuse in the USA has increased over threefold since 1990 to epidemic proportions, with substantial increases in prescription opioid use also reported in other countries, such as Australia and New Zealand. The broad availability of prescription pain medications, coupled with public misconceptions about their safety and addictive potential, have contributed to the recent surge in non-medical use of prescription opioids and corresponding increases in treatment admissions for problems related to opioid misuse. Given competing pressures faced by physicians to both diagnose and treat pain syndromes and identify individuals at risk for addictive disorders, the use of opioids in the treatment of pain poses a significant clinical challenge. This paper reviews the interaction between pain and opioid addiction with a focus on clinical management issues, including risk factors for opioid dependence in patients with chronic pain and the use of assessment tools to identify and monitor at-risk individuals. Treatment options for opioid dependence and pain are reviewed, including the use of the partial µ agonist buprenorphine in the management of concurrent pain and opioid addiction. Physicians should strive to find a reasonable balance between minimising potential adverse effects of opioid medications without diminishing legitimate access to opioids for analgesia. The article discusses the need to identify methods for minimising risks and negative consequences associated with opioid analgesics and poses research directions, including the development of abuse-deterrent opioid formulations, genetic risk factors for opioid dependence and opioid-induced hyperalgesia as a potential target for medication therapy. © 2011 Australasian Professional Society on Alcohol and other Drugs.

Prescription opioid abuse, pain and addiction: Clinical issues and implications

PubMed Central

LING, WALTER; MOONEY, LARISSA; HILLHOUSE, MAUREEN

2014-01-01

Issues Prescription opioid misuse in the USA has increased over threefold since 1990 to epidemic proportions, with substantial increases in prescription opioid use also reported in other countries, such as Australia and New Zealand. The broad availability of prescription pain medications, coupled with public misconceptions about their safety and addictive potential, have contributed to the recent surge in non-medical use of prescription opioids and corresponding increases in treatment admissions for problems related to opioid misuse. Given competing pressures faced by physicians to both diagnose and treat pain syndromes and identify individuals at risk for addictive disorders, the use of opioids in the treatment of pain poses a significant clinical challenge. Approach This paper reviews the interaction between pain and opioid addiction with a focus on clinical management issues, including risk factors for opioid dependence in patients with chronic pain and the use of assessment tools to identify and monitor at-risk individuals. Treatment options for opioid dependence and pain are reviewed, including the use of the partial μ agonist buprenorphine in the management of concurrent pain and opioid addiction. Implications Physicians should strive to find a reasonable balance between minimising potential adverse effects of opioid medications without diminishing legitimate access to opioids for analgesia. Conclusions The article discusses the need to identify methods for minimising risks and negative consequences associated with opioid analgesics and poses research directions, including the development of abuse-deterrent opioid formulations, genetic risk factors for opioid dependence and opioid-induced hyperalgesia as a potential target for medication therapy. PMID:21545561

Understanding opioid overdose characteristics involving prescription and illicit opioids: A mixed methods analysis.

PubMed

Yarborough, Bobbi Jo H; Stumbo, Scott P; Janoff, Shannon L; Yarborough, Micah T; McCarty, Dennis; Chilcoat, Howard D; Coplan, Paul M; Green, Carla A

2016-10-01

Opioid abuse and misuse are significant public health issues. The CDC estimated 72% of pharmaceutical-related overdose deaths in the US in 2012 involved opioids. While studies of opioid overdoses have identified sociodemographic characteristics, agents used, administration routes, and medication sources associated with overdoses, we know less about the context and life circumstances of the people who experience these events. We analyzed interviews (n=87) with survivors of opioid overdoses or family members of decedents. Individuals experiencing overdoses were members of a large integrated health system. Using ICD codes for opioid overdoses and poisonings, we identified participants from five purposefully derived pools of health-plan members who had: 1) prescriptions for OxyContin(®) or single-ingredient sustained-release oxycodone, 2) oxycodone single-ingredient immediate release, 3) other long-acting opioids, 4) other short-acting opioids, or 5) no active opioid prescriptions. Individuals who experienced opioid overdoses abused and misused multiple medications/drugs; experienced dose-related miscommunications or medication-taking errors; had mental health and/or substance use conditions; reported chronic pain; or had unstable resources or family/social support. Many had combinations of these risks. Most events involved polysubstance use, often including benzodiazepines. Accidental overdoses were commonly the result of abuse or misuse, some in response to inadequately treated chronic pain or, less commonly, medication-related mistakes. Suicide attempts were frequently triggered by consecutive negative life events. To identify people at greater risk of opioid overdose, efforts should focus on screening for prescribed and illicit polysubstance use, impaired cognition, and changes in life circumstances, psychosocial risks/supports, and pain control. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Pharmacological characterization of EN-9, a novel chimeric peptide of endomorphin-2 and neuropeptide FF that produces potent antinociceptive activity and limited tolerance.

PubMed

Wang, Zi-Long; Li, Ning; Wang, Pei; Tang, Hong-Hai; Han, Zheng-Lan; Song, Jing-Jing; Li, Xu-Hui; Yu, Hong-Ping; Zhang, Ting; Zhang, Run; Xu, Biao; Zhang, Meng-Na; Fang, Quan; Wang, Rui

2016-09-01

Mounting evidences indicate the functional interactions between neuropeptide FF (NPFF) and opioids, including the endogenous opioids. In the present work, EN-9, a chimeric peptide containing the functional domains of the endogenous opioid endomorphin-2 (EM-2) and NPFF, was synthesized and pharmacologically characterized. In vitro cAMP assay demonstrated that EN-9 was a multifunctional agonist of κ-opioid, NPFF1 and NPFF2 receptors. In the mouse tail-flick test, intracerebroventricularly (i.c.v.) administration of EN-9 produced significant antinociception with an ED50 value of 13.44 nmol, which lasted longer than that of EM-2. In addition, EN-9 induced potent antinociception after both intravenous (i.v.) and subcutaneous (s.c.) injection. Furthermore, the experiments using the antagonists of opioid and NPFF receptors indicated that the central antinociception of EN-9 was mainly mediated by κ-opioid receptor, independently on NPFF receptors. Notably, the central antinociception of EN-9 was not reduced over a period of 6 days repeated i.c.v. injection. Repeated i.c.v. administration of EN-9 with the NPFF1 and NPFF2 receptors antagonist RF9 resulted in a progressive loss of analgesic potency, consistent with the development of tolerance. Moreover, central administration of EN-9 induced the place conditioning aversion only at a high dose of 60 nmol, but not at low doses. At supraspinal level, only high dose of EN-9 (60 nmol, i.c.v.) inhibited gastrointestinal transit via NPFF receptors. Similarly, systemic administration of EN-9 also inhibited gastrointestinal transit at high doses (10 and 30 mg/kg, i.v.). Taken together, the multifunctional agonist of κ-opioid and NPFF receptors EN-9 produced a potent, non-tolerance forming antinociception with limited side effects. Copyright © 2016. Published by Elsevier Ltd.

The delta-opioid receptor agonist SNC80 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-(3-methoxybenzyl)-N,N-diethylbenzamide] synergistically enhances the locomotor-activating effects of some psychomotor stimulants, but not direct dopamine agonists, in rats.

PubMed

Jutkiewicz, Emily M; Baladi, Michelle G; Folk, John E; Rice, Kenner C; Woods, James H

2008-02-01

The nonpeptidic delta-opioid agonist SNC80 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-(3-methoxybenzyl)-N,N-diethylbenzamide] produces many stimulant-like behavioral effects in rodents and monkeys, such as locomotor stimulation, generalization to cocaine in discrimination procedures, and antiparkinsonian effects. Tolerance to the locomotor-stimulating effects of SNC80 develops after a single administration of SNC80 in rats; it is not known whether cross-tolerance develops to the effects of other stimulant compounds. In the initial studies to determine whether SNC80 produced cross-tolerance to other stimulant compounds, it was discovered that amphetamine-stimulated locomotor activity was greatly enhanced in SNC80-pretreated rats. This study evaluated acute cross-tolerance between delta-opioid agonists and other locomotor-stimulating drugs. Locomotor activity was measured in male Sprague-Dawley rats implanted with radiotransmitters, and activity levels were recorded in the home cage environment. Three-hour SNC80 pretreatment produced tolerance to further delta-opioid receptor stimulation but also augmented greatly amphetamine-stimulated locomotor activity in a dose-dependent manner. Pretreatments with other delta-opioid agonists, (+)BW373U86 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-3-hydroxybenzyl]-N,N-diethylbenzamide] and oxymorphindole (17-methyl-6,7-dehydro-4,5-epoxy-3,14-dihydroxy-6,7,2',3'-indolomorphinan), also modified amphetamine-induced activity levels. SNC80 pretreatment enhanced the stimulatory effects of the dopamine/norepinephrine transporter ligands cocaine and nomifensine (1,2,3,4-tetrahydro-2-methyl-4-phenyl-8-isoquinolinanmine maleate salt), but not the direct dopamine receptor agonists SKF81297 [R-(+)-6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide] and quinpirole [trans-(-)-(4alphaR)-4,4a, 5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo[3,4-g] quinoline

Ascending Single-Dose, Double-Blind, Placebo-Controlled Safety Study of Noribogaine in Opioid-Dependent Patients.

PubMed

Glue, Paul; Cape, Gavin; Tunnicliff, Donna; Lockhart, Michelle; Lam, Fred; Hung, Noelyn; Hung, C Tak; Harland, Sarah; Devane, Jane; Crockett, R S; Howes, John; Darpo, Borje; Zhou, Meijian; Weis, Holger; Friedhoff, Lawrence

2016-11-01

Ibogaine is a psychoactive substance that may reduce opioid withdrawal symptoms. This was the first clinical trial of noribogaine, ibogaine's active metabolite, in patients established on methadone opioid substitution therapy (OST). In this randomized, double-blind, placebo-controlled single ascending-dose study, we evaluated the safety, tolerability, and pharmacokinetics of noribogaine in 27 patients seeking to discontinue methadone OST who had been switched to morphine during the previous week. Noribogaine doses were 60, 120, or 180 mg (n = 6/dose level) or matching placebo (n = 3/dose level). Noribogaine was well tolerated. The most frequent treatment-emergent adverse events were noneuphoric changes in light perception ∼1 hour postdose, headache, and nausea. Noribogaine had dose-linear increases for AUC and C max and was slowly eliminated (mean t 1/2 range, 24-30 hours). There was a concentration-dependent increase in QTcI (0.17 ms/ng/mL), with the largest observed mean effect of ∼16, 28, and 42 milliseconds in the 60-, 120-, and 180-mg groups, respectively. Noribogaine showed a nonstatistically significant trend toward decreased total score in opioid withdrawal ratings, most notably at the 120-mg dose; however, the study design may have confounded evaluations of time to resumption of OST. Future exposure-controlled multiple-dose noribogaine studies are planned that will address these safety and design issues. © 2016, The American College of Clinical Pharmacology.

Risk of Prolonged Opioid Use Among Opioid-Naïve Patients Following Common Hand Surgery Procedures.

PubMed

Johnson, Shepard P; Chung, Kevin C; Zhong, Lin; Shauver, Melissa J; Engelsbe, Michael J; Brummett, Chad; Waljee, Jennifer F

2016-10-01

To evaluate prolonged opioid use in opioid-naïve patients after common hand surgery procedures in the United States. We studied insurance claims from the Truven MarketScan databases to identify opioid-naïve adult patients (no opioid exposure 11 months before the perioperative period) who underwent an elective (carpal tunnel release, carpometacarpal arthroplasty/arthrodesis, cubital tunnel release, or trigger finger release) or trauma-related (closed distal radius fracture fixation, flexor tendon repair, metacarpal fracture fixation, or phalangeal fracture fixation) hand surgery procedure between 2010 and 2012 (N = 77,573 patients). Patients were observed for 6 months to determine the number, timing, duration, and oral morphine equivalent dosage of postoperative opioid prescriptions. We assessed prolonged postoperative opioid use, defined as patients who filled a perioperative opioid prescription followed by a prescription between 90 and 180 days after surgery, and evaluated associated risk factors using multivariable logistic regression. In this cohort, 59,725 opioid-naïve patients (77%) filled a perioperative opioid prescription. Of these, 13% of patients continued to fill prescriptions between 90 and 180 days after surgery. Elective surgery patients were more likely to continue to fill opioid prescriptions after 90 days compared with trauma patients (13.5% vs 10.5%). Younger age, female gender, lower income, comprehensive insurance, higher Elixhauser comorbidity index, mental health disorders, and tobacco dependence or abuse were associated with prolonged opioid use. Approximately 13% of opioid-naïve patients continue to fill opioid prescriptions after hand surgery procedures 90 days after surgery. Preoperative interventions centered on opioid alternatives and early cessation, particularly among patients at risk for long-term use, is critical to addressing the prescription opioid crisis in the United States. The current national opioid use epidemic requires

Pain Therapy Guided by Purpose and Perspective in Light of the Opioid Epidemic

PubMed Central

Severino, Amie L.; Shadfar, Arash; Hakimian, Joshua K.; Crane, Oliver; Singh, Ganeev; Heinzerling, Keith; Walwyn, Wendy M.

2018-01-01

Prescription opioid misuse is an ongoing and escalating epidemic. Although these pharmacological agents are highly effective analgesics prescribed for different types of pain, opioids also induce euphoria, leading to increasing diversion and misuse. Opioid use and related mortalities have developed in spite of initial claims that OxyContin, one of the first opioids prescribed in the USA, was not addictive in the presence of pain. These claims allayed the fears of clinicians and contributed to an increase in the number of prescriptions, quantity of drugs manufactured, and the unforeseen diversion of these drugs for non-medical uses. Understanding the history of opioid drug development, the widespread marketing campaign for opioids, the immense financial incentive behind the treatment of pain, and vulnerable socioeconomic and physical demographics for opioid misuse give perspective on the current epidemic as an American-born problem that has expanded to global significance. In light of the current worldwide opioid epidemic, it is imperative that novel opioids are developed to treat pain without inducing the euphoria that fosters physical dependence and addiction. We describe insights from preclinical findings on the properties of opioid drugs that offer insights into improving abuse-deterrent formulations. One finding is that the ability of some agonists to activate one pathway over another, or agonist bias, can predict whether several novel opioid compounds bear promise in treating pain without causing reward among other off-target effects. In addition, we outline how the pharmacokinetic profile of each opioid contributes to their potential for misuse and discuss the emergence of mixed agonists as a promising pipeline of opioid-based analgesics. These insights from preclinical findings can be used to more effectively identify opioids that treat pain without causing physical dependence and subsequent opioid abuse. PMID:29740351

Opioid receptors: from binding sites to visible molecules in vivo

PubMed Central

Kieffer, Brigitte L.; Evans, Christopher J.

2010-01-01

Opioid drugs such as heroin interact directly with opioid receptors whilst other addictive drugs, including marijuana, alcohol and nicotine indirectly activate endogenous opioid systems to contribute to their rewarding properties. The opioid system therefore plays a key role in addiction neurobiology and continues to be a primary focus for NIDA-supported research. Opioid receptors and their peptide ligands, the endorphins and enkephalins, form an extensive heterogeneous network throughout the central and peripheral nervous system. In addition to reward, opioid drugs regulate many functions such that opioid receptors are targets of choice in several physiological, neurological and psychiatric disorders. Because of the multiplicity and diversity of ligands and receptors, opioid receptors have served as an optimal model for G protein coupled receptor (GPCR) research. The isolation of opioid receptor genes opened the way to molecular manipulations of the receptors, both in artificial systems and in vivo, contributing to our current understanding of the diversity of opioid receptor biology at the behavioral, cellular and molecular levels. This review will briefly summarize some aspects of current knowledge that has accumulated since the very early characterization of opioid receptor genes. Importantly, we will identify a number of research directions that are likely to develop during the next decade. PMID:18718480

Opioid system and human emotions.

PubMed

Nummenmaa, Lauri; Tuominen, Lauri

2017-04-10

Emotions are states of vigilant readiness that guide human and animal behaviour during survival-salient situations. Categorical models of emotions posit neurally and physiologically distinct basic human emotions (anger, fear, disgust, happiness, sadness and surprise) that govern different survival functions. Opioid receptors are expressed abundantly in the mammalian emotion circuit, and the opioid system modulates a variety of functions related to arousal and motivation. Yet, its specific contribution to different basic emotions has remained poorly understood. Here, we review how the endogenous opioid system and particularly the μ receptor contribute to emotional processing in humans. Activation of the endogenous opioid system is consistently associated with both pleasant and unpleasant emotions. In general, exogenous opioid agonists facilitate approach-oriented emotions (anger, pleasure) and inhibit avoidance-oriented emotions (fear, sadness). Opioids also modulate social bonding and affiliative behaviour, and prolonged opioid abuse may render both social bonding and emotion recognition circuits dysfunctional. However, there is no clear evidence that the opioid system is able to affect the emotions associated with surprise and disgust. Taken together, the opioid systems contribute to a wide array of positive and negative emotions through their general ability to modulate the approach versus avoidance motivation associated with specific emotions. Because of the protective effects of opioid system-mediated prosociality and positive mood, the opioid system may constitute an important factor contributing to psychological and psychosomatic resilience. © 2017 The British Pharmacological Society.

Co-administration of delta- and mu-opioid receptor agonists promotes peripheral opioid receptor function

PubMed Central

Schramm, Cicely L.; Honda, Christopher N.

2010-01-01

Enhancement of peripheral opioid analgesia following tissue injury or inflammation in animal models is well-documented, but clinical results of peripheral opioid therapy remain inconsistent. Previous studies in the central nervous system have shown that co-administration of μ- and δ-opioid receptor agonists can enhance analgesic outcomes; however, less is known about the functional consequences of opioid receptor interactions in the periphery. The present study examines the effects of intraplantar injection of the μ- and δ-opioid receptor agonists, morphine and deltorphin, alone and in combination on behavioral tests of nociception in naïve rats and on potassium-evoked release of CGRP from sciatic nerves of naïve rats. Neither drug alone affected nociceptive behaviors or CGRP release. Two separate measures of mechanical nociceptive sensitivity remained unchanged after co-administration of the two drugs. In contrast, when deltorphin was co-injected with morphine, dose-dependent and peripherally-restricted increases in paw withdrawal latencies to radiant heat were observed. Similarly, concentration-dependent inhibition of CGRP release was observed when deltorphin and morphine were administered in sequence prior to potassium stimulation. However, no inhibition was observed when morphine was administered prior to deltorphin. All combined opioid effects were blocked by co-application of antagonists. Deltorphin exposure also enhanced the in vivo and in vitro effects of another μ-opioid receptor agonist, DAMGO. Together, these results suggest that under normal conditions, δ-opioid receptor agonists enhance the effect of μ-opioid receptor agonists in the periphery, and local co-administration of δ- and μ-opioid receptor agonists may improve results of peripheral opioid therapy for the treatment of pain. PMID:20970925

Regulated endocytosis of opioid receptors: cellular mechanisms and proposed roles in physiological adaptation to opiate drugs.

PubMed

von Zastrow, Mark; Svingos, Adena; Haberstock-Debic, Helena; Evans, Chris

2003-06-01

Opiate drugs such as morphine and heroin are among the most effective analgesics known. Prolonged or repeated administration of opiates produces adaptive changes in the nervous system that lead to reduced drug potency or efficacy (tolerance), as well as physiological withdrawal symptoms and behavioral manifestations such as craving when drug use is terminated (dependence). These adaptations limit the therapeutic utility of opiate drugs, particularly in the treatment of chronically painful conditions, and are thought to contribute to the highly addictive nature of opiates. For many years it has been proposed that physiological tolerance to opiate drugs is associated with a modification of the number or functional activity of opioid receptors in specific neurons. We now understand certain mechanisms of opioid receptor desensitization and endocytosis in considerable detail. However, the functional roles that these mechanisms play in the complex physiological adaptation of the intact nervous system to opiates are only beginning to be explored.

“Listening” and “talking” to neurons: Implications of immune activation for pain control and increasing the efficacy of opioids

PubMed Central

Watkins, Linda R.; Hutchinson, Mark R.; Milligan, Erin D.; Maier, Steven F.

2008-01-01

It is recently become clear that activated immune cells and immune-like glial cells can dramatically alter neuronal function. By increasing neuronal excitability, these non-neuronal cells are now implicated in the creation and maintenance of pathological pain, such as occurs in response to peripheral nerve injury. Such effects are exerted at multiple sites along the pain pathway, including at peripheral nerves, dorsal root ganglia, and spinal cord. In addition, activated glial cells are now recognized as disrupting the pain suppressive effects of opioid drugs and contributing to opioid tolerance and opioid dependence/withdrawal. While this review focuses on regulation of pain and opioid actions, such immune-neuronal interactions are broad in their implications. Such changes in neuronal function would be expected to occur wherever immune-derived substances come in close contact with neurons. PMID:17706291

Resisting Prescribed Opioids: A Qualitative Study of Decision Making in Patients Taking Opioids for Chronic Noncancer Pain.

PubMed

Paterson, Charlotte; Ledgerwood, Kay; Arnold, Carolyn; Hogg, Malcolm; Xue, Charlie; Zheng, Zhen

2016-04-01

Opioids are increasingly prescribed for chronic noncancer pain across the developed world. Clinical guidelines for management of these patients focus on over-use. However, research into other types of long-term medication indicates that many patients minimize drug use whenever possible. To identify the varying influences on patients' decisions about their use of prescribed opioids and explore whether concepts of resistance and minimization of intake apply to these patients. A multiprofessional team performed a qualitative interview study using the constant-comparative method. Patient's decision making was explored in depth and with a thematic analysis utilizing a published "Model of medicine-taking." A purposive sample of 20 participants drawn from two pain clinics in Melbourne, Australia. The sample was biased toward patients interested in nonmedication pain management options. Patients' needs to obtain relief from severe pain, maintain function, and minimize side effects could lead to under-use as well as over-use of prescribed opioids. In keeping with the published Model of medicine-taking, resistance to taking opioids was a common and important influence on behavior. In the face of severe chronic pain, many participants used a variety of strategies to evaluate, avoid, reduce, self-regulate, and replace opioids. Furthermore, participants perceived a resistance to opioids within the system and among some healthcare professionals. This sometimes adversely affected their adherence. Both patients and doctors exhibit aspects of resistance to the use of prescribed opioids for chronic noncancer pain, suggesting that this shared concern could be the basis of a productive therapeutic alliance to improve communication and shared decision making. Clinical guidelines for opioids use for chronic noncancer pain focus on over-use. Our qualitative interview study found that many patients resisted and minimized the use of opioids. Using a published "Model of medicine-taking," we

Forecasting the future burden of opioids for osteoarthritis.

PubMed

Ackerman, I N; Zomer, E; Gilmartin-Thomas, J F-M; Liew, D

2018-03-01

To quantify the current national burden of opioids for osteoarthritis (OA) pain in Australia in terms of number of dispensed opioid prescriptions and associated costs, and to forecast the likely burden to the year 2030/31. Epidemiological modelling. Published data were obtained on rates of opioid prescribing for people with OA and national OA prevalence projections. Trends in opioid dispensing from 2006 to 2016, and average costs for common opioid subtypes were obtained from the Pharmaceutical Benefits Scheme and Medicare Australia Statistics. Using these inputs, a model was developed to estimate the likely number of dispensed opioid prescriptions and costs to the public healthcare system by 2030/31. In 2015/16, an estimated 1.1 million opioid prescriptions were dispensed in Australia for 403,954 people with OA (of a total 2.2 million Australians with OA). Based on recent dispensing trends and OA prevalence projections, the number of dispensed opioid prescriptions is expected to nearly triple to 3,032,332 by 2030/31, for an estimated 562,610 people with OA. The estimated cost to the Australian healthcare system was $AUD25.2 million in 2015/16, rising to $AUD72.4 million by 2030/31. OA-related opioid dispensing and associated costs are set to increase substantially in Australia from 2015/16 to 2030/31. Use of opioids for OA pain is concerning given joint disease chronicity and the risk of adverse events, particularly among older people. These projections represent a conservative estimate of the full financial burden given additional costs associated with opioid-related harms and out-of-pocket costs borne by patients. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Fatal and non-fatal opioid overdose in opioid dependent patients treated with methadone, buprenorphine or implant naltrexone.

PubMed

Kelty, Erin; Hulse, Gary

2017-08-01

Illicit opioid use is associated with high rates of fatal and non-fatal opioid overdose. This study aims to compare rates of fatal and serious but non-fatal opioid overdose in opioid dependent patients treated with methadone, buprenorphine or implant naltrexone, and to identify risk factors for fatal opioid overdose. Opioid dependent patients treated with methadone (n=3515), buprenorphine (n=3250) or implant naltrexone (n=1461) in Western Australia for the first time between 2001 and 2010, were matched against state mortality and hospital data. Rates of fatal and non-fatal serious opioid overdoses were calculated and compared for the three treatments. Risk factors associated with fatal opioid overdose were examined using multivariate cox proportional hazard models. No significant difference was observed between the three groups in terms of crude rates of fatal or non-fatal opioid overdoses. During the first 28days of treatment, rates of non-fatal opioid overdose were high in all three groups, as were fatal opioid overdoses in patients treated with methadone. However, no fatal opioid overdoses were observed in buprenorphine or naltrexone patients during this period. Following the first 28 days, buprenorphine was shown to be protective, particularly in terms of non-fatal opioid overdoses. After the cessation of treatment, rates of fatal and non-fatal opioid overdoses were similar between the groups, with the exception of lower rates of non-fatal opioid overdose in the naltrexone treated patients compared with the methadone treated patients. After the commencement of treatment, gender, and hospitalisations with a diagnosis of opioid poisoning, cardiovascular or mental health problems were significant predictors of subsequent fatal opioid overdose. Rates of fatal and non-fatal opioid overdose were not significantly different in patients treated with methadone, buprenorphine or implant naltrexone. Gender and prior cause-specific hospitalisations can be used to identify

78 FR 31945 - Clinical Development Programs for Opioid Conversion; Public Workshop; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

... gaps in existing knowledge regarding equianalgesic opioid conversion in clinical practice, to develop a... organization as well as the total number of participants based on space limitations. Registrants will receive... be based on space availability. If registration reaches maximum capacity, FDA will post a notice...

Genetics of Opioid Dependence: A Review of the Genetic Contribution to Opioid Dependence

PubMed Central

Mistry, Chetna J; Bawor, Monica; Desai, Dipika; Marsh, David C; Samaan, Zainab

2014-01-01

This narrative review aims to provide an overview of the impact of opioid dependence and the contribution of genetics to opioid dependence. Epidemiological data demonstrate that opioid dependence is a global trend with far-reaching effects on the social, economic, and health care systems. A review of classical genetic studies of opioid use suggests significant heritability of drug use behavior, however the evidence from molecular genetic studies is inconclusive. Nonetheless, certain genetic variants are important to consider given their role in the pathophysiology of addictive behavior. We undertook a literature review to identify the current state of knowledge regarding the role of genes in opioid dependence. Determining the association of genetic markers could change the current understanding of the various factors contributing to opioid dependence and therefore may improve recognition of individuals at risk for the disorder and prevention and treatment strategies. PMID:25242908

Buprenorphine implants in medical treatment of opioid addiction.

PubMed

Chavoustie, Steven; Frost, Michael; Snyder, Ole; Owen, Joel; Darwish, Mona; Dammerman, Ryan; Sanjurjo, Victoria

2017-08-01

Opioid use disorder is a chronic, relapsing disease that encompasses use of both prescription opioids and heroin and is associated with a high annual rate of overdose deaths. Medical treatment has proven more successful than placebo treatment or psychosocial intervention, and the partial µ-opioid receptor agonist and κ-opioid receptor antagonist buprenorphine is similar in efficacy to methadone while offering lower risk of respiratory depression. However, frequent dosing requirements and potential for misuse and drug diversion contribute to significant complications with treatment adherence for available formulations. Areas covered: This review describes the development of and preliminary data from clinical trials of an implantable buprenorphine formulation. Efficacy and safety data from comparative studies with other administrations of buprenorphine, including tablets and sublingual film, will be described. Key premises of the Risk Evaluation and Mitigation Strategy program for safely administering buprenorphine implants, which all prescribing physicians must complete, are also discussed. Expert commentary: Long-acting implantable drug formulations that offer consistent drug delivery and lower risk of misuse, diversion, or accidental pediatric exposure over traditional formulations represent a promising development for the effective treatment of opioid use disorder.

Association of an Opioid Standard of Practice Intervention With Intravenous Opioid Exposure in Hospitalized Patients.

PubMed

Ackerman, Adam L; O'Connor, Patrick G; Doyle, Deirdre L; Marranca, Sheyla M; Haight, Carolyn L; Day, Christine E; Fogerty, Robert L

2018-06-01

Opioids are commonly used to treat pain in hospitalized patients; however, intravenous administration carries an increased risk of adverse effects compared with oral administration. The subcutaneous route is an effective method of opioid delivery with favorable pharmacokinetics. To assess an intervention to reduce intravenous opioid use, total parenteral opioid exposure, and the rate of patients administered parenteral opioids. A pilot study was conducted in an adult general medical unit in an urban academic medical center. Attending physicians, nurse practitioners, and physician assistants who prescribed drugs were the participants. Use of opioids was compared between a 6-month control period and 3 months following education for the prescribers on opioid routes of administration. Adoption of a local opioid standard of practice, preferring the oral and subcutaneous routes over intravenous administration, and education for prescribers and nursing staff on awareness of the subcutaneous route was implemented. The primary outcome was a reduction in intravenous doses administered per patient-day. Secondary measures included total parenteral and overall opioid doses per patient-day, parenteral and overall opioid exposure per patient-day, and daily rate of patients receiving parenteral opioids. Pain scores were measured on a standard 0- to 10-point Likert scale over the first 5 days of hospitalization. The control period included 4500 patient-days, and the intervention period included 2459 patient-days. Of 127 patients in the intervention group, 59 (46.5%) were men; mean (SD) age was 57.6 (18.5) years. Intravenous opioid doses were reduced by 84% (0.06 vs 0.39 doses per patient-day, P < .001), and doses of all parenteral opioids were reduced by 55% (0.18 vs 0.39 doses per patient-day, P < .001). In addition, mean (SD) daily parenteral opioid exposure decreased by 49% (2.88 [0.72] vs 5.67 [1.14] morphine-milligram equivalents [MMEs] per patient-day). The daily rate

Designing Safer Analgesics via μ-Opioid Receptor Pathways.

PubMed

Chan, H C Stephen; McCarthy, Dillon; Li, Jianing; Palczewski, Krzysztof; Yuan, Shuguang

2017-11-01

Pain is both a major clinical and economic problem, affecting more people than diabetes, heart disease, and cancer combined. While a variety of prescribed or over-the-counter (OTC) medications are available for pain management, opioid medications, especially those acting on the μ-opioid receptor (μOR) and related pathways, have proven to be the most effective, despite some serious side effects including respiration depression, pruritus, dependence, and constipation. It is therefore imperative that both academia and industry develop novel μOR analgesics which retain their opioid analgesic properties but with fewer or no adverse effects. In this review we outline recent progress towards the discovery of safer opioid analgesics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Designing Safer Analgesics via μ-Opioid Receptor Pathways

PubMed Central

Chan, H.C. Stephen; McCarthy, Dillon; Li, Jianing; Palczewski, Krzysztof; Yuan, Shuguang

2017-01-01

Pain is both a major clinical and economic problem, affecting more people than diabetes, heart disease, and cancer combined. While a variety of prescribed or over-the-counter (OTC) medications are available for pain management, opioid medications, especially those acting on the μ-opioid receptor (μOR) and related pathways, have proven to be the most effective, despite some serious side effects including respiration depression, pruritus, dependence, and constipation. It is therefore imperative that both academia and industry develop novel μOR analgesics which retain their opioid analgesic properties but with fewer or no adverse effects. In this review we outline recent progress towards the discovery of safer opioid analgesics. PMID:28935293

Undertreatment of pain and low use of opioids in Latin America.

PubMed

García, César Amescua; Santos Garcia, Joao Batista; Rosario Berenguel Cook, María Del; Colimon, Frantz; Flores Cantisani, José Alberto; Guerrero, Carlos; Rocío Guillén Núnez, María Del; Hernández Castro, John Jairo; Kraychete, Durval Campos; Lara-Solares, Argelia; Lech, Osvandré; Rico Pazos, María Antonieta; Gallegos, Manuel Sempértegui; Marcondes, Lizandra Pattaro

2018-05-01

Pain is highly prevalent among the adult Latin American population. However, many patients with moderate to severe pain do not have access to effective pain management with opioids due to limited access to healthcare, overuse of nonopioid analgesics, regulatory barriers and lack of appropriate information about opioids. There is scarce training on use of opioids among physicians and other healthcare providers, which leads to misconceptions, mainly related to a fear of prescribing opioids. Although opioids are safe and effective drugs for the treatment of moderate to severe chronic pain, the use of opioids in Latin American nations is clearly below standards compared with developed countries.

Discovery of Peripheral κ-Opioid Receptor Agonists as Novel Analgesics.

PubMed

Suzuki, Shinya; Sugawara, Yuji; Inada, Hideaki; Tsuji, Riichiro; Inoue, Atsushi; Tanimura, Ryuji; Shimozono, Rieko; Konno, Mitsuhiro; Ohyama, Tomofumi; Higashi, Eriko; Sakai, Chizuka; Kawai, Koji

2017-01-01

κ-Opioid receptor agonists with high selectivity over the μ-opioid receptor and peripheral selectivity are attractive targets in the development of drugs for pain. We have previously attempted to create novel analgesics with peripheral selective κ-opioid receptor agonist on the basis of TRK-820. In this study, we elucidated the biological properties of 17-hydroxy-cyclopropylmethyl and 10α-hydroxy derivatives. These compounds were found to have better κ-opioid receptor selectivity and peripheral selectivity than TRK-820.

An Ambitious Research Plan to Help Solve the Opioid Crisis: HEAL Initiative

MedlinePlus

... to Help Solve the Opioid Crisis An Ambitious Research Plan to Help Solve the Opioid Crisis Email ... opioid use disorders. The Focused OUD Medications Development Research Project will consist of a series of high- ...

Opioid Abuse and Addiction - Multiple Languages

MedlinePlus

... Opioid addiction, part 8 - español (Spanish) MP4 Healthy Roads Media Comorbidity or dual diagnosis - Opioid addiction, part 9 - English PDF Comorbidity or ... addiction, part 9 - English MP4 Comorbidity or dual diagnosis - Opioid ... MP4 Healthy Roads Media Pregnancy and opioids - Opioid addiction, part 10 - ...

Interactions between opioids and anabolic androgenic steroids: implications for the development of addictive behavior.

PubMed

Nyberg, Fred; Hallberg, Mathias

2012-01-01

Over the past decades, research on doping agents, such as anabolic androgenic steroids (AAS), has revealed that these compounds are often used in combination with other drugs of abuse. It seems that misuse of AAS probably involves more than a desire to enhance appearance or sports performance and studies have revealed that steroids are commonly connected with alcohol, opioids, tobacco, and psychotropic drugs. We have observed that AAS may interact with the endogenous opioids, excitatory amino acids, and dopaminergic pathways involved in the brain reward system. Furthermore, our studies provide evidence that AAS may induce an imbalance in these signal systems leading to an increased sensitivity toward opioid narcotics and central stimulants. In fact, studies performed in various clinics have shown that individuals taking AAS are likely to get addicted to opioids like heroin. This chapter reviews current knowledge on interactions between AAS and endogenous as well as exogenous opioids based not only on research in our laboratory but also on research carried out by several other clinical and preclinical investigators. Copyright © 2012 Elsevier Inc. All rights reserved.

Ascending-dose study of noribogaine in healthy volunteers: pharmacokinetics, pharmacodynamics, safety, and tolerability.

PubMed

Glue, Paul; Lockhart, Michelle; Lam, Fred; Hung, Noelyn; Hung, Cheung-Tak; Friedhoff, Lawrence

2015-02-01

Noribogaine is the active metabolite of the naturally occurring psychoactive substance ibogaine, and may help suppress withdrawal symptoms in opioid-dependent subjects. The objectives of this Phase I study were to assess the safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of noribogaine. In this ascending single-dose, placebo-controlled, randomized, double-blind, parallel-group study in 36 healthy drug-free male volunteers, 4 cohorts (n = 9) received oral doses of 3, 10, 30, or 60 mg or matching placebo, with intensive safety and pharmacokinetic assessments out to 216 hours, along with pharmacodynamic assessments sensitive to the effects of mu-opioid agonists. Noribogaine was rapidly absorbed, with peak concentrations occurring 2-3 hours after oral dosing, and showed dose-linear increases of area under the concentration-time curve (AUC) and Cmax between 3 and 60 mg. The drug was slowly eliminated, with mean half-life estimates of 28-49 hours across dose groups. Apparent volume of distribution was high (mean 1417-3086 L across dose groups). No safety or tolerability issues were identified in any cohort. No mu-opioid agonist pharmacodynamic effects were noted in pupillometry or cold-pressor testing. Single oral doses of noribogaine 3-60 mg were safe and well tolerated in healthy volunteers. © 2014, The American College of Clinical Pharmacology.

Common and specific liability to addiction: approaches to association studies of opioid addiction.

PubMed

Nielsen, David A; Kreek, Mary Jeanne

2012-06-01

Opioid addiction, whether to opiates such as heroin and morphine, and/or to non-medical use of opioids, is a major problem worldwide. Although drug-induced and environmental factors are essential for the liability to develop opioid addiction, the genetic background of an individual is now known also to play a substantial role. The overall goal of this article is to address the common and specific liabilities to addiction in the context of approaches to studies of one addiction, opioid addiction. Literature on identifying genetic variants that may play a role in the development of opioid addiction was reviewed. A substantial number of genetic variants have been reported to be associated with opioid addiction. No single variant has been found in any of the reported GWAS studies with a substantial effect size on the liability to develop heroin addiction. It appears that there is a complex interaction of a large number of variants, some rare, some common, which interact with the environment and in response to specific drugs of abuse to increase the liability of developing opioid addiction. In spite of the inherent difficulties in obtaining large well-phenotyped cohorts for genetic studies, new findings have been reported that are being used to develop testable hypotheses into the biological basis of opioid addiction. Copyright © 2012. Published by Elsevier Ireland Ltd.

Ketamine as an Adjunct to Opioids for Acute Pain in the Emergency Department: A Randomized Controlled Trial.

PubMed

Bowers, Karen J; McAllister, Kelly B; Ray, Meredith; Heitz, Corey

2017-06-01

(mean ± SD = 9.95 ± 4.83 mg) compared to placebo (mean ± SD = 12.81 ± 6.81 mg; p = 0.02). Satisfaction did not differ between groups. Fewer patients in the ketamine group required additional opioid doses. More patients reported light-headedness and dizziness in the ketamine group. Ketamine, as an adjunct to opioid therapy, was more effective at reducing pain over 120 minutes and resulted in a lower total opioid dose as well as fewer repeat doses of analgesia. More side effects were reported in the ketamine group (51% vs. 19%), but the side effect profile appears tolerable. © 2017 by the Society for Academic Emergency Medicine.

Pharmacists’ experiences with dispensing opioids

PubMed Central

Kahan, Meldon; Wilson, Lynn; Wenghofer, Elizabeth Francis; Srivastava, Anita; Resnick, Anne; Janecek, Eva; Sheehan, Carolynn

2011-01-01

Abstract Objective To explore pharmacists’ beliefs, practices, and experiences regarding opioid dispensing. Design Mailed survey. Setting The province of Ontario. Participants A total of 1011 pharmacists selected from the Ontario College of Pharmacists’ registration list. Main outcome measures Pharmacists’ experiences with opioid-related adverse events (intoxication and aberrant drug-related behaviour) and their interactions with physicians. Results A total of 652 pharmacists returned the survey, for a response rate of 64%. Most (86%) reported that they were concerned about several or many of their patients who were taking opioids; 36% reported that at least 1 patient was intoxicated from opioids while visiting their pharmacies within the past year. Reasons for opioid intoxication included the patient taking more than prescribed (84%), the patient using alcohol or sedating drugs along with the opioid (69.9%), or the prescribed dose being too high (34%). Participants’ most common concerns in the 3 months before the survey were patients coming in early for prescription refills, suspected double-doctoring, and requests for replacement doses for lost medication (reported frequently by 39%, 12%, and 16% of respondents, respectively). Pharmacists were concerned about physician practices, such as prescribing benzodiazepines along with opioids. Pharmacists reported difficulty in reaching physicians directly by telephone (43%), and indicated that physicians frequently did not return their calls promptly (28%). The strategies rated as most helpful for improving opioid dispensing were a provincial prescription database and opioid prescribing guidelines. Conclusion Pharmacists commonly observe opioid intoxication and aberrant drug-related behaviour in their patients but have difficulty communicating their concerns to physicians. System-wide strategies are urgently needed to improve the safety of opioid prescribing and to enhance communication between physicians and

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

Nurses and opioids: results of a bi-national survey on mental models regarding opioid administration in hospitals

PubMed Central

Guest, Charlotte; Sobotka, Fabian; Karavasopoulou, Athina; Ward, Stephen; Bantel, Carsten

2017-01-01

Objective Pain remains insufficiently treated in hospitals. Increasing evidence suggests human factors contribute to this, due to nurses failing to administer opioids. This behavior might be the consequence of nurses’ mental models about opioids. As personal experience and conceptions shape these models, the aim of this prospective survey was to identify model-influencing factors. Material and methods A questionnaire was developed comprising of 14 statements concerning ideations about opioids and seven questions concerning demographics, indicators of adult learning, and strength of religious beliefs. Latent variables that may underlie nurses’ mental models were identified using undirected graphical dependence models. Representative items of latent variables were employed for ordinal regression analysis. Questionnaires were distributed to 1,379 nurses in two London, UK, hospitals (n=580) and one German (n=799) hospital between September 2014 and February 2015. Results A total of 511 (37.1%) questionnaires were returned. Mean (standard deviation) age of participants were 37 (11) years; 83.5% participants were female; 45.2% worked in critical care; and 51.5% had more than 10 years experience. Of the nurses, 84% were not scared of opioids, 87% did not regard opioids as drugs to help patients die, and 72% did not view them as drugs of abuse. More English (41%) than German (28%) nurses were afraid of criminal investigations and were constantly aware of side effects (UK, 94%; Germany, 38%) when using opioids. Four latent variables were identified which likely influence nurses’ mental models: “conscious decision-making”; “medication-related fears”; “practice-based observations”; and “risk assessment”. They were predicted by strength of religious beliefs and indicators of informal learning such as experience but not by indicators of formal learning such as conference attendance. Conclusion Nurses in both countries employ analytical and affective mental

Nurses and opioids: results of a bi-national survey on mental models regarding opioid administration in hospitals.

PubMed

Guest, Charlotte; Sobotka, Fabian; Karavasopoulou, Athina; Ward, Stephen; Bantel, Carsten

2017-01-01

Pain remains insufficiently treated in hospitals. Increasing evidence suggests human factors contribute to this, due to nurses failing to administer opioids. This behavior might be the consequence of nurses' mental models about opioids. As personal experience and conceptions shape these models, the aim of this prospective survey was to identify model-influencing factors. A questionnaire was developed comprising of 14 statements concerning ideations about opioids and seven questions concerning demographics, indicators of adult learning, and strength of religious beliefs. Latent variables that may underlie nurses' mental models were identified using undirected graphical dependence models. Representative items of latent variables were employed for ordinal regression analysis. Questionnaires were distributed to 1,379 nurses in two London, UK, hospitals (n=580) and one German (n=799) hospital between September 2014 and February 2015. A total of 511 (37.1%) questionnaires were returned. Mean (standard deviation) age of participants were 37 (11) years; 83.5% participants were female; 45.2% worked in critical care; and 51.5% had more than 10 years experience. Of the nurses, 84% were not scared of opioids, 87% did not regard opioids as drugs to help patients die, and 72% did not view them as drugs of abuse. More English (41%) than German (28%) nurses were afraid of criminal investigations and were constantly aware of side effects (UK, 94%; Germany, 38%) when using opioids. Four latent variables were identified which likely influence nurses' mental models: "conscious decision-making"; "medication-related fears"; "practice-based observations"; and "risk assessment". They were predicted by strength of religious beliefs and indicators of informal learning such as experience but not by indicators of formal learning such as conference attendance. Nurses in both countries employ analytical and affective mental models when administering the opioids and seem to learn from experience

The opioid manager: a point-of-care tool to facilitate the use of the Canadian Opioid Guideline.

PubMed

Furlan, Andrea D; Reardon, Rhoda; Salach, Lena

2012-01-01

The Opioid Manager is designed to be used as a point-of-care tool for providers prescribing opioids for chronic noncancer pain. It condenses the key elements from the Canadian Opioid Guideline and can be used as a chart insert. The Opioid Manager has been validated and is available for download from the Guideline's Web site http://nationalpaincentre.mcmaster.ca/opioidmanager/. The Opioid Manager is divided into the following four parts: A) before you write the first script, B) initiation trial, C) maintenance and monitoring, and D) when is it time to decrease the dose or stop the opioid completely? The Opioid Manager has been downloaded by 1,432 users: 47 percent family physicians, 18 percent pharmacists, 13 percent other physicians, and 22 percent miscellaneous. To show how to use the Opioid Manager, the authors created a 10-minute video that is available on the Internet. The Opioid Manager is being translated to French, Spanish, Portuguese, and Farsi.

Oregon’s Strategy to Confront Prescription Opioid Misuse: A Case Study

PubMed Central

McCarty, Dennis; Bovett, Rob; Burns, Thomas; Cushing, Judy; Glynn, Mary Ellen; Kruse, Senator Jeff; Millet, Lisa M.; Shames, Jim

2014-01-01

Governor John Kitzhaber appointed a Prescription Drug Taskforce to address Oregon’s opioid epidemic. This case study reviews the Taskforce’s participation in the National Governors Association State Policy Academy on Reducing Prescription Drug Abuse. To address the challenge of the misuse and abuse of prescription opioids, the Taskforce developed a strategy for practice change, community education and enhanced access to safe opioid disposal using stakeholder meetings, consensus development, and five action steps: 1) fewer pills in circulation, 2) educate prescribers and the public on the risks of opioid use, 3) foster safe disposal of unused medication, 4) provide treatment for opioid dependence, and 5) continued leadership from the Governor, health plans and health professionals. Although the story is ongoing, there are lessons for leadership in other states and for public health and medical practitioners throughout the country. PMID:25168199

Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

PubMed Central

Banghart, Matthew R.; Shah, Ruchir C.; Lavis, Luke D.

2013-01-01

The spatiotemporal dynamics of opioid signaling in the brain remain poorly defined. Photoactivatable opioid ligands provide a means to quantitatively measure these dynamics and their underlying mechanisms in brain tissue. Although activation kinetics can be assessed using caged agonists, deactivation kinetics are obscured by slow clearance of agonist in tissue. To reveal deactivation kinetics of opioid signaling we developed a caged competitive antagonist that can be quickly photoreleased in sufficient concentrations to render agonist dissociation effectively irreversible. Carboxynitroveratryl-naloxone (CNV-NLX), a caged analog of the competitive opioid antagonist NLX, was readily synthesized from commercially available NLX in good yield and found to be devoid of antagonist activity at heterologously expressed opioid receptors. Photolysis in slices of rat locus coeruleus produced a rapid inhibition of the ionic currents evoked by multiple agonists of the μ-opioid receptor (MOR), but not of α-adrenergic receptors, which activate the same pool of ion channels. Using the high-affinity peptide agonist dermorphin, we established conditions under which light-driven deactivation rates are independent of agonist concentration and thus intrinsic to the agonist-receptor complex. Under these conditions, some MOR agonists yielded deactivation rates that are limited by G protein signaling, whereas others appeared limited by agonist dissociation. Therefore, the choice of agonist determines which feature of receptor signaling is unmasked by CNV-NLX photolysis. PMID:23960100

Averting Opioid-induced Respiratory Depression without Affecting Analgesia.

PubMed

Dahan, Albert; van der Schrier, Rutger; Smith, Terry; Aarts, Leon; van Velzen, Monique; Niesters, Marieke

2018-05-01

The ventilatory control system is highly vulnerable to exogenous administered opioid analgesics. Particularly respiratory depression is a potentially lethal complication that may occur when opioids are overdosed or consumed in combination with other depressants such as sleep medication or alcohol. Fatalities occur in acute and chronic pain patients on opioid therapy and individuals that abuse prescription or illicit opioids for their hedonistic pleasure. One important strategy to mitigate opioid-induced respiratory depression is cotreatment with nonopioid respiratory stimulants. Effective stimulants prevent respiratory depression without affecting the analgesic opioid response. Several pharmaceutical classes of nonopioid respiratory stimulants are currently under investigation. The majority acts at sites within the brainstem respiratory network including drugs that act at α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (ampakines), 5-hydroxytryptamine receptor agonists, phospodiesterase-4 inhibitors, D1-dopamine receptor agonists, the endogenous peptide glycyl-glutamine, and thyrotropin-releasing hormone. Others act peripherally at potassium channels expressed on oxygen-sensing cells of the carotid bodies, such as doxapram and GAL021 (Galleon Pharmaceuticals Corp., USA). In this review we critically appraise the efficacy of these agents. We conclude that none of the experimental drugs are adequate for therapeutic use in opioid-induced respiratory depression and all need further study of efficacy and toxicity. All discussed drugs, however, do highlight potential mechanisms of action and possible templates for further study and development.

Molecular Perspectives for mu/delta Opioid Receptor Heteromers as Distinct, Functional Receptors

PubMed Central

Ong, Edmund W.; Cahill, Catherine M.

2014-01-01

Opioid receptors are the sites of action for morphine and the other opioid drugs. Abundant evidence now demonstrates that different opioid receptor types can physically associate to form heteromers. Understandings of the nature, behavior, and role of these opioid receptor heteromers are developing. Owing to their constituent monomers’ involvement in analgesia, mu/delta opioid receptor (M/DOR) heteromers have been a particular focus of attention. There is now considerable evidence demonstrating M/DOR to be an extant and physiologically relevant receptor species. Participating in the cellular environment as a distinct receptor type, M/DOR availability is complexly regulated and M/DOR exhibits unique pharmacology from that of other opioid receptors (ORs), including its constituents. M/DOR appears to have a range of actions that vary in a ligand- (or ligands-) dependent manner. These actions can meaningfully affect the clinical effects of opioid drugs: strategies targeting M/DOR may be therapeutically useful. This review presents and discusses developments in these understandings with a focus on the molecular nature and activity of M/DOR in the context of therapeutic potentials. PMID:24709907

Persistent opioid use following Cesarean delivery: patterns and predictors among opioid naïve women

PubMed Central

Bateman, Brian T.; Franklin, Jessica M.; Bykov, Katsiaryna; Avorn, Jerry; Shrank, William H.; Brennan, Troyen A.; Landon, Joan E.; Rathmell, James P.; Huybrechts, Krista F.; Fischer, Michael A.; Choudhry, Niteesh K.

2016-01-01

Background The incidence of opioid-related death in women has increased five-fold over the past decade. For many women, their initial opioid exposure will occur in the setting of routine medical care. Approximately 1 in 3 deliveries in the U.S. is by Cesarean and opioids are commonly prescribed for post-surgical pain management. Objective The objective of this study was to determine the risk that opioid naïve women prescribed opioids after Cesarean delivery will subsequently become consistent prescription opioid users in the year following delivery, and to identify predictors for this behavior. Study Design We identified women in a database of commercial insurance beneficiaries who underwent Cesarean delivery and who were opioid-naïve in the year prior to delivery. To identify persistent users of opioids, we used trajectory models, which group together patients with similar patterns of medication filling during follow-up, based on patterns of opioid dispensing in the year following Cesarean delivery. We then constructed a multivariable logistic regression model to identify independent risk factors for membership in the persistent user group. Results 285 of 80,127 (0.36%, 95% confidence interval 0.32 to 0.40), opioid-naïve women became persistent opioid users (identified using trajectory models based on monthly patterns of opioid dispensing) following Cesarean delivery. Demographics and baseline comorbidity predicted such use with moderate discrimination (c statistic = 0.73). Significant predictors included a history of cocaine abuse (risk 7.41%; adjusted odds ratio 6.11, 95% confidence interval 1.03 to 36.31) and other illicit substance abuse (2.36%; adjusted odds ratio 2.78, 95% confidence interval 1.12 to 6.91), tobacco use (1.45%; adjusted odds ratio 3.04, 95% confidence interval 2.03 to 4.55), back pain (0.69%; adjusted odds ratio 1.74, 95% confidence interval 1.33 to 2.29), migraines (0.91%; adjusted odds ratio 2.14, 95% confidence interval 1.58 to 2

CDC Guideline for Prescribing Opioids for Chronic Pain - United States, 2016.

PubMed

Dowell, Deborah; Haegerich, Tamara M; Chou, Roger

2016-03-18

This guideline provides recommendations for primary care clinicians who are prescribing opioids for chronic pain outside of active cancer treatment, palliative care, and end-of-life care. The guideline addresses 1) when to initiate or continue opioids for chronic pain; 2) opioid selection, dosage, duration, follow-up, and discontinuation; and 3) assessing risk and addressing harms of opioid use. CDC developed the guideline using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework, and recommendations are made on the basis of a systematic review of the scientific evidence while considering benefits and harms, values and preferences, and resource allocation. CDC obtained input from experts, stakeholders, the public, peer reviewers, and a federally chartered advisory committee. It is important that patients receive appropriate pain treatment with careful consideration of the benefits and risks of treatment options. This guideline is intended to improve communication between clinicians and patients about the risks and benefits of opioid therapy for chronic pain, improve the safety and effectiveness of pain treatment, and reduce the risks associated with long-term opioid therapy, including opioid use disorder, overdose, and death. CDC has provided a checklist for prescribing opioids for chronic pain (http://stacks.cdc.gov/view/cdc/38025) as well as a website (http://www.cdc.gov/drugoverdose/prescribingresources.html) with additional tools to guide clinicians in implementing the recommendations.

Ethanol Reversal of Cellular Tolerance to Morphine in Rat Locus Coeruleus Neurons

PubMed Central

Llorente, Javier; Withey, Sarah; Rivero, Guadalupe; Cunningham, Margaret; Cooke, Alex; Saxena, Kunal; McPherson, Jamie; Oldfield, Sue; Dewey, William L.; Bailey, Chris P.; Kelly, Eamonn; Henderson, Graeme

2013-01-01

Consumption of ethanol is a considerable risk factor for death in heroin overdose. We sought to determine whether a mildly intoxicating concentration of ethanol could alter morphine tolerance at the cellular level. In rat locus coeruleus (LC) neurons, tolerance to morphine was reversed by acute exposure of the brain slice to ethanol (20 mM). Tolerance to the opioid peptide [d-Ala2,N-MePhe4,Gly-ol]-enkephalin was not reversed by ethanol. Previous studies in LC neurons have revealed a role for protein kinase C (PKC)α in μ-opioid receptor (MOPr) desensitization by morphine and in the induction and maintenance of morphine tolerance, but we have been unable to demonstrate that 20 mM ethanol produces significant inhibition of PKCα. The ability of ethanol to reverse cellular tolerance to morphine in LC neurons was absent in the presence of the phosphatase inhibitor okadaic acid, indicating that dephosphorylation is involved. In human embryonic kidney 293 cells expressing the MOPr, ethanol reduced the level of MOPr phosphorylation induced by morphine. Ethanol reversal of tolerance did not appear to result from a direct effect on MOPr since acute exposure to ethanol (20 mM) did not modify the affinity of binding of morphine to the MOPr or the efficacy of morphine for G-protein activation as measured by guanosine 5′-O-(3-[35S]thio)triphosphate binding. Similarly, ethanol did not affect MOPr trafficking. We conclude that acute exposure to ethanol enhances the effects of morphine by reversing the processes underlying morphine cellular tolerance. PMID:23716621

Illicit Opioid Intoxication: Diagnosis and Treatment

PubMed Central

Fareed, A.; Stout, S.; Casarella, J.; Vayalapalli, S.; Cox, J.; Drexler, K.

2011-01-01

Opioid intoxications and overdose are associated with high rates of morbidity and mortality. Opioid overdose may occur in the setting of intravenous or intranasal heroin use, illicit use of diverted opioid medications, intentional or accidental misuse of prescription pain medications, or iatrogenic overdose. In this review, we focused on the epidemiology of illict opioid use in the United States and on the mechanism of action of opioid drugs. We also described the signs and symptoms, and diagnoses of intoxication and overdose. Lastly, we updated the reader about the most recent recommendations for treatment and prevention of opioid intoxications and overdose. PMID:22879747

The endogenous opioid system in cocaine addiction: what lessons have opioid peptide and receptor knockout mice taught us?

PubMed Central

Yoo, Ji Hoon; Kitchen, Ian; Bailey, Alexis

2012-01-01

Cocaine addiction has become a major concern in the UK as Britain tops the European ‘league table’ for cocaine abuse. Despite its devastating health and socio-economic consequences, no effective pharmacotherapy for treating cocaine addiction is available. Identifying neurochemical changes induced by repeated drug exposure is critical not only for understanding the transition from recreational drug use towards compulsive drug abuse but also for the development of novel targets for the treatment of the disease and especially for relapse prevention. This article focuses on the effects of chronic cocaine exposure and withdrawal on each of the endogenous opioid peptides and receptors in rodent models. In addition, we review the studies that utilized opioid peptide or receptor knockout mice in order to identify and/or clarify the role of different components of the opioid system in cocaine-addictive behaviours and in cocaine-induced alterations of brain neurochemistry. The review of these studies indicates a region-specific activation of the µ-opioid receptor system following chronic cocaine exposure, which may contribute towards the rewarding effect of the drug and possibly towards cocaine craving during withdrawal followed by relapse. Cocaine also causes a region-specific activation of the κ-opioid receptor/dynorphin system, which may antagonize the rewarding effect of the drug, and at the same time, contribute to the stress-inducing properties of the drug and the triggering of relapse. These conclusions have important implications for the development of effective pharmacotherapy for the treatment of cocaine addiction and the prevention of relapse. PMID:22428846

Improving opioid safety practices in primary care: protocol for the development and evaluation of a multifaceted, theory-informed pilot intervention for healthcare providers

PubMed Central

Leece, Pamela; Buchman, Daniel Z; Hamilton, Michael; Timmings, Caitlyn; Shantharam, Yalnee; Moore, Julia; Furlan, Andrea D

2017-01-01

Introduction In North America, drug overdose deaths are reaching unprecedented levels, largely driven by increasing prescription opioid-related deaths. Despite the development of several opioid guidelines, prescribing behaviours still contribute to poor patient outcomes and societal harm. Factors at the provider and system level may hinder or facilitate the application of evidence-based guidelines; interventions designed to address such factors are needed. Methods and analysis Using implementation science and behaviour change theory, we have planned the development and evaluation of a comprehensive Opioid Self-Assessment Package, designed to increase adherence to the Canadian Opioid Guideline among family physicians. The intervention uses practical educational and self-assessment tools to provide prescribers with feedback on their current knowledge and practices, and resources to improve their practice. The evaluation approach uses a pretest and post-test design and includes both quantitative and qualitative methods at baseline and 6 months. We will recruit a purposive sample of approximately 10 family physicians in Ontario from diverse practice settings, who currently treat patients with long-term opioid therapy for chronic pain. Quantitative data will be analysed using basic descriptive statistics, and qualitative data will be analysed using the Framework Method. Ethics and dissemination The University Health Network Research Ethics Board approved this study. Dissemination plan includes publications, conference presentations and brief stakeholder reports. This evidence-informed, theory-driven intervention has implications for national application of opioid quality improvement tools in primary care settings. We are engaging experts and end users in advisory and stakeholder roles throughout our project to increase its national relevance, application and sustainability. The performance measures could be used as the basis for health system quality improvement

Opioids in Gastroenterology: Treating Adverse Effects and Creating Therapeutic Benefits.

PubMed

Camilleri, Michael; Lembo, Anthony; Katzka, David A

2017-09-01

The use of opioid medications on both an acute and chronic basis is ubiquitous in the United States. As opioid receptors densely populate the gastrointestinal tract, symptoms and side effects can be expected in these patients. In the esophagus, dysmotility may result, manifesting with dysphagia and a syndrome indistinguishable from primary achalasia. In the stomach, a marked delay in gastric emptying may occur with postprandial nausea and early satiety. Postoperatively, particularly with abdominal surgery, opioid-induced ileus may ensue. In the colon, opioid-induced constipation is common. A unique syndrome termed narcotic bowel syndrome is characterized by chronic abdominal pain often accompanied by nausea and vomiting in the absence of other identifiable causes. With the recognition of the important role of opioids on gastrointestinal function, novel drugs have been developed that use this physiology. These medications include peripheral acting opioid agonists to treat opioid-induced constipation and combination agonist and antagonists used for diarrhea-predominant irritable bowel syndrome. This review summarizes the most recent data in these areas. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Melatonin reverses morphine tolerance by inhibiting microglia activation and HSP27 expression.

PubMed

Lin, Sheng-Hsiung; Huang, Ya-Ni; Kao, Jen-Hsin; Tien, Lu-Tai; Tsai, Ru-Yin; Wong, Chih-Shung

2016-05-01

Melatonin has been reported to attenuate opioid tolerance. In this study, we explored the possible mechanism of melatonin in diminishing morphine tolerance. Two intrathecal (i.t.) catheters were implanted in male Wistar rats for drug delivery. One was linked to a mini-osmotic pump for morphine or saline infusion. On the seventh day, 50μg of melatonin or vehicle was injected through the other catheter instantly after discontinuation of morphine or saline infusion; 3h later, 15μg of morphine or saline was injected. The antinociceptive response was then measured using the tail-flick test every 30min for 120min. The results showed that chronic morphine infusion elicited antinociceptive tolerance and upregulated heat shock protein 27 (HSP27) expression in the dorsal horn of the rat spinal cord. Melatonin pretreatment partially restored morphine's antinociceptive effect in morphine-tolerant rats and reversed morphine-induced HSP27 upregulation. In addition, chronic morphine infusion induced microglial cell activation and was reversed by melatonin treatment. The present study provides evidence that melatonin, acting via inhibiting morphine-induced neuroinflammation, can be useful as a therapeutic adjuvant for patients under long-term opioid treatment for pain relief. Copyright © 2016 Elsevier Inc. All rights reserved.

Spatiotemporal control of opioid signaling and behavior

PubMed Central

Siuda, Edward R.; Copits, Bryan A.; Schmidt, Martin J.; Baird, Madison A.; Al-Hasani, Ream; Planer, William J.; Funderburk, Samuel C.; McCall, Jordan G.; Gereau, Robert W.; Bruchas, Michael R.

2015-01-01

Summary Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically-sensitive, mu-opioid-like receptor, we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels, and internalizes with similar kinetics as the mu-opioid receptor. To assess in vivo utility we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot, led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. PMID:25937173

Injectable, sustained-release naltrexone for the treatment of opioid dependence: a randomized, placebo-controlled trial

PubMed Central

Comer, Sandra D.; Sullivan, Maria A.; Yu, Elmer; Rothenberg, Jami L.; Kleber, Herbert D.; Kampman, Kyle; Dackis, Charles; O'Brien, Charles P.; Chiang, C. Nora; Hawks, Richard L.

2013-01-01

recalculated without the assumption that missing urine samples were positive, however, a main effect of group was not found for any of the drugs tested with the exception of cocaine, where the percentage of cocaine-negative urines was lower in the placebo group. Adverse events were minimal and generally mild in severity. This sustained-release formulation of naltrexone was well tolerated and produced a robust and dose-related increase in treatment retention. Conclusion The present data provide exciting new evidence for the feasibility, efficacy, and tolerability of long-lasting antagonist treatments for opioid dependence. PMID:16461865

Markers of tolerance development to food allergens.

PubMed

Ponce, M; Diesner, S C; Szépfalusi, Z; Eiwegger, T

2016-10-01

IgE-mediated reactions to food allergens are the most common cause of anaphylaxis in childhood. Although allergies to cow's milk, egg, or soy proteins, in contrast to peanut and tree nut allergens, resolve within the first 6 years of life in up to 60% due to natural tolerance development, this process is not well understood. At present, there is no cure or treatment for food allergy that would result in an induction of tolerance to the symptom-eliciting food. Avoidance, providing an emergency plan and education, is the standard of treatment. Oral immunotherapeutic approaches have been proven reasonable efficacy; however, they are associated with high rates of side-effects and low numbers of patients achieving tolerance. Nevertheless, mechanisms that take place during oral immunotherapy may help to understand tolerance development. On the basis of these therapeutic interventions, events like loss of basophil activation and induction of regulatory lymphocyte subsets and of blocking antibodies have been described. Their functional importance at a clinical level, however, remains to be investigated in detail. Consequently, there is eminent need to understand the process of tolerance development to food allergens and define biomarkers to develop and monitor new treatment strategies for food allergy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of intravenous opioid dose on postoperative ileus.

PubMed

Barletta, Jeffrey F; Asgeirsson, Theodor; Senagore, Anthony J

2011-07-01

Intravenous opioids represent a major component in the pathophysiology of postoperative ileus (POI). However, the most appropriate measure and threshold to quantify the association between opioid dose (eg, average daily, cumulative, maximum daily) and POI remains unknown. To evaluate the relationship between opioid dose, POI, and length of stay (LOS) and identify the opioid measure that was most strongly associated with POI. Consecutive patients admitted to a community teaching hospital who underwent elective colorectal surgery by any technique with an enhanced-recovery protocol postoperatively were retrospectively identified. Patients were excluded if they received epidural analgesia, developed a major intraabdominal complication or medical complication, or had a prolonged workup prior to surgery. Intravenous opioid doses were quantified and converted to hydromorphone equivalents. Classification and regression tree (CART) analysis was used to determine the dosing threshold for the opioid measure most associated with POI and define high versus low use of opioids. Risk factors for POI and prolonged LOS were determined through multivariate analysis. The incidence of POI in 279 patients was 8.6%. CART analysis identified a maximum daily intravenous hydromorphone dose of 2 mg or more as the opioid measure most associated with POI. Multivariate analysis revealed maximum daily hydromorphone dose of 2 mg or more (p = 0.034), open surgical technique (p = 0.045), and days of intravenous narcotic therapy (p = 0.003) as significant risk factors for POI. Variables associated with increased LOS were POI (p < 0.001), maximum daily hydromorphone dose of 2 mg or more (p < 0.001), and age (p = 0.005); laparoscopy (p < 0.001) was associated with a decreased LOS. Intravenous opioid therapy is significantly associated with POI and prolonged LOS, particularly when the maximum hydromorphone dose per day exceeds 2 mg. Clinicians should consider alternative, nonopioid-based pain

Improving the recognition and diagnosis of opioid-induced constipation in clinical practice.

PubMed

Gupta, Anita

2015-10-01

Opioid-induced constipation is a common side effect of opioid therapy that has been under-recognized and undertreated. With the continued increase in opioid use in the United States, along with the growth of the elderly population, more patients will develop OIC, and family physicians will encounter more patients with OIC. OIC negatively affects patient QOL, daily activity, work productivity, and psychological well-being. If not treated effectively, OIC may result in patients attempting to balance their pain relief against their constipation, by self-adjusting their opioid dose. OIC results from opioid actions at enteric opioid receptors. Although commonly prescribed for OIC, laxatives do not target the pathophysiologic mechanism of OIC and have limited efficacy. Specific, effective treatments for OIC, consisting of a subcutaneously administered PAMORA, an oral PAMORA, and an oral chloride channel activator, have been developed and have received US Food and Drug Administration approval. After recognizing the signs and symptoms of OIC to facilitate diagnosis, family physicians can initiate effective treatments in appropriate patients.

Opioid pharmaceuticals and addiction: the issues, and research directions seeking solutions.

PubMed

Walwyn, Wendy M; Miotto, Karen A; Evans, Christopher J

2010-05-01

There are few pharmaceuticals superior to opiates for the treatment of pain. However, with concerns of addiction, withdrawal and questionable efficacy for all types of pain, these compounds are far from a magical panacea for pain-relief. As it is unlikely that other classes of compounds will supersede the opioids in the very near future, it is important to both optimize current opioid therapies and curb the astounding diversion of opioids from their intended analgesic use to non-medical abuse. In optimizing opioid therapeutics it is necessary to enhance the clinical awareness of the benefits of treating pain and combine this with aggressive strategies to reduce diversion for non-medical use. At the heart of the issue of opioid misuse is the role of opioid systems in the reward circuitry, and the adaptive processes associated with repetitive opioid use that manifest during withdrawal. Emerging pharmacological insights of opioid receptors will be reviewed that provide future hope for developing opioid-based analgesics with reduced addictive properties and perhaps, reduced opponent processes. In addition, with the increased understanding of nociceptive circuitry and the molecules involved in transmitting pain, new therapeutic targets have become evident that may result in effective analgesics either alone or in combination with current opioid therapies.

Opioid pharmaceuticals and addiction: The issues, and research directions seeking solutions

PubMed Central

Walwyn, Wendy M.; Miotto, Karen A.; Evans, Christopher J.

2011-01-01

There are few pharmaceuticals superior to opiates for the treatment of pain. However, with concerns of addiction, withdrawal and questionable efficacy for all types of pain, these compounds are far from a magical panacea for pain-relief. As it is unlikely that other classes of compounds will supersede the opioids in the very near future, it is important to both optimize current opioid therapies and curb the astounding diversion of opioids from their intended analgesic use to non-medical abuse. In optimizing opioid therapeutics it is necessary to enhance the clinical awareness of the benefits of treating pain and combine this with aggressive strategies to reduce diversion for non-medical use. At the heart of the issue of opioid misuse is the role of opioid systems in the reward circuitry, and the adaptive processes associated with repetitive opioid use that manifest during withdrawal. Emerging pharmacological insights of opioid receptors will be reviewed that provide future hope for developing opioid-based analgesics with reduced addictive properties and perhaps, reduced opponent processes. In addition, with the increased understanding of nociceptive circuitry and the molecules involved in transmitting pain, new therapeutic targets have become evident that may result in effective analgesics either alone or in combination with current opioid therapies. PMID:20188495

Discharge prescribing of enteral opioids after initiation as a weaning strategy from continuous opioid infusions in the Intensive Care Unit.

PubMed

Kram, Bridgette; Weigel, Kylie M; Kuhrt, Michelle; Gilstrap, Daniel L

To evaluate the proportion of patients receiving a hospital discharge prescription for a scheduled enteral opioid following initiation as a weaning strategy from a continuous opioid infusion in the Intensive Care Unit (ICU). Retrospective, observational study. Five adult ICUs at a large, quaternary care academic medical center. Endotracheally intubated, opioid-naive adults receiving a continuous opioid infusion with a concomitant scheduled enteral opioid initiated. Exclusion criteria were receipt of fewer than two enteral opioid doses, documentation of a long-acting opioid as a home medication, the indication for the enteral opioid was not a weaning strategy, death during hospital admission or discharge to hospice. None. The proportion of ICU and hospital survivors who received a discharge prescription for a scheduled enteral opioid, total duration of continuous opioid infusion, duration of continuous opioid infusion after initiation of an enteral opioid therapy, total duration of enteral therapy, ICU and hospital length of stay. Of 62 included patients, 19 patients (30.6 percent) received a new prescription for a scheduled enteral opioid at hospital discharge. The median duration of enteral opioid therapy was longer for patients who received a discharge prescription compared to those who did not (20.09 vs 8.89 days, p = 0.02), though the remaining endpoints were not different. Utilizing scheduled enteral opioids as a weaning strategy from continuous opioid infusions may place patients at risk of ICU-acquired physical dependence on opioids.

Macroeconomic conditions and opioid abuse.