1
|
Sun P, Zhao W. Control list of high-priority chemicals based on 5-HT-RI functionality and the human health interference effects selective CNN-GRU deep learning model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:169699. [PMID: 38181943 DOI: 10.1016/j.scitotenv.2023.169699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/07/2024]
Abstract
The antidepressant drug known as 5-HT reuptake inhibitor (5-HT-RI) was commonly detected in biological tissues and result in significant adverse health effects. Homology modeling was used to characterize the functionalities (efficacy and resistance), and the adverse outcome pathway was used to characterize its human health interferences (olfactory toxicity, neurotoxicity, and gut microbial interference). The convolutional neural network coupled with the gated recurrent unit (CNN-GRU) deep learning method was used to construct a comprehensive model of 5-HT-RI functionality and human health interference effects selectivity with small sample data. The architecture with 2 SE, 320 neuronal nodes and 6-folds cross-validation showed the best applicability. The results showed that the confidence interval of the constructed model reached 90 % indicating that the model had reliable prediction ability and generalization ability. Based on the CNN-GRU deep learning model, seven high-priority chemicals with a weak comprehensive effect, including D-VEN, (1R,4S)-SER, S-FLX, CTP, S-CTP, NEF, and VEN, were screened. Based on the molecular three-dimensional structure information, a comprehensive-effect three-dimensional quantitative structure-activity relationship (3D-QSAR) model was constructed to confirm the reliability of the constructed control list of 5-HT-RI high-priority chemicals. Analysis with the ranking of calculated values based on the molecular dynamics method and predicted values based on the CNN-GRU deep learning model, we found that the consistency of the three methods was above 85 %. Additionally, by analyzing the sensitivity, molecular electrostatic potential, polar surface area of the comprehensive-effect CNN-GRU deep learning model, and the electrostatic field of the 3D-QSAR models, we found that the significant effects of five key characteristics (DM, Qyy, Qxz, I, and BP), molecular electronegativity, and polarity significantly affected the high-priority degree of 5-HT-RI. In this study, we provided reasonable and reliable prediction tools and discussed theoretical methods for the risk assessment of functionality and human health interference of emerging pollutants such as 5-HT-RI.
Collapse
Affiliation(s)
- Peixuan Sun
- College of New Energy and Environment, Jilin University, Changchun 130012, China.
| | - Wenjin Zhao
- College of New Energy and Environment, Jilin University, Changchun 130012, China.
| |
Collapse
|
2
|
Huang P, Ho CK, Cao D, Inan S, Rawls SM, Li M, Huang B, Pagare PP, Townsend EA, Poklis JL, Halquist MS, Banks M, Zhang Y, Liu-Chen LY. NCP, a dual kappa and mu opioid receptor agonist, is a potent analgesic against inflammatory pain without reinforcing or aversive properties. J Pharmacol Exp Ther 2024; 389:JPET-AR-2023-001870. [PMID: 38409113 PMCID: PMC10949162 DOI: 10.1124/jpet.123.001870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/28/2024] Open
Abstract
While agonists of mu (MOR) and kappa (KOR) opioid receptors have analgesic effects, they produce euphoria and dysphoria, respectively. Other side effects include respiratory depression and addiction for MOR agonists and sedation for KOR agonists. We reported that 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-{[4'-(2'-cyanopyridyl)]carboxamido}cmorphinan (NCP) displayed potent KOR full agonist and MOR partial agonist activities (58%) with 6.5x KOR-over-MOR selectivity in vitro Herein, we characterized pharmacological effects of NCP in rodents. In mice, NCP exerted analgesic effects against inflammatory pain in both the formalin test and the acetic acid writhing test, with A50 values of 47.6 and 14.4 microg/kg (s.c.), respectively. The analgesic effects in the acetic acid writhing test were mediated by the KOR. NCP at doses much higher than those effective in reducing inflammatory pain did not produce antinociception in the hot plate and tail flick tests, inhibit compound 48/80-induced scratching, cause conditioned place aversion (CPA) or preference, impair rotarod performance, inhibit locomotor activity, cause respiratory depression, or precipitate morphine withdrawal. However, NCP (10~100 microg/kg) inhibited gastrointestinal transit with a maximum of ~40% inhibition. In MOR knockout mice, NCP caused CPA, demonstrating that its lack of CPA is due to combined actions on the MOR and KOR. Following s.c. injection, NCP penetrated into the mouse brain. In rats trained to self-administer heroin, NCP (1~320 microg/kg/infusion) did not function as a reinforcer. Thus, NCP produces potent analgesic effects via KOR without side effects except constipation. Therefore, dual full KOR/partial MOR agonists with moderate KOR-over-MOR selectivity may be promising as non-addictive analgesics for inflammatory pain. Significance Statement Developing non-addictive analgesics is crucial for reducing opioid overdose deaths, minimizing drug misuse, and promoting safer pain management practices. Herein, pharmacology of a potential non-addictive analgesic, NCP, is reported. NCP has full KOR agonist / partial MOR agonist activities with a 6.5 x selectivity for KOR over MOR. Unlike MOR agonists, analgesic doses of NCP do not lead to self-administration or respiratory depression. Furthermore, NCP does not produce aversion, hypolocomotion, or motor incoordination, side effects typically associated with KOR activation.
Collapse
Affiliation(s)
- Peng Huang
- Temple University Lewis Katz School of Medicine, United States
| | - Conrad K Ho
- Temple University Lewis Katz School of Medicine, United States
| | - Danni Cao
- Temple University Lewis Katz School of Medicine, United States
| | - Saadet Inan
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Lewis Katz School of Medicine, Temple University, United States
| | - Scott M Rawls
- Temple University Lewis Katz School of Medicine, United States
| | - Mengchu Li
- Virginia Commonwealth University School of Pharmacy, United States
| | - Boshi Huang
- Virginia Commonwealth University School of Pharmacy, United States
| | - Piyusha P Pagare
- Virginia Commonwealth University School of Pharmacy, United States
| | | | | | | | - Matthew Banks
- Virginia Commonwealth University School of Medicine, United States
| | - Yan Zhang
- Virginia Commonwealth University School of Pharmacy, United States
| | - Lee-Yuan Liu-Chen
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, United States
| |
Collapse
|
3
|
Hill R, Sanchez J, Lemel L, Antonijevic M, Hosking Y, Mistry SN, Kruegel AC, Javitch JA, Lane JR, Canals M. Assessment of the potential of novel and classical opioids to induce respiratory depression in mice. Br J Pharmacol 2023; 180:3160-3174. [PMID: 37489013 PMCID: PMC10952895 DOI: 10.1111/bph.16199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 06/08/2023] [Accepted: 07/15/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Opioid-induced respiratory depression limits the use of μ-opioid receptor agonists in clinical settings and is the main cause of opioid overdose fatalities. The relative potential of different opioid agonists to induce respiratory depression at doses exceeding those producing analgesia is understudied despite its relevance to assessments of opioid safety. Here we evaluated the respiratory depressant and anti-nociceptive effects of three novel opioids and relate these measurements to their in vitro efficacy. EXPERIMENTAL APPROACH Respiration was measured in awake, freely moving male CD-1 mice using whole body plethysmography. Anti-nociception was measured using the hot plate test. Morphine, oliceridine and tianeptine were administered intraperitoneally, whereas methadone, oxycodone and SR-17018 were administered orally. Receptor activation and arrestin-3 recruitment were measured in HEK293 cells using BRET assays. KEY RESULTS Across the dose ranges examined, all opioids studied depressed respiration in a dose-dependent manner, with similar effects at the highest doses, and with tianeptine and oliceridine showing reduced duration of effect, when compared with morphine, oxycodone, methadone and SR-17018. When administered at doses that induced similar respiratory depression, all opioids induced similar anti-nociception, with tianeptine and oliceridine again showing reduced duration of effect. These data were consistent with the in vitro agonist activity of the tested compounds. CONCLUSION AND IMPLICATIONS In addition to providing effective anti-nociception, the novel opioids, oliceridine, tianeptine and SR-17018 depress respiration in male mice. However, the different potencies and kinetics of effect between these novel opioids may be relevant to their therapeutic application in different clinical settings.
Collapse
Affiliation(s)
- Rob Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Julie Sanchez
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Laura Lemel
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Mirjana Antonijevic
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | - Yselkla Hosking
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | - Shailesh N. Mistry
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | | | - Jonathan A. Javitch
- Departments of Psychiatry and Molecular Pharmacology and TherapeuticsColumbia University Vagelos College of Physicians & SurgeonsNew YorkNew YorkUSA
- Division of Molecular TherapeuticsNew York State Psychiatric InstituteNew YorkNew YorkUSA
| | - J. Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| |
Collapse
|
4
|
Negus SS, Akbarali HI, Kang M, Lee YK, Marsh SA, Santos EJ, Zhang Y. Role of mu opioid receptor (MOR) agonist efficacy as a determinant of opioid antinociception in a novel assay of pain-depressed behavior in female and male mice. FRONTIERS IN PAIN RESEARCH 2023; 4:1281698. [PMID: 37886350 PMCID: PMC10598607 DOI: 10.3389/fpain.2023.1281698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023] Open
Abstract
Introduction Intermediate efficacy mu opioid receptor (MOR) agonists have potential to retain analgesic effectiveness while improving safety, but the optimal MOR efficacy for effective and safe opioid analgesia is unknown. Preclinical assays of pain-depressed behavior can assess effects of opioids and other candidate analgesics on pain-related behavioral depression, which is a common manifestation of clinically relevant pain and target of pain treatment. Accordingly, the present study goal was to validate a novel assay of pain-depressed locomotor behavior in mice and evaluate the role of MOR efficacy as a determinant of opioid analgesic effects and related safety measures. Methods Male and female ICR mice were tested in a locomotor chamber consisting of 2 compartments connected by a doorway that contained a 1-inch-tall barrier. Dependent measures during 15-min behavioral sessions included crosses between compartments (which required vertical activity to surmount the barrier) and total movement counts (which required horizontal activity to break photobeams in each compartment). Results and Discussion Intraperitoneal injection of lactic acid (IP acid) produced a concentration- and time-dependent depression of both endpoints. Optimal blockade of IP acid-induced behavioral depression with minimal motor impairment was achieved with intermediate-efficacy MOR treatments that also produced less gastrointestinal-transit inhibition and respiratory depression than the high-efficacy MOR agonist fentanyl. Sex differences in treatment effects were rare. Overall, these findings validate a novel procedure for evaluating opioids and other candidate analgesic effects on pain-related behavioral depression in mice and support continued research with intermediate-efficacy MOR agonists as a strategy to retain opioid analgesic effectiveness with improved safety.
Collapse
Affiliation(s)
- S. Stevens Negus
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Hamid I. Akbarali
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Minho Kang
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Young K. Lee
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Samuel A. Marsh
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Edna J. Santos
- Department of Pharmacology & Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States
| |
Collapse
|
5
|
Elder HJ, Walentiny DM, Beardsley PM. Theophylline reverses oxycodone's but not fentanyl's respiratory depression in mice while caffeine is ineffective against both opioids. Pharmacol Biochem Behav 2023; 229:173601. [PMID: 37414364 PMCID: PMC10599235 DOI: 10.1016/j.pbb.2023.173601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
RATIONALE The opioid epidemic remains a pressing public health crisis in the United States. Most of these overdose deaths are a result of lethal respiratory depression. In recent years the increasing incidence of opioid-involved overdose deaths has been driven by fentanyl, which is more resistant to adequate reversal by naloxone (NARCAN ®) than semi-synthetic or classical morphinan predecessors like oxycodone and heroin. For this and other reasons (e.g., precipitating withdrawal) non-opioidergic pharmacotherapies to reverse opioid-depressed respiration are needed. Methylxanthines are a class of stimulant drugs including caffeine and theophylline which exert their effects primarily via adenosine receptor antagonism. Evidence suggests methylxanthines can stimulate respiration by enhancing neural activity in respiratory nuclei in the pons and medulla independent of opioid receptors. This study aimed to determine whether caffeine and theophylline can stimulate respiration in mice when depressed by fentanyl and oxycodone. METHODS Whole-body plethysmography was used to characterize fentanyl and oxycodone's effects on respiration and their reversal by naloxone in male Swiss Webster mice. Next, caffeine and theophylline were tested for their effects on basal respiration. Finally, each methylxanthine was evaluated for its ability to reverse similar levels of respiratory depression induced by fentanyl or oxycodone. RESULTS AND CONCLUSIONS Oxycodone and fentanyl dose-dependently reduced respiratory minute volume (ml/min; MVb) that was reversible by naloxone. Caffeine and theophylline each significantly increased basal MVb. Theophylline, but not caffeine, completely reversed oxycodone-depressed respiration. In contrast, neither methylxanthine elevated fentanyl-depressed respiration at the doses tested. Despite their limited efficacy for reversing opioid-depressed respiration when administered alone, the methylxanthines safety, duration, and mechanism of action supports further evaluation in combination with naloxone to augment its reversal of opioid-depressed respiration.
Collapse
Affiliation(s)
- Harrison J Elder
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - D Matthew Walentiny
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Patrick M Beardsley
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA; Center for Biomarker Research & Precision Medicine, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA.
| |
Collapse
|
6
|
Kelly E, Sutcliffe K, Cavallo D, Ramos-Gonzalez N, Alhosan N, Henderson G. The anomalous pharmacology of fentanyl. Br J Pharmacol 2023; 180:797-812. [PMID: 34030211 DOI: 10.1111/bph.15573] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 11/26/2022] Open
Abstract
Fentanyl is a key therapeutic, used in anaesthesia and pain management. It is also increasingly used illicitly and is responsible for a large and growing number of opioid overdose deaths, especially in North America. A number of factors have been suggested to contribute to fentanyl's lethality, including rapid onset of action, in vivo potency, ligand bias, induction of muscle rigidity and reduced sensitivity to reversal by naloxone. Some of these factors can be considered to represent 'anomalous' pharmacological properties of fentanyl when compared with prototypical opioid agonists such as morphine. In this review, we examine the nature of fentanyl's 'anomalous' properties, to determine whether there is really a pharmacological basis to support the existence of such properties, and also discuss whether such properties are likely to contribute to overdose deaths involving fentanyls. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
Collapse
Affiliation(s)
- Eamonn Kelly
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Katy Sutcliffe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Damiana Cavallo
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | | | - Norah Alhosan
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| |
Collapse
|
7
|
Lawson R, Čechová P, Zarrouk E, Javellaud J, Bazgier V, Otyepka M, Trouillas P, Picard N, Marquet P, Saint-Marcoux F, El Balkhi S. Metabolic interactions of benzodiazepines with oxycodone ex vivo and toxicity depending on usage patterns in an animal model. Br J Pharmacol 2023; 180:829-842. [PMID: 34855983 DOI: 10.1111/bph.15765] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 09/16/2021] [Accepted: 11/03/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Opioids and benzodiazepines are frequently combined in medical as well as in non-medical contexts. At high doses, such combinations often result in serious health complications attributed to pharmacodynamics interactions. Here, we investigate the contribution of the metabolic interactions between oxycodone, diazepam and diclazepam (a designer benzodiazepine) in abuse/overdose conditions through ex vivo, in vivo and in silico approaches. EXPERIMENTAL APPROACH A preparation of pooled human liver microsomes was used to study oxycodone metabolism in the presence or absence of diazepam or diclazepam. In mice, diazepam or diclazepam was concomitantly administered with oxycodone to mimic acute intoxication. Diclazepam was introduced on Day 10 in mice continuously infused with oxycodone for 15 days to mimic chronic intoxication. In silico modelling was used to study the molecular interactions of the three drugs with CYP3A4 and 2D6. KEY RESULTS In mice, in acute conditions, both diazepam and diclazepam inhibited the metabolism of oxycodone. In chronic conditions and at pharmacologically equivalent doses, diclazepam drastically enhanced the production of oxymorphone. In silico, the affinity of benzodiazepines was higher than oxycodone for CYP3A4, inhibiting oxycodone metabolism through CYP3A4. Oxycodone metabolism is likely to be diverted towards CYP2D6. CONCLUSION AND IMPLICATIONS Acute doses of diazepam or diclazepam result in the accumulation of oxycodone, whereas chronic administration induces the accumulation of oxymorphone, the toxic metabolite. This suggests that overdoses of opioids in the presence of benzodiazepines are partly due to metabolic interactions, which in turn explain the patterns of toxicity dependent on usage. LINKED ARTICLES This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
Collapse
Affiliation(s)
- Roland Lawson
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France
| | - Petra Čechová
- Regional Center of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc, Czechia
| | - Eliès Zarrouk
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France
| | - James Javellaud
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France
| | - Václav Bazgier
- Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Michal Otyepka
- Regional Center of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc, Czechia
| | - Patrick Trouillas
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France.,Regional Center of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc, Czechia
| | - Nicolas Picard
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, Limoges, France
| | - Pierre Marquet
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, Limoges, France
| | - Franck Saint-Marcoux
- University of Limoges, IPPRITT, Limoges, France.,INSERM, IPPRITT, U1248, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, Limoges, France
| | - Souleiman El Balkhi
- INSERM, IPPRITT, U1248, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, Limoges, France
| |
Collapse
|
8
|
Bateman JT, Saunders SE, Levitt ES. Understanding and countering opioid-induced respiratory depression. Br J Pharmacol 2023; 180:813-828. [PMID: 34089181 PMCID: PMC8997313 DOI: 10.1111/bph.15580] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/06/2021] [Accepted: 05/23/2021] [Indexed: 02/06/2023] Open
Abstract
Respiratory depression is the proximal cause of death in opioid overdose, yet the mechanisms underlying this potentially fatal outcome are not well understood. The goal of this review is to provide a comprehensive understanding of the pharmacological mechanisms of opioid-induced respiratory depression, which could lead to improved therapeutic options to counter opioid overdose, as well as other detrimental effects of opioids on breathing. The development of tolerance in the respiratory system is also discussed, as are differences in the degree of respiratory depression caused by various opioid agonists. Finally, potential future therapeutic agents aimed at reversing or avoiding opioid-induced respiratory depression through non-opioid receptor targets are in development and could provide certain advantages over naloxone. By providing an overview of mechanisms and effects of opioids in the respiratory network, this review will benefit future research on countering opioid-induced respiratory depression. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
Collapse
Affiliation(s)
- Jordan T Bateman
- Department of Pharmacology & Therapeutics, University of Florida, Gainesville, Florida, USA
| | - Sandy E Saunders
- Department of Pharmacology & Therapeutics, University of Florida, Gainesville, Florida, USA
| | - Erica S Levitt
- Department of Pharmacology & Therapeutics, University of Florida, Gainesville, Florida, USA
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
9
|
Elder HJ, Varshneya NB, Walentiny DM, Beardsley PM. Amphetamines modulate fentanyl-depressed respiration in a bidirectional manner. Drug Alcohol Depend 2023; 243:109740. [PMID: 36608481 PMCID: PMC9881117 DOI: 10.1016/j.drugalcdep.2022.109740] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND The opioid epidemic remains one of the most pressing public health crises facing the United States. Fentanyl and related synthetic opioid agonists have largely driven the rising rates of associated overdose deaths, in part, because of their surreptitious use as substitutes for other opioids and as adulterants in psychostimulants. Deaths involving opioids typically result from lethal respiratory depression, and it is currently unknown how co-use of psychostimulants with opioids affects respiratory toxicity. Considering psychostimulant overdoses have increased over 3-fold since 2013, and half of those co-involved opioids, this is a cardinal question. METHODS Naloxone, d-amphetamine (AMPH), and (±)-methamphetamine (METH) were evaluated for their effects on basal and fentanyl-depressed respiration. Minute volume (MVb) was measured in awake, freely moving mice via whole-body plethysmography to quantify fentanyl-induced respiratory depression and its modulation by dose ranges of each test drug. RESULTS Naloxone immediately reversed respiratory depression induced by fentanyl only at the highest dose tested (10 mg/kg). Both AMPH and METH exhibited bidirectional effects on MVb under basal conditions, producing significant (p ≤ 0.05) depressions then elevations of respiration as dose increased. Under depressed conditions the bidirectional effects of AMPH and METH on respiration were exaggerated, exacerbating and then reversing fentanyl-induced depression as dose increased. CONCLUSIONS These results indicate that co-use of amphetamines with fentanyl may worsen respiratory depression, but conversely, monoaminergic components of the amphetamines may possibly be exploited to mitigate fentanyl overdose.
Collapse
Affiliation(s)
- Harrison J Elder
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Neil B Varshneya
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA; Center for Drug Evaluation and Research, Food and Drug Administration, United States Department of Health and Human Services, Silver Spring, MD, USA
| | - D Matthew Walentiny
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Patrick M Beardsley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA; Center for Biomarker Research & Precision Medicine, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA.
| |
Collapse
|
10
|
Purnell BS, Thompson S, Bowman T, Bhasin J, George S, Rust B, Murugan M, Fedele D, Boison D. The role of adenosine in alcohol-induced respiratory suppression. Neuropharmacology 2023; 222:109296. [PMID: 36377091 PMCID: PMC10208026 DOI: 10.1016/j.neuropharm.2022.109296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/26/2022] [Accepted: 10/17/2022] [Indexed: 11/13/2022]
Abstract
Alcohol-related poisoning is the foremost cause of death resulting from excessive acute alcohol consumption. Respiratory failure is crucial to the pathophysiology of fatal alcohol poisoning. Alcohol increases accumulation of extracellular adenosine. Adenosine suppresses breathing. The goal of this investigation was to test the hypothesis that adenosine signaling contributes to alcohol-induced respiratory suppression. In the first experiment, the breathing of mice was monitored following an injection of the non-selective adenosine receptor antagonist caffeine (40 mg/kg), alcohol (5 g/kg), or alcohol and caffeine combined. Caffeine reduced alcohol-induced respiratory suppression suggesting that adenosine contributes to the effects of alcohol on breathing. The second experiment utilized the same experimental design, but with the blood brain barrier impermeant non-selective adenosine receptor antagonist 8-sulfophenyltheophylline (8-SPT, 60 mg/kg) instead of caffeine. 8-SPT did not reduce alcohol-induced respiratory suppression suggesting that adenosine is contributing to alcohol-induced respiratory suppression in the central nervous system. The third and fourth experiments used the same experimental design as the first, but with the selective A1 receptor antagonist DPCPX (1 mg/kg) and the selective A2A receptor antagonist istradefylline (3.3 mg/kg). Istradefylline, but not DPCPX, reduced alcohol-induced respiratory suppression indicating an A2A receptor mediated effect. In the fifth experiment, alcohol-induced respiratory suppression was evaluated in Adk+/- mice which have impaired adenosine metabolism. Alcohol-induced respiratory suppression was exacerbated in Adk+/- mice. These findings indicate that adenosinergic signaling contributes to alcohol-induced respiratory suppression. Improving our understanding of how alcohol affects breathing may lead to better treatment strategies and better outcomes for patients with severe alcohol poisoning.
Collapse
Affiliation(s)
- Benton S Purnell
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Sydney Thompson
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Tenise Bowman
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Jayant Bhasin
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Steven George
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Brian Rust
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.
| | - Madhuvika Murugan
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Denise Fedele
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA; Brain Health Institute, Rutgers University, Piscataway, NJ, USA.
| |
Collapse
|
11
|
Holland A, Stevens A, Harris M, Lewer D, Sumnall H, Stewart D, Gilvarry E, Wiseman A, Howkins J, McManus J, Shorter GW, Nicholls J, Scott J, Thomas K, Reid L, Day E, Horsley J, Measham F, Rae M, Fenton K, Hickman M. Analysis of the UK Government's 10-Year Drugs Strategy-a resource for practitioners and policymakers. J Public Health (Oxf) 2022:6779883. [PMID: 36309802 DOI: 10.1093/pubmed/fdac114] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/10/2022] [Indexed: 11/12/2022] Open
Abstract
In 2021, during a drug-related death crisis in the UK, the Government published its ten-year drugs strategy. This article, written in collaboration with the Faculty of Public Health and the Association of Directors of Public Health, assesses whether this Strategy is evidence-based and consistent with international calls to promote public health approaches to drugs, which put 'people, health and human rights at the centre'. Elements of the Strategy are welcome, including the promise of significant funding for drug treatment services, the effects of which will depend on how it is utilized by services and local commissioners and whether it is sustained. However, unevidenced and harmful measures to deter drug use by means of punishment continue to be promoted, which will have deleterious impacts on people who use drugs. An effective public health approach to drugs should tackle population-level risk factors, which may predispose to harmful patterns of drug use, including adverse childhood experiences and socioeconomic deprivation, and institute evidence-based measures to mitigate drug-related harm. This would likely be more effective, and just, than the continuation of policies rooted in enforcement. A more dramatic re-orientation of UK drug policy than that offered by the Strategy is overdue.
Collapse
Affiliation(s)
- Adam Holland
- Bristol Medical School, University of Bristol, Bristol, BS8 2BN, UK
| | - Alex Stevens
- School of Social Policy, Sociology and Social Research, University of Kent, Canterbury, CT2 7NZ
| | - Magdalena Harris
- Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Dan Lewer
- Public Health Specialty Registrar, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, UK
| | - Harry Sumnall
- Public Health Institute, Liverpool John Moores University, Liverpool, L3 5UX, UK
| | - Daniel Stewart
- Bristol Medical School, University of Bristol, Bristol, BS8 2BN, UK
| | - Eilish Gilvarry
- Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, NE1 7RU, UK
| | - Alice Wiseman
- Association of Directors of Public Health, London, EC4Y 0HA, UK
| | - Joshua Howkins
- Bristol Medical School, University of Bristol, Bristol, BS8 2BN, UK
| | - Jim McManus
- Association of Directors of Public Health, London, EC4Y 0HA, UK
| | | | - James Nicholls
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, FK9 4LA, UK
| | - Jenny Scott
- Department of Pharmacy & Pharmacology, University of Bath, Bath, BA2 7AY
| | - Kyla Thomas
- Bristol Medical School, University of Bristol, Bristol, BS8 2BN, UK
| | | | - Edward Day
- Institute of Mental Health, University of Birmingham, Birmingham, B15 2TT
| | - Jason Horsley
- National Institute for Health Research Evaluation Trials and Studies Coordinating Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Fiona Measham
- Department of Sociology, Social Policy and Criminology, University of Liverpool, Liverpool, L69 3BX
| | - Maggie Rae
- Epidemiological and Public Health Section, Royal Society of Medicine, London, W1G 0AE, UK
| | | | - Matthew Hickman
- Bristol Medical School, University of Bristol, Bristol, BS8 2BN, UK
| |
Collapse
|
12
|
Mæhle BO, Eide GE, Morild I, Lilleng PK. Petechial hemorrhages, ethanol, and opioids in victims from intoxication. Forensic Sci Int 2022; 338:111406. [PMID: 35908337 DOI: 10.1016/j.forsciint.2022.111406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/04/2022] [Accepted: 07/19/2022] [Indexed: 11/04/2022]
Abstract
Petechial hemorrhages are of interest to forensic pathologists because of their association with pressure on the neck. This study shows the associations between ethanol, opioids in blood and the risk of petechiae in conjunctivae and eye lids of 865 medico-legally examined victims from intoxication, 112 (12.9 %) with petechiae. Livor mortis on the front, face down body position, higher body weight, and younger age of the victims were independently associated with higher risk of petechiae. These variables were used for adjustment in the logistic regression analyzes. We found associations between ethanol, opioids, and the risk of petechiae when analyzed simultaneously. The association between ethanol and the risk of petechiae differed in opioid negative and positive victims (interaction, p = 0.028). In the opioid negative group, the association was J-formed, victims with low to medium level ethanol having lower risk (OR = 0.77) than those without ethanol or opioids, whereas high ethanol level gave a 4-fold higher risk (OR = 3.97). In the opioid positive group, the J-formed pattern was reversed. Victims with low to medium level ethanol had more than 4 times higher risk (OR = 4.65), whereas high level ethanol gave a slightly elevated risk (OR = 1.34) only compared to no ethanol or opioids. The results suggest that ethanol and opioids have a complex association with the risk of petechiae independent of livor mortis, initial body position, body weight, and age in victims from intoxication. Of practical value for the post-mortem examination is that the pathologist must consider both the ethanol level and the presence of opioids when judging the significance of petechiae in the eye regions.
Collapse
Affiliation(s)
- Bjørn Ove Mæhle
- The Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Geir Egil Eide
- Department of Global Public Health and Primary Care, University of Bergen, and Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway
| | - Inge Morild
- The Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway.
| | - Peer Kaare Lilleng
- The Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| |
Collapse
|
13
|
Baird TR, Akbarali HI, Dewey WL, Elder H, Kang M, Marsh SA, Peace MR, Poklis JL, Santos EJ, Negus SS. Opioid-like adverse effects of tianeptine in male rats and mice. Psychopharmacology (Berl) 2022; 239:2187-2199. [PMID: 35211768 PMCID: PMC10055856 DOI: 10.1007/s00213-022-06093-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/13/2022] [Indexed: 01/22/2023]
Abstract
RATIONALE Tianeptine is a mu-opioid receptor (MOR) agonist with increasing reports of abuse in human populations. Preclinical data regarding the abuse potential and other opioid-like adverse effects of tianeptine at supratherapeutic doses are sparse. OBJECTIVES The present study evaluated tianeptine in a rat model of abuse potential assessment and in mouse models of motor, gastrointestinal, and respiratory adverse effects. METHODS Abuse potential was assessed in adult male Sprague-Dawley rats using an intracranial self-stimulation (ICSS) procedure to determine effects of acute and repeated tianeptine on responding for electrical brain stimulation. Male ICR mice were used to determine the effects of tianeptine in assays of locomotor behavior and gastrointestinal motility. Male Swiss-Webster mice were monitored for respiratory changes using whole-body plethysmography. RESULTS In rats, acute tianeptine produced weak and delayed evidence for abuse-related ICSS facilitation at an intermediate dose (10 mg/kg, IP) and pronounced, naltrexone-preventable ICSS depression at a higher dose (32 mg/kg, IP). Repeated 7-day tianeptine (10 and 32 mg/kg/day, IP) produced no increase in abuse-related ICSS facilitation, only modest tolerance to ICSS depression, and no evidence of physical dependence. In mice, tianeptine produced dose-dependent, naltrexone-preventable locomotor activation. Tianeptine (100 mg/kg, SC) also significantly inhibited gastrointestinal motility and produced naloxone-reversible respiratory depression. CONCLUSIONS Tianeptine presents as a MOR agonist with resistance to tolerance and dependence in our ICSS assay in rats, and it has lower abuse potential by this metric than many commonly abused opioids. Nonetheless, tianeptine produces MOR agonist-like acute adverse effects that include motor impairment, constipation, and respiratory depression.
Collapse
Affiliation(s)
- T R Baird
- Integrative Life Sciences Doctoral Program, Virginia Commonwealth University, 1000 West Cary St., Richmond, VA, 23284, USA.,Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284, USA
| | - H I Akbarali
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - W L Dewey
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - H Elder
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - M Kang
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - S A Marsh
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - M R Peace
- Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284, USA
| | - J L Poklis
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - E J Santos
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA
| | - S S Negus
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, 410 N. 12th St, Richmond, VA, 23298, USA.
| |
Collapse
|
14
|
Olofsen E, Algera MH, Moss L, Dobbins RL, Groeneveld GJ, van Velzen M, Niesters M, Dahan A, Laffont CM. Modelling buprenorphine reduction of fentanyl-induced respiratory depression. JCI Insight 2022; 7:156973. [PMID: 35316224 PMCID: PMC9090248 DOI: 10.1172/jci.insight.156973] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/18/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Potent synthetic opioids, such as fentanyl, are increasingly abused, resulting in unprecedented numbers of fatalities from respiratory depression. Treatment with the high-affinity mu-opioid receptor partial agonist buprenorphine may prevent fatalities by reducing binding of potent opioids to the opioid receptor, limiting respiratory depression. METHODS To characterize buprenorphine-fentanyl interaction at the level of the mu-opioid receptor in 2 populations (opioid-naive individuals and individuals who chronically use high-dose opioids), the effects of escalating i.v. fentanyl doses with range 0.075–0.35 mg/70 kg (opioid naive) and 0.25–0.70 mg/70 kg (chronic opioid use) on iso-hypercapnic ventilation at 2–3 background doses of buprenorphine (target plasma concentrations range: 0.2–5 ng/mL) were quantified using receptor association/dissociation models combined with biophase distribution models. RESULTS Buprenorphine produced mild respiratory depression, while high doses of fentanyl caused pronounced respiratory depression and apnea in both populations. When combined with fentanyl, buprenorphine produced a receptor binding–dependent reduction of fentanyl-induced respiratory depression in both populations. In individuals with chronic opioid use, at buprenorphine plasma concentrations of 2 ng/mL or higher, a protective effect against high-dose fentanyl was observed. CONCLUSION Overall, the results indicate that when buprenorphine mu-opioid receptor occupancy is sufficiently high, fentanyl is unable to activate the mu-opioid receptor and consequently will not cause further respiratory depression in addition to the mild respiratory effects of buprenorphine. TRIAL REGISTRATION Trialregister.nl, no. NL7028 (https://www.trialregister.nl/trial/7028) FUNDING Indivior Inc., North Chesterfield, Virginia, USA.
Collapse
Affiliation(s)
- Erik Olofsen
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Marijke Hyke Algera
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Laurence Moss
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Robert L Dobbins
- Drug Discovery and Translational Medicine, Indivior Inc., North Chesterfield, United States of America
| | - Geert J Groeneveld
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Monique van Velzen
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Marieke Niesters
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Albert Dahan
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Celine M Laffont
- Quantitative Clinical Pharmacology, Modeling and Simulation, Indivior Inc., North Chesterfield, United States of America
| |
Collapse
|
15
|
Hill R, Kruegel AC, Javitch JA, Lane JR, Canals M. The respiratory depressant effects of mitragynine are limited by its conversion to 7-OH mitragynine. Br J Pharmacol 2022; 179:3875-3885. [PMID: 35297034 PMCID: PMC9314834 DOI: 10.1111/bph.15832] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/18/2022] [Accepted: 03/03/2022] [Indexed: 12/03/2022] Open
Abstract
Background and Purpose Mitragynine, the major alkaloid in Mitragyna speciosa (kratom), is a partial agonist at the μ opioid receptor. CYP3A‐dependent oxidation of mitragynine yields the metabolite 7‐OH mitragynine, a more efficacious μ receptor agonist. While both mitragynine and 7‐OH mitragynine can induce anti‐nociception in mice, recent evidence suggests that 7‐OH mitragynine formed as a metabolite is sufficient to explain the anti‐nociceptive effects of mitragynine. However, the ability of 7‐OH mitragynine to induce μ receptor‐dependent respiratory depression has not yet been studied. Experimental Approach Respiration was measured in awake, freely moving, male CD‐1 mice, using whole body plethysmography. Anti‐nociception was measured using the hot plate assay. Morphine, mitragynine, 7‐OH mitragynine and the CYP3A inhibitor ketoconazole were administered orally. Key Results The respiratory depressant effects of mitragynine showed a ceiling effect, whereby doses higher than 10 mg·kg−1 produced the same level of effect. In contrast, 7‐OH mitragynine induced a dose‐dependent effect on mouse respiration. At equi‐depressant doses, both mitragynine and 7‐OH mitragynine induced prolonged anti‐nociception. Inhibition of CYP3A reduced mitragynine‐induced respiratory depression and anti‐nociception without affecting the effects of 7‐OH mitragynine. Conclusions and Implications Both the anti‐nociceptive effects and the respiratory depressant effects of mitragynine are partly due to its metabolic conversion to 7‐OH mitragynine. The limiting rate of conversion of mitragynine into its active metabolite results in a built‐in ceiling effect of the mitragynine‐induced respiratory depression. These data suggest that such ‘metabolic saturation’ at high doses may underlie the improved safety profile of mitragynine as an opioid analgesic.
Collapse
Affiliation(s)
- Rob Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, Universities of Nottingham and Birmingham, Midlands, UK
| | - Andrew C Kruegel
- Department of Chemistry, Columbia University, New York, New York, USA
| | - Jonathan A Javitch
- Departments of Psychiatry and Molecular Pharmacology and Therapeutics, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York, USA
| | - J Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, Universities of Nottingham and Birmingham, Midlands, UK
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, Universities of Nottingham and Birmingham, Midlands, UK
| |
Collapse
|
16
|
Hill R, Conibear A, Dewey W, Kelly E, Henderson G. Role of Acetaldehyde in Ethanol Reversal of Tolerance to Morphine-Induced Respiratory Depression in Mice. ADVANCES IN DRUG AND ALCOHOL RESEARCH 2022; 1. [PMID: 35909497 PMCID: PMC7613180 DOI: 10.3389/adar.2021.10143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Background: Opioid users regularly consume other drugs such as alcohol (ethanol). Acute administration of ethanol rapidly reverses tolerance to morphine-induced respiratory depression. However, recent research has suggested that the primary metabolite of ethanol, acetaldehyde, may play a key role in mediating the CNS effects seen after ethanol consumption. This research investigated the role of acetaldehyde in ethanol reversal of tolerance to morphine-induced respiratory depression.Methods: Tolerance was induced in mice by 6-days implantation of a 75 mg morphine pellet with control mice implanted with a placebo pellet. Tolerance was assessed by acute morphine administration on day 6 and respiration measured by plethysmography. Levels of acetaldehyde were inhibited or enhanced by pre-treatments with the acetaldehyde chelator D-penicillamine and the inhibitor of acetaldehyde dehydrogenase disulfiram respectively.Results: Morphine pellet implanted mice displayed tolerance to an acute dose of morphine compared to placebo pellet implanted controls. Acute acetaldehyde administration dose-dependently reversed tolerance to morphine respiratory depression. As previously demonstrated, ethanol reversed morphine tolerance, and this was inhibited by D-penicillamine pre-treatment. An acute, low dose of ethanol that did not significantly reverse morphine tolerance was able to do so following disulfiram pre-treatment.Conclusion: These data suggest that acetaldehyde, the primary metabolite of ethanol, is responsible for the reversal of morphine tolerance observed following ethanol administration.
Collapse
Affiliation(s)
- Rob Hill
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
- Correspondence: Rob Hill,
| | - Alexandra Conibear
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - William Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Eamonn Kelly
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Graeme Henderson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
17
|
Pharmacological and genetic manipulations at the µ-opioid receptor reveal arrestin-3 engagement limits analgesic tolerance and does not exacerbate respiratory depression in mice. Neuropsychopharmacology 2021; 46:2241-2249. [PMID: 34257415 PMCID: PMC8581001 DOI: 10.1038/s41386-021-01054-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 05/01/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023]
Abstract
Opioid drugs are widely used analgesics that activate the G protein-coupled µ-opioid receptor, whose endogenous neuropeptide agonists, endorphins and enkephalins, are potent pain relievers. The therapeutic utility of opioid drugs is hindered by development of tolerance to the analgesic effects, requiring dose escalation for persistent pain control and leading to overdose and fatal respiratory distress. The prevailing hypothesis is that the intended analgesic effects of opioid drugs are mediated by µ-opioid receptor signaling to G protein, while the side-effects of respiratory depression and analgesic tolerance are caused by engagement of the receptor with the arrestin-3 protein. Consequently, opioid drug development has focused exclusively on identifying agonists devoid of arrestin-3 engagement. Here, we challenge the prevailing hypothesis with a panel of six clinically relevant opioid drugs and mice of three distinct genotypes with varying abilities to promote morphine-mediated arrestin-3 engagement. With this genetic and pharmacological approach, we demonstrate that arrestin-3 recruitment does not impact respiratory depression, and effective arrestin-3 engagement reduces, rather than exacerbates, the development of analgesic tolerance. These studies suggest that future development of safer opioids should focus on identifying opioid ligands that recruit both G protein and arrestin-3, thereby mimicking the signaling profile of most endogenous µ-opioid receptor agonists.
Collapse
|
18
|
Scott J, Henderson G. Commentary on Andersen et al.: Time for drug checking for heroin users? Addiction 2021; 116:3113-3114. [PMID: 34196065 DOI: 10.1111/add.15610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/17/2021] [Indexed: 11/26/2022]
Affiliation(s)
- Jenny Scott
- Dept Pharmacy & Pharmacology, University of Bath, Bath, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| |
Collapse
|
19
|
Varshneya NB, Hassanien SH, Holt MC, Stevens DL, Layle NK, Bassman JR, Iula DM, Beardsley PM. Respiratory depressant effects of fentanyl analogs are opioid receptor-mediated. Biochem Pharmacol 2021; 195:114805. [PMID: 34673011 DOI: 10.1016/j.bcp.2021.114805] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/09/2021] [Accepted: 10/13/2021] [Indexed: 02/04/2023]
Abstract
Opioid-related fatalities involving synthetic opioids have reached unprecedented levels. This study evaluated the respiratory depressant effects of seven fentanyl analogs that have either emerged in the illicit drug supply or been identified in toxicological analyses following fatal or non-fatal intoxications. Adult male Swiss Webster mice were administered fentanyl analogs (isobutyrylfentanyl, crotonylfentanyl, para-methoxyfentanyl, para-methoxybutyrylfentanyl, 3-furanylfentanyl, thiophenefentanyl, and benzodioxolefentanyl) and their effects on minute volume as compared to mu-opioid receptor (MOR) agonist standards (fentanyl, morphine, and buprenorphine) were measured using whole body plethysmography (WBP). All drugs elicited significant (p ≤ 0.05) hypoventilation relative to vehicle for at least one dose tested: morphine (1, 3.2, 10, 32 mg/kg), buprenorphine, (0.032, 0.1, 0.32, 1, 3.2 mg/kg), fentanyl (0.0032, 0.01, 0.032, 0.1, 1, 32 mg/kg), isobutyrylfentanyl (0.1, 0.32, 1, 3.2, 10 mg/kg), crotonylfentanyl (0.1, 0.32, 1, 3.2, 10 mg/kg), para-methoxyfentanyl (0.1, 0.32, 1, 3.2, 10 mg/kg), para-methoxybutyrylfentanyl (0.32, 1, 3.2, 10 mg/kg), 3-furanylfentanyl (0.1, 0.32, 1, 3.2, 10 mg/kg), thiophenefentanyl (1, 3.2, 10, 32, 100 mg/kg), and benzodioxolefentanyl (3.2, 10, 32, 100 mg/kg). The ED50 values for hypoventilation showed a rank order of potency as follows: fentanyl (ED50 = 0.96 mg/kg) > 3-furanylfentanyl (ED50 = 2.60 mg/kg) > crotonylfentanyl (ED50 = 2.72 mg/kg) > para-methoxyfentanyl (ED50 = 3.31 mg/kg) > buprenorphine (ED50 = 10.8 mg/kg) > isobutyrylfentanyl (ED50 = 13.5 mg/kg) > para-methoxybutyrylfentanyl (ED50 = 16.1 mg/kg) > thiophenefentanyl (ED50 = 18.0 mg/kg) > morphine (ED50 = 55.3 mg/kg) > benzodioxolefentanyl (ED50 = 10,168 mg/kg). A naloxone pretreatment (10 mg/kg) attenuated the hypoventilatory effects of all drugs. These results establish that the respiratory depressant effects of these fentanyl analogs are at least in part mediated by the MOR.
Collapse
Affiliation(s)
- Neil B Varshneya
- Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
| | - Sherif H Hassanien
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, USA
| | - Melissa C Holt
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, USA
| | - David L Stevens
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Nathan K Layle
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, USA
| | - Jonathon R Bassman
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, USA
| | - Donna M Iula
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, USA
| | - Patrick M Beardsley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA; Center for Biomarker Research & Precision Medicine, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA
| |
Collapse
|
20
|
Treatment of overdose in the synthetic opioid era. Pharmacol Ther 2021; 233:108019. [PMID: 34637841 DOI: 10.1016/j.pharmthera.2021.108019] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 12/16/2022]
Abstract
Overdose deaths are often viewed as the leading edge of the opioid epidemic which has gripped the United States over the past two decades (Skolnick, 2018a). This emphasis is perhaps unsurprising because opioid overdose is both the number-one cause of death for individuals between 25 and 64 years old (Dezfulian et al., 2021) and a significant contributor to the decline in average lifespan (Dowell et al., 2017). Exacerbated by the COVID 19 pandemic, it was estimated there were 93,400 drug overdose deaths in the United States during the 12 months ending December 2020, with more than 69,000 (that is, >74%) of these fatalities attributed to opioid overdose (Ahmad et al., 2021). However, the focus on mortality statistics (Ahmad et al., 2021; Shover et al., 2020) tends to obscure the broader medical impact of nonfatal opioid overdose. Analyses of multiple databases indicate that for each opioid-induced fatality, there are between 6.4 and 8.4 non-fatal overdoses, exacting a significant burden on both the individual and society. Over the past 7-8 years, there has been an alarming increase in the misuse of synthetic opioids ("synthetics"), primarily fentanyl and related piperidine-based analogs. Within the past 2-3 years, a structurally unrelated class of high potency synthetics, benzimidazoles exemplified by etonitazene and isotonitazene ("iso"), have also appeared in illicit drug markets (Thompson, 2020; Ujvary et al. 2021). In 2020, it was estimated that over 80% of fatal opioid overdoses in the United States now involve synthetics (Ahmad et al., 2021). The unique physicochemical and pharmacological properties of synthetics described in this review are responsible for both the morbidity and mortality associated with their misuse as well as their widespread availability. This dramatic increase in the misuse of synthetics is often referred to as the "3rd wave" (Pardo et al., 2019; Volkow and Blanco, 2020) of the opioid epidemic. Among the consequences resulting from misuse of these potent opioids is the need for higher doses of the competitive antagonist, naloxone, to reverse an overdose. The development of more effective reversal agents such as those described in this review is an essential component of a tripartite strategy (Volkow and Collins, 2017) to reduce the biopsychosocial impact of opioid misuse in the "synthetic era".
Collapse
|
21
|
Steel TL, Afshar M, Edwards S, Jolley SE, Timko C, Clark BJ, Douglas IS, Dzierba AL, Gershengorn HB, Gilpin NW, Godwin DW, Hough CL, Maldonado JR, Mehta AB, Nelson LS, Patel MB, Rastegar DA, Stollings JL, Tabakoff B, Tate JA, Wong A, Burnham EL. Research Needs for Inpatient Management of Severe Alcohol Withdrawal Syndrome: An Official American Thoracic Society Research Statement. Am J Respir Crit Care Med 2021; 204:e61-e87. [PMID: 34609257 PMCID: PMC8528516 DOI: 10.1164/rccm.202108-1845st] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background: Severe alcohol withdrawal syndrome (SAWS) is highly morbid, costly, and common among hospitalized patients, yet minimal evidence exists to guide inpatient management. Research needs in this field are broad, spanning the translational science spectrum. Goals: This research statement aims to describe what is known about SAWS, identify knowledge gaps, and offer recommendations for research in each domain of the Institute of Medicine T0-T4 continuum to advance the care of hospitalized patients who experience SAWS. Methods: Clinicians and researchers with unique and complementary expertise in basic, clinical, and implementation research related to unhealthy alcohol consumption and alcohol withdrawal were invited to participate in a workshop at the American Thoracic Society 2019 International Conference. The committee was subdivided into four groups on the basis of interest and expertise: T0-T1 (basic science research with translation to humans), T2 (research translating to patients), T3 (research translating to clinical practice), and T4 (research translating to communities). A medical librarian conducted a pragmatic literature search to facilitate this work, and committee members reviewed and supplemented the resulting evidence, identifying key knowledge gaps. Results: The committee identified several investigative opportunities to advance the care of patients with SAWS in each domain of the translational science spectrum. Major themes included 1) the need to investigate non-γ-aminobutyric acid pathways for alcohol withdrawal syndrome treatment; 2) harnessing retrospective and electronic health record data to identify risk factors and create objective severity scoring systems, particularly for acutely ill patients with SAWS; 3) the need for more robust comparative-effectiveness data to identify optimal SAWS treatment strategies; and 4) recommendations to accelerate implementation of effective treatments into practice. Conclusions: The dearth of evidence supporting management decisions for hospitalized patients with SAWS, many of whom require critical care, represents both a call to action and an opportunity for the American Thoracic Society and larger scientific communities to improve care for a vulnerable patient population. This report highlights basic, clinical, and implementation research that diverse experts agree will have the greatest impact on improving care for hospitalized patients with SAWS.
Collapse
|
22
|
Hill R, Canals M. Experimental considerations for the assessment of in vivo and in vitro opioid pharmacology. Pharmacol Ther 2021; 230:107961. [PMID: 34256067 DOI: 10.1016/j.pharmthera.2021.107961] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/21/2021] [Accepted: 07/06/2021] [Indexed: 12/15/2022]
Abstract
Morphine and other mu-opioid receptor (MOR) agonists remain the mainstay treatment of acute and prolonged pain states worldwide. The major limiting factor for continued use of these current opioids is the high incidence of side effects that result in loss of life and loss of quality of life. The development of novel opioids bereft, or much less potent, at inducing these side effects remains an intensive area of research, with multiple pharmacological strategies being explored. However, as with many G protein-coupled receptors (GPCRs), translation of promising candidates from in vitro characterisation to successful clinical candidates still represents a major challenge and attrition point. This review summarises the preclinical animal models used to evaluate the key opioid-induced behaviours of antinociception, respiratory depression, constipation and opioid-induced hyperalgesia and tolerance. We highlight the influence of distinct variables in the experimental protocols, as well as the potential implications for differences in receptor reserve in each system. Finally, we discuss how methods to assess opioid action in vivo and in vitro relate to each other in the context of bridging the translational gap in opioid drug discovery.
Collapse
Affiliation(s)
- Rob Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom; Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Midlands, United Kingdom.
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom; Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Midlands, United Kingdom.
| |
Collapse
|
23
|
An Effective and Safe Enkephalin Analog for Antinociception. Pharmaceutics 2021; 13:pharmaceutics13070927. [PMID: 34206631 PMCID: PMC8308721 DOI: 10.3390/pharmaceutics13070927] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 11/17/2022] Open
Abstract
Opioids account for 69,000 overdose deaths per annum worldwide and cause serious side effects. Safer analgesics are urgently needed. The endogenous opioid peptide Leu-Enkephalin (Leu-ENK) is ineffective when introduced peripherally due to poor stability and limited membrane permeability. We developed a focused library of Leu-ENK analogs containing small hydrophobic modifications. N-pivaloyl analog KK-103 showed the highest binding affinity to the delta opioid receptor (68% relative to Leu-ENK) and an extended plasma half-life of 37 h. In the murine hot-plate model, subcutaneous KK-103 showed 10-fold improved anticonception (142%MPE·h) compared to Leu-ENK (14%MPE·h). In the formalin model, KK-103 reduced the licking and biting time to ~50% relative to the vehicle group. KK-103 was shown to act through the opioid receptors in the central nervous system. In contrast to morphine, KK-103 was longer-lasting and did not induce breathing depression, physical dependence, and tolerance, showing potential as a safe and effective analgesic.
Collapse
|
24
|
Brackley AD, Toney GM. Oxytocin Receptor Activation Rescues Opioid-Induced Respiratory Depression by Systemic Fentanyl in the Rat. J Pharmacol Exp Ther 2021; 378:96-107. [PMID: 33990416 DOI: 10.1124/jpet.121.000535] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/11/2021] [Indexed: 12/22/2022] Open
Abstract
Opioid overdose intervention by naloxone, a high affinity receptor antagonist, reverses opioid-induced respiratory depression (OIRD) and analgesia by displacing opioids. Systemic naloxone stimulates release of the hypothalamic neuropeptide oxytocin, which has analgesic properties and participates in cardiorespiratory homeostasis. To test the hypothesis that oxytocin can reverse OIRD, we assessed the rescue potential of graded doses (0, 0.1, 2, 5, 10, 50 nmol/kg, i.v.) of oxytocin to counter fentanyl (60 nmol/kg, i.v.)-induced depression of neural inspiration indexed by recording phrenic nerve activity (PNA) in anesthetized (urethane/α-chloralose), vagotomized, and artificially ventilated rats. Oxytocin dose-dependently rescued fentanyl OIRD by almost immediately reversing PNA burst arrest (P = 0.0057) and restoring baseline burst frequency (P = 0.0016) and amplitude (P = 0.0025) at low but not high doses, resulting in inverted bell-shaped dose-response curves. Oxytocin receptor antagonism (40 nmol/kg, i.v.) prevented oxytocin reversal of OIRD (arrest: P = 0.0066, frequency: P = 0.0207, amplitude: P = 0.0022). Vasopressin 1A receptor (V1aR) antagonism restored high-dose oxytocin efficacy to rescue OIRD (P = 0.0170 to P < 0.0001), resulting in classic sigmoidal dose-response curves, and prevented (P = 0.0135) transient hypertension from V1aR cross-activation (P = 0.0275). Alone, vasopressin (5 nmol/kg, i.v.) failed to reverse fentanyl respiratory arrest (P = 0.6184). The nonpeptide oxytocin receptor agonist WAY-267464 (75 nmol/kg, i.v.), which has V1aR antagonist properties, quickly reversed fentanyl OIRD (P < 0.0001), with rapid recovery of PNA frequency (P = 0.0011) and amplitude (P = 0.0044) without adverse hemodynamic consequences (P = 0.9991). Findings indicate that peptide and nonpeptide agonist activation of oxytocin receptors without V1aR cross-activation rescues fentanyl OIRD. Oxytocin receptor agonists could be lifesaving resuscitation agents that enhance rather than interrupt opioid analgesia. SIGNIFICANCE STATEMENT: Oxytocin receptor activation produces analgesia. Here, we demonstrate that activation by the US Food and Drug Administration-approved agonist oxytocin and the nonpeptide partial agonist WAY-267464 can each reverse fentanyl cardiorespiratory depression. Selective targeting of oxytocin receptors for resuscitation from opioid overdose, alone or in combination with an opioid antagonist, could eliminate or attenuate negative side effects associated with traditional opioid receptor antagonism.
Collapse
Affiliation(s)
- Allison Doyle Brackley
- Department of Cellular and Integrative Physiology and Center for Biomedical Neuroscience, University of Texas Health San Antonio, San Antonio, TX
| | - Glenn M Toney
- Department of Cellular and Integrative Physiology and Center for Biomedical Neuroscience, University of Texas Health San Antonio, San Antonio, TX
| |
Collapse
|
25
|
Algera MH, Olofsen E, Moss L, Dobbins RL, Niesters M, van Velzen M, Groeneveld GJ, Heuberger J, Laffont CM, Dahan A. Tolerance to Opioid-Induced Respiratory Depression in Chronic High-Dose Opioid Users: A Model-Based Comparison With Opioid-Naïve Individuals. Clin Pharmacol Ther 2021; 109:637-645. [PMID: 32865832 PMCID: PMC7983936 DOI: 10.1002/cpt.2027] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 08/11/2020] [Indexed: 12/24/2022]
Abstract
Chronic opioid consumption is associated with addiction, physical dependence, and tolerance. Tolerance results in dose escalation to maintain the desired opioid effect. Intake of high-dose or potent opioids may cause life-threatening respiratory depression, an effect that may be reduced by tolerance. We performed a pharmacokinetic-pharmacodynamic analysis of the respiratory effects of fentanyl in chronic opioid users and opioid-naïve subjects to quantify tolerance to respiratory depression. Fourteen opioid-naïve individuals and eight chronic opioid users received escalating doses of intravenous fentanyl (opioid-naïve subjects: 75-350 µg/70 kg; chronic users: 250-700 µg/70 kg). Isohypercapnic ventilation was measured and the fentanyl plasma concentration-ventilation data were analyzed using nonlinear mixed-effects modeling. Apneic events occurred in opioid-naïve subjects after a cumulative fentanyl dose (per 70 kg) of 225 (n = 3) and 475 µg (n = 6), and in 7 chronic opioid users after a cumulative dose of 600 (n = 2), 1,100 (n = 2), and 1,800 µg (n = 3). The time course of fentanyl's respiratory depressant effect was characterized using a biophase equilibration model in combination with an inhibitory maximum effect (Emax ) model. Differences in tolerance between populations were successfully modeled. The effect-site concentration causing 50% ventilatory depression, was 0.42 ± 0.07 ng/mL in opioid-naïve subjects and 1.82 ± 0.39 ng/mL in chronic opioid users, indicative of a 4.3-fold sensitivity difference. Despite higher tolerance to fentanyl-induced respiratory depression, apnea still occurred in the opioid-tolerant population indicative of the potential danger of high-dose opioids in causing life-threatening respiratory depression in all individuals, opioid-naïve and opioid-tolerant.
Collapse
Affiliation(s)
- Marijke Hyke Algera
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Erik Olofsen
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
| | | | | | - Marieke Niesters
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Monique van Velzen
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Geert Jan Groeneveld
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
- Centre for Human Drug ResearchLeidenThe Netherlands
| | | | | | - Albert Dahan
- Department of AnesthesiologyLeiden University Medical CenterLeidenThe Netherlands
| |
Collapse
|
26
|
Zavala CA, Thomaz AC, Iyer V, Mackie K, Hohmann AG. Cannabinoid CB2 Receptor Activation Attenuates Fentanyl-Induced Respiratory Depression. Cannabis Cannabinoid Res 2020; 6:389-400. [PMID: 33998863 PMCID: PMC8612411 DOI: 10.1089/can.2020.0059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction: Overdose fatalities associated with the opioid epidemic are predictably attributable to drug-induced respiratory depression. In terms of illicit opioid abuse, fentanyl is the synthetic opioid responsible for the largest number of overdose deaths. There is, therefore, an urgent need to identify safe and effective therapeutics that can attenuate fentanyl-induced respiratory depression. Identification of effective alternate analgesic strategies that lessen the respiratory depression associated with narcotics would also help improve current strategies for pain management. Our laboratory recently reported that the G protein-biased CB2 cannabinoid receptor agonist LY2828360 suppressed chemotherapy-induced neuropathic nociception and attenuated both morphine tolerance and physical dependence in paclitaxel-treated mice. However, the impact of LY2828360 on other undesirable side effects of opioids, such as opioid-induced respiratory depression, remains unknown. Materials and Methods: We used whole-body plethysmography to assess the impact of the CB2 cannabinoid agonist LY2828360 on fentanyl-induced respiratory depression using wild-type (WT) and CB2 knockout (CB2KO) mice. Results: Fentanyl reduced minute ventilation and respiratory frequency without altering tidal volume in both WT and CB2KO mice. In WT mice, the high dose of fentanyl (0.2 mg/kg intraperitoneal [i.p.]) produced a greater suppression of respiratory parameters compared with the low dose of fentanyl (0.1 mg/kg i.p.). Coadministration of a behaviorally active dose of LY2828360 (3 mg/kg i.p.) with fentanyl (0.2 mg/kg i.p.) attenuated fentanyl-induced respiratory depression in WT mice. Notably, LY2828360 (3 mg/kg i.p.) did not attenuate fentanyl-induced respiratory depression in CB2KO mice, consistent with mediation by CB2 receptors. Moreover, LY2828360 (3 mg/kg i.p.) alone lacked intrinsic effects on respiratory parameters in either WT or CB2KO mice. Conclusion: The combination of a CB2 agonist with fentanyl may represent a safer adjunctive therapeutic strategy compared with a narcotic analgesic alone by attenuating the development of opioid-induced respiratory depression. Moreover, the CB2 agonist, administered alone, did not alter respiration. Our findings suggest that the CB2 cannabinoid agonist LY2828360 may provide CB2-mediated protection against fentanyl-induced respiratory depression, a detrimental and unwanted side effect of opioid use and abuse.
Collapse
Affiliation(s)
- Carmen A. Zavala
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Ana C. Thomaz
- Genome, Cell, and Developmental Biology Program, Indiana University, Bloomington, Indiana, USA
- Program in Neuroscience, Indiana University, Bloomington, Indiana, USA
| | - Vishakh Iyer
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
- Program in Neuroscience, Indiana University, Bloomington, Indiana, USA
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
- Genome, Cell, and Developmental Biology Program, Indiana University, Bloomington, Indiana, USA
- Program in Neuroscience, Indiana University, Bloomington, Indiana, USA
- Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana, USA
| | - Andrea G. Hohmann
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
- Genome, Cell, and Developmental Biology Program, Indiana University, Bloomington, Indiana, USA
- Program in Neuroscience, Indiana University, Bloomington, Indiana, USA
- Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana, USA
| |
Collapse
|
27
|
Azevedo Neto J, Costanzini A, De Giorgio R, Lambert DG, Ruzza C, Calò G. Biased versus Partial Agonism in the Search for Safer Opioid Analgesics. Molecules 2020; 25:molecules25173870. [PMID: 32854452 PMCID: PMC7504468 DOI: 10.3390/molecules25173870] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 02/07/2023] Open
Abstract
Opioids such as morphine—acting at the mu opioid receptor—are the mainstay for treatment of moderate to severe pain and have good efficacy in these indications. However, these drugs produce a plethora of unwanted adverse effects including respiratory depression, constipation, immune suppression and with prolonged treatment, tolerance, dependence and abuse liability. Studies in β-arrestin 2 gene knockout (βarr2(−/−)) animals indicate that morphine analgesia is potentiated while side effects are reduced, suggesting that drugs biased away from arrestin may manifest with a reduced-side-effect profile. However, there is controversy in this area with improvement of morphine-induced constipation and reduced respiratory effects in βarr2(−/−) mice. Moreover, studies performed with mice genetically engineered with G-protein-biased mu receptors suggested increased sensitivity of these animals to both analgesic actions and side effects of opioid drugs. Several new molecules have been identified as mu receptor G-protein-biased agonists, including oliceridine (TRV130), PZM21 and SR–17018. These compounds have provided preclinical data with apparent support for bias toward G proteins and the genetic premise of effective and safer analgesics. There are clinical data for oliceridine that have been very recently approved for short term intravenous use in hospitals and other controlled settings. While these data are compelling and provide a potential new pathway-based target for drug discovery, a simpler explanation for the behavior of these biased agonists revolves around differences in intrinsic activity. A highly detailed study comparing oliceridine, PZM21 and SR–17018 (among others) in a range of assays showed that these molecules behave as partial agonists. Moreover, there was a correlation between their therapeutic indices and their efficacies, but not their bias factors. If there is amplification of G-protein, but not arrestin pathways, then agonists with reduced efficacy would show high levels of activity at G-protein and low or absent activity at arrestin; offering analgesia with reduced side effects or ‘apparent bias’. Overall, the current data suggests—and we support—caution in ascribing biased agonism to reduced-side-effect profiles for mu-agonist analgesics.
Collapse
Affiliation(s)
- Joaquim Azevedo Neto
- Department of Biomedical and Specialty Surgical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (J.A.N.); (G.C.)
| | - Anna Costanzini
- Department of Morphology, Surgery, Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (A.C.); (R.D.G.)
| | - Roberto De Giorgio
- Department of Morphology, Surgery, Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (A.C.); (R.D.G.)
| | - David G. Lambert
- Department of Cardiovascular Sciences, Anesthesia, Critical Care and Pain Management, University of Leicester, Leicester LE1 7RH, UK;
| | - Chiara Ruzza
- Department of Biomedical and Specialty Surgical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (J.A.N.); (G.C.)
- Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, 44122 Ferrara, Italy
- Correspondence:
| | - Girolamo Calò
- Department of Biomedical and Specialty Surgical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (J.A.N.); (G.C.)
| |
Collapse
|
28
|
Stone AC, Carroll JJ, Rich JD, Green TC. One year of methadone maintenance treatment in a fentanyl endemic area: Safety, repeated exposure, retention, and remission. J Subst Abuse Treat 2020; 115:108031. [PMID: 32600619 DOI: 10.1016/j.jsat.2020.108031] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 04/18/2020] [Accepted: 05/06/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Fentanyl is a potent synthetic opioid that has contributed to increasing overdose deaths in the United States in recent years. Concern over safety and efficacy of agonist treatment for fentanyl use may limit access to treatment. This study sought to address these potential concerns in a naturalistic setting. OBJECTIVES Measure 12-month treatment outcomes for methadone maintenance treatment (MMT) in a fentanyl endemic area. OUTCOMES Primary: 1) Treatment retention; 2) sustained remission (defined as 3 consecutive negative screens); 3) return to use; 4) methadone dosage required; and 5) number of days to achieve remission. Secondary: Mortality. METHODS A naturalistic follow-up study and retrospective review of consecutive patients newly admitted to a single methadone maintenance treatment program in Rhode Island. RESULTS We observed 154 unique intake events (representing 151 patients). Eighty percent (n = 121) tested positive for fentanyl at intake. Seventy-five percent of patients achieved remission within the 12-month study period. One-year retention was 53% for fentanyl-exposed individuals and 47% for those not exposed. The majority (99%) of patients who remained in treatment at 12 months achieved remission. We saw prolonged, sustained remission in 44% of patients exposed to fentanyl at intake and 47% of those who were not. Dose and time to remission were similar. Unfortunately, 4 patients died after leaving MMT prematurely. CONCLUSIONS This study suggests MMT is safe despite repeated exposure to fentanyl while taking methadone. Remission is achievable, and MMT is protective against death among fentanyl-exposed patients while in treatment.
Collapse
Affiliation(s)
- Andrew C Stone
- Discovery House CTC, 1625 Diamond Hill Road, Woonsocket, RI 02895, USA.
| | - Jennifer J Carroll
- Department of Sociology & Anthropology, Elon University, 100 Campus Drive, Elon, NC 27244, USA
| | - Josiah D Rich
- The Warren Alpert School of Medicine of Brown University, The Miriam Hospital, 164 Summit Ave, Providence, RI 02903, USA
| | - Traci C Green
- The Warren Alpert School of Medicine of Brown University, Rhode Island Hospital, 55 Claverick Street, Providence, RI 02903, USA
| |
Collapse
|
29
|
Dai Z, Abate MA, Long DL, Smith GS, Halki TM, Kraner JC, Mock AR. Quantifying enhanced risk from alcohol and other factors in polysubstance-related deaths. Forensic Sci Int 2020; 313:110352. [PMID: 32590196 DOI: 10.1016/j.forsciint.2020.110352] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND To quantify how alcohol, polysubstance use and other factors influence opioid concentrations in drug-related deaths in West Virginia (WV), United States. METHODS Multiple linear regression models were employed to identify relationships among alcohol, other factors, and the concentrations of four commonly identified opioids (fentanyl, hydrocodone, oxycodone, methadone), accounting for demographic, toxicological and comorbid characteristics in WV drug-related deaths from 2005 to 2018. RESULTS Alcohol concentrations of 0.08% or above were associated with significant reductions in blood concentrations of fentanyl (27.5%), hydrocodone (30.5%) and methadone (32.4%). Significantly lower predicted concentrations of all opioids studied were associated with multiple opioid vs. single opioid presence, with predicted concentration reductions ranging from 13.7% for fentanyl to 65-66% for hydrocodone and oxycodone. Benzodiazepine presence was associated with small, non-statistically significant changes in opioid concentrations, while stimulant presence was associated with statistically significant reductions in hydrocodone and oxycodone concentrations. CONCLUSIONS Co-ingestion of alcohol, multiple opioids or stimulants were associated with significantly decreased predicted concentrations of commonly identified opioids in drug deaths. Further evidence is provided for enhanced risks from polysubstance use with opioids, which has important public health implications.
Collapse
Affiliation(s)
- Zheng Dai
- School of Public Health, West Virginia University, One Medical Center Drive, Morgantown, WV 26506, United States.
| | - Marie A Abate
- School of Pharmacy, West Virginia University, 1124 Health Sciences North, Morgantown, WV 26506, United States
| | - D Leann Long
- School of Public Health, University of Alabama at Birmingham, 327F Ryals Public Health Building, Birmingham, AL 35294, United States
| | - Gordon S Smith
- School of Public Health, West Virginia University, One Medical Center Drive, Morgantown, WV 26506, United States
| | - Theresa M Halki
- School of Pharmacy, West Virginia University, 1124 Health Sciences North, Morgantown, WV 26506, United States
| | - James C Kraner
- West Virginia Office of the Chief Medical Examiner, West Virginia Department of Health and Human Resources, 619 Virginia Street West, Charleston, WV 25302, United States
| | - Allen R Mock
- West Virginia Office of the Chief Medical Examiner, West Virginia Department of Health and Human Resources, 619 Virginia Street West, Charleston, WV 25302, United States
| |
Collapse
|
30
|
Kliewer A, Gillis A, Hill R, Schmiedel F, Bailey C, Kelly E, Henderson G, Christie MJ, Schulz S. Morphine-induced respiratory depression is independent of β-arrestin2 signalling. Br J Pharmacol 2020; 177:2923-2931. [PMID: 32052419 PMCID: PMC7280004 DOI: 10.1111/bph.15004] [Citation(s) in RCA: 165] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 12/03/2019] [Accepted: 01/17/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE GPCRs can signal through both G proteins and β-arrestin2. For the μ-opioid receptor, early experimental evidence from a single study suggested that G protein signalling mediates analgesia, whereas β-arrestin2 signalling mediates respiratory depression and constipation. Consequently, for more than a decade, much research effort has been focused on developing biased μ-opioid agonists that preferentially target G protein signalling over β-arrestin signalling, as it was believed that such drugs would be analgesics devoid of respiratory depressant activity. However, the prototypical compounds that have been developed based on this concept have so far failed in clinical and preclinical development. EXPERIMENTAL APPROACH The present study was set up to re-examine opioid-induced respiratory depression in β-arrestin2 knockout mice. To this end, a consortium was formed consisting of three different laboratories located in different countries to evaluate independently opioid-induced respiratory depression. KEY RESULTS Our consensus results unequivocally demonstrate that the prototypical μ-opioid agonist morphine (3.75-100 mg·kg-1 s.c. or 3-30 mg·kg-1 i.p.) as well as the potent opioid fentanyl (0.05-0.35 mg·kg-1 s.c.) do indeed induce respiratory depression and constipation in β-arrestin2 knockout mice in a dose-dependent manner indistinguishable from that observed in wild-type mice. CONCLUSION AND IMPLICATIONS Our findings do not support the original suggestion that β-arrestin2 signalling plays a key role in opioid-induced respiratory depression and call into question the concept of developing G protein-biased μ-opioid receptor agonists as a strategy for the development of safer opioid analgesic drugs.
Collapse
Affiliation(s)
- Andrea Kliewer
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Alexander Gillis
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Rob Hill
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Frank Schmiedel
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Chris Bailey
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | - Eamonn Kelly
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Macdonald J Christie
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| |
Collapse
|
31
|
Hill R, Santhakumar R, Dewey W, Kelly E, Henderson G. Fentanyl depression of respiration: Comparison with heroin and morphine. Br J Pharmacol 2020; 177:254-266. [PMID: 31499594 PMCID: PMC6989952 DOI: 10.1111/bph.14860] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/05/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Fentanyl overdose deaths have reached "epidemic" levels in North America. Death in opioid overdose invariably results from respiratory depression. In the present work, we have characterized how fentanyl depresses respiration, and by comparing fentanyl with heroin and morphine, the active breakdown product of heroin, we have sought to determine the factors, in addition to high potency, that contribute to the lethality of fentanyl. EXPERIMENTAL APPROACH Respiration (rate and tidal volume) was measured in awake, freely moving mice by whole body plethysmography. KEY RESULTS Intravenously administered fentanyl produced more rapid depression of respiration than equipotent doses of heroin or morphine. Fentanyl depressed both respiratory rate and tidal volume. Fentanyl did not depress respiration in μ-opioid receptor knockout mice. Naloxone, the opioid antagonist widely used to treat opioid overdose, reversed the depression of respiration by morphine more readily than that by fentanyl, whereas diprenorphine, a more lipophilic antagonist, was equipotent in reversing fentanyl and morphine depression of respiration. Prolonged treatment with morphine induced tolerance to respiratory depression, but the degree of cross tolerance to fentanyl was less than the tolerance to morphine itself. CONCLUSION AND IMPLICATIONS We propose that several factors (potency, rate of onset, lowered sensitivity to naloxone, and lowered cross tolerance to heroin) combine to make fentanyl more likely to cause opioid overdose deaths than other commonly abused opioids. Lipophilic antagonists such as diprenorphine may be better antidotes than naloxone to treat fentanyl overdose.
Collapse
MESH Headings
- Animals
- Analgesics, Opioid/administration & dosage
- Analgesics, Opioid/toxicity
- Dose-Response Relationship, Drug
- Drug Tolerance
- Fentanyl/administration & dosage
- Fentanyl/toxicity
- Heroin/administration & dosage
- Heroin/toxicity
- Injections, Intraperitoneal
- Injections, Intravenous
- Lung/drug effects
- Lung/physiopathology
- Mice, Inbred C57BL
- Mice, Knockout
- Morphine/administration & dosage
- Morphine/toxicity
- Narcotic Antagonists/pharmacology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Respiration/drug effects
- Respiratory Insufficiency/chemically induced
- Respiratory Insufficiency/drug therapy
- Respiratory Insufficiency/metabolism
- Respiratory Insufficiency/physiopathology
- Respiratory Rate/drug effects
- Risk Assessment
- Tidal Volume/drug effects
- Mice
Collapse
Affiliation(s)
- Rob Hill
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Rakulan Santhakumar
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - William Dewey
- Department of Pharmacology and ToxicologyVirginia Commonwealth UniversityRichmondVirginia
| | - Eamonn Kelly
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Graeme Henderson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| |
Collapse
|
32
|
Kelty E, Hulse G, Joyce D. A comparison of blood toxicology in fatalities involving alcohol and other drugs in patients with an opioid use disorder treated with methadone, buprenorphine, and implant naltrexone. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2019; 46:241-250. [DOI: 10.1080/00952990.2019.1698587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Erin Kelty
- School of Population and Global Health, University of Western Australia, Crawley, Western Australia
| | - Gary Hulse
- Division of Psychiatry, University of Western Australia, Crawley, Western Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia
| | - David Joyce
- School of Medicine, University of Western Australia, Crawley, Western Australia
- School of Biomedical Sciences, University of Western Australia, Crawley, Western Australia
| |
Collapse
|
33
|
Prolonged ethanol administration prevents the development of tolerance to morphine-induced respiratory depression. Drug Alcohol Depend 2019; 205:107674. [PMID: 31715438 DOI: 10.1016/j.drugalcdep.2019.107674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/23/2019] [Accepted: 10/01/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Opioid users regularly consume other drugs such as alcohol (ethanol). Acute administration of ethanol can rapidly reverse tolerance to morphine-induced respiratory depression. However, alcohol consumption by opioid users is likely to occur over prolonged time periods. We have therefore sought to determine the effect of prolonged alcohol consumption on the development of tolerance to opioid respiratory depression. METHODS Mice were fed control or ethanol (5%) liquid diet for 16 days. On days 9-16 morphine tolerance was induced by administration of 3 priming injections of morphine followed by subcutaneous implantation of a morphine-filled osmotic mini-pump. Control mice received saline. Respiration was measured by plethysmography and the effect of an acute morphine challenge dose was measured on day 16 to assess the development of morphine tolerance. RESULTS Prolonged ethanol consumption for 14 days did not alter the respiratory depressant effect of an acute dose of morphine. Control mice treated with prolonged morphine developed tolerance to acute morphine respiratory depression whereas ethanol diet fed mice treated with prolonged morphine showed significant respiratory depression during morphine-pump treatment and remained sensitive to the respiratory depressant effect of the acute challenge dose of morphine. The ethanol consumption did not alter blood or brain levels of morphine, whilst conversely prolonged morphine treatment did not alter blood levels of ethanol. CONCLUSIONS Prolonged ethanol consumption prevents the development and maintenance of tolerance to the respiratory depressant effect of morphine. These data suggest that ethanol inhibition of tolerance will greatly increase the risk of fatal heroin overdose in humans.
Collapse
|
34
|
Paulus DJ, Rogers AH, Bakhshaie J, Vowles KE, Zvolensky MJ. Pain severity and prescription opioid misuse among individuals with chronic pain: The moderating role of alcohol use severity. Drug Alcohol Depend 2019; 204:107456. [PMID: 31476642 DOI: 10.1016/j.drugalcdep.2019.02.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 02/22/2019] [Accepted: 02/28/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Chronic pain is a public health problem associated with opioid misuse. Yet, it is important to understand factors underlying opioid misuse in the context of pain. Alcohol use is one factor to consider given past work documenting use of alcohol to manage pain. However, it is unknown whether alcohol use severity exacerbates the relation between pain and opioid misuse. This study sought to examine relations between pain and prescription opioid misuse and the moderating role of alcohol use severity in two online survey studies of individuals with chronic pain. METHOD Individuals with chronic pain (study 1, n = 364; study 2, n = 437) were administered measures of pain, alcohol use, and opioid misuse. RESULTS In study 1, there was a significant interaction of pain severity and alcohol use (b = 0.16, p < 0.001). Pain was significantly related to opioid misuse among those with higher (b = 1.50, p < 0.001), but not lower (b=-0.26, p = 0.430) alcohol use. In study 2, there was a significant interaction of pain severity and alcohol use (b = 0.03, p < 0.001). Pain was significantly related to opioid misuse among those with higher (b = 0.74, p < 0.001), but not lower (b = 0.07, p = 0.620) alcohol use. CONCLUSIONS In two online samples, there was evidence of a novel interaction of pain severity and alcohol use severity in relation to opioid misuse. Although cross-sectional, results replicated in two studies. Pain severity was related to opioid misuse among those with higher but not lower alcohol use. Those who use alcohol, even below suggested cut-offs, may be more likely to misuse opioids when in pain.
Collapse
Affiliation(s)
- Daniel J Paulus
- Medical University of South Carolina, Department of Psychiatry and Behavioral Sciences, 67 President Street, Charleston, South Carolina, 29425 United States; University of Houston, Department of Psychology, 126 Heyne, Houston, Texas, 77204 United States.
| | - Andrew H Rogers
- University of Houston, Department of Psychology, 126 Heyne, Houston, Texas, 77204 United States
| | - Jafar Bakhshaie
- University of Houston, Department of Psychology, 126 Heyne, Houston, Texas, 77204 United States
| | - Kevin E Vowles
- University of New Mexico, Department of Psychology, Logan Hall, MSC03-2220, 1 University of New Mexico, Albuquerque, New Mexico, 87131 United States
| | - Michael J Zvolensky
- University of Houston, Department of Psychology, 126 Heyne, Houston, Texas, 77204 United States; Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston, Texas, 77030 United States; HEALTH Institute, University of Houston, Houston, Texas, 77204 United States.
| |
Collapse
|
35
|
Degenhardt L, Grebely J, Stone J, Hickman M, Vickerman P, Marshall BDL, Bruneau J, Altice FL, Henderson G, Rahimi-Movaghar A, Larney S. Global patterns of opioid use and dependence: harms to populations, interventions, and future action. Lancet 2019; 394:1560-1579. [PMID: 31657732 PMCID: PMC7068135 DOI: 10.1016/s0140-6736(19)32229-9] [Citation(s) in RCA: 383] [Impact Index Per Article: 76.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 08/15/2019] [Accepted: 09/06/2019] [Indexed: 12/15/2022]
Abstract
We summarise the evidence for medicinal uses of opioids, harms related to the extramedical use of, and dependence on, these drugs, and a wide range of interventions used to address these harms. The Global Burden of Diseases, Injuries, and Risk Factors Study estimated that in 2017, 40·5 million people were dependent on opioids (95% uncertainty interval 34·3-47·9 million) and 109 500 people (105 800-113 600) died from opioid overdose. Opioid agonist treatment (OAT) can be highly effective in reducing illicit opioid use and improving multiple health and social outcomes-eg, by reducing overall mortality and key causes of death, including overdose, suicide, HIV, hepatitis C virus, and other injuries. Mathematical modelling suggests that scaling up the use of OAT and retaining people in treatment, including in prison, could avert a median of 7·7% of deaths in Kentucky, 10·7% in Kiev, and 25·9% in Tehran over 20 years (compared with no OAT), with the greater effects in Tehran and Kiev being due to reductions in HIV mortality, given the higher prevalence of HIV among people who inject drugs in those settings. Other interventions have varied evidence for effectiveness and patient acceptability, and typically affect a narrower set of outcomes than OAT does. Other effective interventions focus on preventing harm related to opioids. Despite strong evidence for the effectiveness of a range of interventions to improve the health and wellbeing of people who are dependent on opioids, coverage is low, even in high-income countries. Treatment quality might be less than desirable, and considerable harm might be caused to individuals, society, and the economy by the criminalisation of extramedical opioid use and dependence. Alternative policy frameworks are recommended that adopt an approach based on human rights and public health, do not make drug use a criminal behaviour, and seek to reduce drug-related harm at the population level.
Collapse
Affiliation(s)
- Louisa Degenhardt
- National Drug and Alcohol Research Centre, University of New South Wales Sydney, Sydney, NSW, Australia.
| | - Jason Grebely
- Kirby Institute, University of New South Wales Sydney, Sydney, NSW, Australia
| | - Jack Stone
- Population Health Sciences, University of Bristol, Bristol, UK
| | - Matthew Hickman
- Population Health Sciences, University of Bristol, Bristol, UK
| | - Peter Vickerman
- Population Health Sciences, University of Bristol, Bristol, UK
| | | | - Julie Bruneau
- Research Center, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada; Department of Family and Emergency Medicine, Faculty of Medicine, Université de Montréal, Succursale Centre-Ville, Montreal, QC, Canada
| | | | | | - Afarin Rahimi-Movaghar
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
| | - Sarah Larney
- National Drug and Alcohol Research Centre, University of New South Wales Sydney, Sydney, NSW, Australia
| |
Collapse
|
36
|
Heckroth A, Pludra V, Johannssen C, Guest C, Wiedermann F, Bantel C. The influence of personal values and patient intoxication on nurses concerns about opioids: results of a prospective cross-sectional multi-centre study. Br J Pain 2019; 15:40-53. [PMID: 33628441 PMCID: PMC7882770 DOI: 10.1177/2049463719880333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background: Nurses are the main administrators of opioids in hospitals and enjoy some autonomy when using them to manage pain. Nevertheless evidence suggests they exercise this freedom restrictively with the reasons for this self-limitation remaining unclear. Nurses are influenced by personal and professional values and by patients’ attributes. Intoxicated patients pose a particular challenge. This study therefore investigated whether cautious attitudes towards opioids were aggravated in intoxicated patients and influenced by personal values. Methods: A two-version questionnaire was developed. Each presented a case vignette describing a patient in acute pain who was either intoxicated or not intoxicated. Questionnaires contained identical case statements inquiring about concerns regarding opioids, preferred analgesics and statements about opioids and personal values. They were distributed prospectively in a cross-sectional, multi-centre design. Equal distribution of both questionnaires was achieved through randomization of wards. Regression analysis was employed to determine predictors for responses to the case statements. Results: In total, n = 374 (26%) nurses returned questionnaires, 85% were female, 39% worked in surgery and 64% had >10 years experience. A total of 78% were concerned using opioids in the intoxicated patient and 70% preferred non-opioids instead. Most nurses agreed familiarity with an opioid gives them more confidence and they were more concerned in patients with a history of drug abuse. They neither associated opioids with helping patients to die nor with drug abuse. The majority endorsed value statements representing ‘universalism’, ‘hedonism’ and ‘benevolence’ while disagreeing with ‘power’ and ‘stimulation’. Nurses concerns were predicted by values indicating ‘conformity’ and ‘achievement’. Conclusion: Nurses were concerned giving opioids to intoxicated patients and preferred non-opioids instead. These concerns were predicted by personal values representing ‘Conservation’ (‘conformity’) and ‘Self-Enhancement’ (‘achievement’). Therefore, stigmatizing mental models likely contribute to nurses’ reluctance to use opioids. Interestingly, personal ambition might protect nurses from discriminatory thoughts and practice.
Collapse
Affiliation(s)
- Antje Heckroth
- Carl von Ossietzky Universitat Oldenburg, Oldenburg, Germany
- Hanse Institut Oldenburg, Oldenburg, Germany
| | | | - Christian Johannssen
- Evangelisches Krankenhaus Oldenburg, Oldenburg, Germany
- Hanse Institut Oldenburg, Oldenburg, Germany
| | | | | | - Carsten Bantel
- Carl von Ossietzky Universitat Oldenburg, Oldenburg, Germany
| |
Collapse
|
37
|
Acupuncture/Electroacupuncture as an Alternative in Current Opioid Crisis. Chin J Integr Med 2019; 26:643-647. [PMID: 31630362 DOI: 10.1007/s11655-019-3175-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2019] [Indexed: 01/09/2023]
Abstract
Opioid drugs are the first line of defense in severe pain but the adverse effects associated with opioids are considered as a serious issue worldwide. Acupuncture/electroacupuncture is a type of Chinese medicine therapy which is an effective analgesic therapy, well documented in animals and human studies. Electroacupuncture stimulation could release endogenous opioid peptides causing analgesia in a variety of pain models. It can be used as an alternative therapy to control the opioid crisis.
Collapse
|
38
|
Colvin LA, Bull F, Hales TG. Perioperative opioid analgesia-when is enough too much? A review of opioid-induced tolerance and hyperalgesia. Lancet 2019; 393:1558-1568. [PMID: 30983591 DOI: 10.1016/s0140-6736(19)30430-1] [Citation(s) in RCA: 262] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/21/2018] [Accepted: 02/15/2019] [Indexed: 12/12/2022]
Abstract
Opioids are a mainstay of acute pain management but can have many adverse effects, contributing to problematic long-term use. Opioid tolerance (increased dose needed for analgesia) and opioid-induced hyperalgesia (paradoxical increase in pain with opioid administration) can contribute to both poorly controlled pain and dose escalation. Hyperalgesia is particularly problematic as further opioid prescribing is largely futile. The mechanisms of opioid tolerance and hyperalgesia are complex, involving μ opioid receptor signalling pathways that offer opportunities for novel analgesic alternatives. The intracellular scaffold protein β-arrestin-2 is implicated in tolerance, hyperalgesia, and other opioid side-effects. Development of agonists biased against recruitment of β-arrestin-2 could provide analgesic efficacy with fewer side-effects. Alternative approaches include inhibition of peripheral μ opioid receptors and blockade of downstream signalling mechanisms, such as the non-receptor tyrosine kinase Src or N-methyl-D-aspartate receptors. Furthermore, it is prudent to use multimodal analgesic regimens to reduce reliance on opioids during the perioperative period. In the third paper in this Series we focus on clinical and mechanism-based understanding of tolerance and opioid-induced hyperalgesia, and discuss current and future strategies for pain management.
Collapse
Affiliation(s)
- Lesley A Colvin
- Division of Population Health and Genomics, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK.
| | - Fiona Bull
- Institute for Academic Anaesthesia, Division of Systems Medicine, School of Medicine, Ninewells Hospital, University of Dundee, Dundee, UK
| | - Tim G Hales
- Institute for Academic Anaesthesia, Division of Systems Medicine, School of Medicine, Ninewells Hospital, University of Dundee, Dundee, UK
| |
Collapse
|
39
|
Stone AC, Carroll JJ, Rich JD, Green TC. Methadone maintenance treatment among patients exposed to illicit fentanyl in Rhode Island: Safety, dose, retention, and relapse at 6 months. Drug Alcohol Depend 2018; 192:94-97. [PMID: 30243145 DOI: 10.1016/j.drugalcdep.2018.07.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/14/2018] [Accepted: 07/22/2018] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Illicitly manufactured fentanyl (IMF) is a potent synthetic opioid that has been contributing to overdose deaths in the United States. This study examined intake toxicology and six-month treatment outcomes for patients newly admitted to a single methadone maintenance treatment program (MMTP) in Rhode Island with a high prevalence of illicit fentanyl. METHODS We conducted a retrospective chart review of patients admitted to a single MMTP between November 1st, 2016 and August 31st, 2017 followed for six months. Outcomes measured included: 1) retention in treatment at 6 months; 2) evidence of sustained abstinence; 3) relapse; 4) methadone dosage required to achieve sustained abstinence; and 5) the number of days required to achieve abstinence. RESULTS We observed 154 unique intake events (representing 147 patients). 80% (n = 123) tested positive for fentanyl at intake. During the six-month follow up period, 32% (n = 49) left treatment before six months, two individuals died within five weeks of discontinuation. No deaths were seen among those remaining in treatment. The majority (89%) who remained in treatment at six months achieved abstinence. No significant difference was seen for dose or time to achieve abstinence. Relapse was common (57%). Repeated exposure to fentanyl was seen frequently (71%) while in MMT before and after achieving abstinence. CONCLUSION While there is concern that the potency of IMF may reduce the effectiveness of MAT, this study suggests that MMT is safe, abstinence achievable, and MMT is protective against death among fentanyl-exposed patients.
Collapse
Affiliation(s)
- Andrew C Stone
- Discovery House Comprehensive Treatment Center, 1625 Diamond Hill Road, Woonsocket, RI 02895, USA.
| | - Jennifer J Carroll
- The Warren Alpert School of Medicine of Brown University, Rhode Island Hospital, Department of Emergency Medicine, 55 Claverick Street, Providence, RI 02903, USA
| | - Josiah D Rich
- Brown University and The Center for Prisoner Health and Human Rights, The Miriam Hospital, 164 Summit Ave, Providence, RI 02906, USA
| | - Traci C Green
- The Warren Alpert School of Medicine of Brown University, Rhode Island Hospital, Department of Emergency Medicine, 55 Claverick Street, Providence, RI 02903, USA
| |
Collapse
|
40
|
Zanos P, Georgiou P, Weber C, Robinson F, Kouimtsidis C, Niforooshan R, Bailey A. Oxytocin and opioid addiction revisited: old drug, new applications. Br J Pharmacol 2018; 175:2809-2824. [PMID: 28378414 PMCID: PMC6016632 DOI: 10.1111/bph.13757] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 02/01/2017] [Accepted: 02/13/2017] [Indexed: 12/28/2022] Open
Abstract
Opioid addiction has devastating health and socio-economic consequences, and current pharmacotherapy is limited and often accompanied by side effects, thus novel treatment is warranted. Traditionally, the neurohypophyseal peptide oxytocin (OT) is known for its effects on mediating reward, social affiliation and bonding, stress and learning and memory. There is now strong evidence that OT is a possible candidate for the treatment of drug addiction and depression-addiction co-morbidities. This review summarizes and critically discusses the preclinical evidence surrounding the consequences of pharmacological manipulation of the oxytocinergic system on opioid addiction-related processes, as well as the effects of opioids on the OT system at different stages of the addiction cycle. The mechanisms underlying the effects of OT on opioid addiction, including OT' interaction with the monoaminergic, glutamatergic, opioidergic systems and its effect on the amygdala, the hypothalamic-pituitary-adrenal axis and on memory consolidation of traumatic memories, are also reviewed. We also review clinical evidence on the effects of intranasal OT administration on opioid-dependent individuals and discuss the therapeutic potential along with the limitations that accompany OT-based pharmacotherapies. Review of these studies clearly indicates that the OT system is profoundly affected by opioid use and abstinence and points towards the OT system as an important target for developing pharmacotherapies for the treatment of opioid addiction and co-existing affective disorders, thereby preventing relapse. Therefore, there is a clear need for clinical studies assessing the efficacy of OT-based pharmacotherapies in opioid addiction. LINKED ARTICLES This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.
Collapse
Affiliation(s)
- Panos Zanos
- School of Biosciences and Medicine, Faculty of Health and Medical SciencesUniversity of SurreyGuildfordSurreyUK
- Department of PsychiatryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Polymnia Georgiou
- School of Biosciences and Medicine, Faculty of Health and Medical SciencesUniversity of SurreyGuildfordSurreyUK
- Department of PsychiatryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Carol Weber
- School of Biosciences and Medicine, Faculty of Health and Medical SciencesUniversity of SurreyGuildfordSurreyUK
| | - Fiona Robinson
- Surrey and Borders Partnership NHS Foundation TrustChertseySurreyUK
| | | | | | - Alexis Bailey
- School of Biosciences and Medicine, Faculty of Health and Medical SciencesUniversity of SurreyGuildfordSurreyUK
- Institute of Medical and Biomedical EducationSt George's University of LondonLondonUK
| |
Collapse
|
41
|
Hill R, Disney A, Conibear A, Sutcliffe K, Dewey W, Husbands S, Bailey C, Kelly E, Henderson G. The novel μ-opioid receptor agonist PZM21 depresses respiration and induces tolerance to antinociception. Br J Pharmacol 2018; 175:2653-2661. [PMID: 29582414 PMCID: PMC6003631 DOI: 10.1111/bph.14224] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/12/2018] [Accepted: 03/17/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE 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. EXPERIMENTAL APPROACH G protein (Gi ) 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. KEY RESULTS PZM21 (10-9 - 3 × 10-5 M) produced concentration-dependent Gi 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. CONCLUSION AND IMPLICATIONS 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.
Collapse
Affiliation(s)
- Rob Hill
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Alex Disney
- Department of Pharmacy and PharmacologyUniversity of BathBathUK
| | - Alex Conibear
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Katy Sutcliffe
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - William Dewey
- Department of Pharmacology and ToxicologyVirginia Commonwealth UniversityRichmondVAUSA
| | | | - Chris Bailey
- Department of Pharmacy and PharmacologyUniversity of BathBathUK
| | - Eamonn Kelly
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Graeme Henderson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| |
Collapse
|
42
|
Hill R, Dewey WL, Kelly E, Henderson G. Oxycodone-induced tolerance to respiratory depression: reversal by ethanol, pregabalin and protein kinase C inhibition. Br J Pharmacol 2018; 175:2492-2503. [PMID: 29574756 PMCID: PMC5980627 DOI: 10.1111/bph.14219] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE 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. EXPERIMENTAL APPROACH 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. KEY RESULTS 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. CONCLUSION AND IMPLICATIONS 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.
Collapse
Affiliation(s)
- Rob Hill
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolBS8 1TDUK
| | - William L Dewey
- Department of Pharmacology and ToxicologyVirginia Commonwealth UniversityRichmondVA23298‐0613USA
| | - Eamonn Kelly
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolBS8 1TDUK
| | - Graeme Henderson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolBS8 1TDUK
| |
Collapse
|
43
|
Abstract
This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.
Collapse
Affiliation(s)
- Richard J Bodnar
- Department of Psychology and CUNY Neuroscience Collaborative, Queens College, City University of New York, Flushing, NY 11367, United States.
| |
Collapse
|
44
|
Jacob JC, Sakakibara K, Mischel RA, Henderson G, Dewey WL, Akbarali HI. Ethanol Reversal of Oxycodone Tolerance in Dorsal Root Ganglia Neurons. Mol Pharmacol 2018; 93:417-426. [PMID: 29467238 DOI: 10.1124/mol.117.110775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/08/2018] [Indexed: 01/23/2023] Open
Abstract
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 μM 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 μM 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 µM 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.
Collapse
Affiliation(s)
- Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Kensuke Sakakibara
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Ryan A Mischel
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Graeme Henderson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| |
Collapse
|
45
|
Abstract
The prescribing of opioid analgesics for pain management-particularly for management of chronic noncancer pain (CNCP)-has increased more than fourfold in the United States since the mid-1990s. Yet there is mounting evidence that opioids have only limited effectiveness in the management of CNCP, and the increased availability of prescribed opioids has contributed to upsurges in opioid-related addiction cases and overdose deaths. These concerns have led to critical revisiting and modification of prior pain management practices (e.g., guidelines from the Centers for Disease Control and Prevention), but the much-needed changes in clinical practice will be facilitated by a better understanding of the pharmacology and behavioral effects of opioids that underlie both their therapeutic effects (analgesia) and their adverse effects (addiction and overdose). With these goals in mind, this review first presents an overview of the contemporary problems associated with opioid management of CNCP and the related public health issues of opioid diversion, overdose, and addiction. It then discusses the pharmacology underlying the therapeutic and main adverse effects of opioids and its implications for clinical management of CNCP within the framework of recent clinical guidelines for prescribing opioids in the management of CNCP.
Collapse
Affiliation(s)
- Nora Volkow
- National Institute on Drug Abuse, Rockville, Maryland 20852;
| | - Helene Benveniste
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510;
| | | |
Collapse
|
46
|
Levitt ES, Williams JT. Desensitization and Tolerance of Mu Opioid Receptors on Pontine Kölliker-Fuse Neurons. Mol Pharmacol 2017; 93:8-13. [PMID: 29097440 DOI: 10.1124/mol.117.109603] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022] Open
Abstract
Acute desensitization of mu opioid receptors is thought to be an initial step in the development of tolerance to opioids. Given the resistance of the respiratory system to develop tolerance, desensitization of neurons in the Kölliker-Fuse (KF), a key area in the respiratory circuit, was examined. The activation of G protein-coupled inwardly rectifying potassium current was measured using whole-cell voltage-clamp recordings from KF and locus coeruleus (LC) neurons contained in acute rat brain slices. A saturating concentration of the opioid agonist [Met5]-enkephalin (ME) caused significantly less desensitization in KF neurons compared with LC neurons. In contrast to LC, desensitization in KF neurons was not enhanced by activation of protein kinase C or in slices from morphine-treated rats. Cellular tolerance to ME and morphine was also lacking in KF neurons from morphine-treated rats. The lack of cellular tolerance in KF neurons correlates with the relative lack of tolerance to the respiratory depressant effect of opioids.
Collapse
Affiliation(s)
- Erica S Levitt
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (E.S.L.) and Vollum Institute, Oregon Health and Science University, Portland, Oregon (J.T.W.)
| | - John T Williams
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (E.S.L.) and Vollum Institute, Oregon Health and Science University, Portland, Oregon (J.T.W.)
| |
Collapse
|
47
|
Lyndon A, Audrey S, Wells C, Burnell ES, Ingle S, Hill R, Hickman M, Henderson G. Risk to heroin users of polydrug use of pregabalin or gabapentin. Addiction 2017; 112:1580-1589. [PMID: 28493329 PMCID: PMC5635829 DOI: 10.1111/add.13843] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 02/20/2017] [Accepted: 04/05/2017] [Indexed: 12/13/2022]
Abstract
AIM To examine the risk to heroin users of also using gabapentin or pregabalin (gabapentoids). DESIGN Multi-disciplinary study: we (a) examined trends in drug-related deaths and gabapentoid prescription data in England and Wales to test for evidence that any increase in deaths mentioning gabapentin or pregabalin is associated with trends in gabapentoid prescribing and is concomitant with opioid use; (b) interviewed people with a history of heroin use about their polydrug use involving gabapentin and pregabalin; and (c) studied the respiratory depressant effects of pregabalin in the absence and presence of morphine in mice to determine whether concomitant exposure increased the degree of respiratory depression observed. SETTING England and Wales. PARTICIPANTS Interviews were conducted with 30 participants (19 males, 11 female). MEASUREMENTS (a) Office of National Statistics drug-related deaths from 1 January 2004 to 31 December 2015 that mention both an opioid and pregabalin or gabapentin; (b) subjective views on the availability, use, interactions and effects of polydrug use involving pregabalin and gabapentin; and (c) rate and depth of respiration. RESULTS Pregabalin and gabapentin prescriptions increased approximately 24% per year from 1 million in 2004 to 10.5 million in 2015. The number of deaths involving gabapentoids increased from fewer than one per year prior to 2009 to 137 in 2015; 79% of these deaths also involved opioids. The increase in deaths was correlated highly with the increase in prescribing (correlation coefficient 0.94; 5% increase in deaths per 100 000 increase in prescriptions). Heroin users described pregabalin as easy to obtain. They suggested that the combination of heroin and pregabalin reinforced the effects of heroin but were concerned it induced 'blackouts' and increased the risk of overdose. In mice, a low dose of S-pregabalin (20 mg/kg) that did not itself depress respiration reversed tolerance to morphine depression of respiration (resulting in 35% depression of respiration, P < 0.05), whereas a high dose of S-pregabalin (200 mg/kg) alone depressed respiration and this effect summated with that of morphine. CONCLUSIONS For heroin users, the combination of opioids with gabapentin or pregabalin potentially increases the risk of acute overdose death through either reversal of tolerance or an additive effect of the drugs to depress respiration.
Collapse
Affiliation(s)
- Abigail Lyndon
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - Suzanne Audrey
- School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS, UK
| | - Claudia Wells
- Mortality Analysis, Office for National Statistics, Newport NP10 8XG, UK
| | - Erica S Burnell
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - Suzanne Ingle
- School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS, UK
| | - Rob Hill
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - Matthew Hickman
- School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| |
Collapse
|
48
|
Gonek M, Akbarali HI, Henderson G, Dewey WL. Reversal of oxycodone and hydrocodone tolerance by diazepam. Brain Res 2017; 1674:84-90. [PMID: 28830768 DOI: 10.1016/j.brainres.2017.08.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/07/2017] [Accepted: 08/14/2017] [Indexed: 02/03/2023]
Abstract
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.
Collapse
Affiliation(s)
- Maciej Gonek
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay Street, Richmond, VA 23298-0613, USA.
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay Street, Richmond, VA 23298-0613, USA
| | - Graeme Henderson
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay Street, Richmond, VA 23298-0613, USA
| |
Collapse
|
49
|
Marsden J, Stillwell G, Jones H, Cooper A, Eastwood B, Farrell M, Lowden T, Maddalena N, Metcalfe C, Shaw J, Hickman M. Does exposure to opioid substitution treatment in prison reduce the risk of death after release? A national prospective observational study in England. Addiction 2017; 112:1408-1418. [PMID: 28160345 DOI: 10.1111/add.13779] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/11/2017] [Accepted: 02/01/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIMS People with opioid use disorder (OUD) in prison face an acute risk of death after release. We estimated whether prison-based opioid substitution treatment (OST) reduces this risk. DESIGN Prospective observational cohort study using prison health care, national community drug misuse treatment and deaths registers. SETTING Recruitment at 39 adult prisons in England (32 male; seven female) accounting for 95% of OST treatment in England during study planning. PARTICIPANTS Adult prisoners diagnosed with OUD (recruited: September 2010-August 2013; first release: September 2010; last release: October 2014; follow-up to February 2016; n = 15 141 in the risk set). INTERVENTION AND COMPARATOR At release, participants were classified as OST exposed (n = 8645) or OST unexposed (n = 6496). The OST unexposed group did not receive OST, or had been withdrawn, or had a low dose. MEASUREMENTS Primary outcome: all-cause mortality (ACM) in the first 4 weeks. SECONDARY OUTCOMES drug-related poisoning (DRP) deaths in the first 4 weeks; ACM and DRP mortality after 4 weeks to 1 year; admission to community drug misuse treatment in the first 4 weeks. Unadjusted and adjusted Cox regression models (covariates: sex, age, drug injecting, problem alcohol use, use of benzodiazepines, cocaine, prison transfer and admission to community treatment), tested difference in mortality rates and community treatment uptake. FINDINGS During the first 4 weeks after prison release there were 24 ACM deaths: six in the OST exposed group and 18 in the OST unexposed group [mortality rate 0.93 per 100 person-years (py) versus 3.67 per 100 py; hazard ratio (HR) = 0.25; 95% confidence interval (CI) = 0.10-0.64]. There were 18 DRP deaths: OST exposed group mortality rate 0.47 per 100 py versus 3.06 per 100 py in the OST unexposed group (HR = 0.15; 95% CI = 0.04-0.53). There was no group difference in mortality risk after the first month. The OST exposed group was more likely to enter drug misuse treatment in the first month post-release (odds ratio 2.47, 95% CI = 2.31-2.65). The OST mortality protective effect on ACM and DRP mortality risk was not attenuated by demographic, overdose risk factors, prison transfer or community treatment (fully adjusted HR = 0.25; 95% CI = 0.09-0.64 and HR = 0.15; 95% CI = 0.04-0.52, respectively). CONCLUSIONS In an English national study, prison-based opioid substitution therapy was associated with a 75% reduction in all-cause mortality and an 85% reduction in fatal drug-related poisoning in the first month after release.
Collapse
Affiliation(s)
- John Marsden
- Addictions Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Garry Stillwell
- Addictions Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Hayley Jones
- School of Social and Community Medicine, Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Alisha Cooper
- Alcohol, Drug and Tobacco Division, Health and Wellbeing Directorate, Public Health England, London, UK
| | - Brian Eastwood
- Alcohol, Drug and Tobacco Division, Health and Wellbeing Directorate, Public Health England, London, UK
| | - Michael Farrell
- National Drug and Alcohol Research Centre, University of New South Wales, New South Wales, Australia
| | - Tim Lowden
- Alcohol, Drug and Tobacco Division, Health and Wellbeing Directorate, Public Health England, London, UK
| | - Nino Maddalena
- Alcohol, Drug and Tobacco Division, Health and Wellbeing Directorate, Public Health England, London, UK
| | - Chris Metcalfe
- School of Social and Community Medicine, Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Jenny Shaw
- Institute of Brain, Behaviour and Mental Health, University of Manchester, Manchester, UK
| | - Matthew Hickman
- School of Social and Community Medicine, Faculty of Health Sciences, University of Bristol, Bristol, UK
| |
Collapse
|
50
|
Jacob JC, Poklis JL, Akbarali HI, Henderson G, Dewey WL. Ethanol Reversal of Tolerance to the Antinociceptive Effects of Oxycodone and Hydrocodone. J Pharmacol Exp Ther 2017; 362:45-52. [PMID: 28442580 PMCID: PMC5454589 DOI: 10.1124/jpet.117.241083] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/20/2017] [Indexed: 01/09/2023] Open
Abstract
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.
Collapse
Affiliation(s)
- Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia- (J.C.J., J.L.P., H.I.A., W.L.D.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Justin L Poklis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia- (J.C.J., J.L.P., H.I.A., W.L.D.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia- (J.C.J., J.L.P., H.I.A., W.L.D.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Graeme Henderson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia- (J.C.J., J.L.P., H.I.A., W.L.D.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia- (J.C.J., J.L.P., H.I.A., W.L.D.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| |
Collapse
|