1
|
Wang L, Volkow ND, Berger NA, Davis PB, Kaelber DC, Xu R. Cardiac and mortality outcome differences between methadone, buprenorphine and naltrexone prescriptions in patients with an opioid use disorder. J Clin Psychol 2023; 79:2869-2883. [PMID: 37584532 DOI: 10.1002/jclp.23582] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 07/01/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023]
Abstract
IMPORTANCE More than 109,000 Americans died of drug overdose in 2022, with 81,231 overdose deaths involving opioids. Methadone, buprenorphine and naltrexone are the most widely used medications for opioid use disorders (MOUD) and the most effective intervention for preventing overdose deaths. However, there is a concern that methadone results in long QT syndrome, which increases the risk for fatal cardiac arrythmias. Currently few studies have systematically evaluated both the short-term and long-term differences in cardiac and mortality outcomes between MOUD. OBJECTIVES To compare the risks of cardiac arrythmias, long QT syndrome and overall mortality between patients with opioid use disorders (OUD) who were prescribed methadone, buprenorphine or naltrexone. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study based on a multicenter and nationwide database of electronic health records (EHRs) in the United States. The study population was comprised of 144,141 patients who had medical encounters for OUD in 2016-2022, were prescribed MOUD within 1 month following a medical encounter for OUD diagnosis and had no diagnosis of cardiac arrythmias or long QT syndrome before any MOUD prescription. The study population was divided into three cohorts: (1) Methadone cohort (n = 40,938)-who were only prescribed methadone. (2) Buprenorphine cohort (n = 80,055)-who were only prescribed buprenorphine. (3) Naltrexone cohort (n = 5,738)-who were only prescribed naltrexone. EXPOSURES methadone, buprenorphine, or naltrexone. MAIN OUTCOMES AND MEASURES Cardiac arrythmias, long QT syndrome, and death. Hazard ratio (HR) and 95% confidence interval (CI) of outcomes at six different follow-up time frames (1-month, 3-month, 6-month, 1-year, 3-year, and 5-year) by comparing propensity-score matched cohorts using Kaplan-Meier survival analysis. RESULTS Patients with OUD who were prescribed methadone had significantly higher risks of cardiac arrhythmias, long QT syndrome and death compared with propensity-score matched patients with OUD who were prescribed buprenorphine or naltrexone. For the 1-month follow-up, the overall risk for cardiac arrythmias was 1.03% in the Methadone cohort, higher than the 0.87% in the matched Buprenorphine cohort (HR: 1.20, 95% CI: 1.04-1.39); The overall risk for long QT syndrome was 0.35% in the Methadone cohort, higher than the 0.15% in the matched Buprenorphine cohort (HR: 2.40, 95% CI: 1.75-3.28); The overall mortality was 0.59% in the Methadone cohort, higher than the 0.41% in the matched Buprenorphine cohort (HR: 1.48, 95% CI: 1.21-1.81). The increased risk persisted for 5 years: cardiac arrhythmias (HR: 1.31, 95% CI: 1.23-1.38), long QT syndrome (HR: 3.14, 95% CI: 2.76-3.58), death (HR: 1.50, 95% CI: 1.41-1.59). CONCLUSIONS AND RELEVANCE Methadone was associated with a significantly higher risk for cardiac and mortality outcomes than buprenorphine and naltrexone. These findings are relevant to the development of guidelines for medication selection when initiating MOUD treatment and inform future medication development for OUD that minimizes risks while maximizing benefits.
Collapse
Affiliation(s)
- Lindsey Wang
- Center for Science, Health, and Society, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Nora D Volkow
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland, USA
| | - Nathan A Berger
- Center for Science, Health, and Society, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Pamela B Davis
- Center for Community Health Integration, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - David C Kaelber
- The Center for Clinical Informatics Research and Education, The MetroHealth System, Cleveland, Ohio, USA
| | - Rong Xu
- Center for Artificial Intelligence in Drug Discovery, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| |
Collapse
|
2
|
Bastien G, McAnulty C, Ledjiar O, Socias ME, Le Foll B, Lim R, Hassan AN, Brissette S, Marsan S, Talbot A, Jutras-Aswad D. Effects of Buprenorphine/Naloxone and Methadone on Depressive Symptoms in People with Prescription Opioid Use Disorder: A Pragmatic Randomised Controlled Trial. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2023; 68:572-585. [PMID: 36519188 PMCID: PMC10411362 DOI: 10.1177/07067437221145013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE This study aimed to evaluate the effectiveness of flexible take-home dosing of buprenorphine/naloxone (BUP/NX) and methadone standard model of care in reducing depressive symptoms in people with prescription-type opioid use disorder (POUD). This trial also evaluated whether improvements in depressive symptoms were mediated by opioid use. METHODS Analyzed data came from the OPTIMA study (clinicaltrials.gov identifier: NCT03033732), a pragmatic randomised controlled trial comparing flexible take-home dosing of BUP/NX and methadone standard model of care for reducing opioid use in people with POUD. A total of 272 participants were recruited in four Canadian provinces. Participants were randomised 1:1 to BUP/NX or methadone. After treatment induction, past two-week opioid use was measured using the Timeline Followback every two weeks for a total of 24 weeks. Depressive symptoms were measured with the Beck Depression Inventory at baseline, weeks 12 and 24. RESULTS Both BUP/NX and methadone significantly reduced depressive symptoms at week 12 (aβ ± SE = -3.167 ± 1.233; P < 0.001) and week 24 (aβ ± SE = -7.280 ± 1.285; P < 0.001), with no interaction between type of treatment and time (P = 0.284). Improvements in depressive symptoms were only partially mediated by a reduction in opioid use (proportion mediated = 36.8%; 95% confidence interval = -1.158 to -0.070; P = 0.015). CONCLUSIONS BUP/NX and methadone showed similar effectiveness in decreasing comorbid depressive symptoms in people with POUD. This effect was partially explained by a reduction in opioid use. As both treatments seem equally effective, clinicians are encouraged to tailor the selection of OAT to patients' needs and characteristics.
Collapse
Affiliation(s)
- Gabriel Bastien
- Department of Psychiatry and Addictology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Christina McAnulty
- Department of Psychiatry and Addictology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Omar Ledjiar
- Unité de recherche clinique appliquée, Centre hospitalier universitaire Ste-Justine, Montréal, Québec, Canada
| | - M. Eugenia Socias
- British Columbia Centre on Substance Use, Vancouver, British Columbia, Canada
- Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bernard Le Foll
- Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Center for Addiction and Mental Health, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Family and Community Medicine, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Waypoint Research Institute, Waypoint Centre for Mental Health Care, Penetanguishene, Ontario, Canada
| | - Ron Lim
- Department of Medicine and Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ahmed N. Hassan
- Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Center for Addiction and Mental Health, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Suzanne Brissette
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
- Department of Family and Emergency Medicine, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Stéphanie Marsan
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
- Department of Family and Emergency Medicine, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Annie Talbot
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
- Department of Family and Emergency Medicine, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Didier Jutras-Aswad
- Department of Psychiatry and Addictology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
- Research Centre, Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | | |
Collapse
|
3
|
Butler SH. Some controversies related to questionable clinical uses of methadone for chronic non-cancer pain and in palliative care. Scand J Pain 2021; 21:421-425. [PMID: 33725755 DOI: 10.1515/sjpain-2020-0178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
4
|
Townsend EA, Negus SS, Banks ML. Medications Development for Treatment of Opioid Use Disorder. Cold Spring Harb Perspect Med 2021; 11:a039263. [PMID: 31932466 PMCID: PMC7778216 DOI: 10.1101/cshperspect.a039263] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review describes methods for preclinical evaluation of candidate medications to treat opioid use disorder (OUD). The review is founded on the propositions that (1) drug self-administration procedures provide the most direct method for assessment of medication effectiveness, (2) procedures that assess choice between opioid and nondrug reinforcers are especially useful, and (3) states of opioid dependence and withdrawal profoundly influence both opioid reinforcement and effects of candidate medications. Effects of opioid medications and vaccines on opioid choice in nondependent and opioid-dependent subjects are reviewed. Various nonopioid medications have also been examined, but none yet have been identified that safely and reliably reduce opioid choice. Future research will focus on (1) strategies for increasing safety and/or effectiveness of opioid medications (e.g., G-protein-biased μ-opioid agonists), and (2) continued development of nonopioid medications (e.g., clonidine) that might serve as adjunctive agents to current opioid medications.
Collapse
Affiliation(s)
- E Andrew Townsend
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia 23298, USA
| | - S Stevens Negus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia 23298, USA
| | - Matthew L Banks
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia 23298, USA
| |
Collapse
|
5
|
D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
Collapse
Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy.,Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| |
Collapse
|
6
|
Deen M, Hougaard A, Hansen HD, Schain M, Dyssegaard A, Knudsen GM, Ashina M. Association Between Sumatriptan Treatment During a Migraine Attack and Central 5-HT1B Receptor Binding. JAMA Neurol 2020; 76:834-840. [PMID: 31135819 DOI: 10.1001/jamaneurol.2019.0755] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Importance Triptans, the most efficient acute treatment for migraine attacks, are 5-HT1B/1D receptor agonists, but their precise mechanism of action is not completely understood. The extent to which triptans enter the central nervous system and bind to 5-HT1B receptors in the brain is unknown. Objectives To determine the occupancy of sumatriptan to central 5-HT1B receptors, and to investigate changes in brain serotonin levels during migraine attacks. Design, Setting, and Participants This study of 8 patients in Denmark used a within-participant design and was conducted from April 20, 2015, to December 5, 2016. Participants were otherwise healthy patients with untreated episodic migraine without aura, aged between 18 and 65 years, and recruited from the general community. Data analysis was performed from January 2017 to April 2018. Interventions All participants underwent positron emission tomographic scans after injection of [11C]AZ10419369, a specific 5-HT1B receptor radiotracer. All participants were scanned 3 times: (1) during an experimentally induced migraine attack, (2) after a subcutaneous injection of 6-mg subcutaneous sumatriptan, and (3) on a migraine attack-free day. Scans 1 and 2 were conducted on the same study day. Each scan lasted for 90 minutes. Main Outcome and Measure The primary outcome was the nondisplaceable binding potential of [11C]AZ10419369 across 7 brain regions involved in pain modulation. The binding potential reflects receptor density, and changes in binding potential reflects displacement of the radiotracer. The occupancy of sumatriptan was estimated from the 2 scans before and after sumatriptan administration. Results Eight patients with migraine were included in the study; of these participants, 7 (87%) were women. The mean (SD) age of participants on study day 1 was 29.5 (9.2) years and on study day 2 was 30.0 (8.9) years. Sumatriptan was associated with statistically significantly reduced 5-HT1B receptor binding across pain-modulating regions (mean [SD] binding potential, 1.20 [0.20] vs 1.02 [0.22]; P = .001), corresponding to a mean (SD) drug occupancy rate of 16.0% (5.3%). Furthermore, during migraine attacks, as compared with outside of attacks, 5-HT1B receptor binding was statistically significantly associated with reduced in pain-modulating regions (mean [SD] binding potential, 1.36 [0.22] vs 1.20 [0.20]; P = .02). Conclusions and Relevance Treatment with sumatriptan during migraine attacks appeared to be associated with a decrease in 5-HT1B receptor binding, a finding that is most likely associated with the binding of sumatriptan to central 5-HT1B receptors, but the contribution of ongoing cerebral serotonin release to the lower binding cannot be excluded; the migraine attack-associated decrease in binding could indicate that migraine attacks are associated with increases in endogenous serotonin.
Collapse
Affiliation(s)
- Marie Deen
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anders Hougaard
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Agnete Dyssegaard
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Messoud Ashina
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
7
|
Sander CY, Hansen HD, Wey HY. Advances in simultaneous PET/MR for imaging neuroreceptor function. J Cereb Blood Flow Metab 2020; 40:1148-1166. [PMID: 32169011 PMCID: PMC7238372 DOI: 10.1177/0271678x20910038] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hybrid imaging using PET/MRI has emerged as a platform for elucidating novel neurobiology, molecular and functional changes in disease, and responses to physiological or pharmacological interventions. For the central nervous system, PET/MRI has provided insights into biochemical processes, linking selective molecular targets and distributed brain function. This review highlights several examples that leverage the strengths of simultaneous PET/MRI, which includes measuring the perturbation of multi-modal imaging signals on dynamic timescales during pharmacological challenges, physiological interventions or behavioral tasks. We discuss important considerations for the experimental design of dynamic PET/MRI studies and data analysis approaches for comparing and quantifying simultaneous PET/MRI data. The primary focus of this review is on functional PET/MRI studies of neurotransmitter and receptor systems, with an emphasis on the dopamine, opioid, serotonin and glutamate systems as molecular neuromodulators. In this context, we provide an overview of studies that employ interventions to alter the activity of neuroreceptors or the release of neurotransmitters. Overall, we emphasize how the synergistic use of simultaneous PET/MRI with appropriate study design and interventions has the potential to expand our knowledge about the molecular and functional dynamics of the living human brain. Finally, we give an outlook on the future opportunities for simultaneous PET/MRI.
Collapse
Affiliation(s)
- Christin Y Sander
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, MA, USA
| | - Hanne D Hansen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, MA, USA.,Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Hsiao-Ying Wey
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, MA, USA
| |
Collapse
|
8
|
Holland PR, Sureda-Gibert P, Vila-Pueyo M. Rapid uptake of sumatriptan into the brain: An ongoing question of blood-brain barrier permeability. Cephalalgia 2020; 40:327-329. [PMID: 32000507 PMCID: PMC7605048 DOI: 10.1177/0333102420905131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Philip R Holland
- Headache Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paula Sureda-Gibert
- Headache Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Marta Vila-Pueyo
- Headache Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| |
Collapse
|
9
|
A Survey of Molecular Imaging of Opioid Receptors. Molecules 2019; 24:molecules24224190. [PMID: 31752279 PMCID: PMC6891617 DOI: 10.3390/molecules24224190] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 01/09/2023] Open
Abstract
The discovery of endogenous peptide ligands for morphine binding sites occurred in parallel with the identification of three subclasses of opioid receptor (OR), traditionally designated as μ, δ, and κ, along with the more recently defined opioid-receptor-like (ORL1) receptor. Early efforts in opioid receptor radiochemistry focused on the structure of the prototype agonist ligand, morphine, although N-[methyl-11C]morphine, -codeine and -heroin did not show significant binding in vivo. [11C]Diprenorphine ([11C]DPN), an orvinol type, non-selective OR antagonist ligand, was among the first successful PET tracers for molecular brain imaging, but has been largely supplanted in research studies by the μ-preferring agonist [11C]carfentanil ([11C]Caf). These two tracers have the property of being displaceable by endogenous opioid peptides in living brain, thus potentially serving in a competition-binding model. Indeed, many clinical PET studies with [11C]DPN or [11C]Caf affirm the release of endogenous opioids in response to painful stimuli. Numerous other PET studies implicate μ-OR signaling in aspects of human personality and vulnerability to drug dependence, but there have been very few clinical PET studies of μORs in neurological disorders. Tracers based on naltrindole, a non-peptide antagonist of the δ-preferring endogenous opioid enkephalin, have been used in PET studies of δORs, and [11C]GR103545 is validated for studies of κORs. Structures such as [11C]NOP-1A show selective binding at ORL-1 receptors in living brain. However, there is scant documentation of δ-, κ-, or ORL1 receptors in healthy human brain or in neurological and psychiatric disorders; here, clinical PET research must catch up with recent progress in radiopharmaceutical chemistry.
Collapse
|
10
|
Teklezgi BG, Pamreddy A, Baijnath S, Kruger HG, Naicker T, Gopal ND, Govender T. Time-dependent regional brain distribution of methadone and naltrexone in the treatment of opioid addiction. Addict Biol 2019; 24:438-446. [PMID: 29441714 DOI: 10.1111/adb.12609] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/01/2017] [Accepted: 01/17/2018] [Indexed: 12/15/2022]
Abstract
Opioid addiction is a serious public health concern with severe health and social implications; therefore, extensive therapeutic efforts are required to keep users drug free. The two main pharmacological interventions, in the treatment of addiction, involve management with methadone an mu (μ)-opioid agonist and treatment with naltrexone, μ-opioid, kappa (κ)-opioid and delta (δ)-opioid antagonist. MET and NAL are believed to help individuals to derive maximum benefit from treatment and undergo a full recovery. The aim of this study was to determine the localization and distribution of MET and NAL, over a 24-hour period in rodent brain, in order to investigate the differences in their respective regional brain distributions. This would provide a better understanding of the role of each individual drug in the treatment of addiction, especially NAL, whose efficacy is controversial. Tissue distribution was determined by using mass spectrometric imaging (MSI), in combination with quantification via liquid chromatography tandem mass spectrometry. MSI image analysis showed that MET was highly localized in the striatal and hippocampal regions, including the nucleus caudate, putamen and the upper cortex. NAL was distributed with high intensities in the mesocorticolimbic system including areas of the cortex, caudate putamen and ventral pallidum regions. Our results demonstrate that MET and NAL are highly localized in the brain regions with a high density of μ-receptors, the primary sites of heroin binding. These areas are strongly implicated in the development of addiction and are the major pathways that mediate brain stimulation during reward.
Collapse
Affiliation(s)
- Belin G. Teklezgi
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Annapurna Pamreddy
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Nirmala D. Gopal
- Department of CriminologyUniversity of KwaZulu‐Natal South Africa
| | | |
Collapse
|
11
|
Thompson SJ, Pitcher MH, Stone LS, Tarum F, Niu G, Chen X, Kiesewetter DO, Schweinhardt P, Bushnell MC. Chronic neuropathic pain reduces opioid receptor availability with associated anhedonia in rat. Pain 2019; 159:1856-1866. [PMID: 29794614 PMCID: PMC6095806 DOI: 10.1097/j.pain.0000000000001282] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Supplemental Digital Content is Available in the Text. Chronic pain reduces opioid receptor expression in the rat striatum, where the correlation between receptor expression and anhedonia may represent a molecular substrate for comorbid depression. The opioid system plays a critical role in both the experience and management of pain. Although acute activation of the opioid system can lead to pain relief, the effects of chronic pain on the opioid system remain opaque. Cross-sectional positron emission tomography (PET) studies show reduced availability of brain opioid receptors in patients with chronic pain but are unable to (1) determine whether these changes are due to the chronic pain itself or due to preexisting or medication-induced differences in the endogenous opioid system, and (2) identify the neurobiological substrate of reduced opioid receptor availability. We investigated these possibilities using a well-controlled longitudinal study design in rat. Using [18F]-FDPN-PET in either sham rats (n = 17) or spared nerve injury rats (n = 17), we confirmed reduced opioid receptor availability in the insula, caudate–putamen, and motor cortex of nerve injured rats 3 months after surgery, indicating that painful neuropathy altered the endogenous opioid system. Immunohistochemistry showed reduced expression of the mu-opioid receptor, MOR1, in the caudate–putamen and insula. Neither the opioid peptide enkephalin nor the neuronal marker NeuN differed between groups. In nerve-injured animals, sucrose preference, a measure of anhedonia/depression-like behavior, positively correlated with PET opioid receptor availability and MOR1-immunoreactivity in the caudate–putamen. These findings provide new evidence that the altered supraspinal opioid receptor availability observed in human patients with chronic pain may be a direct result of chronic pain. Moreover, reduced opioid receptor availability seems to reflect decreased receptor expression, which may contribute to pain-induced depression.
Collapse
Affiliation(s)
- Scott J Thompson
- Division of Intramural Research, National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States.,Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Mark H Pitcher
- Division of Intramural Research, National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Laura S Stone
- Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Farid Tarum
- Division of Intramural Research, National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Gang Niu
- Division of Intramural Research, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
| | - Xiaoyuan Chen
- Division of Intramural Research, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
| | - Dale O Kiesewetter
- Division of Intramural Research, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
| | | | - M Catherine Bushnell
- Division of Intramural Research, National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
12
|
Xu Y, Li Z. Imaging metabotropic glutamate receptor system: Application of positron emission tomography technology in drug development. Med Res Rev 2019; 39:1892-1922. [DOI: 10.1002/med.21566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Youwen Xu
- Independent Consultant and Contractor, Radiopharmaceutical Development, Validation and Bio-Application; Philadelphia Pennsylvania
| | - Zizhong Li
- Pharmaceutical Research and Development, SOFIE Biosciences; Somerset New Jersey
| |
Collapse
|
13
|
Shalgunov V, van Waarde A, Booij J, Michel MC, Dierckx RAJO, Elsinga PH. Hunting for the high-affinity state of G-protein-coupled receptors with agonist tracers: Theoretical and practical considerations for positron emission tomography imaging. Med Res Rev 2018; 39:1014-1052. [PMID: 30450619 PMCID: PMC6587759 DOI: 10.1002/med.21552] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/02/2018] [Accepted: 10/19/2018] [Indexed: 12/15/2022]
Abstract
The concept of the high‐affinity state postulates that a certain subset of G‐protein‐coupled receptors is primarily responsible for receptor signaling in the living brain. Assessing the abundance of this subset is thus potentially highly relevant for studies concerning the responses of neurotransmission to pharmacological or physiological stimuli and the dysregulation of neurotransmission in neurological or psychiatric disorders. The high‐affinity state is preferentially recognized by agonists in vitro. For this reason, agonist tracers have been developed as tools for the noninvasive imaging of the high‐affinity state with positron emission tomography (PET). This review provides an overview of agonist tracers that have been developed for PET imaging of the brain, and the experimental paradigms that have been developed for the estimation of the relative abundance of receptors configured in the high‐affinity state. Agonist tracers appear to be more sensitive to endogenous neurotransmitter challenge than antagonists, as was originally expected. However, other expectations regarding agonist tracers have not been fulfilled. Potential reasons for difficulties in detecting the high‐affinity state in vivo are discussed.
Collapse
Affiliation(s)
- Vladimir Shalgunov
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan Booij
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Nuclear Medicine, Ghent University, University Hospital, Ghent, Belgium
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
14
|
Rafique W, Khanapur S, Spilhaug MM, Riss PJ. Reaching out for Sensitive Evaluation of the Mu Opioid Receptor in Vivo: Positron Emission Tomography Imaging of the Agonist [ 11C]AH7921. ACS Chem Neurosci 2017; 8:1847-1852. [PMID: 28590714 DOI: 10.1021/acschemneuro.7b00075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Imaging of the mu opioid receptor (MOR) availability with positron emission tomography (PET) is a pertinent challenge in Neuroscience. Both, regulation of receptor expression and occupancy by endogeneous opioids play into cognitive and behavioral phenotypes of healthy function and disease. Receptor expression in the active and inactive states can be measured using high affinity radioagonist and radioantagonist PET tracers, respectively. Occupancy assessment requires radioligands showing competitive and reversible binding with moderate affinity to the MOR, which may lead to physical extinction of the receptor specific signal in vivo. We investigated a moderately potent, selective MOR agonist in rat to test if a radiotracer design paradigm tailored to competition with endogeneous opioids leads to viable imaging results. The benzamide 3,4-dichlorobenzenecarboxylic acid (dimethylamino)cyclohexyl)methyl amide (AH-7921, 1) was synthesized and characterized in rat brain using autoradiography and positron emission tomography. Compound 1 was found to activate with low nanomolar potency the MOR and to a lesser extent KOR as a full agonist. Concentration dependent binding studies with agonist and antagonist radioligands were conducted to assess competition behavior and obtain inhibition constants. Kinetic analysis of 3,4-dichlorobenzene[11C]carboxylic acid (dimethylamino)cyclohexyl)methyl amide binding in rat brain resulted in low but reproducible binding potential in the thalamus (0.8 ± 0.1). A radioactive metabolite was detected in brain (17%, after 15 min). Nonetheless, we conclude that quantitative imaging of MOR availability is possible when using a moderate affinity radiotracer.
Collapse
Affiliation(s)
- Waqas Rafique
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
| | - Shivashankar Khanapur
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
- Radboud Translational Medicine BV, Geert Grooteplein
21, Postbus 9101, 6500HB Nijmegen, Netherland
| | - Mona M. Spilhaug
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
| | - Patrick J. Riss
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
- Klinik
for Kirurgi og Nevrofag, Oslo Universitets Sykehus HF−Rikshospitalet, Postboks
4950 Nydalen, 0424 Oslo, Norway
- Norsk Medisinsk Syklotronsenter AS, Gaustad, Postboks 4950 Nydalen, 0424 Oslo, Norway
- Radboud Translational Medicine BV, Geert Grooteplein
21, Postbus 9101, 6500HB Nijmegen, Netherland
| |
Collapse
|
15
|
Vicente-Sanchez A, Segura L, Pradhan AA. The delta opioid receptor tool box. Neuroscience 2016; 338:145-159. [PMID: 27349452 DOI: 10.1016/j.neuroscience.2016.06.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 05/29/2016] [Accepted: 06/16/2016] [Indexed: 12/14/2022]
Abstract
In recent years, the delta opioid receptor has attracted increasing interest as a target for the treatment of chronic pain and emotional disorders. Due to their therapeutic potential, numerous tools have been developed to study the delta opioid receptor from both a molecular and a functional perspective. This review summarizes the most commonly available tools, with an emphasis on their use and limitations. Here, we describe (1) the cell-based assays used to study the delta opioid receptor. (2) The features of several delta opioid receptor ligands, including peptide and non-peptide drugs. (3) The existing approaches to detect delta opioid receptors in fixed tissue, and debates that surround these techniques. (4) Behavioral assays used to study the in vivo effects of delta opioid receptor agonists; including locomotor stimulation and convulsions that are induced by some ligands, but not others. (5) The characterization of genetically modified mice used specifically to study the delta opioid receptor. Overall, this review aims to provide a guideline for the use of these tools with the final goal of increasing our understanding of delta opioid receptor physiology.
Collapse
Affiliation(s)
| | - Laura Segura
- Department of Psychiatry, University of Illinois at Chicago, United States
| | - Amynah A Pradhan
- Department of Psychiatry, University of Illinois at Chicago, United States.
| |
Collapse
|
16
|
Lingford-Hughes A. Substitution treatment in addiction: there is more than one way.. Addiction 2016; 111:776-7. [PMID: 26913830 DOI: 10.1111/add.13288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 12/21/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Anne Lingford-Hughes
- Imperial College London, Neuropsychopharmacology Unit, Department of Medicine, Burlington Danes Building Hammersmith campus 160 Du Cane Road, London, W12 0NN, UK.
| |
Collapse
|
17
|
Quelch DR, Katsouri L, Nutt DJ, Parker CA, Tyacke RJ. Imaging endogenous opioid peptide release with [11C]carfentanil and [3H]diprenorphine: influence of agonist-induced internalization. J Cereb Blood Flow Metab 2014; 34:1604-12. [PMID: 25005876 PMCID: PMC4269718 DOI: 10.1038/jcbfm.2014.117] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/11/2014] [Indexed: 01/23/2023]
Abstract
Understanding the cellular processes underpinning the changes in binding observed during positron emission tomography neurotransmitter release studies may aid translation of these methodologies to other neurotransmitter systems. We compared the sensitivities of opioid receptor radioligands, carfentanil, and diprenorphine, to amphetamine-induced endogenous opioid peptide (EOP) release and methadone administration in the rat. We also investigated whether agonist-induced internalization was involved in reductions in observed binding using subcellular fractionation and confocal microscopy. After radioligand administration, significant reductions in [(11)C]carfentanil, but not [(3)H]diprenorphine, uptake were observed after methadone and amphetamine pretreatment. Subcellular fractionation and in vitro radioligand binding studies showed that amphetamine pretreatment only decreased total [(11)C]carfentanil binding. In vitro saturation binding studies conducted in buffers representative of the internalization pathway suggested that μ-receptors are significantly less able to bind the radioligands in endosomal compared with extracellular compartments. Finally, a significant increase in μ-receptor-early endosome co-localization in the hypothalamus was observed after amphetamine and methadone treatment using double-labeling confocal microscopy, with no changes in δ- or κ-receptor co-localization. These data indicate carfentanil may be superior to diprenorphine when imaging EOP release in vivo, and that alterations in the ability to bind internalized receptors may be a predictor of ligand sensitivity to endogenous neurotransmitter release.
Collapse
Affiliation(s)
- Darren R Quelch
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
| | - Loukia Katsouri
- Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - David J Nutt
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
| | - Christine A Parker
- 1] Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK [2] Global Imaging Unit, GlaxoSmithKline, Stevenage, UK
| | - Robin J Tyacke
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
| |
Collapse
|
18
|
Mandeville JB, Liu CH, Vanduffel W, Marota JJA, Jenkins BG. Data collection and analysis strategies for phMRI. Neuropharmacology 2014; 84:65-78. [PMID: 24613447 PMCID: PMC4058391 DOI: 10.1016/j.neuropharm.2014.02.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 02/07/2014] [Accepted: 02/25/2014] [Indexed: 12/24/2022]
Abstract
Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed "phMRI". The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. This article is part of the Special Issue Section entitled 'Neuroimaging in Neuropharmacology'.
Collapse
Affiliation(s)
- Joseph B Mandeville
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.
| | - Christina H Liu
- National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD 20817, USA
| | - Wim Vanduffel
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - John J A Marota
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Bruce G Jenkins
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA
| |
Collapse
|
19
|
Schoultz BW, Hjørnevik T, Reed BJ, Marton J, Coello CS, Willoch F, Henriksen G. Synthesis and evaluation of three structurally related ¹⁸F-labeled orvinols of different intrinsic activities: 6-O-[¹⁸F]fluoroethyl-diprenorphine ([¹⁸F]FDPN), 6-O-[¹⁸F]fluoroethyl-buprenorphine ([¹⁸F]FBPN), and 6-O-[¹⁸F]fluoroethyl-phenethyl-orvinol ([¹⁸F]FPEO). J Med Chem 2014; 57:5464-9. [PMID: 24933507 DOI: 10.1021/jm500503k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We report the synthesis and biological evaluation of a triplet of 6-O-(18)F-fluoroethylated derivatives of structurally related orvinols that span across the full range of intrinsic activities, the antagonist diprenorphine, the partial agonist buprenorphine, and the full agonist phenethyl-orvinol. [(18)F]fluoroethyl-diprenorphine, [(18)F]fluoroethyl-buprenorphine, and [(18)F]fluoroethyl-phenethyl-orvinol were prepared in high yields and quality from their 6-O-desmethyl-precursors. The results indicate suitable properties of the three 6-O-(18)F-fluoroethylated derivatives as functional analogues to the native carbon-11 labeled versions with similar pharmacological properties.
Collapse
Affiliation(s)
- Bent W Schoultz
- Department of Chemistry, University of Oslo , P.O. Box 1033, Blindern, N-0315 Oslo, Norway
| | | | | | | | | | | | | |
Collapse
|
20
|
Bye A. Experiments with cocaine and heroin addicts—are they predictive? Curr Opin Pharmacol 2014; 14:74-80. [DOI: 10.1016/j.coph.2013.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 11/27/2013] [Indexed: 01/11/2023]
|
21
|
Lee MC, Wanigasekera V, Tracey I. Imaging opioid analgesia in the human brain and its potential relevance for understanding opioid use in chronic pain. Neuropharmacology 2013; 84:123-30. [PMID: 23891639 PMCID: PMC4067746 DOI: 10.1016/j.neuropharm.2013.06.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/19/2013] [Accepted: 06/27/2013] [Indexed: 01/09/2023]
Abstract
Opioids play an important role for the management of acute pain and in palliative care. The role of long-term opioid therapy in chronic non-malignant pain remains unclear and is the focus of much clinical research. There are concerns regarding analgesic tolerance, paradoxical pain and issues with dependence that can occur with chronic opioid use in the susceptible patient. In this review, we discuss how far human neuroimaging research has come in providing a mechanistic understanding of pain relief provided by opioids, and suggest avenues for further studies that are relevant to the management of chronic pain with opioids. This article is part of the Special Issue Section entitled ‘Neuroimaging in Neuropharmacology’. Brain mechanisms are crucial to opioid analgesia in humans. Opioids can have a direct effect on brain mechanisms for pain perception. Opioids can also engage descending inhibition of spinal nociception. Drug-induced tolerance, dependence and paradoxical pain may limit chronic opioid analgesic therapy.
Collapse
Affiliation(s)
- Michael C Lee
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom.
| | - Vishvarani Wanigasekera
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom
| | - Irene Tracey
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom.
| |
Collapse
|
22
|
Modeling of PET data in CNS drug discovery and development. J Pharmacokinet Pharmacodyn 2013; 40:267-79. [PMID: 23660778 DOI: 10.1007/s10928-013-9320-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 04/26/2013] [Indexed: 12/22/2022]
Abstract
Positron emission tomography (PET) is increasingly used in drug discovery and development for evaluation of CNS drug disposition and for studies of disease biomarkers to monitor drug effects on brain pathology. The quantitative analysis of PET data is based on kinetic modeling of radioactivity concentrations in plasma and brain tissue compartments. A number of quantitative methods of analysis have been developed that allow the determination of parameters describing drug pharmacokinetics and interaction with target binding sites in the brain. The optimal method of quantification depends on the properties of the radiolabeled drug or radioligand and the binding site studied. We here review the most frequently used methods for quantification of PET data in relation to CNS drug discovery and development. The utility of PET kinetic modeling in the development of novel CNS drugs is illustrated by examples from studies of the brain kinetic properties of radiolabeled drug molecules.
Collapse
|
23
|
Moody DE. Metabolic and toxicological considerations of the opioid replacement therapy and analgesic drugs: methadone and buprenorphine. Expert Opin Drug Metab Toxicol 2013; 9:675-97. [PMID: 23537174 DOI: 10.1517/17425255.2013.783567] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Methadone and buprenorphine are maintenance replacement therapies for opioid dependence; they are also used for pain management. Methadone and buprenorphine (to a lesser extent) have seen sharp increases in mortality associated with their use. They have distinct routes of metabolism (mostly cytochrome P450 dependent), and distinct pharmacologic activity of metabolites. As such, metabolism may play a role in differences in their toxicity. AREAS COVERED This article reviews peer-reviewed literature obtained from PubMed searches and literature referenced within. The review considers first an overview of drug use and mortality over the past decade. It then provides extensive detail on the in vitro and in vivo human metabolism of methadone and buprenorphine. Using both human and experimental animal studies it then presents the pharmacodynamic activity of parent drug and metabolites at the mu-opioid receptor, as P-glycoprotein substrates and plasma/brain concentration ratios, and activity at the hERG K(+) channel. Lessons learned from drug interaction studies in humans are then examined in an attempt to bring together the combined information. EXPERT OPINION The use and misuse of these drugs contributes to the epidemic in opioid-associated mortalities. A better understanding of metabolism-, transport- and co-medication-induced changes will contribute to their safer use.
Collapse
Affiliation(s)
- David E Moody
- University of Utah College of Pharmacy, Department of Pharmacology and Toxicology, Salt Lake City, UT 84108, USA.
| |
Collapse
|
24
|
Varnäs K, Jučaitė A, McCarthy DJ, Stenkrona P, Nord M, Halldin C, Farde L, Kanes S. A PET study with [11C]AZ10419369 to determine brain 5-HT1B receptor occupancy of zolmitriptan in healthy male volunteers. Cephalalgia 2013; 33:853-60. [DOI: 10.1177/0333102413476372] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aim To investigate the occupancy at brain 5-hydroxytryptamine (5-HT) 1B receptors in human subjects after administration of the antimigraine drug zolmitriptan. Methods Positron emission tomography (PET) studies were undertaken using the radioligand [11C]AZ10419369 in eight control subjects at baseline and after administration of zolmitriptan orodispersible tablets. The subjects were examined after two consecutive administrations of 10 mg zolmitriptan, approximately 1 week apart. Two of the subjects were subsequently examined after administration of 5 mg zolmitriptan. One week after the last administration of zolmitriptan five of the subjects underwent additional PET measurements without drug pretreatment. Results After administration of 10 mg zolmitriptan, mean receptor occupancy was 4–5%. No consistent changes in 5-HT1B receptor binding were observed for subjects who received 5 mg zolmitriptan. There was a statistically significant negative relationship between binding potential ( BPND) and plasma concentration of zolmitriptan and the active metabolite 183C91, respectively. All of the five subjects who were examined 1 week after dosing with zolmitriptan showed higher BPND post drug administration compared with baseline. Conclusion This is the first demonstration of CNS 5-HT1B receptor occupancy of a triptan. The findings are consistent with the low receptor occupancy previously reported in PET studies with agonists at other G protein coupled receptors.
Collapse
Affiliation(s)
- Katarina Varnäs
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
| | - Aurelija Jučaitė
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
- AstraZeneca R&D, Clinical Development, Sweden
| | | | - Per Stenkrona
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
| | - Magdalena Nord
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
| | - Christer Halldin
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
| | - Lars Farde
- Karolinska Institutet, Department of Clinical Neuroscience, Sweden
- AstraZeneca iMed CNS/P, Sweden
| | | |
Collapse
|
25
|
Lee MC, Wanigasekera V, Tracey I. Imaging opioid analgesia in the human brain. TRENDS IN ANAESTHESIA AND CRITICAL CARE 2012. [DOI: 10.1016/j.tacc.2012.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Abstract
The early developments of brain positron emission tomography (PET), including the methodological advances that have driven progress, are outlined. The considerable past achievements of brain PET have been summarized in collaboration with contributing experts in specific clinical applications including cerebrovascular disease, movement disorders, dementia, epilepsy, schizophrenia, addiction, depression and anxiety, brain tumors, drug development, and the normal healthy brain. Despite a history of improving methodology and considerable achievements, brain PET research activity is not growing and appears to have diminished. Assessments of the reasons for decline are presented and strategies proposed for reinvigorating brain PET research. Central to this is widening the access to advanced PET procedures through the introduction of lower cost cyclotron and radiochemistry technologies. The support and expertize of the existing major PET centers, and the recruitment of new biologists, bio-mathematicians and chemists to the field would be important for such a revival. New future applications need to be identified, the scope of targets imaged broadened, and the developed expertize exploited in other areas of medical research. Such reinvigoration of the field would enable PET to continue making significant contributions to advance the understanding of the normal and diseased brain and support the development of advanced treatments.
Collapse
Affiliation(s)
- Terry Jones
- PET Research Advisory Company, 8 Prestbury Road, Wilmslow, Cheshire SK9 2LJ, UK.
| | | | | |
Collapse
|
27
|
Hou H, Tian M, Zhang H. Positron emission tomography molecular imaging of dopaminergic system in drug addiction. Anat Rec (Hoboken) 2012; 295:722-33. [PMID: 22467195 DOI: 10.1002/ar.22457] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 03/01/2012] [Indexed: 12/27/2022]
Abstract
Dopamine (DA) is involved in drug reinforcement, but its role in drug addiction remains unclear. Positron emission tomography (PET) is the first technology used for the direct measurement of components of the dopaminergic system in the living human brain. In this article, we reviewed the major findings of PET imaging studies on the involvement of DA in drug addiction, especially in heroin addiction. Furthermore, we summarized PET radiotracers that have been used to study the role of DA in drug addiction. To investigate presynaptic function in drug addiction, PET tracers have been developed to measure DA synthesis and transport. For the investigation of postsynaptic function, several radioligands targeting dopamine one (D1) receptor and dopamine two (D2) receptor are extensively used in PET imaging studies. Moreover, we also summarized the PET imaging findings of heroin addiction studies, including heroin-induced DA increases and the reinforcement, role of DA in the long-term effects of heroin abuse, DA and vulnerability to heroin abuse and the treatment implications. PET imaging studies have corroborated the role of DA in drug addiction and increase our understanding the mechanism of drug addiction.
Collapse
Affiliation(s)
- Haifeng Hou
- Department of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | | | | |
Collapse
|
28
|
Reid AG, Lingford-Hughes AR, Cancela LM, Kalivas PW. Substance abuse disorders. HANDBOOK OF CLINICAL NEUROLOGY 2012; 106:419-31. [PMID: 22608635 DOI: 10.1016/b978-0-444-52002-9.00024-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
29
|
Hassan HE, Myers AL, Coop A, Eddington ND. Differential involvement of P-glycoprotein (ABCB1) in permeability, tissue distribution, and antinociceptive activity of methadone, buprenorphine, and diprenorphine: in vitro and in vivo evaluation. J Pharm Sci 2010; 98:4928-40. [PMID: 19370547 DOI: 10.1002/jps.21770] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Conclusions based on either in vitro or in vivo approach to evaluate the P-gp affinity status of opioids may be misleading. For example, in vitro studies indicated that fentanyl is a P-gp inhibitor while in vivo studies indicated that it is a P-gp substrate. Quite the opposite was evident for meperidine. The objective of this study was to evaluate the P-gp affinity status of methadone, buprenorphine and diprenorphine to predict P-gp-mediated drug-drug interactions and to determine a better candidate for management of opioid dependence. Two in vitro (P-gp ATPase and monolayer efflux) assays and two in vivo (tissue distribution and antinociceptive evaluation in mdr1a/b (-/-) mice) assays were used. Methadone stimulated the P-gp ATPase activity only at higher concentrations, while verapamil and GF120918 inhibited its efflux (p < 0.05). The brain distribution and antinociceptive activity of methadone were enhanced (p < 0.05) in P-gp knockout mice. Conversely, buprenorphine and diprenorphine were negative in all assays. P-gp can affect the PK/PD of methadone, but not buprenorphine or diprenorphine. Our report is in favor of buprenorphine over methadone for management of opioid dependence. Buprenorphine most likely is not a P-gp substrate and concerns regarding P-gp-mediated drug-drug interaction are not expected.
Collapse
Affiliation(s)
- Hazem E Hassan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA
| | | | | | | |
Collapse
|
30
|
Abstract
Psychopharmacology is a powerful approach to the treatment of many psychiatric disorders. In this article I discuss the conceptual and practical issues in relation to the use of mu opioid receptor agonist, antagonist and partial agonist drugs in the treatment of opioid addiction, as this is one therapeutic area where all three types of agents are currently available. The choice of pharmacological agent is largely determined by patient profile, existence of ongoing drug misuse, and the kinetics of the drugs available. These principles, however, can be applied to other disorders as and when other pharmacological approaches become refined in these areas.
Collapse
Affiliation(s)
- David J Nutt
- Division of Experimental Medicine, Imperial College London, Hammersmith Hospital, London, UK.
| |
Collapse
|
31
|
Lingford-Hughes A, Watson B, Kalk N, Reid A. Neuropharmacology of addiction and how it informs treatment. Br Med Bull 2010; 96:93-110. [PMID: 21044987 DOI: 10.1093/bmb/ldq032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Our knowledge about the neuropharmacology of addiction is increasing and is leading to more informed development of pharmacotherapy. Although the dopaminergic mesolimbic system plays a central role in 'liking', reward and motivation, medications directly targeting it have not proved a very fruitful approach to treating addictions. A review of the literature was performed to find articles relating current and developing pharmacological treatments in the clinic and their underlying neuropharmacology. We focussed on the most common addictions for which pharmacology plays an important role. By characterizing what neurotransmitters modulate this dopaminergic pathway, new medications are now in the clinic and being successfully applied to treat a variety of addictions. In addition to modulating this reward pathway, alternative approaches in the future will target learning and memory, improving impulse control and decision-making.
Collapse
Affiliation(s)
- Anne Lingford-Hughes
- Department of Experimental Medicine, Imperial College, Burlington Danes Building, Hammersmith Hospital Site, 160 Du Cane Road, London, UK.
| | | | | | | |
Collapse
|
32
|
Marton J, Schoultz BW, Hjørnevik T, Drzezga A, Yousefi BH, Wester HJ, Willoch F, Henriksen G. Synthesis and evaluation of a full-agonist orvinol for PET-imaging of opioid receptors: [11C]PEO. J Med Chem 2009; 52:5586-9. [PMID: 19694469 DOI: 10.1021/jm900892x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Antagonist radiotracers have shown only a low sensitivity for detecting competition from high-efficacy agonists at opioid receptors (ORs) in vivo. We report that [(11)C]PEO binds with high affinity to mu and kappa-opioid receptors, is a full agonist, and concentrates in brain regions of rats with a high density of the mu-OR after intravenous injection. Blocking studies with mu and kappa-OR selective compounds demonstrated that the binding of [(11)C]PEO is saturable and selective to the mu-OR in rat brain.
Collapse
Affiliation(s)
- János Marton
- ABX Advanced Biochemical Compounds, Biomedizinische Forschungsreagenzien GmbH, Radeberg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Grimwood S, Hartig PR. Target site occupancy: Emerging generalizations from clinical and preclinical studies. Pharmacol Ther 2009; 122:281-301. [DOI: 10.1016/j.pharmthera.2009.03.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 01/17/2023]
|
34
|
Nutt D, Lingford-Hughes A. Addiction: the clinical interface. Br J Pharmacol 2008; 154:397-405. [PMID: 18414399 PMCID: PMC2442452 DOI: 10.1038/bjp.2008.101] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 02/29/2008] [Accepted: 03/03/2008] [Indexed: 11/09/2022] Open
Abstract
This review gives an overview of what we see as the key issues in the human pharmacology of drugs of addiction. We review evidence of efficacy and mechanisms by which treatments act and point out areas where further work is needed. The role of agonist, partial agonist and antagonist treatments for opioid addiction is detailed and current issues relating to the mechanisms of actions at the receptor level and how to improve on compliance are discussed. The role of the brain dopamine and GABA-A systems in drug dependence is considered in relation to the growing pharmacology of these receptor systems, and the current status of novel preclinical targets reviewed. In addition, the different roles of dynamic and kinetic factors in both addiction and its treatment are discussed in relation to the underlying neuropharmacology of the disorders as defined from human and preclinical studies. Finally, some pointers to future research and especially to drug development by pharma are elaborated.
Collapse
Affiliation(s)
- D Nutt
- Psychopharmacology Unit, University of Bristol, Bristol, UK.
| | | |
Collapse
|
35
|
Shi J, Zhao LY, Copersino ML, Fang YX, Chen Y, Tian J, Deng Y, Shuai Y, Jin J, Lu L. PET imaging of dopamine transporter and drug craving during methadone maintenance treatment and after prolonged abstinence in heroin users. Eur J Pharmacol 2008; 579:160-6. [DOI: 10.1016/j.ejphar.2007.09.042] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 09/23/2007] [Accepted: 09/27/2007] [Indexed: 10/22/2022]
|
36
|
Abstract
In vivo functional imaging by means of positron emission tomography (PET) is the sole method for providing a quantitative measurement of mu-, kappa and delta-opioid receptor-mediated signalling in the central nervous system. During the last two decades, measurements of changes to the regional brain opioidergic neuronal activation--mediated by endogenously produced opioid peptides, or exogenously administered opioid drugs--have been conducted in numerous chronic pain conditions, in epilepsy, as well as by stimulant- and opioidergic drugs. Although several PET-tracers have been used clinically for depiction and quantification of the opioid receptors changes, the underlying mechanisms for regulation of changes to the availability of opioid receptors are still unclear. After a presentation of the general signalling mechanisms of the opioid receptor system relevant for PET, a critical survey of the pharmacological properties of some currently available PET-tracers is presented. Clinical studies performed with different PET ligands are also reviewed and the compound-dependent findings are summarized. An outlook is given concluding with the tailoring of tracer properties, in order to facilitate for a selective addressment of dynamic changes to the availability of a single subclass, in combination with an optimization of the quantification framework are essentials for further progress in the field of in vivo opioid receptor imaging.
Collapse
Affiliation(s)
- Gjermund Henriksen
- Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, D-81675 München, Germany
| | | |
Collapse
|
37
|
Abstract
Many breakthrough scientific discoveries have been made using opioid imaging. Developments include the application of ever higher resolution whole-brain positron emission tomography (PET) scanners, the availability of several radioligands, the combination of PET with advanced structural imaging, advances in modeling macroparameters of PET ligand binding, and large-scale statistical analysis of imaging datasets. Suitable single-photon emission computed tomography (SPECT) tracers are lacking, but with the increase in the number of available PET (or PET/CT) cameras and cyclotrons thanks to the clinical successes of PET in oncology, PET may become widespread enough to overcome this. In the coming decade, there should be a more widespread application of the available techniques to patients and an impact in clinical medicine.
Collapse
Affiliation(s)
- Alexander Hammers
- Department of Clinical Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Hammersmith Hospital, DuCane Rd., London W12 0NN, UK; Epilepsy Group, MRC Clinical Sciences Centre, Room 243, Cyclotron Building, Hammersmith Hospital, DuCane Rd., London W12 0NN, UK; Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
| | - Anne Lingford-Hughes
- Academic Unit of Psychiatry, University of Bristol, Cotham House, Cotham Hill, Bristol BS6 6JL, UK; Imaging Department, Division of Clinical Sciences, Faculty of Medicine, Hammersmith Hospital, Imperial College London, DuCane Rd., London W12 0NN, UK
| |
Collapse
|
38
|
Miyawaki I. [Drug dependence study]. Nihon Yakurigaku Zasshi 2007; 130:211-5. [PMID: 17878617 DOI: 10.1254/fpj.130.211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
|
39
|
Ersche KD, Sahakian BJ. The neuropsychology of amphetamine and opiate dependence: implications for treatment. Neuropsychol Rev 2007; 17:317-36. [PMID: 17690986 PMCID: PMC3639428 DOI: 10.1007/s11065-007-9033-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 06/22/2007] [Indexed: 01/08/2023]
Abstract
Chronic use of amphetamines and/or opiates has been associated with a wide range of cognitive deficits, involving domains of attention, inhibitory control, planning, decision-making, learning and memory. Although both amphetamine and opiate users show marked impairment in various aspects of cognitive function, the impairment profile is distinctly different according to the substance of abuse. In light of evidence showing that cognitive impairment in drug users has a negative impact on treatment engagement and efficacy, we review substance-specific deficits on executive and memory function, and discuss possibilities to address these during treatment intervention.
Collapse
Affiliation(s)
- Karen D Ersche
- School of Clinical Medicine, Department of Psychiatry, University of Cambridge, Brain Mapping Unit, Box 255, Addenbrooke's Hospital, Cambridge, UK.
| | | |
Collapse
|
40
|
Williams TM, Daglish MRC, Lingford-Hughes A, Taylor LG, Hammers A, Brooks DJ, Grasby P, Myles JS, Nutt DJ. Brain opioid receptor binding in early abstinence from opioid dependence: positron emission tomography study. Br J Psychiatry 2007; 191:63-9. [PMID: 17602127 DOI: 10.1192/bjp.bp.106.031120] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Although opioid receptor function in humans is clearly reduced during opioid dependence, what happens to the receptor in early abstinence is not understood. AIMS This study sought to examine changes in opioid receptor availability in early abstinence from opioid dependence. METHOD Ten people with opioid dependence who had completed in-patient detoxification and 20 healthy controls underwent [11C]-diprenorphine positron emission tomography. Clinical variables were assessed with structured questionnaires. Opioid receptor binding was characterised as the volume of distribution of [11C]-diprenorphine using a template of predefined brain volumes and an exploratory voxel-by-voxel analysis. RESULTS Compared with controls, participants with opioid dependence had increased [11C]-diprenorphine binding in the whole brain and in 15 of the 21 a priori regions studied. CONCLUSIONS This study suggests that opioid receptor binding is increased throughout the brain in early abstinence from dependent opioid use. These data complement the findings in cocaine and alcohol dependence.
Collapse
Affiliation(s)
- Tim M Williams
- Psychopharmacology Unit, University of Bristol, and Bristol Specialist Drug Service, Blackberry Hill Hospital, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Hume SP, Lingford-Hughes AR, Nataf V, Hirani E, Ahmad R, Davies AN, Nutt DJ. Low sensitivity of the positron emission tomography ligand [11C]diprenorphine to agonist opiates. J Pharmacol Exp Ther 2007; 322:661-7. [PMID: 17488881 DOI: 10.1124/jpet.107.121749] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previously, we reported minimal opioid receptor occupancy following a clinical dose of the micro-opioid agonist, methadone, measured in vivo using positron emission tomography (PET) with [(11)C]diprenorphine and subsequently used rats to obtain experimental data in support of a high receptor reserve hypothesis (Melichar et al., 2005). Here, we report on further preclinical studies investigating opioid receptor occupancy with oxycodone (micro- and kappa-receptor agonist), morphine (micro-receptor agonist), and buprenorphine (partial agonist at the micro-receptor and antagonist at the delta- and kappa-receptors), each given at antinociceptive doses. In vivo binding of [(11)C]diprenorphine was not significantly reduced after treatment with the full agonists but was reduced by approximately 90% by buprenorphine. In addition, given that [(11)C]diprenorphine is a non-subtype-specific PET tracer, there was no regional variation that might feasibly be interpreted as due to differences in opioid subtype distribution. The data support minimal competition between the high-efficacy agonists and the non-subtype-selective antagonist radioligand and highlight the limitations of [(11)C]diprenorphine PET to monitor in vivo occupancy. Alternative means may be needed to address clinical issues regarding opioid receptor occupancy that are required to optimize treatment strategies.
Collapse
Affiliation(s)
- Susan P Hume
- Hammersmith Imanet Ltd., Hammersmith Hospital, London, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
42
|
Henriksen G, Willoch F, Talbot PS, Wester HJ. Recent development and potential use of µ- and κ-opioid receptor ligands in positron emission tomography studies. Drug Dev Res 2007. [DOI: 10.1002/ddr.20161] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
43
|
Abstract
This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 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 (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).
Collapse
Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
| | | |
Collapse
|
44
|
Abstract
Many breakthrough scientific discoveries have been made using opioid imaging, particularly in the fields of pain, addiction and epilepsy research. Recent developments include the application of ever higher resolution whole-brain positron emission tomography (PET) scanners, the availability of several radioligands, the combination of PET with advanced structural imaging, advances in modeling macroparameters of PET ligand binding, and large-scale statistical analysis of imaging datasets. Suitable single-photon emission computed tomography (SPECT) tracers are lacking, but with the increase in the number of available PET (or PET/CT) cameras and cyclotrons thanks to the clinical successes of PET in oncology, PET may become widespread enough to overcome this limitation. In the coming decade, we hope to see a more widespread application of the techniques developed in healthy volunteers to patients and more clinical impact of opioid imaging.
Collapse
Affiliation(s)
- Alexander Hammers
- Department of Clinical Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Hammersmith Hospital, DuCane Rd., London W12 0NN, UK.
| | | |
Collapse
|
45
|
Dhawan J, Deng H, Gatley SJ, Makriyannis A, Akinfeleye T, Bruneus M, Dimaio AA, Gifford AN. Evaluation of the in vivo receptor occupancy for the behavioral effects of cannabinoids using a radiolabeled cannabinoid receptor agonist, R-[125/131I]AM2233. Synapse 2006; 60:93-101. [PMID: 16715483 DOI: 10.1002/syn.20277] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
G-protein coupled receptors exist in both high and low agonist affinity conformations, with tracer levels of agonist radioligands preferentially binding to the former. The goal of the present study was to characterize the in vivo binding of the aminoalkyindole-based, CB1 receptor agonist, R-[125/131I]AM2233 ((2-[125/131I]iodo-phenyl)-[1-(1-methyl-piperidin-2-yl-methyl)-1H-indol-3-yl]-methanone), and to use this radiotracer to selectively measure the receptor occupancy by the related CB1 receptor agonist, WIN55212-2, to the agonist-preferring affinity state of the receptor. In mouse locomotor assays, both WIN55212-2 and AM2233 (racemic) produced an approximately 60% reduction in activity at 1 mg/kg, (i.v.) and completely inhibited activity at 3 mg/kg, confirming their agonist nature. In ex vivo autoradiography, preferential uptake of R-[131I]AM2233 was apparent in CB1 receptor-rich areas, including globus pallidus, substantia nigra, striatum, cerebellum, and hippocampus. Overall brain uptake of R-[131I]AM2233 was 1.3% injected activity/g at 5 min in mice. Coinjection of 3 mg/kg (i.v.) SR141716A, a CB1 receptor antagonist, with R-[125I]AM2233 inhibited the radiotracer binding almost to nonspecific levels in the striatum, globus pallidus, and substantia nigra, although residual binding to a non-CB1 receptor remained in the hippocampus. In contrast to the effect of SR141716A, coinjection of 10 mg/kg (i.v.) WIN55212-2, a high dose that produced an immediate and profound immobility and catalepsy in the mice, reduced CB1 receptor-specific binding of R-[125I]AM2233 in CB1 receptor-rich areas by only 21-43%. These observations suggest that the behavioral effects of CB1 receptor agonists are manifested with a relatively small fraction of the agonist-preferring affinity state of the receptor occupied.
Collapse
MESH Headings
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Benzoxazines
- Binding Sites/drug effects
- Binding Sites/physiology
- Binding, Competitive/drug effects
- Binding, Competitive/physiology
- Brain/anatomy & histology
- Brain/drug effects
- Brain/metabolism
- Cannabinoids/metabolism
- Cannabinoids/pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Indoles/metabolism
- Indoles/pharmacology
- Iodine Radioisotopes/metabolism
- Male
- Mice
- Morpholines/metabolism
- Morpholines/pharmacology
- Motor Activity/drug effects
- Motor Activity/physiology
- Naphthalenes/metabolism
- Naphthalenes/pharmacology
- Neurons/drug effects
- Neurons/metabolism
- Piperidines/metabolism
- Piperidines/pharmacology
- Protein Conformation/drug effects
- Pyrazoles/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Rimonabant
Collapse
Affiliation(s)
- Jasbeer Dhawan
- Medical Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
PURPOSE OF REVIEW Recent positron emission tomographic studies demonstrate a variety of abnormalities in the brains of addicted individuals. This review aims to discuss and highlight these findings. RECENT FINDINGS The recent findings are as follows: (a) the reward response to an addictive substance is associated with increased dopamine release in the striatum. (b) Activation of the orbitofrontal region is involved in the reinforcing properties of a drug. (c) Behavioral, cognitive and affective abnormalities are associated with alterations in specific brain networks and regions (e.g., prefrontal cortices) in drug abusers. (d) Personality traits may play a role in the susceptibility to addiction and the brain's responses to drugs. (e) Sex-differences exist for cue-induced craving. (f) Several studies have confirmed decreased D2 receptors in drug users, which is associated with increased salience to drug cues. (g) Serotonergic transporters are decreased in the current users of 3,4-methylene-deoxy-methamphetamine but found normal in the past users of 3,4-methylene-deoxy-methamphetamine. SUMMARY Abnormalities in the dopaminergic, opioid, and serotonergic systems in drug abusers are seen in positron emission tomography scans. Decreased D2 receptor densities in drug users, whether premorbid or the consequence of substance misuse, imply a source of the susceptibility to relapse of this population. Insights from these studies could lead to better treatment approaches targeting specific neurotransmitter systems.
Collapse
Affiliation(s)
- Linda Chang
- Department of Medicine, Division of Neurology, John A. Burns School of Medicine, University of Hawaii, Queen's University Tower, 7th Floor, 1356 Lusitana St., Honolulu, HI 96813, USA.
| | | |
Collapse
|
47
|
Ingman K, Hagelberg N, Aalto S, Någren K, Juhakoski A, Karhuvaara S, Kallio A, Oikonen V, Hietala J, Scheinin H. Prolonged central mu-opioid receptor occupancy after single and repeated nalmefene dosing. Neuropsychopharmacology 2005; 30:2245-53. [PMID: 15956985 DOI: 10.1038/sj.npp.1300790] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The opioid antagonist nalmefene offers an alternative to traditional pharmacological treatments for alcoholism. The present study was designed to investigate the relationship between nalmefene plasma concentration and central mu-opioid receptor occupancy after a clinically effective dose (20 mg, orally). Pharmacokinetics and mu-opioid receptor occupancy of nalmefene after single and repeated dosing over 7 days was studied in 12 healthy subjects. Serial blood samples were obtained after both dosings, and pharmacokinetic parameters for nalmefene and main metabolites were determined. Central mu-opioid receptor occupancy of nalmefene was measured with positron emission tomography (PET) and [(11)C]carfentanil at four time points (3, 26, 50, 74 h) after both dosings. Nalmefene was rapidly absorbed in all subjects. The mean t(1/2) of nalmefene was 13.4 h after single and repeated dosing. The accumulation of nalmefene and its main metabolites in plasma during the repeated dosing period was as expected for a drug with linear pharmacokinetics, and steady-state was reached for all analytes. Both nalmefene dosings resulted in a very high occupancy at mu-opioid receptors (87-100%), and the decline in the occupancy was similar after both dosings but clearly slower than the decline in the plasma concentration of nalmefene or metabolites. High nalmefene occupancy (83-100%) persisted at 26 h after the dosings. The prolonged mu-opioid receptor occupancy by nalmefene indicates slow dissociation of the drug from mu-opioid receptors. These results support the rational of administering nalmefene when needed before alcohol drinking, and they additionally suggest that a high mu-opioid receptor occupancy can be maintained when nalmefene is taken once daily.
Collapse
Affiliation(s)
- Kimmo Ingman
- Clinical Research Services Turku (CRST), University of Turku, FIN-20521 Turku, Finland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Neurochemical imaging studies can identify molecular targets of abused drugs and link them to the underlying pathology associated with behaviors such as drug dependence, addiction and withdrawal. positron emission tomography (PET) is opening new avenues for the investigation of the neurochemical disturbances underlying drug abuse and addiction and the in vivo mechanisms by which medications might ameliorate these conditions. PET can identify vulnerable human populations, treatment strategies and monitor treatment efficacy. Thus, with this tool and the knowledge it provides, the potential for developing novel drugs and treatment strategies for drug addiction is now close at hand.
Collapse
Affiliation(s)
- Wynne K Schiffer
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
| | | | | | | |
Collapse
|