1
|
Pitschmann V, Hon Z. Drugs as Chemical Weapons: Past and Perspectives. TOXICS 2023; 11:52. [PMID: 36668778 PMCID: PMC9866636 DOI: 10.3390/toxics11010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
The emergence of modern chemical weapons and chemical warfare is traditionally associated with World War I, but the use of poisons in the military has its roots deep in the past. The sources of these poisons have always been natural agents that also served as medicines. This relationship between poison and medicine, and nowadays between chemical warfare and medicine, or between 'military chemistry' and pharmacy, appears to be very important for understanding not only the history but also the possible future of both phenomena. This article looks at some historical examples of the use of drugs as chemical weapons and, conversely, the use of chemical weapons as medicines. It seeks to find answers to some questions that are particularly relevant to the implementation of the Chemical Weapons Convention, which aims to achieve a world without chemical warfare.
Collapse
Affiliation(s)
- Vladimír Pitschmann
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sítná sq. 3105, 272 01 Kladno, Czech Republic
- ORITEST spol. s r.o., Čerčanská 640/30, 140 00 Prague, Czech Republic
| | - Zdeněk Hon
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sítná sq. 3105, 272 01 Kladno, Czech Republic
| |
Collapse
|
2
|
Langmaier J, Skopalová J, Cechová MZ, Kahánková T, Jerga R, Barták P, Samec Z, Navrátil T. Ion transfer voltammetric and LC/MS investigations of the oxidative degradation process of fentanyl and some of its structural analogs. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2023.141848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
3
|
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
|
4
|
Futures-oriented drugs policy research: Events, trends, and speculating on what might become. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2021; 94:103332. [PMID: 34148724 DOI: 10.1016/j.drugpo.2021.103332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/12/2022]
Abstract
One concern in the field of drugs policy is how to make research more futures-oriented. Tracing trends and events with the potential to alter drug futures are seen as ways of becoming more prepared. This challenge is made complex in fast evolving drug markets which entangle with shifting social and material relations at global scale. In this analysis, we argue that drugs policy research orientates to detection and discovery based on the recent past. This narrows future-oriented analyses to the predictable and probable, imagined as extensions of the immediate and local present. We call for a more speculative approach; one which extends beyond the proximal, and one which orientates to possibilities rather than probabilities. Drawing on ideas on speculation from science and technology and futures studies, we argue that speculative research holds potential for more radical alterations in drugs policy. We encourage research approaches which not only valorise knowing in relation to what might happen but which conduct experiments on what could be. Accordingly, we trace how speculative research makes a difference by altering the present through making deliberative interventions on alternative policy options, including policy scenarios which make a radical break with the present. We look specifically at the 'Big Event' and 'Mega Trend' as devices of speculative intervention in futures-oriented drugs policy research. We illustrate how the device of Mega Trend helps to trace as well as to speculate on some of the entangling elements affecting drug futures, including in relation to climate, environment, development, population, drug production, digitalisation, biotechnology, policy and discourse.
Collapse
|
5
|
Valdez CA. Gas Chromatography-Mass Spectrometry Analysis of Synthetic Opioids Belonging to the Fentanyl Class: A Review. Crit Rev Anal Chem 2021; 52:1938-1968. [PMID: 34053394 DOI: 10.1080/10408347.2021.1927668] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The rising number of deaths caused by fentanyl overdosing in the US due to the overwhelming illicit use of this synthetic opioid has started a global campaign to develop efficient ways to control its production and distribution as well as discovering efficient antidotes to mitigate its lethal effects. Another important vein of focused research established by various agencies lies in the development of efficient and practical protocols for the detection of this opioid and analogs thereof in various matrices, whether environmental or biological in nature, particularly in the field of gas chromatography-mass spectrometry (GC-MS). The following review will cover the literature dealing with the detection and identification of synthetic opioids belonging to the fentanyl class by GC-MS means and hyphenated versions of the technique. Detailed descriptions will be given for the GC-MS methods employed for the analysis of the opioid, starting with the nature of the extraction protocol employed prior to analysis to the actual findings presented by the cited reports. Great effort has gone into describing the methods involved in each paper in a detailed manner and these have been compiled by year in tables at the end of each section for the reader's convenience. Lastly, the review will end with concluding remarks about the state of GC-MS analysis with regards to these powerful opioids and what lies ahead for this analytical field.
Collapse
Affiliation(s)
- Carlos A Valdez
- Lawrence Livermore National Laboratory, Forensic Science Center, Livermore, California, USA.,Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA.,Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California, USA
| |
Collapse
|
6
|
Dandrea KE, Cotten JF. A Comparison of Breathing Stimulants for Reversal of Synthetic Opioid-Induced Respiratory Depression in Conscious Rats. J Pharmacol Exp Ther 2021; 378:146-156. [PMID: 34021024 DOI: 10.1124/jpet.121.000675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/11/2021] [Indexed: 11/22/2022] Open
Abstract
Potent synthetic opioids are an important cause of death in the United States' opioid epidemic, and a breathing stimulant may have utility in treating opioid overdose. We hypothesized that sufentanil-induced respiratory depression may be reversed by breathing stimulant administration. Using nose-only plethysmography and arterial blood analysis, we compared effects of several breathing stimulants in reversing sufentanil-induced respiratory depression in conscious rats. We studied taltirelin (1 mg/kg i.v.), PKTHPP (5 mg/kg i.v.), CX717 (30 mg/kg i.v.), BIMU8 (1 mg/kg i.v.), A85380 (30 μg/kg i.v.), and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (150 μg/kg i.v./i.m.) and used sufentanil (10 μg/kg i.v.). By plethysmography (in % baseline, mean ± S.E.M.), taltirelin restored ventilation in sufentanil-treated rats (from 50 ± 5% to 102 ± 8%) by increased breathing rates (from 80 ± 4% to 160 ± 12%). By arterial blood analysis, however, taltirelin did not correct hypoxia, decreased hypercarbia only after 45 minutes, and worsened metabolic acidosis (base excess from +0 ± 1 to -7 ± 1 mEq/l). Additionally, taltirelin increased exhaled carbon dioxide, an estimate of oxygen consumption, by up to 64%. PKTHPP, CX717, BIMU8, and A85380 failed to significantly change ventilation or arterial blood values in sufentanil-treated rats. 8-OH-DPAT, however, improved ventilation (from 54 ± 8% to 92 ± 10%), reversed hypercarbia (from 64 ± 6 to 47 ± 2 mmHg), and shortened time to righting from 43 ± 4 to 15 ± 1 minutes in sufentanil-treated rats placed supine. Taltirelin has limited therapeutic potential, as its ventilatory effects are offset by metabolic acidosis, possibly from increased oxygen consumption. At the doses studied, PKTHPP, CX717, BIMU8, and A85380 have limited effects in reversing sufentanil-induced respiratory depression; 8-OH-DPAT, however, warrants further study. SIGNIFICANCE STATEMENT: Respiratory depression is an important cause of death after potent synthetic opioid overdose. 8-Hydroxy-2-(di-n-propylamino)tetralin or related compounds may be useful in treating respiratory depression as caused by potent synthetic opioids.
Collapse
Affiliation(s)
- Kaye E Dandrea
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Joseph F Cotten
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| |
Collapse
|
7
|
van der Graaf PH. The Pharmacological War Against and With Opioids. Clin Pharmacol Ther 2021; 109:557-559. [PMID: 33615454 DOI: 10.1002/cpt.2157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 12/13/2022]
|
8
|
Negri A, Townshend H, McSweeney T, Angelopoulou O, Banayoti H, Prilutskaya M, Bowden-Jones O, Corazza O. Carfentanil on the darknet: Potential scam or alarming public health threat? THE INTERNATIONAL JOURNAL OF DRUG POLICY 2021; 91:103118. [PMID: 33482605 DOI: 10.1016/j.drugpo.2021.103118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 12/28/2020] [Accepted: 01/01/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND In an age of global insecurity, highly potent synthetic drugs have become a major public health issue. Their online advertisement and sale are facilitated by surface web, darknet markets and social media fuelling substance abuse and addiction, as well as various types of new criminal activities and their growth in sophistication. This study presents a systematic analysis of the darknet sale of one of the most potent synthetic opioids: Carfentanil. With an equianalgesic potency of 10.000 times a unit of morphine, its toxicity is comparable to traditional nerve agents, and it has been previously used as a chemical weapon, causing human fatalities. METHODS Digital trace data was collected retrospectively from all the darknet marketplaces, which have been active in the past five years. Data on vendors offering Carfentanil on Agartha, Empire and Yakuza marketplaces were analysed with regard to items sold and sellers' features as these were the only active markets at the time of search. Searches were carried out in the English language only. RESULTS 63 Cartfentanil vendors operating on 19 darknet marketplaces were identified. Contacts and payments were facilitated with end-to-end encryption messaging mobile applications and content-expiring messages. Although it is known that Agartha is a scam market, and no operative sellers were found on Yakuza, several sellers promoting Carfentanil sales were active in the Empire marketplace with a number of transaction ranging from 4 to 1223. CONCLUSION The availability of highly potent drugs such as Carfentanil on the darknet requires the urgent development of novel scientific methods and tools able to monitor and to predict such new threats, while informing policymaking and protecting the health and the security of citizens.
Collapse
Affiliation(s)
- A Negri
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom; Postgraduate School of Pharmacology and Clinical Toxicology, University of Milan, Milan, Italy
| | - H Townshend
- School of Law, University of Hertfordshire, Hatfield, United Kingdom
| | - T McSweeney
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | | | | | - M Prilutskaya
- Department of Personalized Medicine and Paediatrics, Semey Medical University, Semey, Kazakhstan
| | - O Bowden-Jones
- Club Drug Clinic, Central North West London NHS Foundation Trust, London, United Kingdom
| | - O Corazza
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom.
| |
Collapse
|
9
|
France CP, Ahern GP, Averick S, Disney A, Enright HA, Esmaeli-Azad B, Federico A, Gerak LR, Husbands SM, Kolber B, Lau EY, Lao V, Maguire DR, Malfatti MA, Martinez G, Mayer BP, Pravetoni M, Sahibzada N, Skolnick P, Snyder EY, Tomycz N, Valdez CA, Zapf J. Countermeasures for Preventing and Treating Opioid Overdose. Clin Pharmacol Ther 2020; 109:578-590. [PMID: 33113208 DOI: 10.1002/cpt.2098] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/15/2020] [Indexed: 02/06/2023]
Abstract
The only medication available currently to prevent and treat opioid overdose (naloxone) was approved by the US Food and Drug Administration (FDA) nearly 50 years ago. Because of its pharmacokinetic and pharmacodynamic properties, naloxone has limited utility under some conditions and would not be effective to counteract mass casualties involving large-scale deployment of weaponized synthetic opioids. To address shortcomings of current medical countermeasures for opioid toxicity, a trans-agency scientific meeting was convened by the US National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH) on August 6 and 7, 2019, to explore emerging alternative approaches for treating opioid overdose in the event of weaponization of synthetic opioids. The meeting was initiated by the Chemical Countermeasures Research Program (CCRP), was organized by NIAID, and was a collaboration with the National Institute on Drug Abuse/NIH (NIDA/NIH), the FDA, the Defense Threat Reduction Agency (DTRA), and the Biomedical Advanced Research and Development Authority (BARDA). This paper provides an overview of several presentations at that meeting that discussed emerging new approaches for treating opioid overdose, including the following: (1) intranasal nalmefene, a competitive, reversible opioid receptor antagonist with a longer duration of action than naloxone; (2) methocinnamox, a novel opioid receptor antagonist; (3) covalent naloxone nanoparticles; (4) serotonin (5-HT)1A receptor agonists; (5) fentanyl-binding cyclodextrin scaffolds; (6) detoxifying biomimetic "nanosponge" decoy receptors; and (7) antibody-based strategies. These approaches could also be applied to treat opioid use disorder.
Collapse
Affiliation(s)
- Charles P France
- Department of Pharmacology, Addiction Research, Treatment and Training Center of Excellence, University of Texas Health Science Center, San Antonio, Texas, USA
| | | | - Saadyah Averick
- Neuroscience Institute, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Alex Disney
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | | | - Babak Esmaeli-Azad
- CellCure (Stem Cell Division of CiBots, Inc.), San Diego, California, USA
| | - Arianna Federico
- CellCure (Stem Cell Division of CiBots, Inc.), San Diego, California, USA
| | - Lisa R Gerak
- Department of Pharmacology, Addiction Research, Treatment and Training Center of Excellence, University of Texas Health Science Center, San Antonio, Texas, USA
| | | | | | - Edmond Y Lau
- Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Victoria Lao
- Lawrence Livermore National Laboratory, Livermore, California, USA
| | - David R Maguire
- Department of Pharmacology, Addiction Research, Treatment and Training Center of Excellence, University of Texas Health Science Center, San Antonio, Texas, USA
| | | | - Girardo Martinez
- CellCure (Stem Cell Division of CiBots, Inc.), San Diego, California, USA
| | - Brian P Mayer
- Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Marco Pravetoni
- Department of Pharmacology, Center for Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | | | - Phil Skolnick
- Opiant Pharmaceuticals, Inc., Santa Monica, California, USA
| | - Evan Y Snyder
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Nestor Tomycz
- Neuroscience Institute, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Carlos A Valdez
- Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Jim Zapf
- CellCure (Stem Cell Division of CiBots, Inc.), San Diego, California, USA
| |
Collapse
|
10
|
Mass spectrometric characterization of carfentanil metabolism in human, dog, and rat lung microsomes via comparison to chemically synthesized metabolite standards. Forensic Toxicol 2020. [DOI: 10.1007/s11419-019-00521-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
11
|
Yeung DT, Bough KJ, Harper JR, Platoff GE. National Institutes of Health (NIH) Executive Meeting Summary: Developing Medical Countermeasures to Rescue Opioid-Induced Respiratory Depression (a Trans-Agency Scientific Meeting)-August 6/7, 2019. J Med Toxicol 2020; 16:87-105. [PMID: 31853736 PMCID: PMC6942061 DOI: 10.1007/s13181-019-00750-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/13/2019] [Accepted: 11/18/2019] [Indexed: 01/25/2023] Open
Abstract
On August 6th, 2019, a two-day trans-agency scientific meeting was convened by the United States (U.S.) National Institute of Allergy and Infectious Diseases (NIAID/NIH) on the research and development of medical countermeasures (MCMs) and treatment strategies to mitigate synthetic opioid-induced toxicities. This trans-agency meeting was an initiative of the Chemical Countermeasures Research Program (CCRP) and organized by the NIAID in collaboration with the National Institute of Drug Abuse (NIDA), the Biomedical Advanced Research and Development Authority (BARDA), the Food and Drug Administration (FDA), and the Defense Threat Reduction Agency (DTRA). The CCRP is part of the larger NIH biodefense research program coordinated by NIAID, which also includes MCM research and development programs against biological, radiological, and nuclear threats. Its overarching goal is to integrate cutting-edge research and technological advances in science and medicine to enhance the nation's medical response capabilities during and after a public health emergency involving the deliberate or accidental release of toxic chemicals. The potential of a mass casualty public health event involving synthetic opioids is a rapidly growing concern. As such, the overall goals of this trans-agency meeting are to better understand opioid-induced toxicities and advance the development of MCMs to mitigate and reverse opioid-induced respiratory depression (OIRD) to prevent consequential mortality. The primary objectives of the meeting were (1) highlight the latest research on mechanisms of OIRD and related toxicities, animal models, diagnostics, delivery technologies, and emerging new treatment options to prevent lethality; (2) identify current knowledge gaps to advance medical countermeasure development; (3) hear from the U.S. FDA on regulatory considerations to support new technology and treatment approaches; and (4) provide a forum for networking and collaborative partnerships. To accomplish this, a diverse group of almost 200 US domestic and international subject matter experts spanning fundamental and translational research from academia, industry, and government came together in-person to share their collective expertise and experience in this important field. This report briefly summarizes the information presented throughout the meeting, which was also webcast live in its entirety to registered remote attendees.
Collapse
Affiliation(s)
- David T Yeung
- National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH), Bethesda, MD, USA.
| | - Kristopher J Bough
- National Institute of Drug Abuse/National Institutes of Health (NIDA/NIH), Bethesda, MD, USA
| | - Jill R Harper
- National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH), Bethesda, MD, USA
| | - Gennady E Platoff
- National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH), Bethesda, MD, USA
| |
Collapse
|
12
|
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
|