1
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Vandeputte MM, Bilel S, Tirri M, Corli G, Bassi M, Layle NK, Fantinati A, Walther D, Iula DM, Baumann MH, Stove CP, Marti M. Elucidating the harm potential of brorphine analogues as new synthetic opioids: Synthesis, in vitro, and in vivo characterization. Neuropharmacology 2024; 260:110113. [PMID: 39154855 DOI: 10.1016/j.neuropharm.2024.110113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 07/18/2024] [Accepted: 08/09/2024] [Indexed: 08/20/2024]
Abstract
The emergence of new synthetic opioids (NSOs) has added complexity to recreational opioid markets worldwide. While NSOs with diverse chemical structures have emerged, brorphine currently remains the only NSO with a piperidine benzimidazolone scaffold. However, the emergence of new generations of NSOs, including brorphine analogues, can be anticipated. This study explored the pharmaco-toxicological, opioid-like effect profile of brorphine alongside its non-brominated analogue (orphine) and three other halogenated analogues (fluorphine, chlorphine, iodorphine). In vitro, radioligand binding assays in rat brain tissue indicated that all analogues bind to the μ-opioid receptor (MOR) with nM affinity. While analogues with smaller-sized substituents showed the highest MOR affinity, further in vitro characterization via two cell-based (HEK 293T) MOR activation (β-arrestin 2 and mini-Gαi recruitment) assays indicated that chlorphine, brorphine, and iodorphine were generally the most active MOR agonists. None of the compounds showed significant in vitro biased agonism compared to hydromorphone. In vivo, we investigated the effects of intraperitoneal (IP) administration of the benzimidazolones (0.01-15 mg/kg) on mechanical and thermal antinociception in male CD-1 mice. Chlorphine and brorphine overall induced the highest levels of antinociception. Furthermore, the effects on respiratory changes induced by a fixed dose (15 mg/kg IP) of the compounds were investigated using non-invasive plethysmography. Fluorphine-, chlorphine-, and brorphine-induced respiratory depressant effects were the most pronounced. For some compounds, pretreatment with naloxone (6 mg/kg IP) could not reverse respiratory depression. Taken together, brorphine-like piperidine benzimidazolones are opioid agonists that have the potential to cause substantial harm to users should they emerge as NSOs. This article is part of the Special Issue on "Novel Synthetic Opioids (NSOs)".
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Affiliation(s)
- Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Sabrine Bilel
- Department of Translational Medicine, Section of Legal Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Micaela Tirri
- Department of Translational Medicine, Section of Legal Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Giorgia Corli
- Department of Translational Medicine, Section of Legal Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Marta Bassi
- Department of Translational Medicine, Section of Legal Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Nathan K Layle
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, 48108, USA
| | - Anna Fantinati
- Department of Environmental and Prevention Sciences, University of Ferrara, Ferrara, Italy
| | - Donna Walther
- Designer Drug Research Unit (DDRU), Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Donna M Iula
- Forensic Chemistry Division, Cayman Chemical Company, Ann Arbor, MI, 48108, USA
| | - Michael H Baumann
- Designer Drug Research Unit (DDRU), Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
| | - Matteo Marti
- Department of Translational Medicine, Section of Legal Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy; Collaborative Center of the National Early Warning System, Department for Anti-Drug Policies, Presidency of the Council of Ministers, Italy.
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2
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De Vrieze LM, Walton SE, Pottie E, Papsun D, Logan BK, Krotulski AJ, Stove CP, Vandeputte MM. In vitro structure-activity relationships and forensic case series of emerging 2-benzylbenzimidazole 'nitazene' opioids. Arch Toxicol 2024; 98:2999-3018. [PMID: 38877156 PMCID: PMC11324687 DOI: 10.1007/s00204-024-03774-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 04/24/2024] [Indexed: 06/16/2024]
Abstract
2-Benzylbenzimidazole 'nitazene' opioids are presenting a growing threat to public health. Although various nitazenes were previously studied, systematic comparisons of the effects of different structural modifications to the 2-benzylbenzimidazole core structure on μ-opioid receptor (MOR) activity are limited. Here, we assessed in vitro structure-activity relationships of 9 previously uncharacterized nitazenes alongside known structural analogues. Specifically, we focused on MOR activation by 'ring' substituted analogues (i.e., N-pyrrolidino and N-piperidinyl modifications), 'desnitazene' analogues (lacking the 5-nitro group), and N-desethyl analogues. The results from two in vitro MOR activation assays (β-arrestin 2 recruitment and inhibition of cAMP accumulation) showed that 'ring' modifications overall yield highly active drugs. With the exception of 4'-OH analogues (which are metabolites), N-pyrrolidino substitutions were generally more favorable for MOR activation than N-piperidine substitutions. Furthermore, removal of the 5-nitro group on the benzimidazole ring consistently caused a pronounced decrease in potency. The N-desethyl modifications showed important MOR activity, and generally resulted in a slightly lowered potency than comparator nitazenes. Intriguingly, N-desethyl isotonitazene was the exception and was consistently more potent than isotonitazene. Complementing the in vitro findings and demonstrating the high harm potential associated with many of these compounds, we describe 85 forensic cases from North America and the United Kingdom involving etodesnitazene, N-desethyl etonitazene, N-desethyl isotonitazene, N-pyrrolidino metonitazene, and N-pyrrolidino protonitazene. The low-to-sub ng/mL blood concentrations observed in most cases underscore the drugs' high potencies. Taken together, by bridging pharmacology and case data, this study may aid to increase awareness and guide legislative and public health efforts.
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Affiliation(s)
- Liam M De Vrieze
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Sara E Walton
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
| | - Eline Pottie
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | - Barry K Logan
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
- NMS Labs, Horsham, PA, 19044, USA
| | - Alex J Krotulski
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
| | - Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
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3
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Berardinelli D, Taoussi O, Carlier J, Tini A, Zaami S, Sundermann T, Busardò FP, Auwärter V. In vitro, in vivo metabolism and quantification of the novel synthetic opioid N-piperidinyl etonitazene (etonitazepipne). Clin Chem Lab Med 2024; 62:1580-1590. [PMID: 38311816 DOI: 10.1515/cclm-2023-1360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/21/2024] [Indexed: 02/06/2024]
Abstract
OBJECTIVES N-piperidinyl etonitazene (etonitazepipne) is a newly synthesized opioid related to the 2-benzylbenzimidazole analog class. Etonitazepipne has been formally notified and placed under intensive monitoring in Europe in January 2022. Nitazenes have high affinity at µ-opioid receptor (MOR). Etonitazepipne, specifically shows a EC50 of 2.49 nM, suggesting about 50 times higher potency combined with higher efficacy compared to morphine. Antinociceptive potency l ('hot plate test' with rats) was 192-fold greater than that of morphine. METHODS Here we report on a post-mortem case involving etonitazepipne and its quantification using a standard addition method (SAM) through liquid chromatography tandem mass spectrometry (LC-MS/MS). In addition, characterization and identification of phase I human metabolites using in vitro assay based on pooled human liver microsomes (pHLM) was performed along with the analysis of authentic urine samples by means of high-performance liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). RESULTS The concentration of etonitazepipne in post-mortem blood and urine was 8.3 and 11 ng/mL, respectively. SAM was validated by assessing the following parameters: intraday and interday repeatability, matrix effect and recovery rate in post-mortem blood. A total of 20 and 14 metabolites were identified after pHLM incubation and urine analysis, respectively. Most pronounced in vitro and in vivo transformations were O-deethylation, hydroxylation, ketone reduction, and combinations thereof. CONCLUSIONS Considering small traces of the parent drug often found in real cases, the identification of metabolic biomarkers is crucial to identify exposure to this drug. O-deethylated, oxidated metabolites, and combination thereof are proposed as urinary biomarkers along with the parent compound.
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Affiliation(s)
- Diletta Berardinelli
- Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Ancona, Italy
- Forensic Toxicology, Institute for Legal Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Omayema Taoussi
- Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Ancona, Italy
| | - Jeremy Carlier
- Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Ancona, Italy
| | - Anastasio Tini
- Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Ancona, Italy
| | - Simona Zaami
- Department of Anatomical, Histological, Forensic and Orthopaedic Sciences, Sapienza University of Rome, Rome, Italy
| | - Tom Sundermann
- Institute of Forensic and Traffic Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Francesco Paolo Busardò
- Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Ancona, Italy
| | - Volker Auwärter
- Forensic Toxicology, Institute for Legal Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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4
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Ameline A, Gheddar L, Pichini S, Stove C, Aknouche F, Maruejouls C, Raul JS, Kintz P. In vitro characterization of protonitazene metabolites, using human liver microsomes, and first application to two urines collected from death cases. Clin Chim Acta 2024; 561:119764. [PMID: 38844019 DOI: 10.1016/j.cca.2024.119764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/03/2024] [Accepted: 06/03/2024] [Indexed: 06/10/2024]
Abstract
Protonitazene, or N,N-diethyl-5-nitro-2-[(4-propoxyphenyl)methyl]-1H-benzimidazole-1-ethanamine, is a novel synthetic opioid, which belongs to the nitazene family. Over the last four years, nitazenes have re-emerged on the new psychoactive substances market and have been reported in several fatal intoxication cases. The metabolism of several nitazene analogues have already been studied, but to date, no data exists regarding protonitazene. The aim of the study was the detection of protonitazene and its metabolites in authentic human urine collected in two fatal intoxication cases, comparing the data after in vitro incubation with human liver microsomes, and subsequent analysis by ultra-performance liquid chromatography-tandem mass spectrometry and ultra-performance liquid chromatography-high-resolution mass spectrometry. Protonitazene metabolites, including N-desethyl-protonitazene, 5-amino-protonitazene and 4-hydroxy-nitazene, were characterized in vitro and were identified in the urine of both cases. The ratios between metabolites and parent protonitazene, higher than 1, were calculated to estimate the proportionality of metabolites. The results suggest that testing protonitazene metabolites should increase the window detection of exposure to protonitazene.
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Affiliation(s)
- Alice Ameline
- Institut de Médecine Légale, 11 rue Humann, 67085 Strasbourg, France.
| | - Laurie Gheddar
- Institut de Médecine Légale, 11 rue Humann, 67085 Strasbourg, France
| | - Simona Pichini
- Istituto Superiore di Sanita, 299 viale Regina Elena, 00161 Roma, Italy
| | - Christophe Stove
- Laboratory of Toxicology, Campus Heymans, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Frédéric Aknouche
- Laboratoire SYNLAB Réunion, 19 ter rue Balbolia, 97460 Saint-Paul, France
| | | | | | - Pascal Kintz
- Institut de Médecine Légale, 11 rue Humann, 67085 Strasbourg, France; X-Pertise Consulting, 42 rue Principale, 67026 Mittelhausbergen, France
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5
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Salomone A, Vincenti M. Detecting novel psychoactive substances around the world. Curr Opin Psychiatry 2024; 37:258-263. [PMID: 38818825 DOI: 10.1097/yco.0000000000000939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
PURPOSE OF REVIEW The worldwide spread of novel psychoactive substances (NPS) in the illicit drug market and their continuous increase in number and type, for the purpose of bypassing controlled substance legislation, represents a continuing challenge for forensic scientists, clinicians and enforcement authorities. We aim to provide information regarding the most urgent harms related to NPS consumption in different world regions and the current state of the art for NPS analysis. RECENT FINDINGS Unfortunately, the identification of NPS in biological samples is controversial, especially when samples are limited, or the drug is promptly and extensively metabolized. This causes a lack of information on their real diffusion in different parts of the world and in different populations. New technologies and instrumental detection of NPS in alternative samples are offering comprehensive information about NPS use. SUMMARY The lack of detection and underreporting of NPS in biological samples makes it difficult to obtain complete qualitative and quantitative information about NPS prevalence. The most innovative strategies that have been proposed in the last 2 years to assist NPS analysis and possibly facilitate the understanding of the NPS diffusion around the world are presented.
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Affiliation(s)
- Alberto Salomone
- Department of Chemistry, University of Turin
- Centro Regionale Antidoping, Orbassano, Turin, Italy
| | - Marco Vincenti
- Department of Chemistry, University of Turin
- Centro Regionale Antidoping, Orbassano, Turin, Italy
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6
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Timmerman A, Balcaen M, Coopman V, Degreef M, Pottie E, Stove CP. Activity-based detection of synthetic cannabinoid receptor agonists in plant materials. Harm Reduct J 2024; 21:127. [PMID: 38951904 PMCID: PMC11218095 DOI: 10.1186/s12954-024-01044-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 06/18/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND Since late 2019, fortification of 'regular' cannabis plant material with synthetic cannabinoid receptor agonists (SCRAs) has become a notable phenomenon on the drug market. As many SCRAs pose a higher health risk than genuine cannabis, recognizing SCRA-adulterated cannabis is important from a harm reduction perspective. However, this is not always an easy task as adulterated cannabis may only be distinguished from genuine cannabis by dedicated, often expensive and time-consuming analytical techniques. In addition, the dynamic nature of the SCRA market renders identification of fortified samples a challenging task. Therefore, we established and applied an in vitro cannabinoid receptor 1 (CB1) activity-based procedure to screen plant material for the presence of SCRAs. METHODS The assay principle relies on the functional complementation of a split-nanoluciferase following recruitment of β-arrestin 2 to activated CB1. A straightforward sample preparation, encompassing methanolic extraction and dilution, was optimized for plant matrices, including cannabis, spiked with 5 µg/mg of the SCRA CP55,940. RESULTS The bioassay successfully detected all samples of a set (n = 24) of analytically confirmed authentic Spice products, additionally providing relevant information on the 'strength' of a preparation and whether different samples may have originated from separate batches or possibly the same production batch. Finally, the methodology was applied to assess the occurrence of SCRA adulteration in a large set (n = 252) of herbal materials collected at an international dance festival. This did not reveal any positives, i.e. there were no samples that yielded a relevant CB1 activation. CONCLUSION In summary, we established SCRA screening of herbal materials as a new application for the activity-based CB1 bioassay. The simplicity of the sample preparation, the rapid results and the universal character of the bioassay render it an effective and future-proof tool for evaluating herbal materials for the presence of SCRAs, which is relevant in the context of harm reduction.
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Affiliation(s)
- Axelle Timmerman
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Margot Balcaen
- Belgian Early Warning System on Drugs, Unit Illicit drugs, Health information, Sciensano, Brussels, Belgium
| | | | - Maarten Degreef
- Belgian Early Warning System on Drugs, Unit Illicit drugs, Health information, Sciensano, Brussels, Belgium
| | - Eline Pottie
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
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7
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Taoussi O, Berardinelli D, Zaami S, Tavoletta F, Basile G, Kronstrand R, Auwärter V, Busardò FP, Carlier J. Human metabolism of four synthetic benzimidazole opioids: isotonitazene, metonitazene, etodesnitazene, and metodesnitazene. Arch Toxicol 2024; 98:2101-2116. [PMID: 38582802 PMCID: PMC11169013 DOI: 10.1007/s00204-024-03735-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 03/11/2024] [Indexed: 04/08/2024]
Abstract
Following isotonitazene scheduling in 2019, the availability of alternative 2-benzylbenzimidazole opioids (nitazenes) on the global drug market increased, resulting in many fatalities worldwide. Nitazenes are potent µ-opioid receptor agonists with strong narcotic/analgesic effects, and their concentrations in biological matrices are low, making the detection of metabolite biomarkers of consumption crucial to document use in clinical and forensic settings. However, there is little to no data on the metabolism of the most recently available nitazenes, especially desnitro-analogues. The aim of the research was to assess isotonitazene, metonitazene, etodesnitazene, and metodesnitazene human metabolism and identify specific metabolite biomarkers of consumption. The four analogues were incubated with 10-donor-pooled human hepatocytes, and the incubates were analyzed by liquid chromatography-high-resolution tandem mass spectrometry and data mining with Compound Discoverer (Thermo Scientific); the analysis was supported by in silico metabolite predictions with GLORYx open-access software. Metabolites were identified in postmortem blood and/or urine samples from two metonitazene-positive and three etodesnitazene-positive cases following the same workflow, with and without glucuronide hydrolysis in urine, to confirm in vitro results. Twelve, nine, twenty-two, and ten metabolites were identified for isotonitazene, metonitazene, etodesnitazene, and metodesnitazene, respectively. The main transformations were N-deethylation at the N,N-diethylethanamine side chain, O-dealkylation, and further O-glucuronidation. In vitro and autopsy results were consistent, demonstrating the efficacy of the 10-donor-pooled human hepatocyte model to predict human metabolism. We suggest the parent and the corresponding O-dealkyl- and N-deethyl-O-dealkyl metabolites as biomarkers of exposure in urine after glucuronide hydrolysis, and the corresponding N-deethyl metabolite as additional biomarker in blood.
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Affiliation(s)
- Omayema Taoussi
- Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Via Tronto 10/a, 60126, Ancona AN, Italy
| | - Diletta Berardinelli
- Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Via Tronto 10/a, 60126, Ancona AN, Italy
| | - Simona Zaami
- Department of Anatomical, Histological, Forensic and Orthopaedic Sciences, Sapienza University of Rome, Rome, Italy
| | - Francesco Tavoletta
- Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Via Tronto 10/a, 60126, Ancona AN, Italy
| | - Giuseppe Basile
- Department of Trauma Surgery, IRCCS Galeazzi Orthopedic Institute, Milan, Italy
| | - Robert Kronstrand
- Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden
| | - Volker Auwärter
- Institute of Forensic Medicine, Forensic Toxicology, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Francesco P Busardò
- Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Via Tronto 10/a, 60126, Ancona AN, Italy.
| | - Jeremy Carlier
- Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Via Tronto 10/a, 60126, Ancona AN, Italy
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8
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Buratti E, Mietti G, Cerioni A, Cippitelli M, Froldi R, Cingolani M, Scendoni R. Identification of N-piperidinyl etonitazene in alternative keratinous matrices from a decomposing cadaver. J Forensic Leg Med 2024; 105:102710. [PMID: 38954889 DOI: 10.1016/j.jflm.2024.102710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 05/16/2024] [Accepted: 06/03/2024] [Indexed: 07/04/2024]
Abstract
This short report describes research on N-piperidinyl etonitazene, also known as etonitazepipne, in keratinous matrices (hair and nails) after death related to a suspected opioid overdose. Etonitazepipne belongs to the family of benzimidazole opioids, a class of new synthetic opioids that has penetrated the illicit drug market. Analysis in the case under study showed the presence of etonitazepipne in both hair and nails, confirming that the substance accumulates in the body with repeated intake.
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Affiliation(s)
- Erika Buratti
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Gianmario Mietti
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Alice Cerioni
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Marta Cippitelli
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Rino Froldi
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Mariano Cingolani
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
| | - Roberto Scendoni
- Forensic Medicine Laboratory, Institute of Legal Medicine, University of Macerata, via Don Minzoni n.9, Macerata, Italy.
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9
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Ververi C, Galletto M, Massano M, Alladio E, Vincenti M, Salomone A. Method development for the quantification of nine nitazene analogs and brorphine in Dried Blood Spots utilizing liquid chromatography - tandem mass spectrometry. J Pharm Biomed Anal 2024; 241:115975. [PMID: 38280237 DOI: 10.1016/j.jpba.2024.115975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/31/2023] [Accepted: 01/08/2024] [Indexed: 01/29/2024]
Abstract
The detection of nitazenes in biological fluids is increasingly needed as they are repeatedly reported in intoxication and overdose cases. A simple method for the quantification of low levels of nine nitazene analogs and brorphine in Dried Blood Spots (DBS) was developed and validated. 10 μL of spiked whole blood is deposited on a Capitainer®B card and allowed to dry. The spot is punched out, and extracted with 500 μL methanol:acetonitrile (3:1 v/v) added with 1.5 μL of fentanyl-D5 as the internal standard. After stirring, sonication, and centrifugation of the vial, the solvent is dried under nitrogen, the extract is reconstituted in 30 μL methanol, and 1 μL is injected into a UHPLC-MS/MS instrument. The method validation showed linear calibration in the 1-50 ng/mL range, LOD values ranging between 0.3 ng/mL (isotonitazene) and 0.5 ng/mL (brorphine), average CV% and bias% within 15 % and 10 % for all compounds, respectively. The matrix effect due to blood and filter paper components was within 85-115 % while recovery was between 15-20 %. Stability tests against time and temperature showed no significant variations for storage periods up to 28 days. Room temperature proved to represent the best samples storage conditions. UHPLC-MS/MS proved capable to reliably identify all target analytes at low concentration even in small specimen volumes, as those obtained from DBS cards, which in turn confirmed to be effective and sustainable micro-sampling devices. This procedure improves the efficiency of toxicological testing and provides an innovative approach for the identification of the nitazene class of illicit compounds.
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Affiliation(s)
| | | | - Marta Massano
- Department of Chemistry, University of Turin, Turin, Italy
| | | | - Marco Vincenti
- Department of Chemistry, University of Turin, Turin, Italy; Centro Regionale Antidoping, Orbassano, Turin, Italy
| | - Alberto Salomone
- Department of Chemistry, University of Turin, Turin, Italy; Centro Regionale Antidoping, Orbassano, Turin, Italy
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10
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Glatfelter GC, Vandeputte MM, Chen L, Walther D, Tsai MHM, Shi L, Stove CP, Baumann MH. Alkoxy chain length governs the potency of 2-benzylbenzimidazole 'nitazene' opioids associated with human overdose. Psychopharmacology (Berl) 2023; 240:2573-2584. [PMID: 37658878 DOI: 10.1007/s00213-023-06451-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/15/2023] [Indexed: 09/05/2023]
Abstract
RATIONALE Novel synthetic opioids (NSOs) are emerging in recreational drug markets worldwide. In particular, 2-benzylbenzimidazole 'nitazene' compounds are problematic NSOs associated with serious clinical consequences, including fatal respiratory depression. Evidence from in vitro studies shows that alkoxy chain length can influence the potency of nitazenes at the mu-opioid receptor (MOR). However, structure-activity relationships (SARs) of nitazenes for inducing opioid-like effects in animal models are not well understood compared to relevant opioids contributing to the ongoing opioid crisis (e.g., fentanyl). OBJECTIVES Here, we examined the in vitro and in vivo effects of nitazene analogues with varying alkoxy chain lengths (i.e., metonitazene, etonitazene, isotonitazene, protonitazene, and butonitazene) as compared to reference opioids (i.e., morphine and fentanyl). METHODS AND RESULTS Nitazene analogues displayed nanomolar affinities for MOR in rat brain membranes and picomolar potencies to activate MOR in transfected cells. All compounds induced opioid-like effects on locomotor activity, hot plate latency, and body temperature in male mice, and alkoxy chain length markedly influenced potency. Etonitazene, with an ethoxy chain, was the most potent analogue in MOR functional assays (EC50 = 30 pM, Emax = 103%) and across all in vivo endpoints (ED50 = 3-12 μg/kg). In vivo SARs revealed that ethoxy, isopropoxy, and propoxy chains engendered higher potencies than fentanyl, whereas methoxy and butoxy analogues were less potent. MOR functional potencies, but not MOR affinities, were positively correlated with in vivo potencies to induce opioid effects. CONCLUSIONS Overall, our data show that certain nitazene NSOs are more potent than fentanyl as MOR agonists in mice, highlighting concerns regarding the high potential for overdose in humans who are exposed to these compounds.
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Affiliation(s)
- Grant C Glatfelter
- Designer Drug Research Unit, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA.
| | - Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Li Chen
- Computational Chemistry and Molecular Biophysics Section, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA
| | - Donna Walther
- Designer Drug Research Unit, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA
| | - Meng-Hua M Tsai
- Computational Chemistry and Molecular Biophysics Section, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Michael H Baumann
- Designer Drug Research Unit, National Institute On Drug Abuse, Intramural Research Program, Baltimore, MD, USA
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11
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Maskell PD, Elliott S, Desharnais B, Findell M, Jackson G. A model of evaluative opinion to encourage greater transparency and justification of interpretation in postmortem forensic toxicology. J Anal Toxicol 2023; 47:563-573. [PMID: 37566485 PMCID: PMC10503647 DOI: 10.1093/jat/bkad055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/31/2023] [Accepted: 08/10/2023] [Indexed: 08/13/2023] Open
Abstract
Over the past decades, the calls to improve the robustness of interpretation in forensic science have increased in magnitude. Forensic toxicology has seen limited progress in this regard. In this work, we propose a transparent interpretive pathway for use in postmortem forensic toxicology cases. This process allows the selection of the interpretive methodology based on the amount of previous information that is available for the drug(s) in question. One approach is an assessment of various pharmacological and circumstantial considerations resulting in a toxicological significance score (TSS), which is particularly useful in situations where limited information about a drug is available. When there is a robust amount of case data available, then a probabilistic approach, through the evaluation of likelihood ratios by the forensic toxicologist and of prior probabilities by the fact finder, is utilized. This methodology provides a transparent means of making an interpretive decision on the role of a drug in the cause of death. This will allow the field of forensic toxicology to take a step forward in using best practice in evaluative reporting, a tool already used by many other forensic science disciplines.
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Affiliation(s)
- Peter D Maskell
- Scottish Police Authority Forensic Services, Glasgow G69 8AE, UK
- Forensic Medicine and Science, University of Glasgow, Glasgow G12 8QQ, UK
| | - Simon Elliott
- Elliott Forensic Consulting, Birmingham, UK
- Department of Analytical, Environmental and Forensic Sciences, King’s College London, London SE1 9NH, UK
| | - Brigitte Desharnais
- Department of Toxicology, Laboratoire de sciences judiciaires et de médecine légale, 1701 Parthenais Street, Montréal, QC H2K 3S7, Canada
| | - Martin Findell
- Division of Psychology and Forensic Science, School of Applied Sciences, Abertay University, Dundee DD1 1HG, UK
| | - Graham Jackson
- Division of Psychology and Forensic Science, School of Applied Sciences, Abertay University, Dundee DD1 1HG, UK
- Advance Forensic Science, St. Andrews, Scotland, UK
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12
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Vandeputte MM, Tsai MHM, Chen L, Glatfelter GC, Walther D, Stove CP, Shi L, Baumann MH. Comparative neuropharmacology of structurally distinct non-fentanyl opioids that are appearing on recreational drug markets worldwide. Drug Alcohol Depend 2023; 249:109939. [PMID: 37276825 PMCID: PMC10330921 DOI: 10.1016/j.drugalcdep.2023.109939] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/28/2023] [Accepted: 05/18/2023] [Indexed: 06/07/2023]
Abstract
BACKGROUND The emergence of novel synthetic opioids (NSOs) is contributing to the opioid overdose crisis. While fentanyl analogs have historically dominated the NSO market, a shift towards non-fentanyl compounds is now occurring. METHODS Here, we examined the neuropharmacology of structurally distinct non-fentanyl NSOs, including U-47700, isotonitazene, brorphine, and N-desethyl isotonitazene, as compared to morphine and fentanyl. Compounds were tested in vitro using opioid receptor binding assays in rat brain tissue and by monitoring forskolin-stimulated cAMP accumulation in cells expressing the human mu-opioid receptor (MOR). Compounds were administered subcutaneously to male Sprague-Dawley rats, and hot plate antinociception, catalepsy score, and body temperature changes were measured. RESULTS Receptor binding results revealed high MOR selectivity for all compounds, with MOR affinities comparable to those of morphine and fentanyl (i.e., nM). All drugs acted as full-efficacy MOR agonists in the cyclic AMP assay, but nitazene analogs had greater functional potencies (i.e., pM) compared to the other drugs (i.e., nM). When administered to rats, all compounds induced opioid-like antinociception, catalepsy, and body temperature changes, but nitazenes were the most potent. Similar to fentanyl, the nitazenes had faster onset and decline of in vivo effects when compared to morphine. In vivo potencies to induce antinociception and catalepsy (i.e., ED50s) correlated with in vitro functional potencies (i.e., EC50s) but not binding affinities (i.e., Kis) at MOR. CONCLUSIONS Collectively, our findings indicate that non-fentanyl NSOs pose grave danger to those individuals who use opioids. Continued vigilance is needed to identify and characterize synthetic opioids as they emerge in clandestine drug markets.
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Affiliation(s)
- Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Meng-Hua M Tsai
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Li Chen
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Grant C Glatfelter
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Donna Walther
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Michael H Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
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13
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Zawilska JB, Adamowicz P, Kurpeta M, Wojcieszak J. Non-fentanyl new synthetic opioids - An update. Forensic Sci Int 2023; 349:111775. [PMID: 37423031 DOI: 10.1016/j.forsciint.2023.111775] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/11/2023]
Abstract
BACKGROUND New synthetic opioids (NSO) constitute one of the fastest-growing group of New Psychoactive Substances, which emerged on the illicit drug marker in the second half of 2000's. The most popular and the largest NSO subgroup are high potency fentanyl and its analogs. Subsequent to core-structure scheduling of fentanyl-related substances many opioids with different chemical structures are now emerging on the illicit drug market, rendering the landscape highly complex and dynamic. METHODS PubMed, Scopus and Google Scholar were searched for appropriate articles up to December 2022. Moreover, a search for reports was conducted on Institutional websites to identify documentation published by World Health Organization, United Nations Office on Drugs and Crime, United States Drug Enforcement Administration, and European Monitoring Centre for Drugs and Drug Addiction. Only articles or reports written in English were selected. RESULTS Non-fentanyl derived synthetic opioids, i.e., 2-benzylbenzimidazoles (nitazenes), brorphine, U-compounds, AH-7921, MT-45 and related compounds are characterized, describing them in terms of available forms, pharmacology, metabolism as well as their toxic effects. Sample procedures and analytical techniques available for detection and quantification of these compounds in biological matrices are also presented. Finally, as overdoses involving highly potent NSO may be difficult to reverse, the effectiveness of naloxone as a rescue agent in NSO overdose is discussed. CONCLUSIONS Current review presents key information on non-fentanyl derived NSO. Access to upto-date data on substances of abuse is of great importance for clinicians, public health authorities and professionals performing analyses of biological samples.
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Affiliation(s)
- Jolanta B Zawilska
- Department of Pharmacodynamics, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland.
| | - Piotr Adamowicz
- Department of Forensic Toxicology, Institute of Forensic Research, Westerplatte 9, 31-033 Krakow, Poland
| | - Marta Kurpeta
- Department of Pharmacodynamics, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland
| | - Jakub Wojcieszak
- Department of Pharmacodynamics, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland
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14
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Affiliation(s)
- David Love
- United States Drug Enforcement Administration, Special Testing and Research Laboratory, USA
| | - Nicole S. Jones
- RTI International, Applied Justice Research Division, Center for Forensic Sciences, 3040 E. Cornwallis Road, Research Triangle Park, NC, 22709-2194, USA
- 70113 Street, N.W., Suite 750, Washington, DC, 20005-3967, USA
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15
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De Luca MA, Tocco G, Mostallino R, Laus A, Caria F, Musa A, Pintori N, Ucha M, Poza C, Ambrosio E, Di Chiara G, Castelli MP. Pharmacological characterization of novel synthetic opioids: Isotonitazene, metonitazene, and piperidylthiambutene as potent MU opioid receptor agonists. Neuropharmacology 2022; 221:109263. [PMID: 36154843 DOI: 10.1016/j.neuropharm.2022.109263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 09/07/2022] [Accepted: 09/17/2022] [Indexed: 11/30/2022]
Abstract
Recent trends of opioid abuse and related fatalities have highlighted the critical role of Novel Synthetic Opioids (NSOs). We studied the μ-opioid-like properties of isotonitazene (ITZ), metonitazene (MTZ), and piperidylthiambutene (PTB) using different approaches. In vitro studies showed that ITZ and MTZ displayed a higher potency in both rat membrane homogenates (EC50: 0.99 and 19.1 nM, respectively) and CHO-MOR (EC50: 0.71 and 10.0 nM, respectively) than [D-Ala2, NMe-Phe4, Gly-ol5]-enkephalin (DAMGO), with no difference in maximal efficacy (Emax) between DAMGO and NSOs. ITZ also has higher affinity (Ki: 0.06 and 0.05 nM) at the MOR than DAMGO in both systems, whilst MTZ has higher affinity in CHO-MOR (Ki = 0.23 nM) and similar affinity in rat cerebral cortex (Ki = 0.22 nM). PTB showed lower affinity and potency than DAMGO. In vivo, ITZ displayed higher analgesic potency than fentanyl and morphine (ED50: 0.00156, 0.00578, 2.35 mg/kg iv, respectively); ITZ (0.01 mg/kg iv) and MTZ (0.03 mg/kg iv) reduced behavioral activity and increased dialysate dopamine (DA) in the NAc shell (max. about 200% and 170% over basal value, respectively. Notably, ITZ elicited an increase in DA comparable to that of higher dose of morphine (1 mg/kg iv), but higher than the same dose of fentanyl (0.01 mg/kg iv). In silico, induced fit docking (IFD) and metadynamic simulations (MTD) showed that binding modes and structural changes at the receptor, ligand stability, and the overall energy score of NSOs were consistent with the results of the biological assays.
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Affiliation(s)
| | - Graziella Tocco
- Department of Life and Environmental Sciences, University of Cagliari, Italy
| | | | - Antonio Laus
- Department of Life and Environmental Sciences, University of Cagliari, Italy
| | - Francesca Caria
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Aurora Musa
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Nicholas Pintori
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Marcos Ucha
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - Celia Poza
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - Emilio Ambrosio
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - Gaetano Di Chiara
- Department of Biomedical Sciences, University of Cagliari, Italy; CNR Institute of Neuroscience, Cagliari Section, University of Cagliari, Italy.
| | - M Paola Castelli
- Department of Biomedical Sciences, University of Cagliari, Italy.
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16
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Vandeputte MM, Krotulski AJ, Walther D, Glatfelter GC, Papsun D, Walton SE, Logan BK, Baumann MH, Stove CP. Pharmacological evaluation and forensic case series of N-pyrrolidino etonitazene (etonitazepyne), a newly emerging 2-benzylbenzimidazole 'nitazene' synthetic opioid. Arch Toxicol 2022; 96:1845-1863. [PMID: 35477798 DOI: 10.1007/s00204-022-03276-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/14/2022] [Indexed: 11/25/2022]
Abstract
Novel synthetic opioids continue to emerge on recreational drug markets worldwide. In response to legislative bans on fentanyl analogues, non-fentanyl structural templates, such as 2-benzylbenzimidazoles ('nitazenes'), are being exploited to create new μ-opioid receptor (MOR) agonists. Here, we pharmacologically characterize an emerging cyclic analogue of etonitazene, called N-pyrrolidino etonitazene (etonitazepyne), using in vitro and in vivo methods. A series of analytically confirmed fatalities is described to complement preclinical findings. Radioligand binding assays in rat brain tissue revealed that N-pyrrolidino etonitazene has high affinity for MOR (Ki = 4.09 nM) over δ-opioid (Ki = 959 nM) and κ-opioid (Ki = 980 nM) receptors. In a MOR-β-arrestin2 activation assay, N-pyrrolidino etonitazene displayed high potency (EC50 = 0.348 nM), similar to etonitazene (EC50 = 0.360 nM), and largely exceeding the potencies of fentanyl (EC50 = 14.9 nM) and morphine (EC50 = 290 nM). When administered s.c. to male Sprague Dawley rats, N-pyrrolidino etonitazene induced opioid-like antinociceptive, cataleptic, and thermic effects. Its potency in the hot plate test (ED50 = 0.0017 mg/kg) was tenfold and 2,000-fold greater than fentanyl (ED50 = 0.0209 mg/kg) and morphine (ED50 = 3.940 mg/kg), respectively. Twenty-one overdose fatalities associated with N-pyrrolidino etonitazene were found to contain low blood concentrations of the drug (median = 2.2 ng/mL), commonly in the context of polysubstance use. N-Pyrrolidino etonitazene was reported as a cause of death in at least two cases, demonstrating toxicity in humans. We demonstrate that N-pyrrolidino etonitazene is an extremely potent MOR agonist that is likely to present high risk to users. Continued vigilance is required to identify and characterize emergent 2-benzylbenzimidazoles, and other non-fentanyl opioids, as they appear in the marketplace.
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Affiliation(s)
- Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Alex J Krotulski
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
| | - Donna Walther
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Grant C Glatfelter
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | | | - Sara E Walton
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
| | - Barry K Logan
- Center for Forensic Science Research and Education, Fredric Rieders Family Foundation, Willow Grove, PA, 19090, USA
- NMS Labs, Horsham, PA, 19044, USA
| | - Michael H Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
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