Postmortem findings of organ damage in novel psychoactive substances users: A comprehensive review

INTRODUCTION

Despite the rising number of NPS-related deaths, comprehensive data on their prevalence, identification, and associated organ damage remain scarce.

MATERIALS AND METHODS

A literature search was conducted. Predefined inclusion and exclusion criteria were applied, resulting in the identification of 197 articles.

RESULTS

We identified 446 cases of NPS-related deaths, involving a total of 176 different substances. Synthetic opioids were the most prevalent class (34 %), followed by synthetic cannabinoids (22 %) and cathinones (21 %). Co-ingestion of NPS with other substances occurred in 77 % of cases. Macroscopic findings varied across organs, with congestion and edema most observed in the brain (23 %) and lung (56 %), respectively.

DISCUSSION

The existing literature lacks comprehensive descriptions of organs subjected to autopsy and histological examination in NPS-positive subjects. Despite this limitation, our findings underscore the prominence of lung pathology. Moreover, the prevalence of normal organs in cases of acute intoxication is a significant observation. We advocate for future research to provide more detailed insights to enhance our understanding of the multifaceted landscape of NPS-related deaths.

Assessment of high-efficacy agonism in synthetic cannabinoid receptor agonists containing l-tert-leucinate

Synthetic cannabinoid receptor agonists (SCRAs) represent a class of new psychoactive substances that pose great health risks attributed to their wide-ranging and severe adverse effects. Recent evidence has shown that SCRAs with key moieties can confer superagonism, yet this phenomenon is still not well understood. In this study, we developed a structure-activity relationship (SAR) for SCRA superagonism by comparing eight compounds differing by their head moiety (l-valinate vs. l-tert-leucinate), core moiety (indole vs. indazole), and tail moiety (5-fluoropentyl vs. 4-fluorobenzyl) through different modes of bioluminescence resonance energy transfer (BRET). We found that l-tert-leucinate head moiety and indazole core moiety conferred superagonism across multiple Gαi/o proteins and β-arrestin 2. Finally, after generating CB1R mutant constructs, we found that transmembrane 2 (TM2) interactions to the head moiety of tested SCRAs at F170, F177, and H178 are key to eliciting activity.

The Use of Premixed Drugs in Commodity Packets in the Population: Prevalence and Correlates Revealed by the 2018 National Survey of Substance Use in Taiwan

BACKGROUND

Administering premixed drugs in commodity packets was first reported in Asia in 2015, but there continues to be a dearth of related population-based data. This study aimed at examining (1) the prevalence of drug-packet use in the population and (2) the sociodemographic profiles, particularly gender distribution, of drug-packet users.

METHODS

Data were derived from a survey of 18,626 Taiwanese civilians, aged 12-64 years, using stratified, multi-stage, random sampling in 2018. Participants anonymously completed a computer-assisted self-interview on tablet computers which covered the use and problematic use of illicit drugs/inhalants, prescription drugs, and other psychoactive substances.

RESULTS

Approximately 1.46% of respondents had a lifetime use of illicit drugs, with drugs in commodity packets (0.18%) being ranked the fifth-most commonly used illicit drugs, higher than nitrous oxide (0.14%) and heroin (0.09%). Ten formats of drug packets were endorsed by users. Approximately 81.6% of persons with drug packet use had lifetime use of other illicit drugs. The correlates of the use of drugs in commodity packets were different from those of the exclusive use of other drugs, particularly concerning the lack of gender differences in the former category in the whole sample and the subgroups of various sociodemographic characteristics and other substance use.

CONCLUSION

Drugs in commodity packets have become a common way of administering illicit drugs in the population in Taiwan, and there were no gender differences among users. Our findings have implications for more efficient drug testing and culturally appropriate intervention for drug-packet use.

Subtle Structural Modification of a Synthetic Cannabinoid Receptor Agonist Drastically Increases its Efficacy at the CB1 Receptor

The emergence of synthetic cannabinoid receptor agonists (SCRAs) as illicit psychoactive substances has posed considerable public health risks, including fatalities. Many SCRAs exhibit much higher efficacy and potency compared with the phytocannabinoid Δ9-tetrahydrocannabinol (THC) at the cannabinoid receptor 1 (CB1R), leading to dramatic differences in signaling levels that can be toxic. In this study, we investigated the structure-activity relationships of aminoalkylindole SCRAs at CB1Rs, focusing on 5F-pentylindoles containing an amide linker attached to different head moieties. Using in vitro bioluminescence resonance energy transfer assays, we identified a few SCRAs exhibiting significantly higher efficacy in engaging the Gi protein and recruiting β-arrestin than the reference CB1R full agonist CP55940. Importantly, the extra methyl group on the head moiety of 5F-MDMB-PICA, as compared to that of 5F-MMB-PICA, led to a large increase in efficacy and potency at the CB1R. This pharmacological observation was supported by the functional effects of these SCRAs on glutamate field potentials recorded in hippocampal slices. Molecular modeling and simulations of the CB1R models bound with both of the SCRAs revealed critical structural determinants contributing to the higher efficacy of 5F-MDMB-PICA and how these subtle differences propagated to the receptor-G protein interface. Thus, we find that apparently minor structural changes in the head moiety of SCRAs can cause major changes in efficacy. Our results highlight the need for close monitoring of the structural modifications of newly emerging SCRAs and their potential for toxic drug responses in humans.

Toxicity of Synthetic Cannabinoids in K2/Spice: A Systematic Review

(1) Background: Synthetic cannabinoids (SCs) are emerging drugs of abuse sold as 'K2', 'K9' or 'Spice'. Evidence shows that using SCs products leads to greater health risks than cannabis. They have been associated with greater toxicity and higher addiction potential unrelated to the primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC). Moreover, early cases of intoxication and death related to SCs highlight the inherent danger that may accompany the use of these substances. However, there is limited knowledge of the toxicology of Spice ingredients. This systematic review intends to analyze the toxicity of SCs compounds in Spice/K2 drugs. (2) Methods: Studies analyzing synthetic cannabinoid toxicity and dependence were included in the present review. We searched the PubMed database of the US National Library of Medicine, Google Scholar, CompTox Chemicals, and Web of Science up to May 2022. (3) Results: Sixty-four articles reporting the effects of synthetic cannabinoids in humans were included in our review. Ten original papers and fifty-four case studies were also included. Fourteen studies reported death associated with synthetic cannabinoid use, with AB-CHMINACA and MDMB-CHMICA being the main reported SCs. Tachycardia and seizures were the most common toxicity symptoms. The prevalence of neuropsychiatric symptoms was higher in third-generation SCs. (4) Conclusion: SCs may exhibit higher toxicity than THC and longer-lasting effects. Their use may be harmful, especially in people with epilepsy and schizophrenia, because of the increased risk of the precipitation of psychiatric and neurologic disorders. Compared to other drugs, SCs have a higher potential to trigger a convulsive crisis, a decline in consciousness, and hemodynamic changes. Therefore, it is crucial to clarify their potential harms and increase the availability of toxicology data in both clinical and research settings.

A subtle structural modification of a synthetic cannabinoid receptor agonist drastically increases its efficacy at the CB1 receptor

The emergence of synthetic cannabinoid receptor agonists (SCRAs) as illicit psychoactive substances has posed considerable public health risks that include fatalities. Many SCRAs exhibit much higher efficacy and potency, compared with the phytocannabinoid Δ9-tetrahydrocannabinol (THC), at the cannabinoid receptor 1 (CB1R), a G protein-coupled receptor involved in modulating neurotransmitter release. In this study, we investigated structure activity relationships (SAR) of aminoalkylindole SCRAs at CB1Rs, focusing on 5F-pentylindoles containing an amide linker attached to different head moieties. Using in vitro bioluminescence resonance energy transfer (BRET) assays, we identified a few of SCRAs exhibiting significantly higher efficacy in engaging the Gi protein and recruiting β-arrestin than the reference CB1R full agonist CP55940. Importantly, adding a methyl group at the head moiety of 5F-MMB-PICA yielded 5F-MDMB-PICA, an agonist exhibiting a large increase in efficacy and potency at the CB1R. This pharmacological observation was supported by a functional assay of the effects of these SCRAs on glutamate field potentials recorded in hippocampal slices. Molecular modeling and simulations of the CB1R bound with either of the SCRAs revealed critical structural determinants contributing to the higher efficacy of 5F-MDMB-PICA, and how these subtle differences propagated to the receptor-G protein interface. Thus, we find that apparently minor structural changes in the head moiety of SCRAs can cause major changes in efficacy. Our results highlight the need for close monitoring of structural modifications of newly emerging SCRAs and their potential for toxic drug responses in humans.

'Flying high?'-Jump from a height in a 'Spice' high?: A case report on the synthetic cannabinoid 5F-MDMB-P7AICA

Regarding the high potency of synthetic cannabinoids (SC), many intoxications and fatal cases are reported in literature. Here, we report on a fatality with 5F-MDMB-P7AICA contributing to the occurrence of death. A 31-year-old man died 10 h after he fell from the rooftop of a house. Police investigations revealed that he had consumed a 'legal high' herbal blend some hours earlier. An initial toxicological screening for new psychoactive substances (NPS) was negative. One year after, the analysis of confiscated drug samples revealed the SC 5F-MDMB-P7AICA being unknown at the time of the first investigations. Hence, post-mortem specimens were retrospectively analysed for 5F-MDMB-P7AICA and its dimethylbutanoic acid (DBA) metabolite. Lung, liver, kidney and bile fluid (BF) of the decedent were analysed following solid-phase extraction and standard addition, heart blood (HB) and peripheral blood (PB) by fully validated liquid-liquid extraction and protein precipitation methods. Additionally, hair specimens were analysed to examine a possible chronic consumption of the SC. All specimens were analysed by liquid-chromatography tandem mass spectrometry. 5F-MDMB-P7AICA was detected in HB (0.69 ng/ml), PB (1.2 ng/ml) and hair. DBA was found in HB (46 ng/ml) and PB (5.7 ng/ml) and could additionally be identified in liver and kidney (approximately 4-5 ng/g), lung (approximately 12 ng/g) and BF (approximately 60 ng/g). Compared with the parent compound, much higher concentrations of DBA were quantified. This case shows that drugs found at the scene can provide helpful initial information for further toxicological screenings in biological samples, especially when there is evidence of NPS consumption.

Defining Steric Requirements at CB1 and CB2 Cannabinoid Receptors Using Synthetic Cannabinoid Receptor Agonists 5F-AB-PINACA, 5F-ADB-PINACA, PX-1, PX-2, NNL-1, and Their Analogues

Synthetic cannabinoid receptor agonists (SCRAs) are a diverse class of new psychoactive substances (NPS). They commonly comprise N-alkylated indole, indazole, or 7-azaindole scaffolds with amide-linked pendant amino acid groups. To explore the contribution of the amino acid side chain to the cannabinoid pharmacology of SCRA NPS, a systematic library of side chain-modified SCRAs was prepared based on the recent detections of amino acid derivatives 17 (5F-AB-PINACA), 18 (5F-ADB-PINACA), 15 (PX-1), 19 (PX-2), and 20 (NNL-1). In vitro binding affinities and functional activities at cannabinoid type 1 and 2 receptors (CB₁ and CB₂, respectively) were determined for all the library members using radioligand competition experiments and a fluorescence-based membrane potential assay. Binding affinities and functional activities varied widely across compounds (K_i = 0.32 to >10 000 nM, EC₅₀ = 0.24-1259 nM), with several clear structure-activity relationships (SARs) emerging. Affinity and potency at CB₁ changed as a function of the heterocyclic core (indazole > indole > 7-azaindole) and the pendant amino acid side chain (tert-butyl > iso-propyl > iso-butyl > benzyl > ethyl > methyl > hydrogen). Ensemble docking at CB₁ revealed a clear steric basis for observed SAR trends. Interestingly, although 15 (PX-1) and 19 (PX-2) have been detected in recreational drug markets, they failed to induce centrally CB₁-mediated effects (e.g., hypothermia) in mice using radiobiotelemetry. Together, these data provide insights regarding structural contributions to the cannabimimetic profiles of 17 (5F-AB-PINACA), 18 (5F-ADB-PINACA), 15 (PX-1), 19 (PX-2), 20 (NNL-1), and other SCRA NPS.

Analytical findings in a non-fatal intoxication with the synthetic cannabinoid 5F-ADB (5F-MDMB-PINACA): a case report

The case report centres on analytical findings from a spice sample (mixed with tobacco (as a cigarette) for consumption), and its corresponding plasma sample, smoked by a 31-year-old man who was attended by emergency services following collapse. The man was fully conscious and cooperative during initial medical treatment. Suddenly, he suffered a complete loss of self-control, whereupon the police was notified. The man encountered the police officers when exiting the apartment, at which point he threatened them with clenched fists and reached for a plant bucket in order to strike out in the direction of the officers. At the trial, he described himself as confused and as being completely overwhelmed, having lost self-control, suffered a panic attack and “just wanted to get out the situation”. Furthermore, he stated that he had no recollection of the incident. He feared death due to palpitations, heart pain, dizziness and repetitive anxiety states. Routine systematic as well as extended toxicological analysis of the plasma sample, taken approximately 2 h after the incident, confirmed the use of cannabis and spice. Plasma concentrations of THC, OH-THC and THC-COOH were 8.0 μg/L, 4.0 μg/L and 147 μg/L, respectively. Furthermore, analysis confirmed uptake of 5F-ADB (5F-MDMB-PINACA) via detection of both 5F-ADB and the 5F-ADB N-(5-OH-pentyl) metabolite. The spice sample additionally contained 5F-MDMB-PICA, which was not detected in the plasma sample. A differentiation between a possible co-use and a recent use of cannabis was not possible. In summary, this case once more underlines the health risks of spice use.

Involuntary 5F-ADB-related intoxication following e-cigarette use

The detection of synthetic cannabinoid (SC) intoxication cases is challenging, even more when the involved SC identification is requested in a forensic context. This situation can be complicated by new modes of SC consumption, non-specific symptomatology, and analytical pitfalls. To illustrate these issues, we report the case of a 16-year-old man who presented symptoms evocating of a seizure disorder in the minutes following the use of a friend's e-cigarette. At admission in the emergency department, his electroencephalogram was interpreted as coherent with a recent seizure episode. 5F-ADB, a third generation SC, was detected in the e-liquid and in an early collected (H2 after the e-cigarette use) serum sample (0.50 µg/L), but not in urine samples (H18 and H38). One 5F-ADB metabolite, O-desmethyl-5F-ADB (M5), was detectable in urine up to at least 38 h after intoxication. Neither 5F-ADB nor its metabolites could be detected in victim's hair sampled 3 months after the intoxication. Although leading to a non-specific symptomatology, acute SC intoxication should be considered when the case history is related to e-cigarette or e-liquid use. Early biological samples are recommended, even if analytical screening can be positive for SC metabolites in urine sampled until 2 days after exposure. Accordingly, data from the literature and the present case underscore the relevance of adding both main 5F-ADB metabolites (M5 and 5-OH-pentyl-ADB) to mass spectrum databases used for toxicological screening in order to reduce the risk of false-negative results in intoxication cases involving 5F-ADB.

Analytical Methodologies for the Characterization and Analysis of the Parent Compound and Phase I Metabolites of 4F-MDMB-BICA in Human Microsome, Urine, and Blood Samples

4F-MDMB-BICA is one of the most dangerous new illicit synthetic cannabinoids (SCs) in 2020. Consumption of 4F-MDMB-BICA has been associated with a number of death cases and related serious adverse health effects in Hungary. Therefore, the use of reliable analytical methods to confirm the intake of 4F-MDMB-BICA is an important issue in forensic practice. Besides the detection of the parent compounds of SCs, the screening of their metabolites provides a reliable confirmation of their consumption, in particular, when the parent compound is under the limit of detection. To the best of our knowledge, this is the first report describing the identification of metabolites of 4F-MDMD-BICA after treatment with pooled human liver microsome (pHLM), and in human urine and blood samples using the combination of data obtained by comprehensive UHPLC-HRMS and semi-targeted UHPLC-HRMS/MS methods. Finally, our routine UHPLC-MS/MS method for screening urine and blood SCs was improved by adding the parent compound and selected main biomarkers of 4F-MDMD-BICA. From the pHLM assay of 4F-MDMD-BICA, 30 phase I metabolites were characterized and structural information thus obtained provided the basis of further identification of in vivo urine and blood metabolites. Overall, 20 urinary and 13 blood in vivo metabolites of 4F-MDMD-BICA have been identified by the investigation of five authentic urine and two blood samples. The ester hydrolysis metabolite was selected as a reliable primary biomarker in urine and blood. As secondary targets, urinary mono-hydroxylation metabolite and ester hydrolysis + dehydrogenation metabolite in blood were recommended due to their abundance and selectivity. Overall, the main phase I metabolites of 4F-MDMD-BICA were successfully characterized, and our routine analytical method with related sample preparation procedure provided a reliable analytical tool for screening both 4F-MDMD-BICA and its selected metabolites in urine and blood samples.

Metabolic profiling of synthetic cannabinoid 5F-ADB and identification of metabolites in authentic human blood samples via human liver microsome incubation and ultra-high-performance liquid chromatography/high-resolution mass spectrometry

RATIONALE

Indazole carboxamide synthetic cannabinoids, a prevalent class of recreational drugs, are a major clinical, forensic and public health challenge. One such compound, 5F-ADB, has been implicated in fatalities worldwide. Understanding its metabolism and distribution facilitates the development of laboratory assays to substantiate its consumption. Synthetic cannabinoid metabolites have been extensively studied in urine; studies identifying metabolites in blood are limited and no data on the metabolic stability (half-life, clearance and extraction ratio) of 5F-ADB have been published prior to this report.

METHODS

The in vitro metabolism of 5F-ADB was elucidated via incubation with human liver microsomes for 2 h at 37°C. Samples were collected at multiple time points to determine its metabolic stability. Upon identification of metabolites, authentic forensic human blood samples underwent liquid-liquid extraction and were screened for metabolites. Extracts were analyzed via ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOFMS) operated in positive electrospray ionization mode.

RESULTS

Seven metabolites were identified including oxidative defluorination (M1); carboxypentyl (M2); monohydroxylation of the fluoropentyl chain (M3.1/M3.2) and indazole ring system (M4); ester hydrolysis (M5); and ester hydrolysis with oxidative defluorination (M6). The half-life (3.1 min), intrinsic clearance (256.2 mL min^-1  kg^-1 ), hepatic clearance (18.6 mL min^-1 kg^-1 ) and extraction ratio (0.93) were determined for the first time. In blood, M1 was present in each sample as the most abundant substance; two samples contained M5; one contained 5F-ADB, M1 and M5.

CONCLUSIONS

5F-ADB is rapidly metabolized in HLM. 5F-ADB, M1 and M5 are pharmacologically active at the cannabinoid receptors (CB₁ /CB₂ ) and M1 and M5 may contribute to a user's impairment profile. The results demonstrate that it is imperative that synthetic cannabinoid assays screen for pharmacologically active metabolites, especially for drugs with short half-lives. The authors propose that M1 and M5 are appropriate markers to include in laboratory blood tests screening for 5F-ADB.

Accidental Ingestion of a Novel Psychoactive Substance: A Case Report

Novel psychoactive substances (NPSs) are a new generation of designer drugs that are quickly replacing the traditionally abused street drugs. Since their development, the number of molecules in NPSs and their variants have expanded exponentially. Little is known locally about the toxic effects of the exposure of these NPSs. We report two cases of accidental ingestion of methyl (2S)-2-{[1-(5-fluoropentyl)-1H-indole-3-arbonyl]amino}-3,3-dimethylbutanoate (5-fluoro-MDMB-PICA), a recent NPS. They were drinking the liquid in a winter melon tea bottle, and one patient had a seizure episode directly after ingestion. Both patients were managed supportively and discharged after a brief hospitalization period. Presentation to the emergency departments (EDs) following exposure to NPSs may become more common. Knowledge about the impact of NPS exposure and their clinical effects is lacking amongst emergency physicians in Singapore, and this case report serves as a potential resource for physicians.

On practical problems in precise estimation of 5F-ADB in urine samples

Purpose

The purpose of this work is to establish if there are any problems in precise quantitation of methyl 2-[1-(5-fluoropentyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate (5F-ADB) in human urine by QuEChERS extraction coupled with gas chromatography–tandem mass spectrometry (GC–MS/MS).

Methods

To establish the method for quantifying 5F-ADB in human urine samples, QuEChERS extraction coupled with GC–MS/MS was applied. To elucidate 5F-ADB degradation products, liquid chromatography coupled with linear trap quadrupole-orbitrap hybrid MS (LC–MS) was used.

Results

The applied QuEChERS GC–MS/MS procedure appeared to be satisfactory for 5F-ADB estimation in acidic and alkaline urine samples. Its validation parameters were the following: good linearity (R2 = 0.9988), high detection (limit of detection = 0.33 ng/mL) and quantitation (limit of quantitation = 1.1 ng/mL) sensitivities and satisfactory inter- and intraday precisions (% relative standard deviation below 5.6%). 5F-ADB recovery from acidic urine by QuEChERS procedure was slightly lower than that from urine sample with neutral pH; however, the difference in the recovery was not statistically significant. The recovery of the drug from alkaline urine is extremely low. LC–MS analysis proved the presence of 5F-ADB hydrolysis products in alkaline urine and in alkaline solution of the drug.

Conclusions

The presented studies indicate that the validated QuEChERS technique can be successfully used in routine analyses of 5F-ADB in urine. Yet, due to hydrolytical instability of 5F-ADB, the medical diagnosis of the health condition of the patient suspected of 5F-ADB abuse on the basis of the drug concentration in his/her urine may be incorrect, especially when the urine is alkaline.

Post-Mortem Toxicology: A Systematic Review of Death Cases Involving Synthetic Cannabinoid Receptor Agonists

BACKGROUND

Synthetic cannabinoid receptor agonists (SCRAs) have become the largest group of new psychoactive substances monitored by the European Union Early Warning System. Despite the wide diffusion on the market, data regarding effects, toxicities, and mechanisms as well as toxic/lethal doses are still scarce.

METHODS

A comprehensive literature search for articles published up to January 2019 was performed in multiple electronic databases. Only cases of death in which toxicological analyses revealed the presence of SCRAs in blood or urine and at least an external examination was performed, including those occurred in emergency departments, were included.

RESULTS

Of 380 studies identified, 354 were excluded, while 8 additional manuscripts were included through the screening of relevant references cited in the selected articles. A total number of 34 manuscripts (8 case series and 26 case reports) were included.

CONCLUSIONS

Typical toxic ranges for SCRAs have not been so far identified, and the results of toxicological analyses should be interpreted with caution. In death cases involving SCRAs, a thorough post-mortem examination is a prerequisite to assess the role of the substance use in the deceased and to identify a probable mechanism of death. Even after a comprehensive analysis of clinical, circumstantial, toxicological, and autoptic data, the cause and manner of death remain unclear in some cases.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABAA) or GABAB receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-D-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB1) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.

Identification of synthetic cannabinoids that were seized, consumed, or associated with deaths in Kuwait in 2018 using GC-MS and LC-MS-MS analysis

Synthetic cannabinoids are gaining much popularity worldwide. Although the death rate associated with their use is rising, these drugs are the largest and fastest growing class of novel psychoactive substances. Despite increased concerns regarding adverse effects stemming from the use of synthetic cannabinoids, there is no published data on the subject for the Gulf region or Kuwait, specifically. The current study investigates the diversity of synthetic cannabinoids in Kuwait in 2018. In total, 434 cases from the Narcotics and Psychotropic Laboratory, 70 cases from the Toxicology Laboratory, and six cases from the Forensic Medicine Department were reviewed and analyzed. Numerous synthetic cannabinoid types were identified using GC-MS and LC-MS-MS. The majority of synthetic cannabinoids were members of the indazole-3-carboxamide or indole-3-carboxamide families. Members from the indazole-3-carboxamide family identified in Kuwait were 5F-ADB, FUB-AMB, ADB-FUBINACA, AB-FUBINACA, 5F-ADB-PINACA, 5F-AKB-48, 5Cl-AKB-48, MDMB-FUBINACA, 5F-AB-PINACA, APINACA, and AB-PINACA whereas MDMB-CHMICA, 5F-MDMB-PICA, ADB-BICA, and MMB-CHMICA belonged to the indole-3-carboxamide family. In addition, members of other families were identified, including CBL2201 and UR-144, which belonged to indole-3-carboxylate and cyclopropylindole families, respectively. The most common synthetic cannabinoids were 5F-ADB, FUB-AMB, and 5Cl-AKB-48. Various mixes of two, three, or four types of synthetic cannabinoids were identified, and mixtures of synthetic cannabinoids with other illicit drugs were also present. Our findings show that in Kuwait, the most common mix of synthetic cannabinoids is FUB-AMB with 5F-ADB. These two types were mixed, either together or individually, with methamphetamine, tramadol, heroin, ^Δ9THC, and ketamine. Most importantly, our results reveal the synthetic cannabinoid types that were associated with six reported deaths.

Fatalities related to new psychoactive substances in Singapore-A case series

The use of New Psychoactive Substances (NPS) has become a serious global issue with increasing number of reports of their toxicities and fatalities. Likewise, in Singapore, the number of exhibits containing NPS detected had increased 80% from 2011 to 2014. This is a case series of the first four autopsy cases of fatalities due to or related to the use of NPS in Singapore. In one case, we present the first reported case of death due directly to ADB-FUBINACA toxicity (post-mortem blood concentration of 56ng/ml). Another case was due to 25B-NBOMe toxicity (post-mortem blood concentration of 10ng/ml) while the last two cases were deaths related to 5-Fluoro ADB, where the metabolites of the drug were detected.

Identification and Quantification of 5-Fluoro ADB and the 5-Fluoro ADB Ester Hydrolysis Metabolite in Postmortem Blood Samples by LC–MS/MS

5-Fluoro ADB, also known as 5-fluoro MDMB-PINACA, is a potent synthetic cannabinoid that is an agonist to the human cannabinoid CB1 and CB2 receptors. Adverse physiological and psychological effects that have resulted in hospitalization and/or death have been associated with 5-Fluoro ADB use. In addition, analytical confirmation of 5-Fluoro ADB use has been reported in both forensic human performance toxicology and postmortem cases. An analytical method for the identification and quantification of 5-fluoro ADB and the 5-fluoro ADB ester hydrolysis metabolite in human blood samples by liquid chromatography–tandem mass spectrometry was created and validated. The linear range of this assay was determined to be 0.01–10 ng/mL for 5-fluoro ADB and 10–500 ng/mL for the 5-fluoro ADB ester hydrolysis metabolite. The method met both precision and accuracy requirements. Endogenous and exogenous interferences were not observed. Ion suppression exceeding 25% was observed for 5-fluoro ADB. However, additional experiments were performed to ensure that the observed suppression did not affect other method validation parameters such as limit of detection and accuracy. Blood samples from 36 postmortem cases were analyzed utilizing this methodology. The average blood concentration of 5-fluoro ADB was 0.29 ng/mL in central blood specimens and 0.05 ng/mL in peripheral blood specimens. The average blood concentration of the 5-fluoro ADB ester hydrolysis metabolite was 49 ng/mL in central blood specimens and 21 ng/mL in peripheral blood specimens. A serum sample was also analyzed and had a serum concentration of 0.12 ng/mL for 5-fluoro ADB and 42 ng/mL for the 5-fluoro ADB ester hydrolysis metabolite. As the concentration of the 5-fluoro ADB ester hydrolysis metabolite was found at a greater concentration than that of 5-fluoro ADB, this metabolite may be a useful marker to monitor in an attempt to confirm 5-fluoro ADB use in toxicological investigations.

Forty-Three Fatalities Involving the Synthetic Cannabinoid, 5-Fluoro-ADB: Forensic Pathology and Toxicology Implications

Forty-three fatalities involving the potent synthetic cannabinoid, 5-Fluoro-ADB, are summarized. For each case, a description of the terminal event, autopsy findings, cause of death, qualitative identification of 5-Fluoro-ADB and its ester hydrolysis metabolite, 5-Fluoro-ADB metabolite 7, in urine, and the quantitative values obtained in the blood specimens are outlined. Central blood concentrations ranged from 0.010 to 2.2 ng/mL for 5-Fluoro-ADB and 2.0 to 166 ng/mL for 5-Fluoro-ADB metabolite 7. Peripheral blood concentrations ranged from 0.010 to 0.77 ng/mL and 2.0 to 110 ng/mL for 5-Fluoro-ADB and 5-Fluoro-ADB metabolite 7, respectively. The majority of cases resulted in central to peripheral blood concentration ratios greater than 1 for 5-Fluoro-ADB (58%) and 5-Fluoro-ADB metabolite 7 (71%) suggesting that postmortem redistribution occurs to some extent. Combining the increased cardiac weight and/or gastric volume and toxicology data identifying 5-Fluoro-ADB, it is hypothesized that abuse of this substance may precipitate a dysrhythmia and cause sudden death.

The identification and quantification of synthetic cannabinoids seized in New Zealand in 2017

There has been an explosion of new psychoactive substances (NPS) over the past decade, with synthetic cannabinoids comprising one of the more extensive and chemically diverse groups. Synthetic cannabinoids, like other NPS, are continually evolving with slight alterations in chemical structure, which can lead to unintended and harmful effects for the user. Furthermore, the clandestine preparation of plant material containing one or more synthetic cannabinoid can result in an unevenly distributed product, which poses an additional risk to the user of increased doses. This investigation aimed at providing a snapshot of synthetic cannabinoids in New Zealand in 2017, including the concentrations of synthetic cannabinoids in plant material. Overall, ten different synthetic cannabinoids were detected, with AMB-FUBINACA and 5F-ADB comprising the majority of samples analysed. The synthetic cannabinoid AMB-FUBINACA displayed the greatest range of concentration in plant material, from 5 to over 400 g of synthetic cannabinoid per kilogram of plant material. There was also geographical variation in the synthetic cannabinoids depending on where in New Zealand they were seized from.

Synthetic Cannabinoid Hydroxypentyl Metabolites Retain Efficacy at Human Cannabinoid Receptors

Synthetic cannabinoids (SCs) are novel psychoactive substances that are easily acquired, widely abused as a substitute for cannabis, and associated with cardiotoxicity and seizures. Although the structural bases of these compounds are scaffolds with known affinity and efficacy at the human cannabinoid type-1 receptor (hCB1), upon ingestion or inhalation they can be metabolized to multiple chemical entities of unknown pharmacological activity. A large proportion of these metabolites are hydroxylated on the pentyl chain, a key substituent that determines receptor affinity and selectivity. Thus, the pharmacology of SC metabolites may be an important component in understanding the in vivo effects of SCs. We examined nine SCs (AB-PINACA, 5F-AB-PINACA, ADB/MDMB-PINACA, 5F-ADB, 5F-CUMYL-PINACA, AMB-PINACA, 5F-AMB, APINACA, and 5F-APINACA) and their hydroxypentyl (either 4-OH or 5-OH) metabolites in [3H]CP55,940 receptor binding and the [35S]GTPγS functional assay to determine the extent to which these metabolites retain activity at cannabinoid receptors. All of the SCs tested exhibited high affinity (<10 nM) and efficacy for hCB1 and hCB2 The majority of the hydroxypentyl metabolites retained full efficacy at hCB1 and hCB2, albeit with reduced affinity and potency, and exhibited greater binding selectivity for hCB2 These data suggest that phase I metabolites may be contributing to the in vivo pharmacology and toxicology of abused SCs. Considering this and previous reports demonstrating that metabolites retain efficacy at the hCB1 receptor, the full pharmacokinetic profiles of the parent compounds and their metabolites need to be considered in terms of the pharmacological effects and time course associated with these drugs.

The Chemistry and Pharmacology of Synthetic Cannabinoid Receptor Agonist New Psychoactive Substances: Evolution

Synthetic cannabinoid receptor agonists (SCRAs) are the largest and most structurally diverse class of new psychoactive substances (NPS). Although the earliest SCRA NPS were simply repurposed from historical academic manuscripts or pharmaceutical patents describing cannabinoid ligands, recent examples bear hallmarks of rational design. SCRA NPS manufacturers have applied traditional medicinal chemistry strategies (such as molecular hybridization, bioisosteric replacement, and scaffold hopping) to existing cannabinoid templates in order to generate new molecules that circumvent structure-based legislation. Most SCRAs potently activate cannabinoid type 1 and type 2 receptors (CB₁ and CB₂, respectively), with the former contributing to the psychoactivity of these substances. SCRAs are generally more toxic than the Δ⁹-tetrahydrocannabinol (Δ⁹-THC) found in cannabis, and this may be due to ligand bias, metabolism, or off-target activity. This chapter will chart the evolution of recently identified SCRA NPS chemotypes, as well as their putative manufacturing by-products and thermolytic degradants, and describe structure-activity relationships within each class.

Fatal Poisonings Associated with New Psychoactive Substances

This chapter describes how new psychoactive substances (NPS) have been involved in fatal intoxications from 2010 and onwards. It summarizes the circumstances, antemortem symptoms, and adverse effects that have led to death after ingestion of one or more NPS and tabulates concentrations, and postmortem findings from these intoxications.Consumption of NPS exerts health problems and unknown risks for the users. Data on toxicity of many NPS are scarce or nonexistent and long-term toxicity and risks are still largely unknown. In addition, purity and composition of products containing NPS are often inconsistent or not known, which places users at high risk as evidenced by hospital emergency admissions and deaths.The most serious threat to drug users are the synthetic opioids that with strong central nervous depressant effects have caused numerous accidental deaths spread over the entire globe. The synthetic cannabinoids seem to be the most unpredictable with no clear toxidrome and unknown or poorly understood mechanisms of toxicity, but with adverse effects pointing toward the cardiovascular system. The toxidromes commonly encountered after ingestion of cathinones and phenethylamines are of sympathomimetic and hallucinogenic character, which includes risk of developing a serotonin syndrome, excited delirium, and life-threatening cardiovascular effects. In comparison to their conventional "parent" drug, i.e., heroin, cannabis, and amphetamine, most NPS appear to exhibit more severe adverse effects. The deaths attributed to NPS have dramatically increased in the last years. In our opinion, this is because of the shift from synthetic cannabinoids and cathinones to the even more toxic and dangerously potent fentanyl analogues.