Timeframe Analysis of Novel Synthetic Cannabinoids Effects: A Study on Behavioral Response and Endogenous Cannabinoids Disruption.

This study investigates the impact of SCs consumption by assessing the effects of three novel synthetic cannabinoids (SCs); MDMB-CHMINACA, 5F-ADB-PINACA, and APICA post-drug treatment. SCs are known for their rapid onset (<1 min) and prolonged duration (≥5 h). Therefore, this research aimed to assess behavioral responses and their correlation with endocannabinoids (ECs) accumulation in the hippocampus, and EC's metabolic enzymes alteration at different timeframes (1-3-5-h) following drug administration. Different extents of locomotive disruption and sustained anxiety-like symptoms were observed throughout all-encompassing timeframes of drug administration. Notably, MDMB-CHMINACA induced significant memory impairment at 1 and 3 h. Elevated levels of anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) were detected 1 h post-MDMB-CHMINACA and 5F-ADB-PINACA administration. Reduced mRNA expression levels of fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL) (AEA and 2-AG degrading enzymes, respectively), and brain-derived neurotrophic factor (BDNF) occurred at 1 h, with FAAH levels remaining reduced at 3 h. These findings suggest a connection between increased EC content and decreased BDNF expression following SC exposure. Cognitive disruption, particularly motor coordination decline and progressive loss manifested in a time-dependent manner across all the analyzed SCs. Our study highlights the importance of adopting a temporal framework when assessing the effects of SCs.

Detection of the Synthetic Cannabinoids AB-CHMINACA, ADB-CHMINACA, MDMB-CHMICA, and 5F-MDMB-PINACA in Biological Matrices: A Systematic Review.

New synthetic cannabinoids (SCs) are emerging rapidly and continuously. Biological matrices are key for their precise detection to link toxicity and symptoms to each compound and concentration and ascertain consumption trends. The objective of this study was to determine the best human biological matrices to detect the risk-assessed compounds provided by The European Monitoring Centre for Drugs and Drug Addiction: AB-CHMINACA, ADB-CHMNACA, MDMB-CHMICA, and 5F-MDMB-PINACA. We carried out a systematic review covering 2015 up to the present date, including original articles assessing detection in antemortem human biological matrices with detailed validation information of the technique. In oral fluid and blood, SC parent compounds were found in oral fluid and blood at low concentrations and usually with other substances; thus, the correlation between SCs concentrations and severity of symptoms could rarely be established. When hair is used as the biological matrix, there are difficulties in excluding passive contamination when evaluating chronic consumption. Detection of metabolites in urine is complex because it requires prior identification studies. LC-MS/MS assays were the most widely used approaches for the selective identification of SCs, although the lack of standard references and the need for revalidation with the continuous emergence of new SCs are limiting factors of this technique. A potential solution is high-resolution mass spectrometry screening, which allows for non-targeted detection and retrospective data interrogation.

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 (Ki = 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.

Induction of Liver Size Reduction in Zebrafish Larvae by the Emerging Synthetic Cannabinoid 4F-MDMB-BINACA and Its Impact on Drug Metabolism.

Zebrafish (ZF; Danio rerio) larvae have become a popular in vivo model in drug metabolism studies. Here, we investigated the metabolism of methyl 2-[1-(4-fluorobutyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate (4F-MDMB-BINACA) in ZF larvae after direct administration of the cannabinoid via microinjection, and we visualized the spatial distributions of the parent compound and its metabolites by mass spectrometry imaging (MSI). Furthermore, using genetically modified ZF larvae, the role of cannabinoid receptor type 1 (CB1) and type 2 (CB2) on drug metabolism was studied. Receptor-deficient ZF mutant larvae were created using morpholino oligonucleotides (MOs), and CB2-deficiency had a critical impact on liver development of ZF larva, leading to a significant reduction of liver size. A similar phenotype was observed when treating wild-type ZF larvae with 4F-MDMB-BINACA. Thus, we reasoned that the cannabinoid-induced impaired liver development might also influence its metabolic function. Studying the metabolism of two synthetic cannabinoids, 4F-MDMB-BINACA and methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate (7'N-5F-ADB), revealed important insights into the in vivo metabolism of these compounds and the role of cannabinoid receptor binding.

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.

Drug Administration Routes Impact the Metabolism of a Synthetic Cannabinoid in the Zebrafish Larvae Model.

Zebrafish (Danio rerio) larvae have gained attention as a valid model to study in vivo drug metabolism and to predict human metabolism. The microinjection of compounds, oligonucleotides, or pathogens into zebrafish embryos at an early developmental stage is a well-established technique. Here, we investigated the metabolism of zebrafish larvae after microinjection of methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate (7'N-5F-ADB) as a representative of recently introduced synthetic cannabinoids. Results were compared to human urine data and data from the in vitro HepaRG model and the metabolic pathway of 7'N-5F-ADB were reconstructed. Out of 27 metabolites detected in human urine samples, 19 and 15 metabolites were present in zebrafish larvae and HepaRG cells, respectively. The route of administration to zebrafish larvae had a major impact and we found a high number of metabolites when 7'N-5F-ADB was microinjected into the caudal vein, heart ventricle, or hindbrain. We further studied the spatial distribution of the parent compound and its metabolites by mass spectrometry imaging (MSI) of treated zebrafish larvae to demonstrate the discrepancy in metabolite profiles among larvae exposed through different administration routes. In conclusion, zebrafish larvae represent a superb model for studying drug metabolism, and when combined with MSI, the optimal administration route can be determined based on in vivo drug distribution.

Effects of external influences on synthetic cannabinoid trends in New Zealand, 2014 to 2020.

Over the past decade, synthetic cannabinoids have inundated the global market and now form the largest category of new psychoactive substances. Once these chemicals are available on the global market, they can be applied to plant material in a clandestine environment to create an end-product that is smoked by the user. The synthetic cannabinoids AMB-FUBINACA and 5F-ADB were most frequently detected between 2017 and the beginning of 2019. More recently, these two appear to have been replaced by different synthetic cannabinoids. This investigation summarises the recent trends in synthetic cannabinoids detected in New Zealand between 2017 and 2020 and outlines the potential factors influencing these trends.

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.

Detection and quantification of 5F-ADB and its methyl ester hydrolysis metabolite in fatal intoxication cases by liquid chromatography-high resolution mass spectrometry.

5F-ADB (methyl 2-{[1-(5-fluoropentyl)-1H-indazole-3-carbonyl]amino}-3,3-dimethylbutanoate) is a frequently abused new synthetic cannabinoid that has been sold since at least the end of 2014 on the drug market. It has been classified as an illicit drug in most European countries, and also in Turkey, Japan, and the United States. In this study, 5F-ADB and its methyl ester metabolite were determined in the blood and urine samples taken from fatal cases using liquid chromatography-highresolution mass spectrometry (LC-HRMS). The extraction of samples was performed using a solid-phase extraction method, followed by LC-HRMS analysis. The method was fully validated for linearities, limits of detection (LODs), limits of quantification (LOQs), recoveries, matrix effects, process efficiencies, accuracies, precisions, and stabilities and was applied to 70 blood and 36 urine samples from fatal cases where 5F-ADB was the only drug detected. The LODs were between 0.08 and 0.10ng/mL, and LOQs were between 0.10 and 0.12ng/mL for both blood and urine samples. 5F-ADB and its methyl ester hydrolysis metabolite were found at the blood concentrations ranging from 0.10 to 1.55ng/mL (mean=0.40ng/mL) and 0.15 to 23.4ng/mL (mean=2.69ng/mL), respectively. 5F-ADB was not detected in any urine samples. 5F-ADBmethyl ester hydrolysis metabolite was detected in 35 urine samples with a detection range of 0.28-72.2ng/mL and a mean of 9.02ng/mL. The synthetic cannabinoid 5F-ADB and its methyl ester metabolite were identified and quantified in authentic human blood and/or urine specimens obtained from 70 fatal cases. The method was successfully applied to postmortem blood and urine samples.

Detection of the recently emerged synthetic cannabinoid 4F-MDMB-BINACA in "legal high" products and human urine specimens.

Synthetic cannabinoids (SCs) remain one of the largest groups of new psychoactive substances (NPS) on the European drug market. Although the number of new derivatives occurring on the market has dropped in the last two years, newly emerging NPS still represent a challenge for laboratories performing forensic drug analysis in biological matrices. The newly emerged SC 4F-MDMB-BINACA has been reported by several law enforcement agencies in Europe and the USA since November 2018. This work aimed at revealing urinary markers to prove uptake of 4F-MDMB-BINACA and differentiate from the use of structurally similar SCs. Phase-I metabolites detected in human urine specimens were confirmed by phase-I metabolites generated in vitro using a pooled human liver microsomes (pHLM) assay. Seized materials and test-purchased "legal high" products were analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-qToF-MS). Human urine specimens and pHLM assay extracts were measured with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and confirmed by LC-qToF-MS. In January 2019, the Institute of Legal Medicine in Erlangen (Germany) identified 4F-MDMB-BINACA in three herbal blends. During the same time period, the described SC was identified in a research chemical purchased online. Investigation of phase-I metabolism led to the metabolites M10 (ester hydrolysis) and M11 (ester hydrolysis and dehydrogenation) as reliable urinary markers. Widespread distribution on the German drug market was proven by analysis of urine samples from abstinence control programs and by frequent detection of 4F-MDMB-BINACA in "herbal blends" and "'research chemicals" purchased via the Internet.

Mono-/polyintoxication with 5F-ADB: A case series.

5F-ADB is an indazole-based synthetic cannabinoid. In recent years, it has been detected in legal high products as well as in biological samples and is associated with serious adverse health, behavioral effects and even death. Due to the fast pace of the market of synthetic cannabinoids, data on such newly appearing substances are scarce. As pharmacological properties are often investigated in vitro or by using animal experiments, reports on synthetic cannabinoid findings in human samples along with corresponding case history descriptions are valuable for the interpretation of upcoming routine cases. Herein we report five cases with verified 5F-ADB consumption, including three fatalities, a case of driving under the influence of drugs as well as a case of grievous bodily harm. In four cases, 5F-ADB could be detected in blood or plasma. Concentrations were in the range of 0.11-0.57 µg/L. In one instance 5F-ADB consumption was verified by the detection of 5F-ADB metabolites in postmortem body fluids. The described cases illustrate various adverse effects including confusion (possibly even psychosis), collapse, loss of consciousness, unsafe driving style or changing moods that might be attributed to 5F-ADB.

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.

A case of 5F-ADB / FUB-AMB abuse: Drug-induced or drug-related death?

Synthetic cannabinoids (SCs) belong to the group of new psychoactive substances (NPS) which appear sprayed on herbal mixtures on the "street" drug market and are intended for smoking like marijuana. In the present report we discuss a fatal case of 18-years-old boy, who had smoked SCs since several months and an overuse of SCs during last 48 h of his life has been apprised. The autopsy findings revealed acute respiratory distress syndrome (ARDS). Both toxicological analysis of deceased blood and urine samples and chemical analysis of the herbal mixture seized revealed presence of two SCs - 5F-ADB and FUB-AMB. The amount of 5F-ADB in blood was found to be 3.7 ng/mL by standard addition method. Severe and irreversible morphology changes in lung specimen, leading to ischemic damage of all internal organs and tissues, were observed during histological examination. The present case can be discussed as an example of both drug-induced and drug-related death resulting from acute intoxication with 5F-ADB and FUB-AMB as well as from systematic use of both synthetic cannabinoids.

Metabolic profiling of synthetic cannabinoid 5F-ADB by human liver microsome incubations and urine samples using high-resolution mass spectrometry.

5F-ADB (methyl 2-{[1-(5-fluoropentyl)-1H-indazole-3-carbonyl] amino}-3,3-dimethylbutanoate) is a frequently abused new synthetic cannabinoid that has been sold since at least the end of 2014 on the drug market and has been classified as an illicit drug in most European countries, as well as Turkey, Japan, and the United States. In this study, the in vitro metabolism of 5F-ADB was investigated by using pooled human liver microsomes (HLMs) assay and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). 5F-ADB (5 µmol/L) was incubated with HLMs for up to 3 hours, and the metabolites were identified using LC-HRMS and software-assisted data mining. The in vivo metabolism was investigated by the analysis of 30 authentic urine samples and was compared to the data received from the in vitro metabolism study. Less than 3.3% of the 5F-ADB parent compound remained after 1 hour of incubation, and no parent drug was detected after 3 hours. We identified 20 metabolites formed via ester hydrolysis, N-dealkylation, oxidative defluorination, hydroxylation, dehydrogenation, further oxidation to N-pentanoic acid and glucuronidation or a combination of these reactions in vitro. In 12 urine samples (n = 30), 5F-ADB was detected as the parent drug. Three of the identified main metabolites 5F-ADB carboxylic acid (M20), monohydroxypentyl-5F-ADB (M17), and carboxypentyl ADB carboxylic acid (M8) were suggested as suitable urinary markers. The screening of 8235 authentic urine samples for identified 5F-ADB metabolites in vitro resulted in 3135 cases of confirmed 5F-ADB consumption (38%).

Metabolic fate of the new synthetic cannabinoid 7'N-5F-ADB in rat, human, and pooled human S9 studied by means of hyphenated high-resolution mass spectrometry.

New psychoactive substances (NPS) are an important issue in clinical/forensic toxicology. 7'N-5F-ADB, a synthetic cannabinoid derived from 5F-ADB, appeared recently on the market. Up to now, no data about its mass spectral fragmentation pattern, metabolism, and thus suitable targets for toxicological urine screenings have been available. Therefore, the aim of this study was to elucidate the metabolic fate of 7'N-5F-ADB in rat, human, and pooled human S9 (pS9). The main human urinary excretion products, which can be used as targets for toxicological screening procedures, were identified by Orbitrap (OT)-based liquid chromatography-high resolution-tandem mass spectrometry (LC-HRMS/MS). In addition, possible differentiation of 7'N-5F-ADB and 5F-ADB via LC-HRMS/MS was studied. Using the in vivo and in vitro models for metabolism studies, 36 metabolites were tentatively identified. 7'N-5F-ABD was extensively metabolized in rat and human with minor species differences observed. The unchanged parent compound could be found in human urine but metabolites were far more abundant. The most abundant ones were the hydrolyzed ester (M5), the hydrolyzed ester in combination with hydroxylation of the tertiary butyl part (M11), and the hydrolyzed ester in addition to glucuronidation (M30). Besides the parent compound, these metabolites should be used as targets for urine-based toxicological screening procedures. Two urine-paired human plasma samples contained mainly the parent compound (c = 205 µg/L, 157 µg/L) and, at a higher abundance, the compound after ester hydrolysis (M5). In pS9 incubations, the parent compound, M5, and M30 were detectable among others. Furthermore, a differentiation of both compounds was possible due to different retention times and fragmentation patterns.

Identification and quantification of synthetic cannabinoids in 'spice-like' herbal mixtures: Update of the German situation in 2018.

In June 2018, 15 'Spice-like' herbal products from German language internet shops were analyzed. In total, three different synthetic cannabinoids (SCs) were identified by gas chromatography-mass spectrometry (GC-MS). Two of the active ingredients were identified as the recently described 5F-ADB and Cumyl-PeGaClone. The third compound was identified as the so far unknown SC 5F-Cumyl-PeGaClone. 5F-Cumyl-PeGaClone was subject to an in-depth characterization by nuclear magnetic resonance spectroscopy (NMR), electron ionization mass spectrometry (EI-MS), electrospray ionization tandem mass spectrometry (ESI-MS/MS), infrared and uItraviolet-visible spectroscopy (IR and UV/Vis). In addition, all SCs in all products were quantified by a GC-MS method using JWH-018 as internal standard and corresponding response factors. While Cumyl-PeGaClone and 5F-ADB were detected in one, respectively two products, the newly identified 5F-Cumyl-PeGaClone was detected as the only active ingredient in the remaining twelve products. The SC content ranged from 14.7 to 76.2mg/g (average: 32.1mg/g).

Impaired Driving Associated with the Synthetic Cannabinoid 5f-Adb.

Synthetic marijuana compounds are more potent than Δ9-tetrahydrocannabinol (∆9-THC) and are known to produce a wide variety of clinical symptoms including cardiac toxicity, seizures, and death. Erratic driving by a 45 y/o male was witnessed in the fall of 2017 and roadside evaluation of the driver by the responding law enforcement officer concluded that the driver was intoxicated. Comprehensive analysis of the cigarettes by gas chromatography-mass spectrometry detected the synthetic cannabinoid 5-fluoro-ADB (5F-ADB or 5F-MDMB-PINACA). Validated forensic liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were used to detect the 5-fluoro ADB metabolite 7 (26.37 ng/mL) in the driver's blood sample. No other drugs were detected. This case report is one of the first to conclusively show that designer synthetic cannabinoids, commonly referred to as "K2" and "Spice", can significantly impair driving at relatively low concentrations.

Fatal intoxication by 5F-ADB and diphenidine: Detection, quantification, and investigation of their main metabolic pathways in humans by LC/MS/MS and LC/Q-TOFMS.

Despite the implementation of a new blanket scheduling system in 2013, new psychoactive substance (NPS) abuse remains a serious social concern in Japan. We present a fatal intoxication case involving 5F-ADB (methyl 2-[1-(5-fluoropentyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate) and diphenidine. Postmortem blood screening by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOFMS) in the information-dependent acquisition mode only detected diphenidine. Further urinary screening using an in-house database containing NPS and metabolites detected not only diphenidine but also possible 5F-ADB metabolites; subsequent targeted screening by LC/tandem mass spectrometry (LC/MS/MS) allowed for the detection of a very low level of unchanged 5F-ADB in postmortem heart blood. Quantification by standard addition resulted in the postmortem blood concentrations being 0.19 ± 0.04 ng/mL for 5F-ADB and 12 ± 2.6 ng/mL for diphenidine. Investigation of the urinary metabolites revealed pathways involving ester hydrolysis (M1) and oxidative defluorination (M2), and further oxidation to the carboxylic acid (M3) for 5F-ADB. Mono- and di-hydroxylated diphenidine metabolites were also found. The present case demonstrates the importance of urinary metabolite screening for drugs with low blood concentration. Synthetic cannabinoids (SCs) fluorinated at the terminal N-alkyl position are known to show higher cannabinoid receptor affinity relative to their non-fluorinated analogues; 5F-ADB is no exception with high CB1 receptor activity and much greater potency than Δ9 -THC and other earlier SCs, thus we suspect its acute toxicity to be high compared to other structurally related SC analogues. The low blood concentration of 5F-ADB may be attributed to enzymatic and/or non-enzymatic degradation, and further investigation into these possibilities is underway.

Acute intoxication caused by synthetic cannabinoids 5F-ADB and MMB-2201: A case series.

Synthetic cannabinoids are relatively new substances of abuse. Recently, abuse of synthetic cannabinoids has been increasingly reported in the lay press and medical literature. When new compounds are introduced, their use is initially not restricted by prohibition therefore their consumption cannot be verified by standard drug tests. The use of these compounds among adolescents and young adults is constantly growing, making it important for emergency services to be familiar with the signs and symptoms of intoxication present. Overdose and chronic use of these substances can cause adverse effects including altered mental status, tachycardia, and loss of consciousness. Here, we report five cases of acute intoxication by synthetic cannabinoids 5F-ADB and MMB-2201 with analytical confirmation.