Analytical confirmation of synthetic cannabinoids in a cohort of 179 presentations with acute recreational drug toxicity to an Emergency Department in London, UK in the first half of 2015

In vitro cannabinoid activity profiling of generic ban-evading brominated synthetic cannabinoid receptor agonists and their analogs

Following the enactment of a generic ban in China in 2021, the synthetic cannabinoid market has been evolving, now encompassing even wider structural diversity. Compounds carrying a brominated core such as ADB-5'Br-BUTINACA (ADMB-B-5Br-INACA) and tail-less analogs, such as ADB-5'Br-INACA (ADMB-5Br-INACA), MDMB-5'Br-INACA, and ADB-INACA (ADMB-INACA), have been detected since late 2021. This study investigated the cannabinoid receptor (CB) activation potential of synthesized (S)-enantiomers of these substances, as well as of two predicted analogs MDMB-5'Br-BUTINACA (MDMB-B-5Br-INACA) and ADB-5'F-BUTINACA (ADMB-B-5F-INACA), using CB1 and CB2 β-arrestin 2 recruitment assays and a CB1 intracellular calcium release assay. Surprisingly, the tail-less (S)-ADB-5'Br-INACA and (S)-MDMB-5'Br-INACA retained CB activity, albeit with a decreased potency compared to their tailed counterparts (S)-ADB-5'Br-BUTINACA and (S)-MDMB-5'Br-BUTINACA, respectively, which were potent and efficacious CB1 agonists. Also, at CB2, tail-less analogs showed a lower potency but increased efficacy. Removing the bromine substitution ((S)-ADB-INACA) resulted in a reduced activity at CB1; however, this effect was less prominent at CB2. Looking at tailed analogs, replacing the bromine with a fluorine substitution ((S)-ADB-5'F-BUTINACA) resulted in an increased potency and efficacy at both receptors. Furthermore, as ADB-5'Br-INACA and MDMB-5'Br-INACA have been frequently detected together in Scottish prisons, this study also evaluated the CB1 receptor activation potential of different mixtures of their respective reference standards, showing no unexpected cannabimimetic effect of combining both substances. Lastly, two powders seized by Belgian Customs and confirmed to contain ADB-5'Br-INACA and MDMB-5'Br-INACA, respectively, were assessed for CB activity. Based on the comparison with their reference standards, varying degrees of purity were suspected.

GC-MS/MS analysis of synthetic cannabinoids 5F-MDMB-PICA and 5F-CUMYL-PICA in forensic cases

Aim: Validate a method to quantify 1-(5-fluoropentyl)-N-(2-phenylpropan-2-yl)-1H-indole-3-carboxamide (5F-CUMYL-PICA) and methyl 2-[[1-(5-fluoropentyl) indole-3-carbonyl] amino]-3,3-dimethyl-butanoate (5F-MDMB-PICA) in blood samples using GC-MS/MS. Materials & methods: A solid-phase extraction (SPE) method has been developed to quantify 5F-MDMB-PICA and 5F-CUMYL-PICA in authentic human blood samples. Results & conclusion: The limit of detection (LOD) was 0.1 and 0.11 ng/ml for 5F-CUMYL-PICA and 5F-MDMB-PICA, respectively, while the limit of quantification (LOQ) was 0.50 ng/ml for both two compounds. Recovery was 91.40, 82.54 and 85.10% for SPE, supported liquid extraction (SLE) and ISOLUTE C18; matrix effects 15, 24 and 22.5% for SPE, SLE and ISOLUTE C18; accuracy was 2.4-5.5 and 3.9-7.3% for SPE, SLE and ISOLUTE C18, while precision was 4.6-7.7 and 6.4-8.3% for SPE, SLE and ISOLUTE C18, respectively. The concentrations of 5F-CUMYL-PICA and 5F-MDMB-PICA in the authentic human blood samples were 2.18 and 3.07 ng/ml, respectively. The validated method was successfully used in supporting the quantification of analytes in blood.

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.

Isotonitazene, a novel psychoactive substance opioid, detected in two cases following a local surge in opioid overdoses

BACKGROUND

Isotonitazene is a novel opioid that was first reported in Europe in 2019. There have been no reports of the detection of isotonitazene in patients presenting to the emergency department with acute drug toxicity.

AIM

There was an increase in presentations to our emergency department with acute opioid toxicity in August 2021. We aim to describe this outbreak and provide detail on two cases in which isotonitazene was quantified in serum samples.

METHODS

Serum samples were available for comprehensive toxicological analysis for two presentations. Written consent was obtained and the samples were analysed through a Thermo XRS ultrahigh-performance liquid chromatography system, interfaced to a Thermo Q Exactive high-resolution accurate mass spectrometer, operating in heated positive ion electrospray mode. Acquired data were processed using Toxfinder software (Thermo) against a regularly updated in-house database.

RESULTS

There was an increase in acute opioid presentations to our emergency department from a median of 10 per month to 36 in August 2021. Twenty were treated with naloxone, and 23 were admitted to the hospital for observation and treatment. Serum sample analysis from two patients with acute opioid toxicity responsive to naloxone detected the presence of isotonitazene (0.18 and 0.81 ng/ml).

CONCLUSION

We report a cluster of acute opioid toxicity presentations to our Emergency Department with detection of isotonitazene in two cases. Analytical screening is important in determining the presence of novel psychoactive substances (NPS) and to help inform the public health of the implications of NPS use, particularly during clusters of acute recreational drug toxicity presentations.

In vitro characterization of the pyrazole-carrying synthetic cannabinoid receptor agonist 5F-3,5-AB-PFUPPYCA and its structural analogs

The synthetic cannabinoid receptor agonist (SCRA) market is undergoing important changes since the enactment of the 2021 class-wide generic SCRA ban in China, one of the most important source countries for new psychoactive substances (NPS). Recently, various compounds with new structural features, synthesized to bypass this legislation, have entered the recreational drug market. Certain monocyclic pyrazole-carrying "FUPPYCA" SCRAs have been sporadically detected since 2015 without gaining further popularity. However, as evidenced by their recent detection in Scottish prisons, 5F-3,5-AB-PFUPPYCA and 3,5-ADB-4en-PFUPPYCA have re-emerged, potentially triggered by the new legislative ban. The aim of this study was to characterize the in vitro intrinsic CB₁ and CB₂ receptor activation potential of 5F-3,5-AB-PFUPPYCA and 3,5-ADB-4en-PFUPPYCA, as well as 4 analogs (5F-3,5-ADB-PFUPPYCA, 3,5-AB-CHMFUPPYCA, 5,3-AB-CHMFUPPYCA and 5,3-ADB-4en-PFUPPYCA) using live cell β-arrestin 2 recruitment assays. Most analogs were essentially inactive at either CB₁ or CB₂, with only 3,5-AB-CHMFUPPYCA, 5,3-AB-CHMFUPPYCA and 5,3-ADB-4en-PFUPPYCA showing a limited activation potential at CB₁. Furthermore, the importance of the position of the tail structure was demonstrated, with 5,3 regioisomers being more active than their 3,5 analogs. Moreover, all compounds exhibited antagonistic behavior at both receptors, which may be associated with their structural resemblance to cannabinoid antagonists and inverse agonists. Although the 3,5 regioisomers of these "FUPPYCA" SCRAs circumvent the Chinese ban, it is unlikely that these SCRAs will pose a major threat to public health, given the lack of pronounced CB receptor activity.

Synthetic Cannabinoid Receptor Agonists in Postmortem Casework in Scotland

Synthetic cannabinoid receptor agonists (SCRAs) have been a concern to forensic toxicologists since their emergence as drugs of abuse in the mid-late 2000s. The extent of their use in Scotland appears to be low especially when compared to other drug groups such as opioids and benzodiazepines. There is a concern, however, that the use is widespread in prison populations in particular. In this work, samples of blood and urine collected during routine postmortem examination between April 2017 and March 2019 were subjected to analysis of SCRA compounds. Circumstantial and demographic information was collected on positive cases to build up a body of evidence for where SCRAs may be most likely to contribute to the cause of death. Thirteen out of 133 cases (10%) tested were positive for one or more compound in one or more matrix. Overall, the detection of 5F-MDMB-PINACA or its O-desmethyl acid metabolite was most common, followed by the metabolite shared by AB-FUBINACA and MMB-FUBINACA. SCRA-positive cases were predominantly males (92%), and the age range of all decedents was 21-49 years old (median 36 years). The majority of cases were certified as drug-related deaths (DRDs, 38%), natural/medical (31%) or suicide (23%), and two of the DRDs mentioned SCRAs specifically in the cause of death. The concentrations of SCRAs detected did not seem to be as important to the determination of the cause of death as their mere presence, but quantitative results were reported (where possible) in order to build up a body of evidence for SCRA concentrations in different case types.

Accuracy of substance exposure history in patients attending emergency departments after substance misuse; a comparison with biological sample analysis

CONTEXT

Acute toxicity caused by illicit substance use is a common reason for emergency department (ED) presentation. Knowledge of the substances involved is helpful for predicting and managing potential toxicity, but limited information is available about the accuracy of patient-reported substance exposure. This study assessed the accuracy of the history of exposure in those reporting use of a single substance by comparison with those identified by detailed toxicological analysis, focusing on synthetic cannabinoid receptor agonists (SCRA).

METHODS

Adults (≥16 years) presenting between March 2015 and July 2021 to participating UK hospitals with toxicity after reporting use of a single illicit substance were included. Exposure details were documented from medical records and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry (HRAM LCMS). Sensitivity, specificity, and positive and negative predictive values of the exposure history were calculated by comparison with biological sample analysis ("gold standard").

RESULTS

Single substance exposure was reported for 474 (median age 33 years, IQR: 18 range 16-75, 80% males) patients. Analysis commonly identified multiple substances (Median 3, IQR 2-5). A history of exposure was documented for 121 of 151 patients where a SCRA or metabolite was detected on analysis (sensitivity 80.1%, 95% CI 72.9, 86.2%). Corresponding proportions were lower for 3,4-methylenedioxymethamphetamine (MDMA, 44/70, 62.9%., 95% CI 50.5%, 74.1%), heroin 41/108 (38.0% 95% CI 28.8-47.8%) and cocaine (22/56, 31.3%, 95% CI 20.9, 43.6%).

CONCLUSIONS

Multiple undeclared substances were detected analytically in most patients reporting single substance use. Clinicians should be alert to the potential presence and toxicity of unreported substances when managing patients presenting after substance misuse.

Trends in hospital presentations following analytically confirmed synthetic cannabinoid receptor agonist exposure before and after implementation of the 2016 UK Psychoactive Substances Act

BACKGROUND AND AIMS

The United Kingdom (UK) Psychoactive Substances Act (PSA), implemented on the 26^th  May 2016, made the production, supply and sale of all non-exempted psychoactive substances illegal. The aim of this study was to measure trends in hospital presentations for severe toxicity following analytically confirmed synthetic cannabinoid receptor agonist (SCRA) exposure before and after implementation of the PSA.

DESIGN

Observational study.

SETTING

Thirty-four hospitals across the UK participating in the Identification of Novel Psychoactive Substances (IONA) study.

PARTICIPANTS

A total of 627 (79.9% male) consenting individuals who presented to participating hospitals between July 2015 and December 2019 with severe acute toxicity and suspected novel psychoactive substances exposure.

MEASUREMENTS

Toxicological analyses of patient samples were conducted using liquid-chromatography tandem mass-spectrometry. Time-series analysis was conducted on the monthly number of patients with and without analytically confirmed SCRA exposure using Poisson segmented regression.

FINDINGS

SCRAs were detected in 35.7% (n = 224) of patients. After adjusting for seasonality and the number of active sites, models showed no clear evidence of an upward or downward trend in the number of SCRA exposure cases in the period before (incidence rate ratio [IRR], 1.12; 95% CI, 0.99-1.26; P = 0.068) or after (IRR, 0.97; 95% CI, 0.94-1.01; P = 0.202) the implementation of the PSA. There was also no clear evidence of an upward or downward trend in non-SCRA exposure cases before (IRR, 1.12; 95% CI, 0.98-1.27; P = 0.105) or after (IRR, 1.01; 95% CI, 0.98-1.04; P = 0.478) implementation of the PSA.

CONCLUSIONS

There is no clear evidence of an upward or downward trend in the number of patients presenting to UK hospitals with severe acute toxicity following analytically confirmed synthetic cannabinoid receptor agonist exposure since the implementation of the Psychoactive Substances Act.

Fourth Generation of Synthetic Cannabinoid Receptor Agonists: A Review on the Latest Insights

BACKGROUND

Over the past few years, an emerging number of new psychoactive substances (NPSs) entered the illicit market. NPSs are designed to resemble the effects of classical drugs of abuse, reinforcing their effects and duration. Among the most abused NPS, synthetic cannabinoids are cannabinoid receptor agonists (SCRAs) that mimic the effect of the main psychotropic phytocannabinoid Δ9-tetrahydrocannabinol (THC).

METHODS

We herein reviewed the international literature to provide available information on the newest SCRAs generation.

RESULTS

Compared to the previous SCRAs generations, the structures of the last generation result in increased affinity for and efficacy at cannabinoid CB₁ receptors, which are thought to be mainly responsible for the psychoactive effects of THC and its analogues. Accordingly, these more potent cannabimimetic effects may increase the number of adverse reactions such as neurological disorders (e.g., psychosis, agitation, irritability, paranoia, confusion, and anxiety), psychiatric episodes (e.g., hallucinations, delusions, self-harm), other physical conditions (e.g., tachycardia, hypertension, arrhythmia, chest pain, nausea, vomiting, and fever) and deaths. In the last decade, more than a hundred SCRAs from different chemical classes emerged on the illicit web market. SCRAs have been thoroughly studied: they were physico-chemically characterized, and pharmaco-toxicological characteristics were investigated. The last SCRAs generations include increasingly potent and toxic compounds, posing a potential health threat to consumers.

CONCLUSION

From November 2017 to February 2021, at least 20 new "fourth-generation" SCRAs were formally reported to international drug agencies. Our understanding of the neurotoxicity of these compounds is still limited due to the lack of global data, but their potency and their toxicity are likely higher than those of the previous generations.

Cannabinoid receptor activation potential of the next generation, generic ban evading OXIZID synthetic cannabinoid receptor agonists

In recent years, several nations have implemented various measures to control the surge of new synthetic cannabinoid receptor agonists (SCRAs) entering the recreational drug market. In July 2021, China put into effect a new generic legislation, banning SCRAs containing one of 7 general core scaffolds. However, this has driven manufacturers towards the synthesis of SCRAs with alternative core structures, exemplified by the recent emergence of "OXIZID SCRAs". Here, using in vitro β-arrestin2 recruitment assays, we report on the CB₁ and CB₂ potency and efficacy of five members of this new class of SCRAs: BZO-HEXOXIZID, BZO-POXIZID, 5-fluoro BZO-POXIZID, BZO-4en-POXIZID and BZO-CHMOXIZID. All compounds behaved as full agonists at CB₁ and partial agonists at CB₂ . Potencies ranged from 84.6 - 721 nM at CB₁ and 2.21 - 25.9 nM at CB₂ . Shortening the n-hexyl tail to a pentyl tail enhanced activity at both receptors. Fluorination of this pentyl analog did not yield a higher receptor activation potential, whereas an unsaturated tail resulted in decreased potency and efficacy at CB₁ . The cyclohexyl methyl analog BZO-CHMOXIZID was the most potent compound at both receptors, with EC₅₀ values of 84.6 and 2.21 nM at CB₁ and CB₂ , respectively. Evaluation of the activity of a seized powder containing BZO-4en-POXIZID suggested a high purity, in line with HPLC-DAD, GC-MS, LC-QTOF-MS and FTIR and NMR analysis. Furthermore, all tested compounds showed a preference for CB₂ , except for BZO-POXIZID. Overall, these findings inform public health officials, law enforcement agencies and clinicians on these newly emerging SCRAs.

NNL-3: A Synthetic Intermediate or a New Class of Hydroxybenzotriazole Esters with Cannabinoid Receptor Activity?

Synthetic cannabinoid receptor agonists (SCRAs) remain a prolific class of new psychoactive substances (NPS) and continue to expand rapidly. Despite the recent identification of hydroxybenzotriazole (HOBt) containing SCRAs in synthetic cannabis samples, there is currently no information regarding the pharmacological profile of these NPS with respect to human CB₁ and CB₂ receptors. In the current study, a series consisting of seven HOBt indole-, indazole-, and 7-azaindole-carboxylates bearing a range of N-alkyl substituents were synthesized and pharmacologically evaluated. Competitive binding assays at CB₁ and CB₂ demonstrated that all analogues except a 2-methyl-substituted derivative had low affinity for CB₁ (K_i = 3.80-43.7 μM) and CB₂ (K_i = 2.75-18.2 μM). A fluorometric functional assay revealed that 2-methylindole- and indole-derived HOBt carboxylates were potent and efficacious agonists of CB₁ (EC₅₀ = 12.0 and 63.7 nM; E_max = 118 and 120%) and CB₂ (EC₅₀ = 10.9 and 321 nM; E_max = 91 and 126%). All other analogues incorporating indazole and 7-azaindole cores and bearing a range of N1-substituents showed relatively low potency for CB₁ and CB₂. Additionally, a reporter assay monitoring β-arrestin 2 (βarr2) recruitment to the receptor revealed that the 2-methylindole example was the most potent and efficacious at CB₁ (EC₅₀ = 131 nM; E_max = 724%) and the most potent at CB₂ (EC₅₀ = 38.2 nM; E_max = 51%). As with the membrane potential assay, the indazole and other indole HOBt carboxylates were considerably less potent at both receptors, and analogues comprising a 7-azaindole core showed little activity. Taken together, these data suggest that NNL-3 demonstrates little CB1 receptor activity and is unlikely to be psychoactive in humans. NNL-3 is likely an unintended SCRA manufacturing byproduct. However, the synthesis of NNL-3 analogues proved simple and general, and some of these showed potent cannabimetic profiles in vitro, indicating that HOBt esters of this type may represent an emerging class of SCRA NPS.

Acute toxicity from the synthetic cathinone N-ethylpentylone (ephylone) in the United Kingdom

INTRODUCTION

Acute toxicity caused by New Psychoactive Substances (NPS) has created a significant burden for Emergency Departments (EDs). Here we report characteristics of people presenting with toxicity after exposure to the synthetic cathinone N-ethylpentylone (NEP).

METHODS

Adults presenting to hospital with severe acute toxicity after suspected NPS use were recruited between March 2015 and October 2020. Clinical features were recorded using consistent methodology and biological samples analysed using liquid chromatography-tandem mass-spectrometry.

RESULTS

NEP was detected in at least one sample from 9 of 893 patients recruited during the period of study, all presenting between 2016 and 2019 and 8 presenting in southern England. Commonly reported clinical features included tachycardia (6), agitation (6), confusion (6), mydriasis (5), hallucinations (4), acidosis (3) and elevated creatine kinase (3). Co-used drugs, detected in 6 patients, may have contributed to these features, but agitation and hallucinations were also reported in all 3 patients without analytical evidence of co-use.

CONCLUSIONS

NEP was detected infrequently in episodes of drug toxicity in the UK between 2016 and 2019, especially in southern England. Clinical characteristics of toxicity are similar to those of other cathinones, although co-use of other drugs is common and may contribute to the features observed.

Systematic evaluation of a panel of 30 synthetic cannabinoid receptor agonists structurally related to MMB-4en-PICA, MDMB-4en-PINACA, ADB-4en-PINACA, and MMB-4CN-BUTINACA using a combination of binding and different CB1 receptor activation assays-Part II: Structure activity relationship assessment via a β-arrestin recruitment assay

Synthetic cannabinoid receptor agonists (SCRAs) are the second largest class of new psychoactive substances (NPS) and are associated with serious adverse effects and even death. Despite this, little pharmacological data are available for many of the most recent SCRAs. This study consists of three different parts, aiming to systematically evaluate a panel of 30 SCRAs using binding and different in vitro human cannabinoid 1 receptor (CB₁ ) activation assays. The present Part II investigated the SCRA analogs for their CB₁ activation via a β-arrestin recruitment assay. The panel was systematically designed to include key structural sub-features of recent SCRAs. Thus, the 4-pentenyl tail of MMB-4en-PICA and MDMB-4en-PINACA was retained while incorporating varying head groups from other prevalent SCRAs, including amides and esters of L-valine, L-tert-leucine, and L-phenylalanine, and adamantyl and cumyl moieties. All 30 SCRAs activated CB₁ , with indazoles generally showing the greatest potency (EC₅₀  = 1.88-281 nM), followed by indoles (EC₅₀  = 11.5-2293 nM), and the corresponding 7-azaindoles (EC₅₀  = 62.4-9251 nM). Several subunit-linked structure-activity relationships were identified: (i) tert-leucine-functionalized SCRAs were more potent than the corresponding valine derivatives; (ii) no major difference in potency or efficacy was observed between tert-leucine/valine-derived amides and the corresponding methyl esters; however, phenylalanine analogs were affected by this change; and (iii) minor structural changes to the 4-pentenyl substituent had little influence on activity. These findings elucidate structural features that modulate the CB₁ activation potential of currently prevalent SCRAs and a systematic panel of analogs, some of which may appear in NPS markets in future.

Risk Management in First Aid for Acute Drug Intoxication

Drug abuse (cannabis, cocaine, opiates, and synthetic drugs) is an increasing phenomenon, especially in the younger population, thus leading to more cases of intoxication requiring evaluation in the emergency department and subsequent hospitalization. In 2017, 34.2% of students reported having used an illegal psychoactive substance in their lifetime, while 26% reported having done so over the past year. We made a review about the effectiveness of the role of the temporary observation unit in the emergency department to improve management of acute drugs intoxication. We checked medical literature from the last 10 years (2009-2019). The following electronic databases were systematically searched: MEDLINE-PubMed, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials. Then, a systematic review was carried out according to the Preferred Reporting Items for Systematic Review standards. Intoxicated patients usually display a favorable medical course, few diagnostic and therapeutic interventions, a short stay in the hospital, and, when hospitalization is needed, semi-intensive therapy is a feasible solution; therefore, intoxicated patients are ideal candidates for a temporary observation unit. The emergency department is very important to manage intoxicated patients; however, the hospitalization of these patients is often not necessary.

Metabolism, CB1 cannabinoid receptor binding and in vivo activity of synthetic cannabinoid 5F-AKB48: Implications for toxicity

AKB48 and its fluorinated derivative 5F-AKB48 are synthetic cannabinoids (SCs) which have caused hospitalizations and deaths in human users. Abuse of SCs is dangerous because users may mistake them for natural cannabis, which is generally considered to be unlikely to elicit adverse effects. The present studies were designed to investigate the in vitro oxidative metabolism of 5F-AKB48 by human microsomal fractions from different organs and sexes as well as recombinant human cytochrome P450s (P450s). Mass spectrometry data tentatively provides evidence for the existence of mono-, di-, and trihydroxylated metabolites in a successive metabolism. Experiments utilizing P450s revealed that the most active enzymes (CYP2D6, CYP2J2, CYP3A4, and CYP3A5) effectively produced mono- and dihydroxylated metabolites, while CYP3A4/5 also produced significant amounts of the trihydroxylated metabolite. Moreover, although the affinity and potency of Phase I metabolite 4OH-5F-AKB48 is reduced when compared to that of the parent drug, this metabolite nevertheless retains similar high affinity for CB1 receptors, and greater efficacy for G protein activation, when compared to THC. Finally, 5F-AKB48 produced time- and dose-dependent cannabimimetic effects in mice which were more potent, but shorter acting, than those of Δ⁹-THC, and were attenuated by prior treatment with the CB1 antagonist rimonabant. Based on our data, we hypothesize that while many cases of toxicity result from genetic mutations, which can lead to a decrease or even absence of activity for Phase I drug-metabolizing enzymes, other P450s could potentially increase their role in the metabolism of these SCs. Because many metabolites of SCs remain biologically active, they could contribute to the deleterious effects of these substances.

Sociodemographic and clinical characteristics of synthetic cannabinoid users in a large psychiatric emergency department in Turkey

Synthetic cannabinoid (SC) use is a global concern and is creating new challenges for treatment services. Although some studies have been reported, there is a need for further research regarding the sociodemographic and clinical characteristics of SC users so that general and psychiatric emergency departments can provide more effective treatments. We aimed to investigate the sociodemographic and clinical characteristics in a cohort of patients using SC who presented to the psychiatric emergency department of the University of Health Sciences, Istanbul Erenköy Training and Research Hospital for Psychiatry and Neurology (ERSHEAH) in Istanbul, Turkey. This cross-sectional and retrospective medical record review examined 340 SC users who presented to the emergency department of ERSHEAH in a 3-month period. The mean age of the SC users was 26.8 ± 7.5 years and 92.6% were men. Psychotic symptoms were present in 247 SC users (78.8%). Severe intoxication was diagnosed in 26 SC users (7.6%), although SC was detectable in the samples of only 6 patients (13.6%). Impaired consciousness (42.3%) was the most common reason for referral to the general hospital and increased liver enzyme levels (15.9%) were the most common indication in the laboratory findings. We observed that the SC users in our sample presenting as psychiatric emergencies were mostly young men experiencing psychotic symptoms. Determining the sociodemographic and clinical properties of SC users may provide an important contribution to fast recognition and more effective management of acute symptoms of SC users in emergency departments.

CUMYL-4CN-BINACA Is an Efficacious and Potent Pro-Convulsant Synthetic Cannabinoid Receptor Agonist

Synthetic cannabinoid receptor agonists (SCRAs) are the largest class of new psychoactive substances (NPS). New examples are detected constantly, and some are associated with a series of adverse effects, including seizures. CUMYL-4CN-BINACA (1-(4-cyanobutyl)-N-(2-phenylpropan-2-yl)indazole-3-carboxamide) is structurally related to potent, cumylamine-derived SCRAs such as 5F-CUMYL-PINACA, but is unusual due to a terminal aliphatic nitrile group not frequently encountered in SCRAs or pharmaceuticals. We report here that CUMYL-4CN-BINACA is a potent CB1 receptor agonist (K i = 2.6 nM; EC50 = 0.58 nM) that produces pro-convulsant effects in mice at a lower dose than reported for any SCRA to date (0.3 mg/kg, i.p). Hypothermic and pro-convulsant effects in mice could be reduced or blocked, respectively, by pretreatment with CB1 receptor antagonist SR141716, pointing to at least partial involvement of CB1 receptors in vivo. Pretreatment with CB2 receptor antagonist AM-630 had no effect on pro-convulsant activity. The pro-convulsant properties and potency of CUMYL-4CN-BINACA may underpin the toxicity associated with this compound in humans.

Spicing it up - synthetic cannabinoid receptor agonists and psychosis - a systematic review

Synthetic cannabinoid receptor agonists (SCRAs) are suggested to have increased potential to induce psychosis compared to natural cannabis (NC). In this review we synthesise current knowledge about the association of SCRA use with psychotic symptoms. Following a literature search we identified 2 toxicology reports, 4 case-control studies, 3 cross-sectional studies and 15 case reports. In each of the case reports, we identified the presence or absence of symptoms based on the items of the Postitive and Negative Syndrome Scele (PANSS). The toxicology reports highlighted the main presenting features as being toxic psychosis and delirium (40%), agitation (10%) and hallucinations (4-7%). The median age was 25 years, and around 80% cases were male. Cross-sectional studies reported that SCRA use was present in approximately 10-13% patients presenting to acute psychiatric services, and was often the cause of their presentation, and that psychotic symptoms were present in 15% patients attending emergency departments following SCRA use. Case-control studies reported that SCRA use was significantly associated with psychotic symptoms and that SCRA users had higher levels of positive psychotic symptoms than NC users. The case reports supported the association of SCRA use with a wide range of positive and negative psychotic symptoms as well as with self-harm, agitation and aggressive behaviour. SCRA use is relatively prevalent in patients with psychosis and may lead to psychotic symptoms in individuals with no past psychiatric history. Further work is required to understand the long term risks of SCRA use and optimal management strategies.

Toxic leukoencephalopathy with extrapyramidal dysfunction due to synthetic cannabinoids

Neurologic sequelae of synthetic cannabinoids are not well understood. We report a case of a woman who developed hyperreflexia, paratonia and cogwheel rigidity after consumption of synthetic cannabinoids. MR imaging demonstrated T2/FLAIR signal enhancement in the supratentorial white matter and globus pallidus internus.

Evolution of clinical characteristics and outcomes of synthetic cannabinoid receptor agonist exposure in the United States: analysis of National Poison Data System data from 2010 to 2015

BACKGROUND AND AIMS

New synthetic cannabinoid receptor agonists (SCRAs) are synthesized each year to evade US governmental regulation and sold for recreational use. Our aim was to estimate the changes in the clinical effects and patient disposition associated with SCRA exposure from 2010 to 2015.

DESIGN

A retrospective observational cohort study.

SETTING

National Poison Data System that collects data on reports of poisonings from US poison centers.

PARTICIPANTS

A total of 19 388 isolated SCRA cases between 1 January 2010 and 31 December 2015 were identified. The mean age was 24.6 years and 77.8% were male.

MEASUREMENTS

Primary outcome was the change in the trend of patient disposition, i.e. treated and released versus hospitalization (e.g. non-critical care, critical care unit or psychiatry) between 2010 and 2015. Secondary outcomes included the trends in the clinical effects and their duration, and therapeutic interventions nationally and regionally.

FINDINGS

Reports of SCRA exposure peaked in 2011 (n = 5305) and 2015 (n = 5475). The majority of patients required supportive care and were treated and released from an emergency department. Hospitalization increased by annual percentage change in the log odds (APCO) of 21.0% (P < 0.0001) during the 6 years, with significant increases in admissions to critical care units and non-critical care units. Overall, tachycardia (32.1%), agitation/irritation (25.6%) and drowsiness/lethargy (20.4%) were the most frequently reported clinical effects from SCRA exposure. Clinical effects resolved within 2-8 hours in 52.8% of cases, but their duration increased markedly by 2015. Regionally, the largest number of SCRA cases was reported in the South (n = 9374, 48.6%). SCRA cases in the Northeast were hospitalized more frequently (27.4%), with cases in the Midwest being admitted more frequently to critical care units (15.3%). However, there were no significant differences in clinical toxicity or disposition among the regions.

CONCLUSION

Hospitalization resulting from toxicity from synthetic cannabinoid receptor agonists exposure in the United States increased significantly between 2010 and 2015.

Change in the new psychoactive substances associated with Emergency Department acute toxicity presentations associated with the introduction of the UK 2016 Psychoactive Substances Act

OBJECTIVES

In May 2016, the Psychoactive Substances Act (PSA) came into effect in UK making it an offence to produce or supply new psychoactive substances (NPS). The aim of this study was to determine whether this was associated with a change in Emergency Department (ED) presentations with acute NPS toxicity.

METHOD

ED presentations to our inner-city hospital in London, UK, with acute NPS toxicity in the 12 months before and after the PSA introduction [June 2015-May 2016 (2015/2016) and June 2016-May 2017 (2016/2017)] were obtained from our database. The following data were extracted: (i) demographics; (ii) NPS(s) self-reported [categorized as synthetic cannabinoids (SC), cathinones, and "other NPS")]; and (iii) month of presentation.

RESULTS

There were 1884 presentations with recreational drug toxicity, 447 (23.7%) involved NPS. There was no difference in the overall proportion of presentations involving an NPS in 2015/2016 [n = 196 (22.3%)] and 2016/2017 [251 (24.9%); (p = .48)]. There were a mean ± SD of 16.3 ± 3.7 NPS-related presentations per month in 2015/2016 and 20.9 ± 9.2 in 2016/2017; there was no significant change in overall monthly NPS-related presentations between these periods (p = .15). However, mean ± SD monthly SC-related presentations increased from 2015/2016 (5.9 ± 2.5) to 2016/2017 (17 ± 9.8); p = .004. Mean monthly cathinone-related presentations decreased from 2015/2016 (8.8 ± 4.2) to 2016/2017 (3.8 ± 2.7); p = .001. There was no significant change in monthly mean "other NPS" presentations from 2015/2016 (1.8 ± 2.2) to 2016/2017 (0.5 ± 0.8); p = .062. Between 2015/2016 and 2016/2017, SCs as a proportion of NPS-related presentations increased (r = .90) whilst cathinones decreased (r = -0.82).

CONCLUSION

NPS present front-line health services with unique challenges, and the PSA 2016 represents a major legislative effort in UK to limit their availability and supply. The burden of NPS use on this inner-city  ED remains large 12 months after this legislation has come into force, with evolving patterns of NPS use.

Synthetic Cannabinoid use in a Case Series of Patients with Psychosis Presenting to Acute Psychiatric Settings: Clinical Presentation and Management Issues

Background: Novel Psychoactive Substances (NPS) are a heterogeneous class of synthetic molecules including synthetic cannabinoid receptor agonists (SCRAs). Psychosis is associated with SCRAs use. There is limited knowledge regarding the structured assessment and psychometric evaluation of clinical presentations, analytical toxicology and clinical management plans of patients presenting with psychosis and SCRAs misuse. Methods: We gathered information regarding the clinical presentations, toxicology and care plans of patients with psychosis and SCRAs misuse admitted to inpatients services. Clinical presentations were assessed using the PANSS scale. Vital signs data were collected using the National Early Warning Signs tool. Analytic chemistry data were collected using urine drug screening tests for traditional psychoactive substances and NPS. Results: We described the clinical presentation and management plan of four patients with psychosis and misuse of SCRAs. Conclusion: The formulation of an informed clinical management plan requires a structured assessment, identification of the index NPS, pharmacological interventions, increases in nursing observations, changes to leave status and monitoring of the vital signs. The objective from using these interventions is to maintain stable physical health whilst rapidly improving the altered mental state.

Impact of synthetic cannabinoid use on hospital stay in patients with bipolar disorder versus schizophrenia, or other psychotic disorders

Synthetic cannabinoid products have become popular and have led to an increased number of patients presenting to emergency departments and psychiatric hospitals. The purpose of this study was to evaluate the impact of synthetic cannabinoid use at admission on length of stay and doses of antipsychotics at discharge in individuals with bipolar disorder, schizophrenia and other psychotic disorders. We retrospectively examined medical records of 324 inpatients admitted from January 2014 to July 2015. We found that synthetic cannabinoid use predicted length of stay and antipsychotic dose using structural equation modeling. Further, the association of synthetic cannabinoid use with length of stay was partly mediated by antipsychotic dose. These associations were independent of specific diagnosis. In conclusion, patients with bipolar disorder, schizophrenia, or other psychotic disorders who reported synthetic cannabinoid use at admission had shorter length of stay and received lower doses of antipsychotics, irrespective of clinical diagnoses.

Patterns of Acute Toxicity Associated with New Psychoactive Substances

This chapter begins by considering why it is important to understand the clinical patterns of acute toxicity associated with new psychoactive substances (NPS), the challenges associated with gathering these data, the sources of information available and the limitations of each. It describes the data triangulation approach that can be used to combine individual, each inherently limited, data sources to help build the picture of the pattern of acute non-fatal toxicity associated with NPS. The chapter illustrates the data triangulation approach by the use of clinical examples and aims to consider mechanism of action data in conjunction with clinical features to provide an overarching understanding of the clinical presentation. Examples of the most important individual and groups of NPS were identified using multimodal literature searching based on the most relevant terms. The chapter provides descriptive accounts that are a complete reference source on the patterns of acute toxicity.

In vitro metabolism of the synthetic cannabinoids CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA and CUMYL-4CN-B7AICA

Synthetic cannabinoid consumption trends underlie fast changes and provide several challenges to clinical and forensic toxicologists. Due to their extensive metabolism, parent compounds are hardly detectable in urine. Therefore, knowledge of the metabolism of synthetic cannabinoids is essential to allow their detection in biological matrices. The aim of the present study was the elucidation of the metabolism of CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA, and CUMYL-4CN-B7AICA with a focus on the analytical and interpretational differentiation of the compounds. Microsomal assay mixtures containing co-substrates, 10 μg/mL substrate and 1 mg/mL pooled human liver microsomes were incubated for 1 hour at 37°C. Investigation of the metabolites was performed on a Thermo Fischer Ultimate 3000 UHPLC system coupled to a Sciex 6600 QTOF System. Hydroxylation was observed to be a major biotransformation step for all 5 cumyl-derivatives, followed by dihydroxylation. For CUMYL-PINACA, a major metabolic pathway was hydroxylation at the pentyl moiety, followed by a second hydroxylation at that pentyl moiety or oxidation to ketone. A major metabolic pathway for the compounds containing a nitrile function was nitrile hydrolysis followed by carboxylation and further hydroxylation. For the fluorinated compounds, oxidative defluorination and carboxylation were abundant metabolic steps. Some of the metabolic transformations lead to structurally identical metabolites, which should not be used as marker for the intake of a particular parent compound. In addition, several constitutional isomers containing either an indazole or azaindole core structure were detected, which should be differentiated by retention time rather than by their mass spectra alone.

Pharmacology of Cumyl-Carboxamide Synthetic Cannabinoid New Psychoactive Substances (NPS) CUMYL-BICA, CUMYL-PICA, CUMYL-5F-PICA, CUMYL-5F-PINACA, and Their Analogues

Synthetic cannabinoids (SC) are the largest class of new psychoactive substances (NPS), and are increasingly associated with serious adverse effects. The majority of SC NPS are 1,3-disubstituted indoles and indazoles featuring a diversity of subunits at the 1- and 3-positions. Most recently, cumyl-derived indole- and indazole-3-carboxamides have been detected by law enforcement agencies and by emergency departments. Herein we describe the synthesis, characterization, and pharmacology of SCs CUMYL-BICA, CUMYL-PICA, CUMYL-5F-PICA, CUMYL-PINACA, CUMYL-5F-PINACA, and related analogues. All cumyl-derived SCs were potent, efficacious agonists at CB₁ (EC₅₀ = 0.43-12.3 nM) and CB₂ (EC₅₀ = 11.3-122 nM) receptors in a fluorometric assay of membrane potential, with selectivity for CB₁ activation (3.1-53 times over CB₂). CUMYL-PICA and CUMYL-5F-PICA were evaluated in rats using biotelemetry, and induced hypothermia and bradycardia at doses of 1 mg/kg. Hypothermia was reversed by pretreatment with a CB₁, but not CB₂, antagonist, confirming that cumyl-derived SCs are cannabimimetic in vivo.