Clinical and Forensic Toxicological Aspects of Synthetic Cannabinoids: A Narrative Review and Update

Background: Synthetic cannabinoids (SCs) are highly abused of New Psychoactive Substances (NPS). SCs has known under street names such as “Spice”, “herbal incense” and “K2”, act as endocannabinoids (CB) receptor full agonists and have unpredictable toxicity and abuse potential. This narrative review was conducted to update the present evidence about the clinical and forensic toxicological aspects of SCs. Methods: PubMed, Scopus and Google Scholar databases from 2015 to 2020 (up to 1st May) were searched using the terms “synthetic cannabinoids”, “synthetic cannabimimetics”, “ K2”, “Spice”, “clinical toxicology”, “forensic toxicology”, “poisoning”, “toxicity”, “abuse” , “addiction”, “analysis” and “determination” to identify the relevant articles. In addition, a manual search of reference lists of the retrieved articles was conducted. Results: ADB-FUBINACA, XRL-11, 5F-ADB, 5F-PB-22, MDMB-CHMICA and MMB-2201are the commonly reported SCs analogues among acute toxicities and fatalities cases. Adverse reactions and toxic effects of SCs including psychoneurological, cardiovascular, renal and gastrointestinal involvements. Deaths related to SCs have been reported due to stroke and cardiac dysrhythmia. Analysis of SCs in biological samples in the clinical and postmortem setting need to sophisticated analytical instruments. Liquid chromatography tandem mass spectrometry (LC-MS/MS) has a crucial role for detection of SCs and their metabolites in biological samples. Conclusion: Unlike natural cannabinoids, the SCs abuse/poisoning has serious and life-threatening effects in abuser. Also, analysis of SCs is not included in the routine forensic urine drug testing. Therefore, suitable measures for information to the public and health care professionals for prevention of SCs abuse are recommended.