Acute side effects after consumption of the new synthetic cannabinoids AB-CHMINACA and MDMB-CHMICA

In 2014, the "European Monitoring Centre for Drugs and Drug Addiction" (EMCDDA) reported on 30 novel synthetic cannabinoids (SCs). Among these were indole- and indazole-based valine derivatives with a cyclohexylmethyl side chain (e.g., AB-CHMINACA and MDMB-CHMICA), which represent a new class of SCs.

A prospective observational study of patients treated in emergency departments (EDs) after the intake of SCs was conducted. Clinical and laboratory data were combined and reported to a poison control centre. Serum and/or urine samples of ED patients were analyzed using LC-MS/MS.

Forty four patients (39 male, five female, 12-48 years) were included. AB-CHMINACA (MDMB-CHMICA) was identified in 20 (19) serum samples, and in 21 (25) urine samples, respectively. In 19 of the cases, more than one SC was present. Other psychoactive substances (mainly amfetamines) were identified in seven cases, but in five out of these in urine samples only. Based on the Poison Severity Score, severity of poisoning was minor (4), moderate (31) or severe (9). Most frequently reported neuropsychiatric symptoms were CNS-depression (n = 21, 61%), disorientation (n = 20, 45%), generalized seizures (n = 12, 27%), combativeness (n = 8, 18%) and extreme agitation (n = 7, 16%). Duration of symptoms lasting 24 hours or longer occurred in 15 cases (34%).

The prevalence of certain neuropsychiatric symptoms was higher in our study than in former reports after the intake of SCs of the aminoalkylindole-type (first generation) SCs. In addition, severe poisoning and duration of symptoms were also higher.

In this study, the valine derivative AB-CHMINACA and the tert-leucine derivative MDMB-CHMICA ("third generation of SCs") seem to be associated with more severe clinical toxicity than was previously reported in patients exposed to earlier generation SCs such as JWH-018. However, this observation needs to be confirmed with a larger cohort of patients with analytically confirmed abuse of third generation SCs. The rapid turnover of SCs on the drug market together with the occurrence of SCs such as AB-CHMINACA and MDMB-CHMICA is alarming, especially because of the unexpectedly high frequency of neuropsychiatric symptoms.