Linking in vitro and ex vivo CB1 activity with serum concentrations and clinical features in 5F-MDMB-PICA users to better understand SCRAs and their metabolites.

In 71 patients who used the synthetic cannabinoid 5F-MDMB-PICA, serum concentrations of the drug correlated with ex vivo activation of the CB1 cannabinoid receptor in a sigmoidal pattern. Two active metabolites were identified, but their overall contribution to cannabinoid activity in serum was negligible. Clinically, higher ex vivo cannabinoid activity was associated with a significant decrease in the Glasgow Coma Scale score, indicating reduced consciousness. In vitro pharmacological profiling could predict an individual's ex vivo CB1 activity, which in turn related to level of consciousness.

Study at a glance

Abstract

Synthetic cannabinoid receptor agonists (SCRAs) pose a danger to public health. This study focused on individuals experiencing recreational drug toxicity who had used 5F-MDMB-PICA.Patient records were evaluated regarding vital signs, Glasgow Coma Scale (GCS) and clinical features. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) confirmed and quantified the presence of 5F-MDMB-PICA (and/or metabolites) as the only SCRA present in the serum of 71 patients. Cannabinoid activity was evaluated by a cannabinoid receptor (CB1) bioassay, to assess the relationship between serum concentrations and ex vivo human CB1 activation potential. Furthermore, a link with the clinical presentation was appraised.5F-MDMB-PICA and five metabolites were pharmacologically profiled in vitro, revealing theoretically possible contributions of two active in vivo metabolites to overall cannabinoid activity. Serum concentrations of 5F-MDMB-PICA were correlated to the ex vivo cannabinoid activity, revealing a sigmoidal relationship. The latter could also be predicted based on pharmacological characterization of 5F-MDMB-PICA and its metabolites and an in-depth investigation of the bioassay outcome. Clinically, the GCS showed a significant trend (decrease) with increasing ex vivo cannabinoid activity.This is the first study to evaluate possible toxic effects of 5F-MDMB-PICA in a unique large patient cohort. It allows a better understanding of 5F-MDMB-PICA and metabolites in humans, suggesting a negligible contribution by 5F-MDMB-PICA metabolites to the overall cannabinoid activity in serum. Additionally, this work shows that in vitro pharmacological characterization allows close prediction of an individual's ex vivo CB1 activity, the latter showing a relationship with the level of consciousness.