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.