Pharmacokinetics and pharmacodynamics of the synthetic cannabinoid, 5F-MDMB-PICA, in male rats.

5F-MDMB-PICA is a popular synthetic cannabinoid associated with analytically confirmed intoxications. In vitro studies show 5F-MDMB-PICA is a potent cannabinoid-1 receptor (CB 1) agonist, but little information is available about in vivo pharmacokinetics and pharmacodynamics. To this end, the present study had three aims: 1) to develop a validated method for detection of 5F-MDMB-PICA and its metabolites in rat plasma, 2) to utilize the method for investigating pharmacokinetics of 5F-MDMB-PICA in rats, and 3) to relate 5F-MDMB-PICA pharmacokinetics to pharmacodynamic effects. 5F-MDMB-PICA and its metabolites were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) and method validation followed forensic standards. Male Sprague-Dawley rats bearing surgically implanted jugular catheters and subcutaneous (s.c.) temperature transponders received 5F-MDMB-PICA (50, 100, or 200 μg/kg, s.c.) or its vehicle. Blood samples were drawn at 15, 30, 60, 120, 240, and 480 min post-injection, and plasma was assayed using LC-MS/MS. At each blood draw, body temperature, and catalepsy scores were recorded. Maximum plasma concentrations (C max) of 5F-MDMB-PICA rose linearly with increasing dose (1.72–6.20 ng/mL), and plasma half-life (t 1/2) ranged from 400 to 1000 min 5F-MDMB-PICA-3,3-dimethylbutanoic acid and 5OH-MDMB-PICA were the only metabolites detected, and plasma concentrations were much lower than the parent drug. 5F-MDMB-PICA induced robust hypothermia and catalepsy-like symptoms that were significantly correlated with concentrations of 5F-MDMB-PICA. Radioligand binding in rat brain membranes revealed 5F-MDMB-PICA displays high affinity for CB 1 (IC 50 = 2 nM) while metabolites do not. In summary, 5F-MDMB-PICA is a potent CB 1 agonist in rats whose pharmacodynamic effects are related to circulating concentrations of the parent drug and not its metabolites. • 5F-MDMB-PICA is a potent CB 1 agonist in rats. • 5F-MDMB-PICA induces sustained hypothermia and catalepsy in rats (50–200 μg/kg). • Plasma concentrations of 5F-MDMB-PICA increase in parallel with dose administered. • Only two metabolites were detected in plasma, both at low levels. • Pharmacodynamic effects are related to circulating levels of 5F-MDMB-PICA. [ABSTRACT FROM AUTHOR]