S.07.05 Cannabis co-administration potentiates MDMA effects on temperature and heart rate

Abstract

3,4-methylenedioxymethamphetamine (MDMA or “ecstasy”) is a frequently used club-drug in Western societies. Ecstasy users generally are multi-drug users, and cannabis (THC) is commonly combined with MDMA. MDMA is a potent psychostimulant, increasing heart rate, blood pressure and body temperature. THC also increases heart rate but does not markedly affect blood pressure due to vasodilatory effects. Since MDMA impairs heat loss through vasoconstriction, THC co-administration may attenuate MDMA induced temperature increase. We performed a four-way, double blind, randomized, crossover, placebo-controlled study in 16 healthy volunteers. Both single drug conditions (MDMA (100 mg po) and vaporized δ9-THC (4, 6, and 6 mg, interval of 90 min)) increased heart rate robustly with an average peak increase of 30 beats per minute, and co-administration showed additive effects (all comparisons p <0.01). Blood pressure and temperature were increased in the MDMA condition and the MDMA plus THC condition (p <0.01). MDMA increased epinephrine (p = 0.03) and norepinephrine concentrations (p