Is the 3,4-methylendioxypyrovalerone/mephedrone combination responsible for enhanced stimulant effects? A rat study with investigation of the effect/concentration relationships.

An MDPV/4-MMC combination results in enhanced stimulant effects in the rat, despite significant reduction in MDPV bioavailability. Enhanced effects could be explained by increased MDPV distribution and/or possible complementation at the brain dopaminergic targets. However, the exact consequences of the MDPV/4-MMC combination in humans remain to be clarified.