In-vivo metabolism in the rat and mouse of antrafenine to 1- m-trifluoromethylphenylpiperazine

Abstract

Abstract The analgesic antrafenine forms 1- m-trifluoromethylphenylpiperazine (mCF3PP) during its biotransformation in the rat and mouse. At least 14 and 3% of an antrafenine dose (25 mg kg−1 p.o.) reaches the systemic circulation as mCF3PP in the mouse and rat respectively. The metabolite easily enters the brain, reaching concentrations several times those in body fluids. This, together with the fact that mCF3PP is known to produce several pharmacological effects compatible with a stimulatory action on 5-hydroxytryptamine postsynaptic receptors, suggests that this metabolite may contribute to the parent drug's pharmacological effects.