Nantenine: an antagonist of the behavioral and physiological effects of MDMA in mice.

Rationale: No selective antagonists for the effects of MDMA have yet been identified. The structurally-similar, naturally-occurring plant alkaloid nantenine (9,10-methylenedioxy-1,2 dimethoxyaporphine) may represent such a compound.

Objectives: To investigate the capacity of nantenine to block and/or reverse MDMA-induced hyperthermia, lethality, locomotor stimulation, and head twitches in mice, and to compare these actions with those of the selective alpha1 antagonist prazosin and the selective 5-HT2A antagonist M100907.