Evidence for a non-dopaminergic action of amantadine.

Amantadine and dopamine have been applied by microiontophoresis to single neurones in the cerebral cortex. While the dopamine receptor blocker alpha-flupenthixol antagonized responses to dopamine, it only partially reduced responses to amantadine. The effects of alpha-flupenthixol on dopamine and amantadine responses were highly significantly different (P < 0.001). Amantadine was probably not acting on noradrenaline receptors since it was unaffected by propranolol. Thus, amantadine may have a non-catecholaminergic action, which may explain the previously noted inability of catecholamine depletion to prevent the effects of the drug.