Memantine hydrochloride is a hydrochloride obtained by reaction of memantine with one equivalent of hydrochloric acid. A low to moderate affinity uncompetitive (open-channel); NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels. It has a role as an antidepressant, an antiparkinson drug, a dopaminergic agent, a neuroprotective agent and a NMDA receptor antagonist. It contains a memantinium(1+).