Tetrabenazine induces acute dystonic reactions.

Four patients suffered acute dystonic reactions caused by tetrabenazine. Because dystonic reactions have previously been reported only after dopamine receptor blockade and not with dopamine depletion, it is likely that the ability of tetrabenazine to induce acute dystonia is due to its dopamine receptor blocking properties. Because tetrabenazine can induce acute dystonia even when combined with alpha-methyl-p-tyrosine, presynaptic dopamine stores may not be necessary for these reactions to occur.