Marked improvement of tardive dystonia after replacing haloperidol with risperidone in a schizophrenic patient.

We report on a schizophrenic patient whose tardive dystonia, delusions, and auditory hallucinations showed remarkable concurrent improvement after replacing haloperidol with risperidone. The present finding suggests that the 5-hydroxytryptamine-2 (5-HT2) antagonistic action of risperidone has brought about the improvement in tardive dystonia. The 5-HT2 antagonistic action of risperidone, in addition to its dopamine antagonistic action, may have also lessened psychotic symptoms in the current case.