Clozapine and risperidone treatment of psychosis in Parkinson's disease

The authors compared efficacy and safety of risperidone and clozapine for t he treatment of psychosis in a double-blind trial with 10 subjects with Par kinson's disease (PD) and psychosis, Mean improvement in the Brief Psychiat ric Rating Scale psychosis score was similar in the clozapine and the rispe ridone groups (P = 0.23). Although the mean motor Unified Parkinson's Disea se Rating Scale score worsened in the risperidone group and improved in the clozapine group, this difference did not reach statistical significance. O ne subject on clozapine developed neutropenia. In subjects with PD, risperi done may be considered as an alternative to clozapine because it is as effe ctive for the treatment of psychoses without the hematologic, antimuscarini c, and seizure Sine effects. However, risperidone may worsen extrapyramidal symptoms more than clozapine and therefore must be used with caution.