Risperidone versus clozapine in the treatment of psychosis in six patients with Parkinson's disease and other akinetic-rigid syndromes.

BACKGROUND

We report six cases of psychosis in patients with akinetic-rigid syndromes who were treated with risperidone.

RESULTS

Five of the six patients experienced intolerable exacerbation of parkinsonism. Four subsequently did well on clozapine therapy. One patient required nursing home placement and a feeding gastrostomy as a result of the worsening parkinsonism during risperidone treatment, but was able to return home and have the gastrostomy removed after switching from risperidone to clozapine. Two of the five patients who worsened motorically also developed encephalopathy during risperidone treatment; the encephalopathy resolved when the patients were switched to clozapine treatment. Only one patient, the youngest, did well on risperidone therapy.

CONCLUSION

We believe that risperidone is not a substitute for clozapine in treating psychosis in parkinsonian patients and should be used with caution.