CLOZAPINE FOR THE TREATMENT OF LEVODOPA-INDUCED PSYCHOSIS AND DYSKINESIA IN PARKINSONS-DISEASE

The treatment of psychosis in patients with Parkinson's disease (PD) i s one of the most difficult problems in clinical psychiatry. Clozapine 's low propensity to induce extrapyramidal side effects makes it an at tractive treatment for psychotic patients with PD. A number of publish ed uncontrolled studies suggest that low-dose clozapine is effective i n these patients. However, the dose range, side effect profiles and le ngth of treatment have varied in these reports. In this article, the a uthors review the literature and report on the effects of clozapine in a patient with Parkinson's disease and psychosis. Clozapine (50 mg pe r day) resulted in a complete resolution of psychosis, improvement of motor function, reduction of ''off'' time and a major improvement in l evodopa-induced dystonic dyskinesias. The only adverse effect was mild sedation during the first two weeks of clozapine treatment. The lack of acute blockade of striatal D2 receptors by clozapine and the failur e of chronic clozapine treatment to suppress striatal dopamine release may account for its beneficial effect in Parkinson's disease. Additio nally, an ameliorating effect of clozapine on parkinsonism might be du e to its action on serotonergic systems leading to release of striatal dopamine.