SUPPRESSION OF DYSKINESIAS IN ADVANCED PARKINSONS-DISEASE .2. INCREASING DAILY CLOZAPINE DOSES SUPPRESS DYSKINESIAS AND IMPROVE PARKINSONISM SYMPTOMS

We gave increasing daily doses of clozapine to six patients with advan ced Parkinson's disease (PD) and levodopa-induced dyskinesias. Clozapi ne reduced the daily dyskinesia time five-fold, increased ''on'' time eight-fold, and doubled the serum [DOPA] producing half-maximal dyskin esia. Parkinsonism scores after overnight DOPA withdrawal improved wit h increasing daily clozapine intake, and there was no clozapine dose-r elated shift in levodopa dose response for relief of parkinsonism. Pat ients experienced sedation, sialorrhea, and orthostatic hypotension. C lozapine appears to be an effective agent for suppression of levodopa- induced dyskinesias in PD.