BENZTROPINE VERSUS CLOZAPINE FOR THE TREATMENT OF TREMOR IN PARKINSONS-DISEASE

Four open-label studies have reported beneficial effects of clozapine on the tremor of idiopathic Parkinson's disease (PD). We performed a d ouble-blind crossover trial with a 2-week washout, comparing low-dose clozapine to benztropine for the treatment of tremor in PD. Twenty-two subjects enrolled and 19 completed the study. Benztropine and clozapi ne were equally effective in improving tremor and the motor score of t he United Parkinson's Disease Rating Scale at mean doses of 3.0 and 39 mg/day, respectively. Significant adverse events were experienced wit h each drug, but leukopenia was not encountered. We conclude that the atypical antipsychotic drug clozapine is helpful in the treatment of t remor in PD and should be considered when all other drug therapies fai l.