CLOZAPINE IN THE TREATMENT OF TREMOR IN PARKINSONS-DISEASE

Tremor at rest is a classic symptom of Parkinson's disease that causes significant disability and distress for the patient and is generally only weakly responsive to conventional treatment, like anticholinergic and dopaminergic medication. This study describes the treatment with Clozapine in patients with Parkinson's disease, who despite optimal an tiparkinson medical therapy still have a major disabling tremor at res t. Clozapine is an ''atypical'' neuroleptic agent, producing fewer ext ra pyramidal side effects common to conventional antipsychotic drugs. Clozapine, however, has as its most serious complication agranulocytos is, and hence all patients taking Clozapine must undergo bloodtests at least several times a month. Under these frequent blood monitoring co nditions, in this study Clozapine produced a substantial alleviation o f parkinsonian tremor in 17 of 23 patients (73%). The beneficial respo nse was reached with a relative low dose of Clozapine (18 mg./day), wh ile previous antiparkinson medication was kept unchanged. The improvem ent of tremor at rest was noticeable generally within 2 weeks of begin ning Clozapine therapy. No tolerance to the antitremor efficacy of Clo zapine was seen during study-period of at least 6 months. Leucopenia d eveloped in one patient, other major adverse events were hypersalivati on and day-time drowsiness. These findings confirm the substantial ant itremor efficacy of Clozapine in Parkinson's disease.