Clozapine in Huntington's chorea

In an open-label trial, we evaluated the efficacy of clozapine on abnormal involuntary movements in five patients with Huntington's chorea. We administered clozapine at increasing doses of 25, 50, and 150 mg/d for 3 weeks. Subjective self-evaluation of all patients reported reduction of chorea and improvement of daily living activities. At the end of the trial, all patients requested to continue with clozapine. Objective evaluation with the Abnormal Involuntary Movements Scale demonstrated in all patients moderate-to-marked reduction of abnormal involuntary movements without any significant side effects; the improvement was dose-dependent and markedly decreased 1 week after drug withdrawal.