Pilot study with clozapine in patients with HIV-associated psychosis and drug-induced parkinsonism

Clozapine (CZP) is an atypical antipsychotic drug that does not appear to block striatal dopamine receptors. In six patients who met the criteria of HIV-associated psychosis and who had previously developed moderate parkinsonism as a result of the use of typical neuroleptic agents, CZP was added in an open, rising dose study. Subjects were evaluated at baseline after at least 7 days without neuroleptic drugs and then monthly for 3 months of the experimental treatment using three rating scales: Brief Psychiatric Rating Scale (BPRS), Clinical Global Impression (CGI), and motor examination of the Unified Parkinson's Disease Rating Scale (UPDRS). A significant reduction in psychopathology as represented in the BPRS total score (54.2 at baseline versus 23.9 at month 3) and CGI (2 and 8, respectively) was obtained with a mean CZP dose of 27.08 mg/day. Parkinsonism also improved by an average of 76.5% at the end of the study. One patient did not complete the study as a result of a progressive decrease in leukocyte count while on CZP. These preliminary results suggest that the pharmacologic properties of CZP may be of value in the management of HIV-psychotic patients.