Treatment of drug-induced psychosis with quetiapine and clozapine in Parkinson's disease.

Abstract

Drug-induced psychosis is a major problem that complicates the treatment of PD, and occurs in up to 22% of patients.1 Because conventional neuroleptics are poorly tolerated in patients with PD, most authors recommend a two-step approach, consisting first of a reduction of dopaminergic drugs to the minimum level required, followed by the initiation of an atypical antipsychotic drug if necessary.2 Clozapine has been shown to significantly improve psychosis without worsening motor symptoms of parkinsonism.3 However, frequent monitoring of the white blood cell count makes the use of this drug cumbersome and expensive. Risperidone and olanzapine have been shown to worsen PD symptoms.4,5⇓ Quetiapine has been recently suggested as a possible treatment for PD because it reduces psychosis without worsening motor symptoms, and because its use does not require blood monitoring.6,7⇓ We performed a retrospective review of our own use of quetiapine in drug-induced psychosis of PD to evaluate its …