[Value of clozapine in treatment of psychotic disorder in Parkinson disease].

Psychosis secondary to dopaminergic therapy can limit the ability to manage motor symptoms of advanced Parkinson's disease (PD). Scholz and Dichgans (1985) were the first to report the use of clozapine in drug-induced psychosis in PD. The rationale for use of clozapine in parkinsonian patients is supported by his original pharmacological profile with weak extra-pyramidal side effects. A Medline search was performed of literature from 1985 to 1994. The literature search was not limited to the English language. Numerous authors (23 articles) using case reports or open trials among more than 100 patients suggested that clozapine would be useful in treating drug-induced psychosis in PD. We analysed the available information addressing: 1) clinical efficacy, 2) clinical predictors of outcome, 3) delay of action, 4) influence of clozapine on extrapyramidal symptomatology, 5) adverse effects and treatment withdrawal causes, 6) long-term follow-up data. However, the partially negative result of the only double-blind placebo-controlled trials, it may be stated that in some clinical situation of psychosis in PD, the use of clozapine may represent an opportune alternative when other therapeutic strategies have failed.