Atypical antipsychotics for Parkinson’s disease psychosis: a systematic review and meta-analysis

PURPOSE: To assess the present evidence regarding the efficiency, safety, and potential risks of pharmacotherapy used for Parkinson’s disease psychosis (PDPsy) treatment. PATIENTS AND METHODS: We searched the following databases: PubMed, the Cochrane Library, ISI Web of Science, and Embase using the following terms: atypical antipsychotics, pimavanserin, olanzapine, quetiapine, clozapine, Parkinson’s disease and psychosis. We systematically reviewed all randomized placebo-controlled trials comparing an atypical antipsychotic with a placebo. RESULTS: A total of 13 randomized placebo-controlled trials for a total 1142 cases were identified involving pimavanserin (n=4), clozapine (n=2), olanzapine (n=3), and quetiapine (n=4). For each atypical antipsychotic, a descriptive synthesis and meta-analyses was presented. Pimavanserin was associated with a significant improvement in psychotic symptoms compared to a placebo without worsening motor function. Clozapine was efficacious in alleviating psychotic symptoms and did not exacerbate motor function either. Quetiapine and Olanzapine did not demonstrate significant differences in reducing psychotic symptoms but may aggravate motor function. CONCLUSIONS: There is strong evidence that pimavanserin is effective for the treatment of PDPsy. Clozapine is also recommended but should be used with caution due to its side effects. In the future, more well-designed randomized controlled trials (RCTs) are needed to confirm and update the findings reported in this meta-analysis.