Antipsychotics for the management of psychosis in Parkinson's disease: systematic review and meta-analysis

Background Antipsychotics can exacerbate motor symptoms in Parkinson's disease psychosis. Aims To systematically review the literature on the efficacy and acceptability of antipsychotics for Parkinson's disease psychosis. Method Randomised controlled trials comparing an antipsychotic with placebo were systematically reviewed. Results The final selection list included nine studies using quetiapine (3), clozapine (2), olanzapine (3) and pimavanserin (1). A narrative synthesis and meta-analyses (where appropriate) were presented for each antipsychotic. Clozapine demonstrated superiority over placebo in reducing psychotic symptoms. Quetiapine and olanzapine did not significantly improve psychotic symptoms. All three antipsychotics may exacerbate motor symptoms. Quetiapine studies were associated with high drop-out rates due to adverse events. Pimavanserin is a novel treatment that warrants further investigation. Conclusions Further research is needed. Clozapine and pimavanserin appear to be a promising treatment for Parkinson's disease psychosis.