Pimavanserin in the Treatment of Parkinson's Disease Psychosis: Meta-analysis and Meta-regression of Randomized Clinical Trials.

Background: Up to 60 percent of patients with Parkinson's disease (PD) develop Parkinson's disease psychosis (PDP). PDP is associated with a significant economic burden. The management of PDP has been divided into two approaches--one focuses on decreasing the doses of anti-Parkinsonian medications and the other involves prescribing atypical antipsychotics. Of these atypical antipsychotics, pimavanserin is United States (US) Food and Drug Administration (FDA)-approved specifically for the treatment of PDP. Objective: The goal was to evaluate the safety and efficacy of pimavanserin in the treatment of PDP based on data from randomized clinical trials. Methods: All the articles, which assessed pimavanserin's effect on the treatment of PDP, were retrieved from Google Scholar, PubMed, and abstracts from annual scientific sessions. The data on dose, therapy duration, patient numbers, and study duration were collected. These data were analyzed with random effect modeling using the inverse variance method and the Mantel-Haenszel method. Results: Four studies comparing pimavanserin to a placebo provided data on 680 patients (263 placebo, 417 pimavanserin). Treatment with pimavanserin was associated with a significant reduction in scores using the Scale of Assessment of Positive Symptoms, Hallucinations, and Delusion (SAPS-H+D) (mean difference [MD]: -1.55 [-2.71, -0.379], p=0.009). The groups had similar composite scores for Unified Parkinson's Disease Rating Scale II and III (UPDRS II and III) (MD: 0.093 [-1.28, 1.46], p=0.89). Interestingly, pimavanserin was protective against orthostatic hypotension (risk ratio: 0.33 [0.30, 0.37], p<0.001). All other adverse events were similarly distributed across both groups. Conclusion: There was a significant improvement in psychosis symptoms in patients with PD who took pimavanserin. Pimavanserin was also shown to be protective against orthostatic hypotension. [ABSTRACT FROM AUTHOR]