Pimavanserin trumps atypical antipsychotics in preventing death in Parkinson’s disease patients

Use of pimavanserin appears to be more effective than atypical antipsychotic agents in reducing mortality among Parkinson’s disease patients during the first 180 days of treatment, reveals a study. However, such benefit is seen only in community-dwelling patients and not in nursing home residents.

This retrospective new-user cohort study included Medicare beneficiaries with Parkinson’s disease who started treatment with pimavanserin (n=3,227) or atypical antipsychotics (n=18,442) from April 2016 to March 2019. The mean age of pimavanserin users was approximately 78 years; 45 percent were female.

The authors estimated all-cause mortality for pimavanserin vs atypical antipsychotics using segmented proportional hazards regression over 1‒180 and 181+ days of treatment. They also addressed potential confounding through inverse probability of treatment weighting (IPTW).

Users of atypical antipsychotics had more prevalent comorbidities before IPTW, but these comorbidities were well balanced between groups after IPTW.

Mortality was about 35-percent lower with pimavanserin vs atypical antipsychotics in the first 180 days of treatment (hazard ratio [HR], 0.65, 95 percent confidence interval [CI], 0.53‒0.79), with approximately one excess death per 30 atypical antipsychotic-treated patients.

However, no additional mortality advantage was seen with pimavanserin during treatment beyond 180 days (HR, 1.05, 95 percent CI, 0.82‒1.33). There was also no mortality advantage with pimavanserin among nursing home patients.

“Pimavanserin, a serotonin 5-HT₂ antagonist, is indicated for treatment of hallucinations and delusions associated with Parkinson’s disease psychosis,” the authors said. “In premarketing trials in patients with Parkinson’s disease psychosis, 11 percent of patients died during open-label pimavanserin treatment.”

On the other hand, off-label use of antipsychotics in Parkinson’s disease psychosis increases mortality among patients with dementia.