Pimavanserin Associated With Lower Mortality in Some Patients With Parkinson Disease

Pimavanserin use is associated with lower mortality in community-dwelling older adults with Parkinson disease, a recent study showed. In the first 180 days of treatment, mortality was lower in patients treated with pimavanserin than in patients treated with atypical antipsychotic medications. Researchers published these and other findings in the American Journal of Psychiatry.

During premarketing trials for pimavanserin in patients with Parkinson disease psychosis, 11% of patients died. Postmarketing studies also included reports of deaths. Previous studies found mortality rate was 50% higher in patients treated with atypical antipsychotics than with placebo.

To explore mortality rates further, the researchers who conducted the current study compared the mortality rate in US Medicare patients diagnosed with Parkinson disease who used either pimavanserin or atypical antipsychotics. The retrospective cohort study included 3227 patients taking pimavanserin and 18,442 taking atypical antipsychotics. Quetiapine was the most commonly used drug (78%).

Within the study period, 207 pimavanserin users and 1752 atypical antipsychotic users died. During the first 180 days of follow-up, the adjusted death rates were 13 per 100 person-years with pimavanserin and 21 with atypical antipsychotic use. After 180 days, death rates changed to 18 and 17 per 100 person-years, respectively. For hospice patients and patients in nursing homes, death rates were about the same in each group.

Although the study used large sample sizes and drew from a national database, the study had a few limitations. Researchers could not compare drug use with no drug use. Heterogeneity in characteristics of pimavanserin users and in indications for atypical antipsychotics. Regardless, the study helps address knowledge gaps regarding mortality risks in patients with Parkinson disease psychosis.