BACKGROUND: Parkinson's disease-related psychosis (PDP) increases patients’ risk of falls. Pimavanserin is an atypical antipsychotic approved in the US in 2016 for the treatment of hallucinations and delusions associated with PDP.
OBJECTIVE: To compare the risk of falls/fractures among patients with PDP treated with pimavanserin versus other atypical antipsychotics.
PATIENTS AND METHODS: We identified a cohort of patients with PDP aged ≥ 40 years initiating either pimavanserin or a comparator antipsychotic (clozapine, quetiapine, risperidone, olanzapine, aripiprazole, brexpiprazole) in US commercial insurance and supplementary Medicare claims (2015-2019). Comparators were propensity score matched 2:1 with pimavanserin initiators; incidence rates (IRs) of falls/fractures were compared using incidence rate ratios (IRRs) and 95% confidence intervals (CIs).
RESULTS: We identified 112 eligible pimavanserin initiators and 982 comparators. Pimavanserin initiators were younger and had fewer severe comorbidities, indicators of impairment, and healthcare encounters, though they had higher PD medication use. The crude IRs (cases/100 person-years) (95% CI) for composite falls/fractures were 17.8 (7.7-35.0) for pimavanserin and 40.8 (35.0-47.4) for comparators. Matching retained 108 pimavanserin initiators and 216 comparator--all characteristics were well balanced after matching--with a matched IRR (pimavanserin vs. comparator) of 0.71 (95% CI, 0.27-1.67). Sensitivity analysis IRR estimates were consistently below 1.00, with a sensitivity analysis not requiring a diagnosis of psychosis resulting in an IRR estimate of 0.55 (95% CI, 0.34-0.86).
CONCLUSIONS: The results of this study do not suggest any increase in risk of falls or fractures associated with pimavanserin compared with other antipsychotics in patients with PDP. Sensitivity analyses suggest a decreased risk.
