Potentially Inappropriate Medication Use in Patients With Parkinson's Disease: Analysis of Korean National Health Insurance Claims Data.

Background and purpose: Polypharmacy is common in Parkinson's disease (PD). This includes appropriate medications for PD-related symptoms and comorbid conditions, but also potentially inappropriate medications (PIMs). We aimed to determine the prescribing trends of PIMs based on the 2019 Beers Criteria in Korean patients with PD.

Methods: This retrospective observational study analyzed PD patients aged 40 years or older whose PIM prescribing patterns from 2014 to 2019 were included in the HIRA (Korean Health Insurance Review and Assessment Service) nationwide claims database in South Korea. The prevalence and usage were analyzed for both overall PIMs and PIMs that can exacerbate PD symptoms (PIM^PDs). Additionally, the most frequently prescribed PIMs and PIM^PDs were investigated.

Results: PIMs were used at least once in 38.3% of 257,142 patients with PD. The mean number of PIM items used per patient was 2.61. The PIM usage ratio, corresponding to the proportion of the total amount of PIMs to all medications per patient, was 19.7%. The proportion of patients taking PIMs among all PD patients decreased significantly up to 2018 but then increased in 2019, while the PIM usage ratio increased steadily up to 2018 and then decreased in 2019. Excluding the representative PD medications, the most frequently prescribed PIM was amitriptyline. PIM^PDs were also commonly used, including levosulpiride and haloperidol.

Conclusions: The prevalence and usage of PIMs were high in Korean PD patients during 2014-2019, and the utilization of PIM^PDs persisted throughout this period. These findings can be used to develop evidence-based guidelines for robust polypharmacy management strategies to ensure the safety of medications used by PD patients.