Temporal evolution of antiparkinsonian drug prescription over 17 years: a real-world data analysis of Korean patients with Parkinson's disease.

BACKGROUND: Evidence-based guidelines guide Parkinson’s disease (PD) management, but real-world prescription patterns may differ owing to patient and practice variability. Large-scale, longitudinal data can clarify how antiparkinsonian drugs are prescribed in practice. METHODS: We analyzed nationwide claims from the Korean National Health Insurance Service between 2002 and 2019. Patients with PD were identified using ICD-10 G20 plus V124 code. Initial prescriptions, combination regimens, and dosage adjustments were examined in 160,476 patients. For 64,779 patients receiving levodopa or dopamine-agonist (DA) monotherapy with complete 3-year follow-up, levodopa-equivalent daily dose (LEDD) was calculated quarterly. Group-based trajectory modeling identified longitudinal LEDD patterns, and Sankey plots visualized prescription transitions. RESULTS: Monotherapy was the initial treatment in 66.3% of patients, predominantly levodopa, whose use increased with age. DA monotherapy decreased with age, and DA prescriptions stabilized around 10% after 2010. In the polytherapy group (33.7%), > 90% received levodopa- or DA-based combinations. The mean initial LEDD was approximately 200 mg/day across age groups. Four LEDD trajectories were identified: consistently high (5%), moderately increasing (17%), low-to-moderate stable (29%), and low stable (49%). From 2003–2010 to 2011–2019, the low-stable group decreased (56% → 42%), whereas moderate-increasing and low-to-moderate stable groups increased (14% → 20% and 24% → 32%). Sankey plots indicated that medication adjustments occurred mainly during the first 3–4 quarters after initiation, differing by trajectory group. CONCLUSIONS: This real-world analysis demonstrates stable dominance of levodopa, age-dependent DA use, and temporal shifts toward earlier, active titration. Distinct LEDD trajectories and early adjustment patterns underscore the need for individualized pharmacotherapy strategies in PD.