Impact of Carbidopa-Levodopa Enteral Suspension Initiation on Oral Medication Treatment Patterns in Persons with Parkinson’s Disease: A Retrospective Cohort Analysis

Abstract

Introduction: Parkinson’s disease (PD) patients experience gradual worsening of symptoms as their disease progresses, necessitating complicated poly-pharmaceutical regimens. These complex therapeutic regimens lead to decreases in quality of life and impact adherence to medications, which may lead to poorer symptom management. At later stages of disease, more permanent solutions exist for management of PD, such as carbidopa-levodopa enteral suspension (CLES).Objective: The objective for this research was to characterize the impact of CLES on medication treatment patterns in persons with PD. Methods: We conducted a retrospective time-series analysis of a real-world claims database from the years 2015 to 2022, to evaluate medication utilization in adults with PD who initiated CLES (n=32). This population was covariate-balanced propensity score matched to eligible non-CLES controls in a 1:4 nearest neighbor (n=128) match. The index date was the date CLES was prescribed. Outcome measures, pills per day (PPD) and levodopa-equivalent daily dosages (LEDD), were created for each of the 12-months following from index for all individuals. We ran generalized mixed model regressions for all analyses to assess changes in outcomes over time. Results: PPD was reduced in CLES initiators compared to matched CLES non-initiators, a result that was seen in the first month and sustained through 12 months after treatment initiation (p<0.01 for each month). The likelihood of taking 5 or more PPD was reduced by up to 94% in individuals initiating CLES when compared to controls (OR 0.06, 95% CI 0.01, 0.37 in month 4 after treatment). Mean oral LEDD was reduced in CLES initiators compared to controls, with reductions ranging between 250 and 497 mg compared to baseline. The proportion of individuals taking 500 mg or more LEDD was significantly reduced within the first half of the year after treatment but was not found to be reduced after 6 months when compared to controls. Conclusion: Results suggest that CLES substantially reduced medication burden, improving aspects of overall pill burden in addition to oral levodopa requirements for individuals with advanced PD, with the greatest impact seen within the first month after treatment.