Objective: The aim is to explore the relationship between high prescription drug use (polypharmacy), and its unintended effects on individuals with Parkinson’s Disease (PD).

Background: Polypharmacy may reflect both greater comorbidity burden and the cumulative effects of taking multiple medications known to impact motor, cognitive and psychological variables. But there is little evidence of the effects of polypharmacy in people with PD.

Method:

An observational cohort (n=164) provided a wide range of modifiable and non-modifiable variables alongside standard tests of PD severity (MDS-UPDRS I-IV & PDQ-39). Analysis of variance and post-hoc t-tests tested for differences between levels of polypharmacy. ElasticNet and LASSO techniques explored a richly phenotyped dataset to identify previously unrecognized variables or combinations of variables associated with polypharmacy. Correlation and linear regression described the relationship between polypharmacy and other variables.

Results: Theory-driven exploration indicated that greater medication burden was associated with poorer physical performance and quality of life. Significant group differences (0-4, 5-9, and 10+ Rx medications) were observed for measures of physical performance, and PDQ-39 scores. Correlation and regression showed polypharmacy significantly associated with gait speed, SPPB total score, Figure of 8 steps, and PDQ-39 (r=.2, p<.05), although relationships were modest in magnitude (R2=.07). No consistent significant associations were found for cognition or psychological measures. Exploratory analysis identified slowness on Timed Up and Go, painful off-state dystonia, support group attendance, sedentary time, and central pulse pressure as significantly related to polypharmacy. The final stepwise model was statistically significant (R2=.38).

Conclusion:

Numerous associations between polypharmacy and a range of variables were observed in individuals with PD, raising concern that medication burden and potential drug interactions may adversely affect daily life. Further work should investigate specific drug classes and evaluate whether deprescribing strategies may confer health and functional benefits in selected patients. More evidence regarding directionality and causality is needed.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/polypharmacy-and-its-impact-in-individuals-with-parkinsons-disease-theory-and-data-driven-approaches/