Polypharmacy and Hyperpolypharmacy in Older Individuals with Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM: Polypharmacy (concomitant use of 5–9 medicines) and hyperpolypharmacy (concomitant use of over 10 medicines) were observed to be more frequent in older adults (≥65 years) and associated with adverse outcomes. Their prevalence and risk in older patients with Parkinson's disease (PD) remain unknown. We aimed to synthesize the extant evidence on the prevalence and risk of polypharmacy and hyperpolypharmacy in older adults with PD. METHODS: A systematic literature search was performed in PubMed/MEDLINE, Scopus, and Embase databases to identify pertinent studies published from 2000 to July 2021. Observational studies reporting the prevalence and association with disease of polypharmacy/hyperpolypharmacy in older adults with PD were meta-analyzed. Pooled prevalence and odds ratio (OR) with 95% confidence intervals (CIs) were calculated. RESULTS: Out of the total 499 studies identified, 6 fulfilled the inclusion criteria and comprised 7,171 participants. The overall prevalence of polypharmacy and hyperpolypharmacy was 40% (95% CI: 37–44) and 18% (95% CI: 13–23), respectively. A meta-analysis of 4 studies indicated a significant association between polypharmacy (OR: 1.94, 95% CI: 1.26–2.62; p < 0.001) and PD. Hyperpolypharmacy was also strongly associated with PD (OR: 3.11, 95% CI: 2.08–4.14; p < 0.001). CONCLUSION: Polypharmacy (40%) and hyperpolypharmacy (18%) are highly prevalent and eventually increase the risk of drug-related problems in older adults with PD. Therefore, interventions that ensure rational geriatric pharmacotherapy are of critical importance for the older population with neurogenerative disorders.