Risk of Parkinson’s disease among users of alpha-adrenergic receptor antagonists: a systematic review and meta-analysis

Background: Recent studies have tried to establish an association between the use of alpha-1-adrenergic receptor antagonists (A1ARAs) used in benign prostatic hyperplasia (BPH) and the risk of PD. The objective of the study is to compare the risk of Parkinson’s disease (PD) between terazosin/alfuzosin/doxazosin (TZ/AZ/DZ) users and tamsulosin users. Methods: PubMed, Google Scholar, and Embase were systematically searched from inception to April 2023. Observational studies comparing the risk of PD among patients using different types of A1ARAs were included in the meta-analysis. The primary outcome was the hazard ratio (HR) with a 95% CI for the risk of occurrence of PD among A1ARAs users of two different classes. Results: This study was based on a total of 678 433 BPH patients, out of which 287 080 patients belonged to the TZ/AZ/DZ cohort and 391 353 patients belonged to the tamsulosin cohort. The pooled incidence of PD was higher in tamsulosin users (1.28%, 95% CI: 1.04–1.55%) than in TZ/AZ/DZ drug users (1.11%, 95% CI: 0.83–1.42%). The risk of occurrence of PD was significantly lower in patients taking TZ/AZ/DZ than tamsulosin ( n = 610,363, HR = 0.82, 95% CI = 0.71–0.94, P = 0.01; I 2 = 87.4%). Conclusion: This meta-analysis demonstrated that patients with BPH who take TZ/AZ/DZ have a lower risk for developing PD than those who take tamsulosin.