Fall risk related to subtype-specific alpha-antagonists for benign prostatic hyperplasia: a nationwide Korean population-based cohort study

Background: Subtype-specific alpha-antagonists are medications commonly prescribed for lower urinary-tract symptoms, benign prostatic hyperplasia in older populations. Our study aims to investigate the association between subtype-specific alpha-antagonists and fall risk. Methods: A total of 4,202,739 men aged 60–75 years eligible for Korean Health Insurance Review and Assessment Service (HIRA) during 2017–2018 were enrolled retrospectively. After propensity score matching, 53,303 people in the exposed and unexposed groups were considered in the final study analysis. Results: The subtype-specific alpha-antagonists significantly increased the risk of fall in the exposed cohort compared to the unexposed cohort (odds ratio [OR] 1.80; 95% confidence interval [CI] 1.62–2.00). Low income increased the fall risk only in the unexposed cohort (OR 1.34; 95% CI 1.04–1.73). A seasonal difference appeared only in the exposed cohort, with a significantly higher risk of fall in summer (OR 1.23; 95% CI 1.03–1.47). A total of 968 events occurred in the exposed group, and 455 of these falls occurred on the first day of medication (47%). Conclusions: Subtype-specific alpha-antagonists significantly increased the risk of falls, especially on the first day of drug initiation and during the summer season. Education on orthostatic hypotension and fall prevention should be implemented when prescribing subtype-specific alpha-antagonists.