Combination Therapy with Alpha-Blockers and Antimuscarinics for Persistent Overactive Bladder Symptoms in Men

Abstract

Introduction: Men with benign prostatic obstruction (BPO) often have persistent overactive bladder (OAB) symptoms despite alpha-blocker monotherapy. Adding an antimuscarinic is controversial due to retention risk. This review evaluates efficacy and safety of combination therapy.

Methods: We searched CENTRAL, Embase, and clinicaltrials.gov (2010–2024) for RCTs comparing alpha-blocker plus antimuscarinic vs. alpha-blocker alone in men with post-void residual (PVR) <250 mL. Primary outcomes: OAB symptom score and PVR change. Secondary: acute urinary retention (AUR).

Results: Twelve RCTs (n=2,871) met inclusion. Combination therapy reduced OAB score by mean 2.7 points more than monotherapy (95%CI 1.9–3.5). PVR increased by a mean of 18 mL (95%CI 10–26), not clinically significant. AUR occurred in 2.1% of combination vs. 1.2% of monotherapy (RR 1.7, p=0.12). Dry mouth (16% vs. 5%) and constipation (9% vs. 3%) were more common with combination.

Discussion: Benefits exceed risks for men with PVR <150 mL. Most trials used immediate-release antimuscarinics; extended-release formulations may have better tolerability. Limited data exist for men over 80 years or with baseline PVR >150 mL.

Conclusions: In men with persistent OAB despite alpha-blockers and PVR <150 mL, adding an antimuscarinic improves symptoms without significantly increasing retention risk. Monitoring PVR at 4–8 weeks is prudent.