Twelve-week, prospective, open-label, randomized trial on the effects of an anticholinergic agent or antidiuretic agent as add-on therapy to an alpha-blocker for lower urinary tract symptoms

Purpose: The effects of an anticholinergic or antidiuretic agent as add-on therapy to an alpha-blocker for lower urinary tract symptoms (LUTS) according to a voiding diary in 3 days are unknown. We prospectively investigated the efficacy of an anticholinergic or antidiuretic agent as add-on therapy for nocturia in men previously treated with an alpha-blocker for LUTS.

Subjects and methods: Patients were randomly subdivided into two groups. All patients had a 4-week washout. Group A had alpha-blocker for 4 weeks, then an alpha-blocker plus an anticholinergic agent for 4 weeks, and, finally, 4 weeks of an alpha-blocker plus an antidiuretic agent. Group B had an alpha-blocker for 4 weeks, then an alpha-blocker plus an antidiuretic agent for 4 weeks, and, finally, 4 weeks of an alpha-blocker plus an anticholinergic agent. In both groups, patients were subdivided into nocturnal polyuria, decreased nocturnal bladder capacity (NBC), or nocturia by both causes subgroups. A 3-day voiding diary, total International Prostate Symptom Score (IPSS), IPSS sub-scores, Overactive Bladder Symptom Score, uroflowmetry, and post-void residual urine volume, were assessed at baseline, and at 4, 8, and 12 weeks.

Results: A total of 405 patients completed the study. During treatment, the changes from baseline in total IPSS and IPSS sub-scores were significantly decreased at 4 weeks and were maintained for 12 weeks. In the nocturnal polyuria subgroup of Groups A and B, the number of episodes of nocturia in 3 days, nocturnal urine volume, and nocturnal index were significantly decreased using an alpha-blocker plus an antidiuretic agent. In the decreased NBC subgroup of Groups A and B, IPSS storage sub-score, Overactive Bladder Symptom Score, number of episodes of nocturia in 3 days, number of episodes of urgency in 3 days, and NBC index were all significantly decreased using an alpha-blocker plus an anticholinergic agent.

Conclusion: An anticholinergic agent or antidiuretic agent as an add-on therapy in men previously treated with an alpha-blocker improves nocturia including LUTS.