Safety and Tolerability of Solifenacin Add-on Therapy to α-Blocker Treated Men With Residual Urgency and Frequency

PurposeVICTOR was a 12-week, double-blind, placebo controlled trial assessing the safety and tolerability of solifenacin plus tamsulosin in men with residual overactive bladder symptoms after tamsulosin monotherapy. Efficacy of solifenacin plus tamsulosin vs placebo plus tamsulosin was also evaluated.Materials and MethodsA total of 398 men 45 years old or older were randomized to 12 weeks of solifenacin plus tamsulosin or placebo plus tamsulosin once daily. The study population had 8 or more micturitions per 24 hours and 1 or more urgency episode per 24 hours after taking tamsulosin for 4 or more weeks, a total International Prostate Symptom Score of 13 or greater, a Patient Perception of Bladder Condition score of 3 or greater, a post-void residual of 200 ml or less and a peak flow rate of 5 ml per second or greater. Adverse events were monitored throughout the study. The primary efficacy end point was mean change from baseline to week 12 in micturitions per 24 hours. Secondary measures included mean change in urgency episodes per 24 hours, and changes in Patient Perception of Bladder Condition, Urgency Perception Scale and total International Prostate Symptom Scores.ResultsThe most frequent adverse events in the solifenacin plus tamsulosin and placebo plus tamsulosin groups were dry mouth (7% and 3%, respectively) and dizziness (3% and 2%, respectively). Of the patients on solifenacin plus tamsulosin 7 (3%) reported retention and 3 required catheterization. No patients on placebo plus tamsulosin reported retention. Patients on solifenacin plus tamsulosin vs placebo plus tamsulosin showed larger reductions in frequency but not of statistical significance (−1.05 vs −0.67, p = 0.135). However, patients on solifenacin plus tamsulosin vs placebo plus tamsulosin did show statistically significant reductions in urgency (−2.18 vs −1.10, p <0.001). Patient reported outcome measures showed no significant between group differences.ConclusionsSolifenacin plus tamsulosin was well tolerated. There was a low incidence of urinary retention requiring catheterization. At week 12 solifenacin plus tamsulosin decreased daily micturitions and urgency episodes. Only urgency reached statistical significance vs placebo plus tamsulosin.