Effect of Discontinuation of Tamsulosin in Korean Men with Benign Prostatic Hyperplasia Taking Tamsulosin and Dutasteride: An Open-Label, Prospective, Randomized Pilot Study

Objective: This study was conducted to examine the effect of discontinuing tamsulosin in patients with benign prostatic hyperplasia who had been receiving combination therapy with tamsulosin and dutasteride. Methods: The study sample consisted of 108 men with benign prostatic hyperplasia and lower urinary tract symptoms who visited our urology clinics between April 2008 and December 2010. All were assessed using the International Prostate Symptom Score (IPSS). The patients had IPSS of 8-19 and prostate volumes >= 25 mL by transrectal ultrasonography. They were put on tamsulosin and dutasteride, and the efficacy of this regimen was assessed every 12 weeks. After 48 weeks, patients were divided at random into a group continuing to take the same drug combination (group 1) and a group taking only dutasteride 0.5 mg (group 2). Results: Sixty-nine of the original 108 patients completed the study, 36 (52%) in group 1 and 33 (48%) in group 2. The mean age of all patients was 67.96 +/- 7.88 years and mean prostatic volume was 40.45 +/- 12.81 mL. Mean prostate-specific antigen was 3.31 (0.4-9.9) ng/mL at the outset. The IPSS scores of the two groups at first visit, 48 and 72 weeks were, respectively, 14.69 versus 15.85 (P = 0.322), 12.08 versus 12.85 (P = 0.582) and 10.89 versus 11.06 (P = 0.897.) There was a statistically significant difference between the baseline and 72-week IPSS scores in both groups (group 1: P < 0.001, group 2: P < 0.001). Conclusion: In patients with moderate IPSS, discontinuing tamsulosin after 48 weeks of combined tamsulosin and dutasteride therapy has no significant effect on outcome.