• 5-alpha reductase inhibitor;
  • benign prostatic hyperplasia;
  • dutasteride;
  • Japanese;
  • tamsulosin

Objectives:  To assess the efficacy and safety of dutasteride in Japanese men with benign prostatic hyperplasia (BPH).

Methods:  This was a randomized, double-blind, placebo-controlled, parallel-group study. A total of 378 subjects with clinical BPH having an International Prostate Symptom Score (IPSS) of 8 points or greater, a prostate volume of 30 mL or greater, and a maximal urinary flow rate (Qmax) of 15 mL/s or less were randomized to receive placebo or dutasteride once daily for 52 weeks. Subjects were stratified according to tamsulosin use at baseline. The numbers of subjects with and without tamsulosin use were 242 and 136, respectively. IPSS, Qmax, prostate volume and drug safety were evaluated.

Results:  Continued improvement in IPSS was noted in the dutasteride group, and dutasteride significantly decreased IPSS compared with placebo. At week 52, dutasteride significantly improved Qmax and prostate volume compared with placebo. Drug-related sexual function events in the dutasteride group were infrequent and generally were not treatment limiting.

Conclusions:  Dutasteride improves urinary symptoms and flow rate and reduces prostate volume. In Japanese men with BPH, it is effective and generally well tolerated during the one-year treatment period.