Silodosin versus naftopidil for the treatment of benign prostatic hyperplasia: A multicenter randomized trial
Yamaguchi K, Aoki Y, Yoshikawa T, Hachiya T, Saito T, Takahashi S. Int J Urol. 2013 Jun 3. doi: 10.1111/iju.12160. [Epub ahead of print]


Department of Urology, Nihon University School of Medicine, Tokyo, Japan; Sakura Clinical Study Group, Tokyo, Japan.


This was a multicenter randomized trial to investigate the clinical efficacy and the impact on sexual function of alpha-1A selective silodosin and alpha-1D selective naftopidil for treatment of benign prostatic hyperplasia. A total of 97 patients with lower urinary tract symptoms/benign prostatic hyperplasia who had an International Prostate Symptom Score of 8 or more were randomly assigned to receive silodosin (8 mg/day, n = 53) or naftopidil (75 mg/day, n = 44). Before and 4, 8 and 12 weeks after treatment, International Prostate Symptom Score and its quality of life score were used to assess lower urinary tract symptoms. Also, International Index of Erectile Function-5, and an original questionnaire were used to evaluate erectile function and ejaculation for sexually active patients, respectively. The silodosin group showed advantages in terms of voiding symptoms and quality of life of International Prostate Symptom Score when compared with the naftopidil group. Both silodosin and naftopidil showed no significant effect on International Index of Erectile Function-5. A total of 23 sexually active patients in the silodosin group experienced more ejaculatory impairment than 21 patients in the naftopidil group, with a decrease of ejaculation volume (87% vs 40%, P = 0.003), prolonged time to ejaculation (56% vs 33%, P = 0.027) and decrease of orgasm (50% vs 39%, P = 0.027). These results suggest that alpha-1A selective blockers are more effective for voiding symptoms, whereas alpha-1D selective blockers offer a minor degree of ejaculatory dysfunction.