Silodosin for men with chronic prostatitis/chronic pelvic pain syndrome: results of a phase II multicenter, double-blind, placebo controlled study.

Abstract

We evaluated the efficacy and safety of 2 doses of silodosin vs placebo in men with moderate to severe abacterial chronic prostatitis/chronic pelvic pain syndrome who had not been treated previously with α-blockers for chronic prostatitis/chronic pelvic pain syndrome. In this multicenter, randomized, double-blind, phase II study, men 18 years old or older with chronic prostatitis/chronic pelvic pain syndrome, a total National Institutes of Health Chronic Prostatitis Symptom Index score of 15 or greater and a National Institutes of Health Chronic Prostatitis Symptom Index pain score of 8 or greater received 4 or 8 mg silodosin, or placebo once daily for 12 weeks. The primary efficacy end point was change from baseline to week 12 in National Institutes of Health Chronic Prostatitis Symptom Index total score. Of 151 patients (mean age 48 years) 52 received 4 mg silodosin, 45 received 8 mg silodosin and 54 received placebo. Silodosin 4 mg was associated with a significant decrease in total National Institutes of Health Chronic Prostatitis Symptom Index score (mean ± SD change -12.1 ± 9.3) vs placebo (-8.5 ± 7.2, p = 0.0224), including a decrease in urinary symptom (-2.2 ± 2.7, placebo -1.3 ± 3.0, p = 0.0102) and quality of life (-4.1 ± 3.1, placebo -2.7 ± 2.5, p = 0.0099) subscores. The 4 mg dose of silodosin also significantly increased Medical Outcomes Study Short Form 12 physical component scores (4.2 ± 8.1, placebo 1.7 ± 9.0, p = 0.0492). During global response assessment 56% of patients receiving 4 mg silodosin vs 29% receiving placebo reported moderate or marked improvement (p = 0.0069). Increasing the dose of silodosin to 8 mg resulted in no incremental treatment effects. Silodosin 4 mg relieved symptoms and improved quality of life in men with chronic prostatitis/chronic pelvic pain syndrome but its efficacy requires confirmation in additional studies.