Objectives. To investigate whether treatment of inflammatory chronic pelvic pain syndrome (ICPPS) with finasteride has any influence on symptoms associated with ICPPS.

Methods. Forty-one patients with ICPPS were randomized (1:3) to treatment with either placebo (25%, n = 10) or finasteride 5 mg daily (75%, n = 31) for 12 months. Efficacy was evaluated by analysis of symptomatic improvement through responses to symptom questionnaires, pain evaluation on an analytical visual scale, analgesic use as reported in patient diaries, urine flow and residual volume, and prostate volume.

Results. Prostatitis Symptom Severity Index and prostatism scores dropped significantly in patients in the finasteride group (P < 0.001 and P < 0.05, respectively). There were no statistically significant differences in pain between the groups. There were significant differences in the changes of prostate volume and in serum prostate-specific antigen concentrations between the finasteride and placebo groups (P < 0.03 and P < 0.02, respectively). The groups did not differ with regard to side effects.

Conclusions. Our results indicate that finasteride has an effect in ICPPS. The mechanisms by which finasteride works in these patients are unclear and could not be solved in this pilot study, which had relatively few patients. A further trial with larger numbers is required to confirm these results.