Early effect of dutasteride added to alpha-1 blocker therapy for patients with lower urinary tract symptoms associated with benign prostatic hyperplasia

Objective To investigate the hypothesis that 5-alpha-reductase inhibitors exert early ameliorative effects on voiding and storage symptoms in men with lower urinary tract symptom-associated benign prostatic hyperplasia. Methods This was a prospective study involving the participation of eight outpatient clinics in Chiba Prefecture, Japan. The patients received dutasteride (0.5 mg) once daily orally for 24 weeks as an add-on to their ongoing therapy with an alpha-1 blocker. The study patients recorded their urinary symptoms every day for 14 days after starting dutasteride. The International Prostate Symptom Score, prostate volume, uroflowmetry results, and residual urine volume were checked at 3 and 6 months after starting dutasteride. Results A total of eighty-eight patients participated in the present study; 74 were eligible for analysis of the early effects of dutasteride. The median age was 69.6 years (range 54–89), the median prostate volume was 50.3 mL (range 24.7–103.3) and the median International Prostate Symptom Score was 17.6 (range 8–35). The proportion of patients with International Prostate Symptom Score improvements (≥3 points, or ≥25%) or 3 points or more decreased International Prostate Symptom Score were defined effective, 37 (50.0%) and 47 (63.5%) experienced improvement at 1 month after administration, respectively. Conclusion This is the first prospective clinical study to show the early beneficial effects of 5-alpha-reductase inhibitors for lower urinary tract symptom-associated benign prostatic hyperplasia. Patients with severe symptoms were found to be responsive to dutasteride. The influence of the placebo effect was not denied. Further study is necessary.