Comparison of α-Blocker Monotherapy and α-Blocker Plus 5α-Reductase Inhibitor Combination Therapy Based on Prostate Volume for Treatment of Benign Prostatic Hyperplasia

OBJECTIVE: This study compared alpha-blocker monotherapy with combination therapy involving an alpha-blocker and a 5-alpha reductase inhibitor for benign prostatic hyperplasia (BPH), according to baseline prostate volume. METHODS: Korean men diagnosed with BPH were randomized to 12 months' treatment with 0.2 mg tamsulosin or 0.2 mg tamsulosin plus 0.5 mg dutasteride. Prostate specific antigen (PSA), prostate volume, transition zone volume (TZV), International Prostate Symptom Score (IPSS), maximal urinary flow rate (Q(max)), postvoid residual urine volume and sexual function were assessed at baseline and after 12 months' treatment. Variables were analysed based on baseline prostate volumes of <= 35 ml or > 35 ml. RESULTS: In total, 216 men with BPH were included. Combination therapy resulted in significant improvements in prostate volume, TZV, PSA, IPSS and Q(max), which were most pronounced in men with a prostate volume >35 ml. CONCLUSIONS: Tamsulosin monotherapy was sufficient treatment for BPH in Korean men with a prostate volume <= 35 ml. Combination tamsulosin and dutasteride therapy provided greater benefits than tamsulosin monotherapy in men with BPH whose prostate volume was > 35 ml.