Tadalafil Administered Once Daily for Treatment of Lower Urinary Tract Symptoms in Korean men with Benign Prostatic Hyperplasia: Results from a Placebo-Controlled Pilot Study Using Tamsulosin as an Active Control

Objectives: Assess the efficacy and safety of once-daily tadalafil or tamsulosin versus placebo during 12 weeks on lower urinary tract symptoms (LUTS) in Korean men with benign prostatic hyperplasia (BPH). Methods: Following a 4-week placebo run-in period, 151 Korean men were randomly assigned to receive once-daily tadalafil 5 mg, tamsulosin 0.2 mg, or placebo for 12 weeks. Results: The International Prostate Symptom Score (IPSS) least squares mean changes from baseline to endpoint were numerically but not significantly improved in the tadalafil (-5.8) and tamsulosin (-5.4) groups compared with placebo (-4.2, P > 0.05). Decreases in IPSS obstructive and irritative subscores, IPSS Quality of Life score, and BPH Impact Index from baseline to endpoint were largest in the tadalafil group followed by tamsulosin, though none separated significantly from placebo. Increases in maximum urinary flow rate were small and not significantly different than placebo; the increase was largest in the tadalafil group (2.5 mL/sec), followed by the placebo (2.3 mL/sec) and tamsulosin (2.1 mL/sec) groups. The percentage of subjects reporting at least one treatment-emergent adverse event was 26.5, 13.7 and 3.9% in the tamsulosin, tadalafil and placebo groups, respectively. Conclusions: In this pilot study in Korean men, those with BPH and treated with tadalafil 5 mg or tamsulosin 0.2 mg once daily experienced a reduction in LUTS, which was numerically (but not statistically) significant compared with the placebo. Tadalafil was well tolerated and few subjects discontinued the study due to treatment-emergent adverse events. Larger studies in Asian men with BPH and LUTS treated with phosphodiesterase type 5 inhibitors are needed.