Monotherapy with Tadalafil or Tamsulosin Similarly Improved Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Hyperplasia in an International, Randomised, Parallel, Placebo-Controlled Clinical Trial

BackgroundTadalafil improved lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH; LUTS/BPH) in clinical studies but has not been evaluated together with an active control in an international clinical study.ObjectiveAssess tadalafil or tamsulosin versus placebo for LUTS/BPH.Design, setting, and participantsA randomised, double-blind, international, placebo-controlled, parallel-group study assessed men ≥45 yr of age with LUTS/BPH, International Prostate Symptom Score (IPSS) ≥13, and maximum urinary flow rate (Qmax) ≥4 to ≤15 ml/s. Following screening and washout, if needed, subjects completed a 4-wk placebo run-in before randomisation to placebo (n = 172), tadalafil 5 mg (n = 171), or tamsulosin 0.4 mg (n = 168) once daily for 12 wk.MeasurementsOutcomes were assessed using analysis of covariance (ANCOVA) or ranked analysis of variance (ANOVA) (continuous variables) and Cochran-Mantel-Haenszel test or Fisher exact test (categorical variables).Results and limitationsIPSS significantly improved versus placebo through 12 wk with tadalafil (−2.1; p = 0.001; primary efficacy outcome) and tamsulosin (−1.5; p = 0.023) and as early as 1 wk (tadalafil and tamsulosin both −1.5; p < 0.01). BPH Impact Index significantly improved versus placebo at first assessment (week 4) with tadalafil (−0.8; p < 0.001) and tamsulosin (−0.9; p < 0.001) and through 12 wk (tadalafil −0.8, p = 0.003; tamsulosin −0.6, p = 0.026). The IPSS Quality-of-Life Index and the Treatment Satisfaction Scale–BPH improved significantly versus placebo with tadalafil (both p < 0.05) but not with tamsulosin (both p > 0.1). The International Index of Erectile Function–Erectile Function domain improved versus placebo with tadalafil (4.0; p < 0.001) but not tamsulosin (−0.4; p = 0.699). Qmax increased significantly versus placebo with both tadalafil (2.4 ml/s; p = 0.009) and tamsulosin (2.2 ml/s; p = 0.014). Adverse event profiles were consistent with previous reports. This study was limited in not being powered to directly compare tadalafil versus tamsulosin.ConclusionsMonotherapy with tadalafil or tamsulosin resulted in significant and numerically similar improvements versus placebo in LUTS/BPH and Qmax. However, only tadalafil improved erectile dysfunction.Trial registrationClinicaltrials.gov ID NCT00970632