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

Abstract

Background: Tadalafil 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.

Objective: Assess tadalafil or tamsulosin versus placebo for LUTS/BPH.

Design, setting, and participants: A 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 (Q(max)) ≥4 to ≤15ml/s. Following screening and washout, if needed, subjects completed a 4-wk placebo run-in before randomisation to placebo (n=172), tadalafil 5mg (n=171), or tamsulosin 0.4mg (n=168) once daily for 12 wk.

Measurements: Outcomes 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 limitations: IPSS 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). Q(max) increased significantly versus placebo with both tadalafil (2.4ml/s; p=0.009) and tamsulosin (2.2ml/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.

Conclusions: Monotherapy with tadalafil or tamsulosin resulted in significant and numerically similar improvements versus placebo in LUTS/BPH and Q(max). However, only tadalafil improved erectile dysfunction.

Trial registration: Clinicaltrials.gov ID NCT00970632.