Tadalafil 2.5 or 5mg administered once daily for 12 weeks in men with both erectile dysfunction and signs and symptoms of benign prostatic hyperplasia: Results of a randomized, placebo-controlled, double-blind study

Introduction. Erectile dysfunction (ED) and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH-LUTS) commonly coexist in aging men. Tadalafil, a phosphodiesterase type 5 inhibitor approved for treating ED, is currently being evaluated for treating BPH-LUTS. Aims. This multinational Phase 3 study assessed effects of tadalafil 2.5 or 5mg once daily on ED and BPH-LUTS in men with both conditions during 12 weeks of double-blinded therapy. Methods. Men were ≥45 years old, sexually active, and experiencing ED for ≥3 months and BPH-LUTS for >6 months. Randomization (baseline) followed a 4-week placebo lead-in; changes from baseline were assessed via analysis of covariance and compared to placebo. A gatekeeping procedure controlled for multiple comparisons of co-primary and key secondary measures at end point (last post-baseline observation). Main Outcome Measures. The co-primary measures were the International Index of Erectile Function-erectile function (IIEF-EF) domain and International Prostate Symptom Score (IPSS) score; key secondary measures were the Sexual Encounter Profile Question 3 (SEP Q3) and BPH Impact Index (BII). Treatment-emergent adverse events, serious adverse events, orthostatic vital signs, clinical laboratory and uroflowmetry parameters, and postvoid residual volume were assessed. Results. Tadalafil 2.5mg (N=198) and 5mg (N=208) significantly improved IIEF-EF domain scores (both P<0.001) vs. placebo (N=200) at end point. For IPSS, improvements were significant with tadalafil 5mg (P<0.001), but not 2.5mg, for observations from 2 weeks through end point (least-squares mean±standard error change from baseline at end point, placebo -3.8±0.5, tadalafil 2.5mg -4.6±0.4, and 5mg -6.1±0.4). Tadalafil 5mg significantly improved SEP Q3 and BII (P<0.001). Overall, tadalafil was well tolerated with no clinically adverse changes in orthostatic vital signs or uroflowmetry parameters. Conclusions. Tadalafil 5mg significantly improved both ED and BPH-related outcomes through 12 weeks and was well tolerated.