Effects of Once-Daily Tadalafil on Erectile Function in Men with Erectile Dysfunction and Signs and Symptoms of Benign Prostatic Hyperplasia

Background: Lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH; BPH-LUTS) may be associated with erectile dysfunction (ED). Objective: To evaluate the effects of once-daily tadalafil on erectile function in men with ED and BPH-LUTS. Design, setting, and participants: Post hoc analysis of a phase 2-3, multinational, randomized, double-blind, placebo-controlled, parallel-group study of men with ED and moderate-to-severe LUTS secondary to BPH who reported being sexually active. In contrast to typical ED trials, no sexual activity threshold was required to participate. Interventions: Screening and 4-wk washout period for patients taking BPH and/or ED treatments; 4-wk placebo run-in period; then once-daily placebo or tadalafil 2.5, 5, 10, or 20 mg for 12 wk. Measurements: International Index of Erectile Function-Erectile Function (IIEF-EF) domain score, International Prostate Symptom Score (IPSS), peak urinary flow rate (Q(max)), and postvoid residual volume (PVR). Analyses were performed in men who reported being sexually active with a female partner and who expected to remain so throughout the study. IIEF-EF data are presented for the BPH/ED population overall and for subgroups stratified by baseline age group, body mass index, BPH-LUTS severity, prostate-specific antigen, prior alpha-blocker use, and prior ED therapy. Results and limitations: Overall, 581 men were included (placebo, n = 115: tadalafil 2.5 mg, n = 113; tadalafil 5 mg, n = 117; tadalafil 10 mg, n = 120; tadalafil 20 mg, n = 116). IIEF-EF domain score improvements from baseline to end point with tadalafil were 5.4 (2.5 mg), 6.8 (5 mg), 7.9 (10 mg), and 8.2 (20 mg) versus 2.0 with placebo (least-squares means; all p values < 0.001). IIEF-EF domain score improvements were observed with tadalafil for all subgroup analyses, with no significant differences between subgroup or subgroup-by-treatment interaction terms. IPSS improvements from baseline to end point were significantly greater for all tadalafil doses versus placebo (all p values <0.05). Changes in Q(max) and PVR were small and not clinically meaningful. Conclusions: These data support the use of once-daily tadalafil in men with ED and BPH-LUTS.