Tadalafil once daily in men with erectile dysfunction: an integrated analysis of data obtained from 1913 patients from six randomized, double-blind, placebo-controlled, clinical studies

Background: This analysis explores tadalafil once-daily treatment for 12 wk in clinical subpopulations of men with erectile dysfunction (ED).

Objective: Assess the efficacy and safety of once-daily tadalafil 2.5mg and 5mg in patients with different ED characteristics and comorbidities.

Design, setting, and participants: This analysis integrated data from six randomized, double-blind, placebo-controlled studies that assigned 1913 men with ≥3-mo history of ED either to once-daily placebo (n=596), tadalafil 2.5mg (n=394), or tadalafil 5mg (n=923). Clinical factors examined included: ethnicity, age, obesity, alcohol consumption, smoking, comorbidities, concomitant medication, and ED characteristics (etiology, duration, severity).

Outcome measurements and statistical analysis: Descriptive statistics were reported for efficacy and safety, including International Index of Erectile Function Erectile Function Domain (IIEF-EF) scores and Sexual Encounter Profile question 3 (SEP3) responses. Clinical factors were included in analysis of covariance models using last observation carried forward for SEP3 and IIEF-EF scores.

Results and limitations: Both tadalafil doses significantly improved SEP3 responses (least-squares [LS] mean change: 17.8% and 23.6%, respectively) and IIEF-EF scores (LS mean change: 4.2; 5.4) compared with placebo (p<0.01). Treatment with 2.5mg and 5mg tadalafil resulted in IIEF-EF LS mean improvements ≥4 (minimal clinically important difference [MCID]) in patients with hypertension (4.3 [95% confidence interval (CI), 2.9-5.7]; 4.7 [95% CI, 3.5-5.8]), cardiac disorder (7.0 [95% CI, 4.7-9.3]; 6.3 [95% CI, 4.4-8.2]), or hyperlipidemia (5.3 [95% CI, 3.4-7.1]; 5.8 [95% CI, 4.3-7.4]). Obese patients (4.7 [95% CI, 3.4-6.0]), smokers (4.8 [95% CI, 3.0-6.7]), and psychogenic ED (7.3 [95% CI, 5.0-9.6]) reached MCID only after treatment with 5mg tadalafil. Severity-specific MCID (IIEF-EF change ≥7) was achieved by 44.5% of patients with severe baseline ED treated with tadalafil 5mg, compared with 11.6% of placebo-treated patients. No unexpected safety findings were observed. These analyses were performed on integrated data and can only provide descriptive results to guide further investigations.

Conclusions: Treatment with tadalafil 2.5mg or 5mg once daily was well tolerated and resulted in clinically important improvements in patients with mild (54.3% and 74.8%, respectively), moderate (51.3% and 63.1%, respectively), or severe (33.7% and 44.5%, respectively) ED.