Randomized, Double-Blind, Crossover Trial of Sildenafil in Men With Mild to Moderate Erectile Dysfunction: Efficacy at 8 and 12 Hours Postdose

• Published in: Urology (Ridgewood, N.J.) Vol. 71; no. 4; pp. 686 - 692
• Main Authors: McCullough, Andrew R, Steidle, Christopher P, Klee, Brian, Tseng, Li-Jung
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.2008; Elsevier Science
• Subjects: Adult; Aged; Biological and medical sciences; Cross-Over Studies; Double-Blind Method; Erectile Dysfunction - drug therapy; Half-Life; Humans; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Orgasm; Patient Satisfaction; Piperazines - pharmacokinetics; Piperazines - therapeutic use; Purines - pharmacokinetics; Purines - therapeutic use; Sildenafil Citrate; Sulfones - pharmacokinetics; Sulfones - therapeutic use; Treatment Outcome; Urology; Vasodilator Agents - pharmacokinetics; Vasodilator Agents - therapeutic use; Human; Nephrology; Vasodilator agent; Erection disorders; 3',5'-Cyclic-GMP phosphodiesterase; Enzyme; Treatment efficiency; Enzyme inhibitor; Male; Esterases; Phosphoric diester hydrolases; Urology; Phosphodiesterase inhibitor; Phosphodiesterase 5 inhibitor; Randomization; Hydrolases; Adult; Clinical trial; Sildenafil; Male genital diseases
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/j.urology.2007.12.025

Objectives To clarify the period of responsiveness to sildenafil. Methods Under a double-blind protocol, men with mild to moderate erectile dysfunction (International Index of Erectile Function [IIEF] Erectile Function domain score, 11 to 25) were randomized to sildenafil (100 mg) or placebo and attempted intercourse 8 hours (range, 7 to 9 hours) postdose (first 4-week phase) and 12 hours (11 to13 hours) postdose (second 4-week phase after treatment crossover). The primary outcome was the per-patient proportion (PPP; least squares means [95% confidence interval]) of affirmative responses to the Sexual Encounter Profile question 3 (SEP3: “Did your erection last long enough for you to have successful intercourse?”). Results For sildenafil (n = 174) versus placebo (n = 177), baseline values were similar but the PPP of successful intercourse attempts increased to 76% (69% to 82%) versus 50% (43% to 57%) in phase 1 (odds ratio [OR] = 3.2) and 79% (72% to 85%) versus 52% (44% to 60%) in phase 2 (OR = 3.5), and the PPP of Erection Hardness Score 4 erections (completely hard and fully rigid) was 41% (34% to 48%) versus 10% (7% to 15%) in phase 1 (OR = 6.2) and 44% (37% to 51%) versus 17% (12% to 23%) in phase 2 (OR = 4.0). Thus, at 12 hours, the odds of successful intercourse tripled and of a completely hard erection quadrupled. The sildenafil group achieved greater ( P <0.001) PPP of successful penetration (SEP2), satisfaction with erection hardness (SEP4), and satisfaction with the sexual experience (SEP5); improvement in IIEF domain scores; and treatment satisfaction on the Erectile Dysfunction Inventory of Treatment Satisfaction. Conclusions In men with mild to moderate ED, responsiveness to sildenafil may persist much longer than 4 hours.