Context: Erectile dysfunction is common in men with diabetes.
Objective: To assess the efficacy and safety of oral sildenafil citrate in the treatment of erectile dysfunction in men with diabetes.
Design: A multicenter, randomized, double-blind, placebo-controlled, flexible dose-escalation study conducted May through November 1996.
Setting: Patients' homes and 19 clinical practice centers in the United States.
Patients: A total of 268 men (mean age, 57 years) with erectile dysfunction (mean duration, 5.6 years) and diabetes (mean duration, 12 years).
Interventions: Patients were randomized to receive sildenafil (n = 136) or placebo (n = 132) as needed, but not more than once daily, for 12 weeks. Patients took the study drug or placebo 1 hour before anticipated sexual activity. The starting dose of sildenafil citrate was 50 mg, with the option to adjust the dose to 100 mg or 25 mg based on efficacy and tolerability, to be taken as needed.
Main outcome measures: Self-reported ability to achieve and maintain an erection for sexual intercourse according to the International Index of Erectile Function and adverse events.
Results: Two hundred fifty-two patients (94%) completed the study (131/136 in the sildenafil group, 121/132 in the placebo group). By intention-to-treat analysis, at 12 weeks, 74 (56%) of 131 patients in the sildenafil group reported improved erections compared with 13 (10%) of 127 patients in the placebo group (P<.001). The proportion of men with at least 1 successful attempt at sexual intercourse was 61 % (71/ 117) for the sildenafil group vs 22% (25/114) for the placebo group (P<.001). Adverse events related to treatment were reported for 22 (16%) of 136 patients taking sildenafil and 1 (1%) of 132 patients receiving placebo. The most common adverse events were headache (11% sildenafil, 2% placebo), dyspepsia (9% sildenafil, 0% placebo), and respiratory tract disorder (6% sildenafil, 2% placebo), predominantly sinus congestion or drainage. The incidence of cardiovascular adverse events was comparable for both groups (3% sildenafil, 5% placebo).
Conclusion: Oral sildenafil is an effective and well-tolerated treatment for erectile dysfunction in men with diabetes.