[Clinical, multicentric, and open study to evaluate the efficacy of and tolerance to sildenafil in patients with erectile dysfunction].

Erectile dysfunction (ED), defined by the Impotence-NIH Consensus Conference as the "persistent inability to achieve and/or maintain erection sufficient for satisfactory sexual activity" affect more than 100 million men worldwide, at particular severity levels. The global prevalence of ED is estimated to affect about 10%, but has been found to increase significantly with age (39% in men 40 years of age and 67% at 70 years of age). In men aged 40 to 70 years, the severe ED prevalence increased of three folds, 5 to 15%.