Prognostic Factors for Response to Sildenafil in Patients with Erectile Dysfunction

Objective: To assess the clinical efficacy of sildenafil as treatment for erectile dysfunction (ED) the factors associated with treatment failure were investigated.

Methods: Open, prospective study including 244 patients suffering from ED who were evaluated by anamnesis, physical exploration, blood test, dynamic penile color duplex ultrasonography and Sexual Health Inventory for Male (SHIM). The efficacy of sildenafil was assessed by repeating the SHIM 2 months after therapy, independent of the final dose used. Side effects were also recorded. Factors influencing treatment outcome were evaluated by univariate and multivariate statistical analysis.

Results: Overall, sildenafil was effective in 56.8% of 213 eligible patients. When the etiologic diagnosis was not included in the multivariate analysis, antecedents of diabetes mellitus, non-nerve-sparing radical prostatectomy and SHIM basal score were selected as predictors of a poor response. In a second analysis including etiologic diagnosis, only SHIM basal score and etiological diagnosis proved to be of prognostic value. Side effects were noticed by 24.4% of patients, none of them being severe.

Conclusions: Sildenafil is a rather effective and well-tolerated treatment for ED. The basal severity of ED and etiological diagnosis are the prognostic factors most significantly associated with treatment outcome.