Clinical efficacy of sildenafil citrate based on etiology and response to prior treatment

Purpose: We assess the clinical efficacy of sildenafil citrate and predictors of satisfactory outcome. Materials and Methods: All patients treated with sildenafil citrate within the first 6 weeks of its release were evaluated with a self-administered questionnaire before and at completion of therapy to assess etiology of erectile dysfunction, level of sexual function, libido, response to previous therapies, response to therapy with sildenafil citrate and quality of life. Sexual function was measured before and during therapy using an abbreviated version of the International Index of Erectile Function, with a successful outcome defined as a level of satisfaction of 4 or 5 on a 5-point scale. Results: Followup was obtained in 267 of the 308 patients who entered the study. Mean age plus or minus standard deviation was 61 +/- 9.6 years and duration of erectile dysfunction was 4.1 +/- 3 years. Overall satisfaction with sildenafil citrate for the entire patient population was 65% and response to prior therapies did not affect satisfaction. There was a significant positive correlation between baseline sexual function and response to sildenafil citrate but even patients with severe erectile dysfunction had a 41% satisfaction rate. Etiology of erectile dysfunction had a significant impact on satisfaction rate, with neurogenic causes of erectile dysfunction (diabetes, prostate surgery and so forth) having significantly lower rates than psychogenic or vasculogenic erectile dysfunction. Conclusions: Sildenafil citrate is a highly effective oral agent for the treatment of erectile dysfunction in clinical practice. The best predictors for response to sildenafil citrate therapy are baseline sexual function and etiology of erectile dysfunction. However, we could not identify any patient characteristic that would predict absolute failure for sildenafil citrate therapy. Therefore, all patients with erectile dysfunction who do not have specific contraindications should be considered for sildenafil citrate therapy.