Sildenafil in the treatment of erectile dysfunction: an overview of the clinical evidence

Abstract

Erectile dysfunction (ED) is a highly prevalent disease associated with aging as well as with several risk factors including hypertension, heart disease, obesity, dyslipidemia, diabetes, hypogonadism, drugs-related, and pelvic surgery. Many of these factors are components of the metabolic syndrome, a multiplex risk factor for cardiovascular disease (CVD). ED shares common risk factors with CVD. Endothelial dysfunction seems to be the early underlying pathophysiology across both conditions. The efficacy, tolerability and cardiovascular safety of sildenafil has been evaluated in numerous large, randomized, doubleblind, placebo-controlled clinical studies in the broad population of men with ED including men with several co-morbid conditions. Sildenafil is effective in several specific patient populations including the difficult-to-treat subpopulations such as diabetes mellitus and after radical prostatectomy. It is associated with rapid onset of action--within 14 minutes for some men--and an extended duration of action for up to 12 hours. Sildenafil improves quality of life and satisfaction for treated men and is well tolerated with a favorable safety profile. New data suggest that sildenafil has beneficial effects in several chronic conditions. It has been approved for the treatment of idiopathic pulmonary hypertension. Numerous articles have suggested that it improves endothelial function and a possible role on premature ejaculation or treatment of lower urinary tract symptoms has been suggested.

Figure 1

Time to onset of erection resulting in successful intercourse. *P=0.0343, †P=0.0011, ‡P=0.0001. Copyright © 2003. Reproduced with permission from Padma-Nathan H, Stecher VJ, Sweeney M, et al. 2003. Minimal time to successful intercourse after sildenafil citrate: results of a randomized, double-blind, placebo-controlled trial. Urology, 62:400–3. Abbreviations: SEP3, Sexual Encounter Profile question 3.

Figure 2

Mean score for the Sexual Encounter Profile question 3 (SEP3) for subgroups by erectile dysfunction (ED) characteristics. *p<0.001, †p<0.02, ‡p<0.0002. Copyright © 2002. Carson CC, Burnett AL, Levine LA, et al. 2002. The efficacy of sildenafil citrate (Viagra) in clinical populations: an update. Urology, 60:12–27.

Figure 3

Patients reporting satisfaction with treatment effect on erections and improvement in ability to engage in sexual activity at end of 1 year, 2 years, and 3 years of open-label treatment with sildenafil. Copyright © 2002. Carson CC, Burnett AL, Levine LA, et al. 2002. The efficacy of sildenafil citrate (Viagra) in clinical populations: an update. Urology, 60:12–27.