The Effects of Phosphodiesterase-5 Inhibitors in Men with “Normal” Erectile Function

A common belief among the lay population is that oral phosphodiesterase-5 inhibitors will make a “normal” man become “supernormal” regarding his erectile capabilities. Two studies on this topic have been published, both of which have emanated from Italy. In the first study,¹ which was reviewed in a previous issue of Reviews in Urology,² investigators concluded that sildenafil (50 mg) improved erections in normal men. However, the average age of study subjects was 39 years, an age that impotence experts would most likely not equate with “normal” erectile capabilities.

Sildenafil Does not Improve Sexual Function in Men Without Erectile Dysfunction but Does Reduce the Postorgasmic Refractory Time

Mondaini N, Ponchietti R, Muir GH, et al.

Int J Impot Res. 2003;15:225–228.

In the second study, by Mondaini and colleagues, the investigators lowered the threshold of normal age to a mean age of 33 years in the sildenafil group (n = 30) and 31 years in the placebo group (n = 30). The International Index of Erectile Function (IIEF) score was 26 or greater at baseline for all subjects in both groups. Patients received sildenafil, 25 mg, or placebo and recorded their posttreatment IIEF score and refractory time to obtaining a second erection.

Study results demonstrated no difference in erectile function between the subjects who received sildenafil and those who received placebo. However, the subjects who received sildenafil recorded a lower refractory time than those who received placebo (P < .04). A criticism of this study is that the subjects received only 1 pill, so that outcome measures were made after only 1 trial. Nevertheless, this study suggests that sildenafil will not make a normal man supernormal in terms of his erection but may reduce the refractory time in young men. Whether it is appropriate for a physician to treat a patient with the goal of improving latency time is debatable.