Are there any studies on the use of PDE-5 inhibitors by asymptomatic men and women?

"There's actually one study that I'm aware of that used sildenafil (Viagra) in asymptomatic or 'normal' men. And they did show some improvement in the patients that were taking the PDE-5 inhibitor versus those that were given placebo, but it wasn't a significant amount," responded session moderator Culley C. Carson, III, MD, of the University of North Carolina Hospital, Chapel Hill.

A member of the audience commented that he thinks giving a PDE-5 inhibitor to an asymptomatic patient is a mistake that would lead to a psychological dependence on the medication. Dr. Carson agreed.

"It's an expensive way to enhance something that's already working well. And there is the risk of priapism. The risk is small, but it's got to be more so for patients with normal erections," he said.

Panel member Andrew McCullough, MD, of the New York University School of Medicine, addressed the second part of the question concerning women.

"There was a study done with sildenafil. It's not that it didn't show efficacy, but the placebo response rate was so high that there was a very small segment of women that it helped," he explained. "The predominant female sexual dysfunction isn't arousal disorder, it's hypoactive sexual desire. By the time you cull out all the women who don't fit the profile, you're dealing with less than 10% of the women who would be candidates for a PDE-5 inhibitor. The only subset of women who do well on PDE-5 inhibitors are the women on selective serotonin reuptake inhibitors."