Tadalafil May Lessen Ejaculatory and Orgasmic Dysfunctions

Daniel M. Keller, PhD

February 06, 2013

Tadalafil appears to have wider benefits on sexual function than just improving erections. An integrated analysis of 17 double-blind, randomized, placebo-controlled 12-week trials of the drug as needed in patients with erectile dysfunction showed significant improvements in ejaculatory and orgasmic functions. Benefits were seen across all baseline levels of erectile, ejaculatory, and orgasmic dysfunction severity.

The analysis was published online January 29 and in the February issue of BJU International.

Lead author Darius A. Paduch, MD, PhD, associate professor of urology and reproductive medicine and director of sexual health and medicine at Weill Cornell Medical College in New York City, told Medscape Medical News that men with even mild erectile dysfunction may have disorders of ejaculation and orgasm.

"We need to change our vocabulary in how we think about sexual dysfunction in men, that erection is not the only aspect of sexual dysfunction," he said. "From our study, we actually clearly show that sexual satisfaction is clearly correlated to ability of getting orgasm [and] ability to ejaculate."

In the studies included in this analysis, ejaculatory dysfunction (EjD), orgasmic dysfunction (OD), and satisfaction were determined according to patient responses to specific questions on the International Index of Erectile Function (IIEF), as well as the Sexual Encounter Profile for satisfaction. Of the 3581 participants (mean age, 54.9 years; mean body mass index, 26.8 kg/m2), 1512 had severe EjD, 1812 had severe OD, 50.9% were white, and 39.3% were of Asian descent.

The researchers found that tadalafil is an "extremely powerful modulator" of ejaculatory and orgasmic function, Dr. Paduch said. "Across all the severity of erectile dysfunction...tadalafil was actually able to help with ability to achieve orgasm and ability to ejaculate."

Tadalafil 10 or 20 mg improved ejaculatory function in 66% of men with severe EjD vs 36% of men taking placebo (P < .001). For men with severe OD, 66% taking tadalafil reported improvements vs 35% taking placebo (P < .001). The more severe the EjD or OD, the greater the proportion of men experiencing improvement compared with placebo.

On the basis of this study and another analyzing the efficacy of testosterone for EjD and OD, Dr. Paduch recommends first improving the testosterone level, "and then you can start the patient on 3 months of tadalafil and let them...relax more.... Very often I think that they work so hard [to reach orgasm] that they counteract their arousal because they're all stressed out."

One limitation of the study was the use of the IIEF, which has unknown performance to measure responses to treatment for EjD and OD. Further research is needed to validate the IIEF for these purposes. In addition, Dr. Paduch would like to test tadalafil for these conditions in men who do not have erectile dysfunction.

This study included treatment with tadalafil, so it cannot be determined whether similar effects would occur using the other marketed phosphodiesterase type-5 inhibitors.

"We all see those patients, [but] until the study came [out], nobody really had any proof that anything works," Dr. Paduch concluded.

Asked for independent comment, Joseph Harryhill, MD, assistant clinical professor of urology at the University of Pennsylvania in Philadelphia, told Medscape Medical News, "It is encouraging to see that there has been some progress being made in an area where I think there's been a real lack of research...because we're talking about a condition that is probably underreported." Clinicians, he said, often fail to ask about "disorders of ejaculation such as delay or inability to ejaculate."

He noted that in the study, among men with mild erectile dysfunction, a significant number had ejaculatory problems. "Even in men without erectile dysfunction, the incidence may be greater than 10% of men that have problems with ejaculation," Dr. Harryhill said. "This is definitely a little bit of a breath of fresh air that a medication that we know and we're comfortable with using might also have an indication for treating ejaculatory problems as well."

The original studies and this integrated analysis were supported by Eli Lilly and Company. Dr. Paduch receives research support and is a speaker for Eli Lilly. Dr. Harryhill has disclosed no relevant financial relationships.

BJU Int. 2013;111:334-343. Full text