Tadalafil shows promise as therapy for erectile dysfunction following bilateral nerve-sparing radical retropubic prostatectomy for prostate cancer, according to a presentation at the annual meeting of the Sexual Medicine Society.

More than 50 percent of patients report erectile dysfunction 18 months or longer after undergoing the surgical procedure. In the current trial, 62 percent of such men had improved erections after taking the drug compared with 23 percent of men who had been given placebo.

"Despite numerous advances in prostatectomy technique, data suggest that localized nerve trauma leaves many men with erectile dysfunction that is quite challenging to manage," said Joel Kaufman, M.D. "In this trial, men taking Cialis (tadalafil) reported an improvement in measures of improved erections, and maintaining erections for both penetration and completion of intercourse."

Tadalafil is a new investigational PDE5 inhibitor. The clinical trial was a phase III multicenter study with 303 participants who had undergone bilateral nerve sparing radical prostatectomy 12-48 months before enrollment. Patients had a 4-week treatment-free period before randomization to drug or placebo for 12 weeks. The investigators also had a subgroup of 201 men who had retained some ability to achieve an erection after the surgery.

Among other findings, 54 percent of men receiving tadalafil were able to have successful vaginal penetration compared with 32 percent of men receiving placebo. In the subgroup of men with some erectile function, 71 percent had improved erections while receiving the drug compared with 24 percent receiving placebo.

Adverse drug effects reported by at least 5 percent of participants were headache, dyspepsia, and muscle aches.