Sildenafil Treats Urinary Symptoms of BPH as well as ED

June 3, 2007
John Schieszer

Internal Medicine World Report, October 2006, Volume 0, Issue 0

From the American Urological Association

ATLANTA—For the first time, an oral phosphodiesterase type 5 (PDE-5) inhibitor has been shown to improve lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH) in men with concomitant erectile dysfunction (ED), according to data presented at the annual meeting of the American Urological Association.

Results of this study in men (aged ≥45 years) with ED and concomitant lower urinary tract symptoms showed that if taken daily, sildenafil (Viagra) was comparable to alpha-1 blockers in improving the International Prostate Symptom Score (IPSS) in these patients.

“This is the first study of its kind,” said lead investigator Kevin McVary, MD, of Northwestern University Feinberg School of Medicine, Chicago. “It is important, because it links the 2 diseases biologically. If you can affect a man’s erectile dysfunction simultaneously while trying to impact his lower urinary tract symptoms with 1 pill, it is very intriguing and exciting.”

Previous studies have suggested that PDE-5 inhibition promotes relaxation of smooth muscles in the lower urinary tract and may improve urinary tract symptoms.

In this 12-week, double-blind, placebo-controlled study, 366 men who scored ≤25 on the erectile function domain of the International Index of Erectile Function, had an IPSS of ≥12, and a prostate-specific antigen score <10 ng/mL were instructed to take sildenafil (50 mg) or placebo every night at bedtime or 30 minutes to 1 hour before anticipated sexual activity.

Changes in total IPSS, subscores for irritative and obstructive symptoms, quality of life, BPH impact index, and maximum urinary flow rate (Qmax) were also assessed.

After 2 weeks, the dose was titrated to 100 mg, with the option of resuming the 50 mg dose if needed. At week 12, the men receiving sildenafil demonstrated improvements in erectile function domain scores compared with placebo. Irritative and obstructive subscores were also significantly lower in the sildenafil group compared with the placebo group.

Overall, sildenafil significantly reduced the impact of lower urinary tract symptoms, as asse-ssed by the IPSS quality-of-life questionnaire and the BPH index, but not by Qmax. The most common side effects were headache (12% in the sildenafil group vs 6% in the placebo group) and dyspepsia (9% vs 1%, respectively).

Dr McVary said the improvements in lower urinary tract symptoms and significant improvements in quality-of-life measures, but with no significant change in Qmax, suggest that a new pathophysiology paradigm may be needed to explain the etiology of lower urinary tract symptoms. &#8220;This has been a very controversial area,&#8221; he told IMWR.

&#8220;Both diseases occur with aging in men, and it was thought to be just overlapping curves. It was thought that they both happened with age. But to show that you can impact them with a medication shows there is a common pathophysiology,&#8221; he added.

Ira Sharlip, MD, of the University of California, San Francisco, said these findings are significant, but it is important to see if other PDE-5 inhibitors have similar effects, and whether therapy with any of these agents can be safe and effective on a long-term basis (6-12 months) when taken daily for concomitant lower urinary tract symptoms.

&#8220;The findings are important, and I think this therapy is generally safe,&#8221; Dr Sharlip told IMWR.