Data on ED, LUTS offer unique opportunity for urologists

Several studies presented at the 2006 AUA annual meeting provided evidence of a relationship between erectile dysfunction and lower urinary tract symptoms, with some data showing that treatment of LUTS will improve ED and vice versa. Treating multiple conditions at once means that patients may be able to receive better overall care, but physicians must avoid simply treating symptoms and take a more global approach to patient care, according to Steven A. Kaplan, MD. In this Urology Times interview, Dr. Kaplan, professor of urology and chief of the Institute of Bladder and Prostate Health at Weill Cornell Medical College, Cornell University, New York, discusses current findings on the association between ED and LUTS and their implications for patient management. He was interviewed by UT Editorial Consultant Philip M. Hanno, MD, MPH, professor of urology at the University of Pennsylvania, Philadelphia.

Q Please describe the work that led to the concept that erectile dysfunction and lower urinary tract symptoms are related.

A There's been a host of very fundamental studies conducted at a number of institutions. We know that nitric oxide plays a role in erectile function, and we certainly know the role of phosphodiesterase type-5 inhibitors in erectile dysfunction. But it is important to understand that nitric oxide is expressed in the prostate, as well. Clearly, we know about the role of alpha-receptors in the prostate and voiding function. We also know the role of alpha-receptors and antiadrenergics in erectile function. There are changes in blood flow in the pelvis as both men and women age. We know that decreases in pelvic vascularity may be a predisposing factor in bladder and sexual dysfunction. And there are some alternative theories as well, including autonomic dysfunction and alternative pathways, such as Rho-kinase. Taken together, basic science work in laboratory animals and extensive epidemiologic work have elucidated the strong association between voiding and sexual function.

Q Is the opposite also true? Is there evidence that the treatment of erectile dysfunction improves lower urinary tract symptoms?

A It's interesting and very exciting that at this year's AUA, there were three abstracts presented about using PDE-5 inhibitors either as a monotherapy or as a part of combination therapy in patients with LUTS. Both tadalafil (Cialis) and sildenafil (Viagra) showed significant improvement in symptoms compared with placebo in the monotherapy studies. Of note, neither of them showed improvement in flow rate; there was subjective improvement, not objective improvement.

In a study that our group presented, we used combination therapy, based on the previous premise that an alpha-blocker helps improve both LUTS and urine flow and a PDE-5 inhibitor was a benefit to erectile dysfunction. The results were fascinating. The alpha-blocker alfuzosin SR (Uroxatral) as monotherapy improved voiding symptoms and enhanced sexual function a little bit. Sildenafil also improved sexual function and improved voiding somewhat. But the combination was the best for both voiding and sexual dysfunction.

When you combine both an alpha-blocker and a PDE-5 inhibitor, they en-hance each other, so that voiding function is better than it is with monotherapy, and sexual function is better than it is with monotherapy. This is important because, as we evolve from treating just a voiding problem or a sexual problem, we'll need to determine what type of combination therapies apply. This is just one example of how a combined therapy actually proves that our theories are correct.

Q Ejaculatory dysfunction has been noted in 12% of patients taking tamsulosin. In looking at the literature, I haven't seen this described with other alpha-blockers, but I seem to recall that some patients who have been on doxazosin have had ejaculatory dysfunction. Can the alpha-blockers result in ejaculatory dysfunction?