INVESTIGATIVE UROLOGY

Combination of Phosphodiesterase-5 Inhibitors and Alpha-Blockers in Patients with Benign Prostatic Hyperplasia: Treatments of Lower Urinary Tract Symptoms, Erectile Dysfunction, or Both?
Carson CC
University of North Carolina, Chapel Hill, North Carolina, USA
BJU Int. 2006; 97 (Suppl 2): 39-43

• As the prevalence of both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) increases with age, physicians could be in the position to manage these two conditions simultaneously. Moreover, medical therapies for either one of these conditions can affect the other and this should be carefully considered when making treatment decisions. Pharmacotherapy for benign prostatic hyperplasia (BPH)/LUTS can cause side- effects affecting sexual function. Hence, 5alpha-reductase inhibitors such as finasteride and dutasteride are associated with a greater risk of ED, ejaculatory disorders (EjD) and decreased libido than is placebo. Among alpha (1)-adrenergic blockers, tamsulosin is associated with an increased risk of EjD. However, some alpha (1)-adrenergic blockers can also have a positive impact on erection. This is the case for alfuzosin, which has been shown to enhance erectile function in experimental models, probably by reducing the sympathetic tone and thus relaxing corpus cavernosum smooth muscle cells. Phosphodiesterase 5 (PDE-5) inhibitors are commonly used to treat ED. There is increasing evidence that they might also have a beneficial effect on LUTS, probably through the nitric-oxide pathway. Nitric oxide is an important mediator of the relaxation of isolated bladder and urethral smooth muscle, and could modulate prostatic smooth muscle tone. Alpha (1)-adrenergic blockers and PDE-5 inhibitors can therefore have a positive impact on both ED and LUTS. Although placebo-controlled studies are needed to confirm the impact of these drugs, alone or combined, on both ED and LUTS, this reinforces the need for a common approach to managing these two highly prevalent and bothersome conditions.
  
  
• Editorial Comment
  Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) association is a very much discussed theme in urology practice and many papers have been published during the last few years. Those involved with clinical practice have been learning from patients that when they take a phosphodiesterase-5 inhibitor they void better. Also, we learned from patients that when they are under treatment for LUTS with alpha-blockers, they void better and they improve their sexual function. Why this occur? Although it is hard to find placebo controlled studies in the literature on this topic, Doctor Carson provide us with a wonderful and thorough review on the current knowledge on combination of phosphodiesterase-5 inhibitors and alpha-blockers in patients with benign prostatic hyperplasia. Dr. Carson concluded that the concept of improving both lower urinary tract symptoms and erectile dysfunction with phosphodiesterase-5 inhibitors and alpha-blockers reinforces the need to have a common approach for managing this situation. I strongly recommend this paper for all urologists and other physicians dealing with LUTS and ED.

Dr. Francisco Sampaio
Full-Professor and Chair, Urogenital Research Unit
State University of Rio de Janeiro
Rio de Janeiro, Brazil