Phosphodiesterase-5 Inhibitors for Lower Urinary Tract Symptoms in Men

Abstract

To review the efficacy of phosphodiesterase-5 (PDE-5) inhibitors for the treatment of lower urinary tract symptoms in men. MEDLINE and International Pharmaceutical Abstracts were searched (1970-August 2007) using the terms phosphodiesterase inhibitor, sildenafil, vardenafil, tadalafil, lower urinary tract symptoms, and benign prostatic hypertrophy. English-language clinical trials, case reports, and background material were evaluated for safety and efficacy data. References of reviewed articles were examined and used to identify additional sources. Erectile dysfunction (ED) and lower urinary tract symptoms have numerous shared risk factors and are common in aging men. PDE-5 inhibitors may relax urinary tract smooth muscle tissue, which has led to interest in their utility for lower urinary tract symptoms. Six 12 week clinical trials were identified. Three uncontrolled trials (N = 168) examined the effects of on-demand sildenafil ED dosing on lower urinary tract symptoms. The 2 largest trials found that, the greater the ED response, the larger the reduction in lower urinary tract symptoms. A single prospective placebo-controlled trial (N = 369) studied sildenafil 100 mg daily in men with ED and lower urinary tract symptoms. Lower urinary tract symptoms improved significantly in the sildenafil group; patients with the worst lower urinary tract symptoms experienced the greatest benefits. An open-label trial (N = 62) compared daily sildenafil 25 mg, alfuzosin 10 mg, or sildenafil 25 mg plus alfuzosin 10 mg on ED and lower urinary tract symptoms. Combination therapy resulted in greater improvements in ED and lower urinary tract symptoms and urinary flow than did either drug alone. The effects of daily tadalafil 20 mg were studied in 281 men with lower urinary tract symptoms independent of ED. Tadalafil produced statistically significant but clinically modest improvements in lower urinary tract symptoms when compared with placebo. PDE-5 inhibitors consistently produced modest reductions in lower urinary tract symptoms. Further studies are needed to fully elucidate the efficacy, cost effectiveness, safety, and appropriate place in therapy of PDE-5 inhibitors. At this time, data are insufficient to routinely recommend chronic use of PDE-5 inhibitors for lower urinary tract symptoms in men.