Mulhall JP et al. (2006) Assessment of the impact of sildenafil citrate on lower urinary tract symptoms in men with erectile dysfunction. J Sex Med 3: 662–667

Previous studies have suggested a physiologic link between lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia, and erectile dysfunction. In addition, anecdotal evidence exists for a beneficial effect of the phosphodiesterase-5-inhibitor sildenafil citrate (Viagra®, Pfizer, NY) on LUTS.

In this noncontrolled, nonrandomized study, Mulhall and colleagues enrolled 48 Viagra®-naive men (mean age 62 ± 11 years) with erectile dysfunction, who scored >10 on the International Prostate Symptom Score (IPSS) at baseline. Men completed both the International Index of Erectile Function (IIEF) and the IPSS questionnaires before, and at least 3 months after, the start of 'as-needed' Viagra® therapy.

After treatment (mean 2 uses per week), a marked improvement was seen in the mean health-related quality-of-life and in the IEFF erectile-dysfunction domain score. IPSS markedly improved after treatment in 60% of participants. The degree of IPSS improvement was not related to baseline IPSS, or to change in or baseline erectile-function score, however, which the authors suggest might reflect differences between the severity of LUTS and the severity of erectile dysfunction in individual patients.

The authors suggest that an improvement in erectile function might improve a patient's perceived quality of life, such that the severity of LUTS seems reduced. Viagra® might also reduce LUTS by inducing relaxation of smooth muscle of the prostate and/or bladder neck. A randomized, controlled trial of Viagra® in this setting, that uses objective measures of LUTS improvement, is underway.