Phosphodiesterase type 5 inhibitors in the management of non-neurogenic male lower urinary tract symptoms: Critical analysis of current evidence

Context: A large body of epidemiologic data suggests a causal relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED). Recently reported studies on phosphodiesterase type 5 inhibitors (PDE5-Is) and LUTS have further contributed to the understanding of mechanisms involved in this relationship and of potential treatment options. Objective: A nonsystematic descriptive review was performed to summarize the literature concerning the role of PDE5-Is in men with LUTS, particularly looking at data derived from clinical trials in relation to the different PDE5-Is or their association with α-blockers. Evidence acquisition: A comprehensive electronic search was conducted in October 2010 using the Medline database to identify all publications relating to ED and BPH and treatment with sildenafil, vardenafil, tadalafil, udenafil, UK-369003, and combination therapy with alfuzosin and tamsulosin. Evidence synthesis: In studies in which either ED or LUTS was the entry criterion, sildenafil appears to improve both erectile function and LUTS in subjects with ED. Placebo-controlled trials of tadalafil and vardenafil showed improvement of LUTS secondary to benign prostatic hyperplasia (BPH), but none of the studies showed a significant effect on urodynamic measures. Exploratory studies with UK-369003 showed improvements in LUTS and ED. Sildenafil or tadalafil associated with alfuzosin or tamsulosin showed greater benefits for the combination therapy for both LUTS and ED. The coadministration of udenafil and an α-blocker in patients with BPH and ED also appeared to improve both LUTS and ED severity. Conclusions: Consistent evidence of improvements in LUTS has been shown with PDE5-Is, either alone or in combination with α-blockers. However, effects on urodynamics or objective measures of urinary flow are lacking. Further areas of research include investigation of mechanism of PDE5-Is, urodynamic studies, identification of new efficacy end points, head-to-head comparison with standard of care, potential benefit of add-on treatment, and long-term outcomes.