The Relationship between Erectile Dysfunction and Lower Urinary Tract Symptoms and the Role of Phosphodiesterase Type 5 Inhibitors

Abstract Context The relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) and the potential interplay of phosphodiesterase type 5 inhibitors (PDE5-I) have clinical implications for both patient screening and treatment. Objective To describe the current literature assessing the LUTS–ED relationship and the role of PDE5-I from both a basic science and clinical intervention perspective. Evidence acquisition We focused on data recently published (1990–2008) describing epidemiologic and mechanistic manuscripts of the LUTS–ED relationship with emphasis on papers involving PDE5-I—particularly those using level 1 evidence clinical trials. Base key words used included BPH, LUTS, ED, and phosphodiesterase inhibitors in combination with such secondary key words as nitric oxide, autonomic hyperactivity, Rho-kinase, atherosclerosis, and mechanism. We abstracted >200 articles and reviewed >100. Evidence synthesis The large overlap of elderly men with both LUTS and ED likely stems from a cause-and-effect relationship. Thus far, four proposed mechanisms attempt to explain the relationship between LUTS and ED. Multiple studies showing that PDE5-I improved LUTS have been performed. Understanding the role of PDE5-I in the LUTS and ED relationship affects patient screening and treatment but also raises further research questions. Conclusions The future use of phosphodiesterase inhibitors as either prophylaxis or as a primary treatment for LUTS looms as a possibility and may not be limited to men.