A Review of Combined Phosphodiesterase-5-Inhibitors and -Blockers versus Phosphodiesterase-5-Inhibitors Alone for Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia

Guidelines from the American Urological Association (AUA) and the European Association of Urology (EAU) present conflicting recommendations regarding combination therapy of phosphodiesterase 5 inhibitors (PDE5is) with alpha-blockers to treat benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS). Use of PDE5is is widespread in the population of patients with LUTS/BPH. In this scoping review, we examine the evidence regarding the safety and efficacy of combined PDE5is and alpha-blockers compared to PDE5i medications alone. A search was conducted using PubMed, Cochrane, and Web of Science to identify manuscripts discussing the safety of PDE5i and alpha-blockers in combination or comparing this combination to PDE5is alone in the treatment of LUTS/BPH. Study designs, data, and conclusions were qualitatively analyzed. Combination therapy was found to be safe across all studies; importantly, no evidence documents increased risk of hypotension. Most studies reported added improvement in symptom and quality of life scores compared to PDE5i alone, with additional International Prostate Symptom Score (IPSS) change ranging from -1.30 to -8.50 and IPSS quality of life score change ranging from -0.15 to -1.50. Objective metrics such as postvoid residual volumes and maximum flow rate were inconsistently reported. Taken together, the current body of data suggests that combining PDE5i alpha-blocker therapy is safe and that there are opportunities for additional symptomatic improvement, though it should be utilized for select patients. Situations with particular utility could include patients with comorbid erectile dysfunction or without sufficient improvement on monotherapy.