The role of phosphodiesterase type-5 inhibitors in treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia.

Phosphodiesterase type-5 (PDE-5) inhibitors are approved as the first line of therapy for the treatment of erectile dysfunction. However, different studies have been performed to study the use of these agents in other areas of urology. There are many studies related to the use of PDE-5 inhibitors as a monotherapy or combination therapy with alpha-blockers for lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). It has been shown that contractions induced by various agents or electrical field stimulation in organ bath models of prostatic tissue can be reversed by PDE-5 inhibitors. Age, body mass index and the severity of LUTS are important factors for the selection of patients suitable for this treatment. It has also been reported that the use of PDE-5 inhibitors can relieve the chronic pelvic ischemia and endothelial dysfunction associated with metabolic syndrome. Most of the side effects observed with PDE-5 inhibitors are minimal and tolerable. The use of PDE-5 inhibitors is absolutely contraindicated in patients taking nitrate preparations. A significant interaction has not been observed even when a patient is taking several antihypertensive agents concurrently. Co-administration of alpha-blockers and PDE-5 inhibitors may result in orthostatic hypotension; therefore, patients should be stable on α-blocker therapy before the initiation of the combination therapy, and the initial PDE-5 inhibitor dose should be the lowest possible. In this review, our aim was to evaluate the role of PDE-5 inhibitors in the treatment of LUTS associated with BPH by analyzing the current literature.