Phosphodiesterase-5 inhibitors and benign prostatic hyperplasia

Purpose of review Benign prostatic hyperplasia (BPH) is prevalent in old men and often results in lower urinary tract symptoms (LUTS). Phosphodiesterase-5 (PDE5) inhibitors increase intracellular concentrations of cyclic guanosine monophosphate. PDE5 inhibitors (sildenafil, tadalafil, vardenafil, etc.) are first-line treatments for erectile dysfunction. Recently, PDE5 inhibitors have been found to regulate smooth muscle tone in human prostate. This article focuses on the use of PDE5 inhibitors for BPH/LUTS treatment and highlights the clinical significance. Recent findings Preclinical and clinical studies have provided promising evidence that PDE5 inhibitors may be an effective and well tolerated treatment option for BPH/LUTS. Combination therapy using PDE5 inhibitors and alpha 1-adrenergic blockers resulted in greater improvements in BPH/LUTS than did either drug alone. Summary There has been increasing interest in the use of PDE5 inhibitors to treat BPH/LUTS. Combination of PDE5 inhibitors and alpha 1-adrenergic blockers may have an additive beneficial effect on BPH/LUTS compared with monotherapy. Mechanisms of action of nitric oxide/cyclic guanosine monophosphate/PDE5 pathway in the treatment of BPH/LUTS deserve further investigations. Larger-scale, well designed clinical trials in future are needed to ascertain the safety, efficacy and cost-effectiveness of PDE5 inhibitors in the treatment of LUTS secondary to BPH.