PDE5 inhibitors and their applications.

PDE5 belongs to a superfamily of enzymes that catalyzes the hydrolysis of cyclic nucleotides cAMP and cGMP to the corresponding 5-nucleoside monophosphate. PDE5 takes part in many physiological and pathological functions, therefore selective PDE5 inhibitors are potentially useful for a variety of pathologies. At the present, PDE5 inhibitors available on the market have been used for the treatment of erectile dysfunction but, at the same time, are in clinical trials investigating other pathologies such as pulmonary arterial hypertension, coronary vasospasm, benign prostatic hyperplasia etc. This review analyzes the PDE5 inhibitors currently in clinical use, the drugs in clinical trials and the most representative chemical classes published in literature in this last decade.