[The safety of tadalafil in the treatment of erectile dysfunction]

The cyclic nucleotide (cGMP) signalling pathway mediates the smooth-muscle relaxing effects of nitric oxide necessary for normal erectile function. Down-regulation of this pathway is the pathophysiological pivot of many forms of erectile dysfunction (ED) and leads to the development of some chronic diseases, such as hypertension and type 2 diabetes mellitus. Therefore, selective inhibition of the enzyme that catalyses the degradation of cGMP promotes erectile responses to sexual stimulation. Recently, a new phosphodiesterase type 5 (PDE-5) inhibitor tadalafil has emerged, which has a prolonged half-life. Here is a review of recent studies on the safety of tadalafil in the treatment of ED.