Avanafil is a PDE5 inhibitor approved for erectile dysfunction by FDA and by EMA. Avanafil is known as Stendra and Spedra by Vivus Inc. Avanafil acts in the corpus cavernosum penis, as well as the retina. Similar drugs are sildenafil, tadalafil and vardenafil. It has very fast onset of action. It is absorbed quickly and reach the maximum concentration in 30–45 minutes. About 2/3 of the participants were active in 15 minutes.