Avanafil-13C5,15N,d2 is 15N and deuterated labeled Avanafil (HY-18252). Avanafil (TA-1790) is a potent and selective phosphodiesterase-5 (PDE-5) inhibitor with IC50 values of 5.2 nM, 630 nM, 5700 nM, 6200 nM, 12000 nM, 27000 nM, 51000 nM and 53000 nM for