Several medications have been used in the treatment of PPHN including Phospho Diesterase Enzyme (PDE) inhibitors, PDE5 inhibitors, PDE3 inhibitors, Endothelin receptor (ETR) antagonists, PGs, Calcium channel blockers, magnesium sulfate, scavengers of ROS, and RhoA/Rho kinase inhibitors. This evidence concerns the gene PDE5A and persistent fetal circulation syndrome.