PDE5A and Eisenmenger syndrome: Several FDA-approved PDE5 inhibitors have been employed in treatment of different health conditions, such as type II diabetes (insulin resistance), mountain sickness, Eisenmenger’s syndrome, Raynaud’s disease, intrauterine growth retardation (IUGR), benign prostatic hypertrophy (BPH) and Bladder pain syndrome/interstitial cystitis (BPS/IC).