Omapatrilat (INN, proposed trade name Vanlev) is an experimental antihypertensive agent that was never marketed. It inhibits both neprilysin (neutral endopeptidase, NEP) and angiotensin-converting enzyme (ACE). NEP inhibition results in elevated natriuretic peptide levels, promoting natriuresis, diuresis, vasodilation, and reductions in preload and ventricular remodeling. It was discovered and developed by Bristol-Myers Squibb but failed in clinical trials as a potential treatment for congestive heart failure due to safety concerns about its causing angioedema. Omapatrilat angioedema was attributed to its dual mechanism of action, inhibiting both angiotensin-converting enzyme (ACE), and neprilysin (neutral endopeptidase), both of these enzymes are responsible for the metabolism of bradykinin which causes vasodilation, angioedema, and airway obstruction.