rac-Trandolapril-d 5 (rac-RU44570-d 5 ) is deuterium labeled Trandolapril. Trandolapril (RU44570) is a nonsulfhydryl proagent that is hydrolysed to the active diacid Trandolaprilat. Trandolapril is an orally administered angiotensin converting enzyme ( ACE ) inhibitor that has been used in the treatment of hypertension and congestive heart failure (CHF), and after myocardial infarction (MI).