rac-Trandolapril-d5 (rac-RU44570-d5) 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)[1][2].