Candesartan cilexetil is a prodrug of the potent, long-acting, and selective angiotensin II type 1 receptor (AT1) antagonist, candesartan. Clinical trials indicate a 4-16 mg/day dose of candesartan cilexetil effectively reduces diastolic blood pressure. 1H-1-ethyl Candesartan cilexetil is a process-related impurity commonly found in the bulk synthesis of candesartan cilexetil.