ACE inhibitors: A drug that inhibits ACE (angiotensin converting enzyme) which is important to the formation of angiotensin II. Angiotensin II causes arteries in the body to constrict and thereby raises the blood pressure. ACE inhibitors lower the blood pressure by inhibiting the formation of angiotensin II. This relaxes the arteries. Relaxing the arteries not only lowers blood pressure, but also improves the pumping efficiency of a failing heart and improves cardiac output in patients with heart failure. ACE inhibitors are therefore used for blood pressure control and congestive heart failure.

The currently available ACA inhibitors include: benazepril (brand name: LOTENSIN), captopril (brand name: CAPOTEN), lisinopril (brand names: ZESTRIL and PRINIVIL), quinapril (brand name: ACCUPRIL), and ramipril (brand name: ALTACE).

ACE inhibitors may slow the progress of diabetic kidney disease in middle-aged persons with type 2 diabetes. Some (but not all) experts have therefore recommended giving ACE inhibitors to all middle-aged type 2 diabetics. (Reference: Annals of Internal Medicine 1999;131:660-667, 707-708.)

Historically, it is interesting that the ACE inhibitors were originally developed from the venom of a poisonous Brazilian snake.