ACE inhibitor

ACE inhibitors interrupt a hormone system the body uses to raise blood pressure. The body makes a powerful vessel-tightening hormone called angiotensin II in two steps; the “ACE” enzyme runs the final step, and these drugs jam that enzyme, so less angiotensin II is made and vessels relax.

With vessels more relaxed and the body holding onto less salt and water, blood pressure falls and the strained heart has less to push against. Their generic names end in “-pril,” such as the well-known examples used worldwide.

Beyond lowering blood pressure, they protect the heart and kidneys over time. They are a foundation treatment in heart failure from a weak pump and after large heart attacks, where they slow the harmful remodeling that would otherwise enlarge and weaken the heart, and they help protect the kidneys in people with diabetes.

Two characteristic side effects flag this class: a persistent dry cough from a build-up of bradykinin, and rarely a more serious swelling called angioedema. They also raise blood potassium and can stress the kidneys, so blood tests are checked after starting or increasing the dose.