Angiotensin Converting Enzyme (ACE) Inhibitors

What is an angiotensin converting enzyme (ACE) inhibitor?

ACE inhibitors are drugs that help relax blood vessels. Relaxing blood vessels allows blood to flow more easily and lowers the blood pressure. Lowering the blood pressure reduces or prevents heart attacks or strokes and makes it easier to treat heart failure. Heart failure occurs when the heart is either too weak or too damaged to pump blood properly. ACE inhibitors appear to decrease the amount of damage to the heart muscle following a heart attack.

Lisinopril, benazepril, enalapril, captopril, ramipril, quinapril, and trandolapril are examples of ACE inhibitors. Which one is best for you depends on your condition and health.

How do ACE inhibitors work?

Angiotensin converting enzyme (ACE) is a substance in the body that changes an inactive blood chemical to a very active blood vessel constrictor, or "squeezer." Blood vessel constrictors cause blood vessels to narrow. The body uses ACE to help regulate the blood pressure. It makes the blood vessels constrict when blood pressure needs to be higher. In some people with high blood pressure (hypertension) the enzyme is overactive. This can cause high blood pressure and increase the workload of the heart and other organs. ACE inhibitors slow the activity of this enzyme.

When are ACE inhibitors used?

High blood pressure (hypertension) and heart failure are the most common reason for the use of ACE inhibitors. The drugs may be used alone or with other drugs.

ACE inhibitors are used to treat heart failure. Poor pumping ability of the heart leads to buildup of fluid in body tissues and the lungs. Symptoms such as tiredness, swelling of the legs and ankles, and trouble breathing are common. ACE inhibitors relieve these symptoms by reducing blood pressure to ease the workload of the heart.

ACE inhibitors limit muscle damage done to the heart by a heart attack. These drugs help the heart heal in a normal shape after a heart attack so it can pump better. They can help prevent heart attacks in people who are at high risk.

ACE inhibitors also work on the kidneys by increasing blood flow and reducing the tendency of the body to retain fluids. They can help prevent kidney problems in people with diabetes.

What should be monitored while taking ACE inhibitors?

Your healthcare provider will check your blood pressure regularly. Checks of your blood potassium level may be necessary. If you have heart failure, you also need to limit your salt intake and to weigh yourself regularly.

Report these side effects to your healthcare provider right away:

• a dry, hacking cough that lasts more than a few days
• severe dizziness or fainting
• skin rash
• muscle weakness
• swelling of the tissues in your face, eyes, lips, tongue, or throat, especially if it interferes with breathing.

Not all of the ACE inhibitors have the same side effects. If you develop symptoms while on the drug, contact your healthcare provider right away. Fortunately, most people taking the drug have no symptoms.