Angiotensin Converting Enzyme (ACE) Inhibitors

What is an angiotensin converting enzyme (ACE) inhibitor?

Angiotensin converting enzyme inhibitors (also called ACE inhibitors) are medicines that help relax blood vessels. Relaxing the 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 slows the worsening of heart failure. Captopril, enalapril, fosinopril, lisinopril, and quinapril are examples of ACE inhibitors. Which one is best for you depends on your condition and health.

When are ACE inhibitors used?

Angiotensin converting enzyme (ACE) inhibitors are a medicine that may be used to prevent, treat, or improve the symptoms of several health conditions, such as:

• High blood pressure - lowers blood pressure by relaxing blood vessels
• Heart failure - helps the heart pump more easily
• Heart attacks - helps better healing of the heart after a heart attack
• Heart disease prevention - helps prevent strokes or heart attacks
• Kidney disease - slows or prevents damage if you have high blood pressure or diabetes.

ACE inhibitors may be used alone or with other medicines.

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. This can cause high blood pressure and force your heart to work harder. ACE inhibitors slow the activity of the angiotensin converting enzyme, so blood vessels relax and open up. This lowers blood pressure, which makes it easier for the heart to pump blood.

Even if your blood pressure is normal, this medicine can help your heart condition unless there is a reason you cannot take it.

What will be checked while I am taking ACE inhibitors?

Your healthcare provider will check your blood pressure regularly. You may also have blood tests to check your kidney function and your blood potassium level, especially if you also take diuretics or potassium supplements. If you have heart failure, you may also need to limit the salt in your diet and weigh yourself regularly.

Although angiotensin converting enzyme (ACE) inhibitors are well tolerated by most people, some people should not take ACE inhibitors for a variety of reasons. For example, you will need to avoid taking an ACE inhibitor if:

• You have severe kidney disease, such as renal artery stenosis.
• You have a history of a severe reaction to this medicine, such as angioedema, which is a swelling and redness of the head, mouth, lips, tongue, or neck. The swelling can make it hard to breathe.
• You also need to take NSAIDs (nonsteroidal anti-inflammatory drugs). The combination of NSAIDs and ACE inhibitors may make heart failure worse, harm the kidneys, or increase blood pressure.
• You are pregnant or plan to become pregnant. ACE inhibitors may cause birth defects.

When should I call my healthcare provider?

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 (this may be a sign that your blood pressure is too low)
• 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 medicine have no symptoms.