Angiotensin-converting enzyme (ACE) inhibitors are medicines that help relax the veins and arteries to lower blood pressure. ACE inhibitors prevent an enzyme in the body from making angiotensin 2, a substance that narrows blood vessels. This narrowing can cause high blood pressure and forces the heart to work harder. Angiotensin 2 also releases hormones that raise blood pressure.

Many ACE inhibitors are available. The best one for you depends on many things, including your overall health. For example, people with chronic kidney disease may benefit from having an ACE inhibitor as one of their medicines.

Examples of ACE inhibitors include:

• Benazepril (Lotensin).
• Captopril.
• Enalapril (Vasotec).
• Fosinopril.
• Lisinopril (Zestril).
• Moexipril.
• Perindopril.
• Quinapril.
• Ramipril (Altace).
• Trandolapril.

ACE inhibitors are used to prevent, treat or improve symptoms in conditions such as:

• High blood pressure, also called hypertension.
• Coronary artery disease.
• Heart failure.
• Diabetes.
• Certain chronic kidney diseases.
• Heart attacks.
• Scleroderma, a disease that involves hardening of the skin and connective tissues.
• Migraines.

Sometimes, another blood pressure medicine, such as a diuretic or calcium channel blocker, is used with an ACE inhibitor. ACE inhibitors should not be taken with an angiotensin receptor blocker, an angiotensin receptor neprilysin inhibitor or a direct renin inhibitor.

Side effects of ACE inhibitors may include:

• Dry cough.
• Too much potassium in the blood.
• Extreme tiredness or dizziness from blood pressure going too low.
• Headaches.
• Loss of taste.
• Rarely, short-term worsening of kidney function.

Rarely, ACE inhibitors can cause swelling under the skin. If swelling occurs in the throat, it can be life-threatening.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve), decrease how well ACE inhibitors work.

Taking ACE inhibitors during pregnancy increases the risk of birth defects in the baby. If you're pregnant or plan to become pregnant, other options may be available to treat high blood pressure.

Talk to your health care professional if you have any questions about the medicines you take.