Like HowStuffWorks on Facebook!

Angiotensin-Converting Enzyme Inhibitors (ACE Inhibitors)

        Health | Heart

Angiotensin-converting enzyme inhibitors are called ACE inhibitors for short. ACE inhibitors can be used alone or in a combination pill with a diuretic or a calcium channel blocker.

When are ACE inhibitors prescribed?

These medicines can quickly reduce your high blood pressure. For this reason, they are especially useful if you have diabetes or heart failure, or if you are at high risk for heart problems. These medicines have been shown to delay the onset and progression of kidney disease by 30% to 60%. They can also limit how far other complications caused by high blood pressure will progress. ACE inhibitors are also often used after heart attacks to help prevent further heart damage.

In addition to these benefits, these medicines have a few risks. In very rare cases, ACE inhibitors can cause your kidneys to retain too much potassium. Also, rarely, they may reduce your number of white blood cells, which puts you at risk for infection.

Common Names for ACE Inhibitors

The following table lists some of the common brand and generic names for ACE inhibitors combinations.

brand generic
Accupril quinapril HCl
Altace ramipril
Capoten captopril
Lotensin benazepril HCl
Mavik trandolapril
Monopril fosinopril sodium
Prinivil lisinopril
Univasc moexipril
Vasotec enalapril maleate
Zestril lisinopril

How ACE Inhibitors Work

ACE inhibitors block your body's production of a chemical called angiotensin II. This chemical raises your blood pressure. It does this by narrowing your arteries. When angiotensin II is blocked, your blood vessels relax and your blood flows more easily. That means your blood pressure goes down, and your heart works more efficiently. ACE inhibitors also help your kidneys get rid of small amounts of sodium. That helps decrease your blood pressure.

Precautions and Possible Side Effects

Precautions you should take if you are on an ACE inhibitor:

  • Tell your doctor if you are pregnant, think you might be, or are planning to become pregnant soon. You should not take ACE inhibitors in any of these cases.
  • Do not use potassium supplements unless instructed to do so by your doctor. They can cause problems when taken with this medicine.
  • Use antacids only with caution. You may take an antacid to ease heartburn. If you do, wait several hours after you take it before you take your ACE inhibitor.
  • Tell your doctor if you experience faintness or dizziness. Blood pressure medicines can occasionally cause dizziness. This is most likely to happen when you change position suddenly. But this may also be caused by other physical or medical problems that have nothing to do with your medicines.

Possible side effects of ACE inhibitors that you may notice:

  • dizziness or faintness
  • chronic dry cough
  • loss of taste
  • skin rash

Not everyone who takes ACE inhibitors will have these side effects. You should not be afraid to take your medicine because of the side effects listed. They are listed so that you can watch out for them and tell your doctor right away if you experience any of them.

Possible side effects of ACE inhibitors that you may not notice:

  • reduced kidney function
  • reduced number of white blood cells, which can lead to serious infections

Although you may not be aware that your body is experiencing these changes, your doctor will be able to test for these possible side effects at an office visit. Be sure to keep all follow-up appointments with your doctors.

Possible Drug Interactions With ACE Inhibitors

Before you take an ACE inhibitor, tell all your doctors and your pharmacist about all the medicines you take. Include medicines you take for your blood pressure as well as for any other problem. Tell them about everything you take and how much you take each day, including all of the following:

  • prescription medicines
  • over-the-counter medicines
  • herbs
  • vitamin and mineral supplements

It's best to keep an updated list of these and bring a copy to give to your doctor. That way you can add to it whenever you take something new or delete the types you no longer take. Make a copy for each of your doctors so that they can keep it in your file. This complete list helps your doctor be better prepared to prescribe an ACE inhibitor that is the least likely to interact with your other treatments.