What to Know About ACE Inhibitors

Table of Contents
View All
Table of Contents

Angiotensin-converting enzyme (ACE) inhibitors are oral medications that lower blood pressure. ACE inhibitors are used to treat hypertension (high blood pressure), coronary artery disease, and heart failure, and to help control the progression of diabetes and kidney disease.

ACE inhibitors have been FDA-approved for treating hypertension since 1981. Over time, ACE inhibitor use has expanded dramatically to treat cardiovascular disease and related conditions.

A woman with prescription bottle at laptop
Hero Images / Getty


Diabetes and heart disease processes tend to go hand in hand. High blood pressure is very common among people with diabetes. It also contributes to the development of diabetic nephropathy (kidney disease).

Furthermore, those with diabetes tend to have worse outcomes (longer hospitalizations, longer recovery times, and higher risks of infection) from major heart problems. Therefore, healthcare providers treat hypertension in concert with diabetes.

While ACE inhibitors don’t directly lower blood sugar, they can contribute to blood sugar control by increasing the body’s sensitivity to insulin. Insulin helps the body metabolize glucose (sugar) and move it from the bloodstream into cells, where it acts as a source of energy.

In addition to their overall benefits for heart health, ACE inhibitors have been shown to offer numerous benefits for people with diabetes. These include:

  • Delaying the onset of type 2 diabetes
  • Lowering the risk of heart attack, stroke, and kidney disease
  • Reducing overall mortality
  • Decreasing the risk of mortality from cardiovascular conditions

Many ACE inhibitors are available in the United States. Examples include:

  • Capoten (captopril)
  • Prinivil and Zestril (lisinopril)
  • Vasotec (enalapril)
  • Lotensin (benazepril)
  • Altace (ramipril)
  • Accupril (quinapril)
  • Monopril (fosinopril)
  • Mavik (trandolapril)
  • Aceon (perindopril)
  • Univasc (moexipril)

“Off-Label” Uses

In addition to the benefits above, ACE inhibitors may be used to help control abnormal heart rhythms, particularly after a heart attack.

ACE inhibitors are also used off-label in the treatment of such diseases as rheumatoid arthritis, migraines, Raynaud’s phenomenon, and Bartter syndrome.

How ACE inhibitors Work

ACE inhibitors lower blood pressure by preventing the body from producing the hormone angiotensin II. Angiotensin II causes vasoconstriction (narrowing of blood vessels) and fluid retention, resulting in hypertension.

By reducing blood pressure and fluid retention, ACE inhibitors help to prevent heart failure. ACE inhibitors may also prevent and control diabetic nephropathy (kidney disease) and help control diabetic retinopathy (eye problems). ACE inhibitors do not slow the heart or directly lower blood sugar. 

Precautions and Contraindications

People with very low blood pressure (hypotension) or who have had an allergy or cough related to ACE inhibitors should not use ACE inhibitors. Neither should those with renal artery stenosis. People with significant kidney damage will likely require adjusted dosing of ACE inhibitors.

ACE inhibitors can harm a fetus or infant, so women who are pregnant, trying to conceive, or breastfeeding should not use them. If you become pregnant while taking an ACE inhibitor, let your healthcare provider know so you can switch to a different medication right away.

ACE Inhibitors and Common Pain Relievers

If you take NSAIDs regularly or even occasionally, check with your healthcare provider about other medication options: NSAIDS make ACE inhibitors less effective as well as increase the risk of kidney damage and unusually high potassium levels (called hyperkalemia). Taking them once in a while shouldn’t pose a problem, but check with your practitioner to be sure they're safe for you, and always take as small a dose as possible.

How to Take and Store

Your initial dose of an ACE inhibitor will vary depending on other medications you may be taking. Some ACE inhibitors should be taken with food: check the directions for your medications, which should also be stored according to package instructions (generally in a cool, dry place, like a cupboard or medicine cabinet).

It may be best to avoid taking an ACE inhibitor before bed, to avoid blood pressure dropping too low during the night. You can track your blood pressure levels, then check with your healthcare provider, to find the optimal time for you to take these medications.

Alcohol is also best avoided while taking an ACE inhibitor. Since both lower blood pressure, drinking may interact in unpredictable and unsafe ways with these medications.

Side Effects

ACE inhibitors are generally very well tolerated. Still, some side effects are possible.

For example, all blood pressure medications carry a risk of low blood pressure (hypotension). Symptoms of low blood pressure include:

  • sweating
  • nausea
  • lightheadedness
  • dizziness, fainting

If you experience a bout of low blood pressure, perhaps after standing up too quickly, try lying down for a few minutes, then eating a small, healthy snack and drinking a glass of water.

If symptoms last longer than 15 minutes, seek immediate medical help. In certain cases, particularly among older people, prolonged lightheadedness can be a sign of a heart attack or stroke. If your symptoms pass but re-occur frequently, check with your healthcare provider: your blood pressure medication dosages may need to be lowered.

Rarely, ACE inhibitors can also cause low blood sugar (hypoglycemia). This can occur in people with diabetes who have blood sugar levels that are otherwise well controlled by diet and other antidiabetic medications. High potassium levels, called hyperkalemia, can also occur in rare cases—be sure to tell your healthcare provider if you use a salt substitute that has high potassium, such as Lo Salt.

The most common side effect of ACE inhibitors is less severe: a dry or hacking cough can develop in 5 to 20 percent of those who take them. One study found about 10 percent of people experienced trouble with coughing after starting to take ACE inhibitors, with about 3 percent switching to a different medication as a result. The chances of developing a cough may be as much as two and a half times higher in people of Asian ancestry than in those of European ancestry. If you develop a cough, discuss it with your healthcare providers: they may switch you to angiotensin receptor blockers, another type of blood pressure medication that does not cause coughing.

Angiotensin receptor blockers (ARBs) are similar to ACE inhibitors. People who are allergic to ACE inhibitors or who develop a cough related to ACE inhibitors can often switch to ARBs with good effect.

Fatigue and headaches may occasionally be side effects of ACE inhibitors. Skin allergic reactions can also range from mild to severe. Rarely, ACE inhibitors can cause tissue swelling, called angioedema. This risk is higher in African Americans, smokers, and women.

Even if they seem minor, report any side effects of medications you're talking to your healthcare providers: they could be signs of a more serious problem and are also usually avoidable. Be especially sure to do so when you first start taking a new medication such as an ACE inhibitor.

Salt Intake and ACE Inhibitors

Too much salt in your diet can decrease or cancel out the benefits of ACE inhibitors. On the other hand, salt restriction or diuretic medications will enhance ACE inhibitors’ effects. Tell your healthcare provider if your salt consumption changes: he or she may need to adjust your ACE inhibitor dosage.

Warnings and Interactions

People with diabetes should always tell their healthcare providers about their other prescription and over-the-counter medications, as well as any herbs and supplements they're currently taking, before starting on ACE inhibitors. Those taking ACE inhibitors should also check with their healthcare providers before starting any additional medications.

Was this page helpful?
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Messerli FH, Bangalore S, Bavishi C, Rimoldi SF. Angiotensin-Converting Enzyme Inhibitors in Hypertension: To Use or Not to Use?. J Am Coll Cardiol. 2018;71(13):1474-1482. doi:10.1016/j.jacc.2018.01.058

  2. Johns Hopkins Medicine. Johns Hopkins Diabetes Guide ACE inhibitors.

  3. Merck Manual Professional Version. Oral angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers for hypertension.

  4. U.S. National Library of Medicine. MedlinePlus. ACE inhibitors. Reviewed July 25, 2018.

  5. American Heart Association. Low blood pressure - when blood pressure is too low. Reviewed October 31, 2016

  6. Bangalore S, Kumar S, Messerli FH. Angiotensin-converting enzyme inhibitor associated cough: deceptive information from the Physicians' Desk Reference. Am J Med. 2010;123(11):1016-30. doi:10.1016/j.amjmed.2010.06.014

Additional Reading