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ACE Inhibitors

ACE inhibitors (angiotensin-converting enzyme inhibitors) are medications that lower your blood pressure. They do this by blocking your body’s conversion of angiotensin into a form that raises your blood pressure. These drugs can treat heart and blood vessel conditions, like high blood pressure, heart failure, kidney problems and more.

Overview

What are ACE inhibitors?

ACE inhibitors (angiotensin-converting enzyme inhibitors) are medicines that keep a blood protein called ACE from converting angiotensin I into angiotensin II. Angiotensin II raises blood pressure by tightening your blood vessels and limiting how much salt and water your kidneys remove from your body.

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ACE also breaks down bradykinin, a protein that relaxes your blood vessels and helps your kidneys remove sodium from your body. Both actions help your blood pressure go down.

Blocking ACE means there’s less angiotensin II to raise your blood pressure, and there’s more bradykinin to lower your blood pressure. That means better blood pressure readings for you.

ACE inhibitors can lower your blood pressure and protect your kidneys. Healthcare providers often use this drug class to treat and prevent cardiovascular (heart and blood vessel) conditions.

ACE inhibitor medicines are common. They help with:

  • Treating high blood pressure (hypertension)
  • Treating heart failure (inability of your heart to pump enough blood)
  • Treating you after a heart attack (lack of blood flow to your heart muscle)
  • Treating you after acute coronary syndrome (blockage slowing or stopping blood flow to your heart — the medicine doesn’t treat the blockage itself, but helps your heart recover after the blockage is addressed)
  • Preventing heart attack and stroke in people at high risk for either
  • Preventing and slowing the progression of kidney failure in people with diabetes

ACE inhibitor medications also treat several kidney diseases in people who don’t have diabetes, including:

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  • Nephrotic syndrome (having kidney damage or its symptoms)
  • Proteinuria (too much protein in your urine)
  • Glomerular disease (problems with your kidney’s filtration system)
  • Post-transplant glomerulonephritis (kidney inflammation and filtration problems)

Types of ACE inhibitors

A list of these medicines includes:

Treatment Details

How do I take this medicine?

You’ll most likely take an ACE inhibitor once a day. In some cases, people need two doses a day. You take all ACE inhibitor drugs by mouth except for enalaprilat. You receive this through an IV in your arm, most commonly only when you’re admitted to the hospital.

If you miss a dose of your ACE inhibitor, unless it’s closer to the time for your next dose than the one you missed, you should take the dose as soon as possible. If it’s been too long, wait and take only the next dose. Don’t take more than your prescribed dose to “catch up” because this can make your blood pressure too low.

Keep taking ACE inhibitors as prescribed. Talk to your healthcare provider before you stop taking these medications. Stopping them suddenly can cause a heart attack, stroke or worsening heart failure. If you’re having bad side effects, your healthcare provider can help you switch to another drug.

How long will I need this treatment?

High blood pressure requires long-term treatment. If you’re taking an ACE inhibitor for this reason, you can expect to take it for years to come. The same is true if you’re taking it for many of the other conditions it treats.

What are the potential benefits and risks of this treatment?

Healthcare providers often make ACE inhibitors their first choice for treating high blood pressure and other heart and blood vessel conditions. This is because:

  • They work. Extensive scientific research has shown that ACE inhibitors are effective.
  • They’re preventive. ACE inhibitor drugs don’t just treat existing conditions. They can also prevent those issues from happening (either for the first time or again).
  • They often combine well with other drugs. Companies that make medicines often combine ACE inhibitors with certain other types of blood pressure medications into a single drug.
  • They’re safe. Side effects of ACE inhibitors are usually minor. Severe side effects are especially rare. In many cases, you can take these medicines for the rest of your life.

In general, the most common side effects for almost all ACE inhibitor medicines include:

  • Dry cough
  • Dizziness
  • Headache
  • Drowsiness
  • Angioedema (swelling)
  • Fatigue
  • Weakness
  • Decreased ability to taste or a noticeable metallic taste (less common)
  • Upset stomach or nausea (less common)
  • Rash (less common)

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Some general reasons for avoiding ACE inhibitors include:

  • Pregnancy or breastfeeding (switch medicines before trying to get pregnant)
  • History of angioedema
  • Any past reaction to an ACE inhibitor
  • Severe kidney disease or narrowing of the arteries that supply blood to your kidneys (renal artery stenosis)

What should you avoid when taking ACE inhibitors?

ACE inhibitor drugs can interact with many medications. A few possible serious interactions include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs): These over-the-counter pain and inflammation medications can make ACE inhibitors less effective or decrease kidney function.
  • Medications that affect your potassium or sodium levels: These can make your levels too low or high, like having too much potassium in your blood (hyperkalemia).
  • Angiotensin-receptor blockers (ARBs): When you take an ARB with an ACE inhibitor, they can sometimes affect your kidney function, lower blood pressure and cause hyperkalemia.
  • Medications that affect your kidneys: One example is aliskiren, which inhibits an enzyme called renin. This enzyme helps manage your body’s blood pressure.

Your provider may want you to avoid or limit salt in the foods you eat. You may also want to avoid salt substitutes that contain potassium until you talk to your provider about whether they’re right for you.

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While it isn’t dangerous, capsaicin — which makes foods like peppers spicy — can sometimes worsen an ACE inhibitor-related cough.

Recovery and Outlook

How long will it take for me to feel better?

Some ACE inhibitor medications can start working one hour after you take them. You should take certain ACE inhibitors one hour before eating a meal. This is because having food in your digestive system may lower your body’s ability to absorb the medicine. Your provider can tell you if you should take your medicine before eating.

Is there anything I can do to make this treatment easier on me?

You shouldn’t stand up too quickly after you start taking ACE inhibitors. Standing up too quickly can make you feel dizzy or pass out.

When should I call my healthcare provider?

You should seek immediate medical attention if you experience any of the following while taking ACE inhibitors:

  • Swelling (especially in your face, mouth or throat) that may be a sign of angioedema
  • Any symptom of an allergic reaction, especially hives, itching or trouble swallowing or breathing
  • Fainting (passing out) or almost passing out
  • Any symptoms of a heart attack or stroke
  • Jaundice (yellowing of the whites of your eyes or your skin, which can be a sign of serious liver problems)

At least once a year, your provider will check your kidney function and electrolyte levels. This may involve blood and urine testing. If your levels are abnormal or your kidneys aren’t working well, your provider may adjust your ACE inhibitor dose.

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A note from Cleveland Clinic

With so many different types of blood pressure medicines around, it can be hard to know what’s what. ACE inhibitors are some of the first blood pressure medicines providers prescribe. They work well for many people. If you have questions about these medications, don’t hesitate to ask your provider.

Care at Cleveland Clinic

When your heart needs some help, the cardiology experts at Cleveland Clinic are here for you. We diagnose and treat the full spectrum of cardiovascular diseases.

Medically Reviewed

Last reviewed on 11/07/2025.

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