Angiotensin-converting enzyme inhibitors, often shortened to ACE inhibitors, are a type of medications that lower your blood pressure. They interfere with how your body converts angiotensin into a form that raises your blood pressure. These drugs can treat cardiovascular conditions like high blood pressure, heart failure, kidney problems and more.
Angiotensin-converting enzyme inhibitors, often shortened to ACE inhibitors or ACE-I, are a class of medications that help lower your blood pressure and can protect your kidneys. They’re used to treat cardiovascular (heart- or circulatory system-related) conditions like high blood pressure, heart failure, diabetes-related kidney disease and more.
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ACE inhibitors work just like the name suggests, blocking angiotensin-converting enzyme (ACE) from converting angiotensin I into angiotensin II. Because angiotensin II raises blood pressure in multiple ways, reducing the amount in the body is an effective way to lower blood pressure.
ACE is part of your body’s blood pressure control process. Enzymes like ACE are useful because they are catalysts. That means they make it easier for certain chemical reactions to happen.
ACE raises your blood pressure in two ways:
Angiotensin (an-gee-oh-ten-sin) is a hormone found in your body in four different forms (the names of the forms use Roman numerals). ACE turns angiotensin I into angiotensin II, which has multiple effects throughout your body.
Some of those effects — all of which increase your blood pressure — include:
Bradykinin (bray-dee-ky-nin) is a protein that lowers your blood pressure by relaxing your blood vessels and helping your kidneys remove sodium from your body. ACE breaks bradykinin down. Less available bradykinin makes your blood pressure go up.
Blocking ACE means there’s less angiotensin II to raise your blood pressure, and there’s more bradykinin to lower your blood pressure.
ACE inhibitors can treat the following conditions:
ACE inhibitors also treat several kidney diseases in people who don’t have diabetes, including:
ACE inhibitors are very commonly prescribed, especially for blood pressure and other cardiovascular conditions. In 2019, about 12.9 million people with Medicare Part D coverage — about 27% of all Medicare Part D beneficiaries — were prescribed an ACE inhibitor.
There are 10 different ACE inhibitors (as of Aug. 2021) approved by the FDA. They are:
All of the ACE inhibitors are taken orally (by mouth). One, enalapril, can also be given in intravenous (IV) form, meaning it can be delivered right to your bloodstream.
ACE inhibitors have several advantages that make them first-line medications for treating high blood pressure and other cardiovascular conditions. Those include:
ACE inhibitors do have certain side effects. The majority of these are minor, but some are serious and need immediate medical care. Your healthcare provider can best explain the possible side effects, especially those you should watch for because they are dangerous or severe.
In general, the most common side effects for almost all ACE inhibitors include:
Less-common side effects include:
Certain severe side effects can happen with all ACE inhibitors. These include:
There are several reasons why you shouldn’t take ACE inhibitors (these are “contraindications”). You should also ask your healthcare provider if you have any questions about reasons you should or shouldn’t take a medication. They are best prepared to explain any reasons why you shouldn’t take an ACE inhibitor, because they can listen to and answer your questions, review your medical record and look for any potential causes for concern.
Some general reasons include the following:
Because ACE inhibitors affect your circulatory system, they can interact with many medications. Your healthcare provider or a pharmacist are the best sources of information when it comes to explaining potential medication interactions.
A few possible serious interactions include:
These over-the-counter pain and inflammation relief medications can sometimes interact with ACE inhibitors and make them less effective or cause a decrease in kidney function. Talk to your healthcare provider before you take any NSAID if you are already taking an ACE inhibitor.
NSAIDs come in both prescription and over-the-counter forms. Over-the-counter NSAIDs include:
NSAIDs are very commonly combined with other medications like acetaminophen (the main ingredient in Tylenol®, sometimes called paracetamol internationally), which isn’t an NSAID on its own. You may want to read the label and ask a pharmacist for guidance to make sure any over-the-counter medication you want to take doesn't contain an NSAID without your knowing.
ACE inhibitors affect how your body retains (or doesn’t retain) sodium and potassium. That means other medications that also affect those levels can cause you to have too much of those. Hyperkalemia (too much potassium in the blood), in particular, is a concern with ACE inhibitors.
Where ACE inhibitors stop angiotensin’s conversion into a usable form, angiotensin-receptor blockers (ARBs) keep your body from using most of its angiotensin II. When used together, they can sometimes affect your kidney function, lower blood pressure and cause dangerous hyperkalemia.
An example of this is a medication called aliskiren, which inhibits an enzyme called renin. Renin is also an important part of your body’s control over blood pressure.
In general, follow your healthcare provider’s guidance when it comes to what you should or shouldn’t eat or drink. This is especially true if your provider tells you to follow a low-sodium diet. Not following that guidance could affect your sodium levels. You also should avoid salt substitutes that contain potassium until you talk to your provider about whether or not those substitutes are safe.
While it isn't dangerous, capsaicin — the chemical compound that makes foods like peppers spicy — can sometimes worsen an ACE inhibitor-related cough.
ACE inhibitors are typically safe for long-term use. In many cases, you can take them indefinitely and for the rest of your life.
You should talk to your healthcare provider before you stop taking these medications. Stopping them suddenly can cause serious and life-threatening medical events, especially ones like heart attack, stroke or worsening heart failure.
Depending on why you take an ACE inhibitor, it may be possible to improve your blood pressure to the point where it’s no longer needed. Your doctor can help taper off your dose until it’s safe to stop taking it.
In cases where you still have the original health condition but want to stop taking an ACE inhibitor, your healthcare provider can usually help you. They can offer medication alternatives and assist you in switching to another drug that can also help you.
If you miss a dose of your ACE inhibitor — unless it is 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 cause severe, dangerous lowering of blood pressure.
Your healthcare provider is the best person to advise you on when to call them or seek medical attention.
In general, you should seek immediate medical attention if you experience any of the following:
A note from Cleveland Clinic
ACE inhibitors are an important tool when it comes to treating a wide range of health problems. Depending on what you need and your circumstances, they may be able to help improve your health now and prevent problems in the future. If you have questions about these medications, your primary care provider is a great source of information and guidance. They can offer you options and then help you as you work to manage your health and well-being.
Last reviewed by a Cleveland Clinic medical professional on 10/22/2021.
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