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.
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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:
ACE inhibitor medications also treat several kidney diseases in people who don’t have diabetes, including:
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A list of these medicines includes:
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.
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.
Healthcare providers often make ACE inhibitors their first choice for treating high blood pressure and other heart and blood vessel conditions. This is because:
In general, the most common side effects for almost all ACE inhibitor medicines include:
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Some general reasons for avoiding ACE inhibitors include:
ACE inhibitor drugs can interact with many medications. A few possible serious interactions include:
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.
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.
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.
You should seek immediate medical attention if you experience any of the following while taking ACE inhibitors:
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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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.
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.

Last reviewed on 11/07/2025.
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