ACE Inhibitor: What They Do and How to Use Them Safely

ACE inhibitors are a group of blood pressure medicines you’ve probably heard about. They lower blood pressure by blocking the angiotensin-converting enzyme (ACE), which reduces a hormone that tightens blood vessels. That helps your heart pump easier and can protect your kidneys, especially if you have diabetes.

How ACE inhibitors work and when they’re used

Common ACE inhibitors include lisinopril, enalapril, ramipril, and benazepril. Doctors use them for high blood pressure, heart failure, after a heart attack, and to slow kidney damage in people with diabetes. If your doctor tells you to take one, it’s usually because the drug can lower the risk of complications over time—not just lower a number on the chart.

These drugs don’t act like painkillers or quick fixes. They change how your body controls blood pressure, so the effects build over days or weeks. If your blood pressure is high and you also have heart or kidney concerns, ACE inhibitors are often a first-line option.

Safety tips, common side effects, and monitoring

There are a few side effects to watch for. A dry, persistent cough is common and annoying for some people. If that happens, many switch to an ARB (angiotensin receptor blocker) like valsartan. A rare but serious risk is angioedema — sudden swelling of the face, lips, throat, or tongue. If you get swelling or trouble breathing, go to the ER right away.

ACE inhibitors can also raise potassium and creatinine levels. Your doctor should check blood tests before starting the drug and again 1–2 weeks after starting or increasing the dose. If potassium goes too high, you may need dose changes or stop potassium supplements and certain salts. Avoid combining ACE inhibitors with potassium-sparing diuretics without medical advice.

Avoid ACE inhibitors if you’re pregnant or planning pregnancy — they can harm the fetus. Tell your doctor about any kidney artery problems, previous angioedema, or allergy to this drug class. Also mention frequent NSAID use (ibuprofen, naproxen), because NSAIDs can reduce how well ACE inhibitors work and increase kidney risks.

Practical tips: take your pill at the same time each day, stand up slowly at first if you feel dizzy, and keep a list of all meds and supplements to show your doctor. If you get a new prescription from another provider, remind them you’re on an ACE inhibitor.

Questions? Read our article on valsartan if a cough forces a switch — ARBs are a common alternative. If you notice swelling, severe dizziness, fainting, or breathing trouble, seek urgent care. For routine checks, keep up with blood tests for kidney function and potassium so your treatment stays safe and effective.