ACE inhibitors — what they do and what to watch for

ACE inhibitors are a common group of drugs used to lower blood pressure, protect the heart after a heart attack, and slow kidney damage in diabetes. They work by blocking the angiotensin-converting enzyme, which reduces a hormone that narrows blood vessels. The result: blood flows easier and the heart works with less effort.

Common ACE inhibitors you’ll see

Some names you’ll often hear: lisinopril, enalapril, ramipril, captopril, and perindopril. Doctors pick one based on how you respond, other medicines you take, and any kidney issues. Typical starting doses vary—lisinopril often starts at 5–10 mg once daily, enalapril at 5 mg twice daily, and ramipril at 2.5 mg once daily—but your doctor will adjust the dose to fit your needs.

Wondering how fast they work? Many people notice lower blood pressure within a week, but full benefits may take a few weeks. If you feel dizzy or faint after the first dose, tell your doctor right away—blood pressure can drop suddenly when starting treatment.

Side effects, interactions, and simple safety steps

The most common side effect is a dry, persistent cough. If that shows up, your doctor may switch you to a different class of drug. Other important issues: high potassium (which can affect the heart), lightheadedness from low blood pressure, and rarely angioedema—swelling of the face or throat—which needs emergency care.

Watch for interactions. Avoid combining ACE inhibitors with potassium supplements or potassium-sparing diuretics unless your doctor checks your labs. NSAIDs (like ibuprofen) can make ACE inhibitors less effective and raise the risk of kidney problems. Lithium and some diabetes drugs can also interact—keep a complete list of your medicines and share it with your prescriber.

Quick monitoring steps your doctor will likely follow: check kidney function and blood potassium around 1–2 weeks after starting or after a dose change, then periodically after that. If you have kidney disease or dehydration, monitoring is more frequent. If you become pregnant or plan to get pregnant, stop ACE inhibitors and call your doctor—these drugs can harm the fetus.

Buying ACE inhibitors online? Use a licensed pharmacy and never skip the prescription. Scams and unsafe sellers sell counterfeit or expired pills. If you’re ordering internationally, confirm the pharmacy’s license and look for pharmacist contact info. When in doubt, ask your regular clinic or pharmacist for help.

Questions you can bring to your doctor: Why this ACE inhibitor for me? What dose will we start with? How soon will you check my blood tests? When should I call you about side effects? Clear answers make treatment safer and easier to stick with.