Types of medicine
What Is an ARB (Angiotensin II Receptor Blocker)?
Angiotensin II receptor blocker · say it: AN-jee-oh-TEN-sin TOO ree-SEP-ter BLOK-erAlso written: ARB, angiotensin receptor blocker, sartan, AT1 blocker
Short answer
An angiotensin II receptor blocker (ARB) is a blood pressure medicine that relaxes blood vessels. Names usually end in '-sartan', like losartan.
What it means
Angiotensin II is a hormone that narrows blood vessels and makes the body hold on to salt and water. ARBs block its effect, so vessels relax and blood pressure falls. Examples include losartan, valsartan, candesartan and irbesartan. They are used for high blood pressure, heart failure and to protect the kidneys in diabetes.
Their labels carry a boxed warning about fetal toxicity: they can harm an unborn baby, so they should be stopped as soon as pregnancy is known. Labels also warn about high potassium, kidney function changes (especially with dehydration or NSAIDs), and low blood pressure, so blood tests are usually done after starting.
ARBs work in a similar system to ACE inhibitors (names ending in '-pril'), but they rarely cause the dry cough that ACE inhibitors can, and are often used instead.
Where you may see it
- Boxed warnings on losartan, valsartan and other '-sartan' labels
- Leaflets about pregnancy and potassium
- Blood pressure clinic letters
📄 How it looks on a report
When pregnancy is detected, discontinue as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus.
🙅 What it does not mean
- An ARB is not the same as an ACE inhibitor, though they work in a similar way.
- Feeling well does not mean you can stop it; high blood pressure often has no symptoms.
- It does not mean potassium supplements or salt substitutes are fine; ask first.
🎯 Check yourself
Which of these is the right meaning of “Angiotensin II receptor blocker”?
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Angiotensin II receptor blocker”
Plain-English explanations of each medicine, from its official FDA label.
- Losartan Potassium
an angiotensin II receptor blocker (ARB), a type of medicine used to lower blood pressure
- Valsartan
An angiotensin II receptor blocker (ARB), a type of medicine used to treat high blood pressure and certain heart conditions
🔗 Read more from trusted sources
- “Angiotensin II receptor blocker” on MedlinePlus ↗
US National Library of Medicine
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