Angiotensin II Receptor Blockers (ARBs) for High Blood Pressure

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Angiotensin II Receptor Blockers (ARBs) for High Blood Pressure


Generic NameBrand Name
losartanCozaar, Hyzaar

How It Works

These medicines block the action of a hormone that causes blood vessels to narrow. As a result, blood vessels may relax and open up. This makes it easier for blood to flow through the vessels, which reduces blood pressure. Also, these drugs increase the release of sodium and water into the urine, which also lowers blood pressure.

Why It Is Used

Angiotensin II receptor blockers (ARBs) may be used alone or combined with other medicine—often a diuretic—to treat high blood pressure.

ARBs may be used by people who cannot take ACE inhibitor medicines. ACE inhibitors can cause an annoying cough. This cough may be hard for some people to live with. So doctors may prescribe an ARB instead. ARBs are less likely to cause a cough.

ARBs are also used by people have heart problems such as coronary artery disease or heart failure. ARBs might be used by people who type 2 diabetes and have early signs of kidney disease or who have kidney disease from diabetes (diabetic nephropathy).

How Well It Works

Angiotensin II receptor blockers (ARBs) reduce blood pressure as effectively as angiotensin-converting enzyme (ACE) inhibitors but are less likely to cause the cough that is associated with ACE inhibitors.

If you are taking an ARB because you have diabetes and early signs of kidney problems, or have kidney disease, these medicines can slow or prevent further damage to your kidneys.1

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

  • Trouble breathing.
  • Hives.
  • Swelling of your face, lips, tongue, or throat.

Common side effects of this medicine include:

  • Dizziness or lightheadedness.
  • Sinus problems, such as a stuffy nose or a runny nose.
  • Stomach problems.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Tell your doctor about all of the other medicines that you take, including prescription and over-the-counter medicines. ARBs may interact with other medicines such as NSAID pain relievers (nonsteroidal anti-inflammatory drugs), antacids, potassium supplements, certain diuretics, and lithium. If you are taking one of these medicines, talk with your doctor before taking an ARB.

For tips on taking blood pressure medicine, see:

Click here to view an Actionset. High Blood Pressure: Taking Medicines Properly.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

Do not use this medicine if you are pregnant or planning to get pregnant. If you need to use this medicine, talk to your doctor about how you can prevent pregnancy.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Drugs for hypertension (2009). Treatment Guidelines From The Medical Letter, 7(77): 1–10.


By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Primary Medical Reviewer Andrew Swan, MD, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer Robert A. Kloner, MD, PhD - Cardiology
Last Revised June 6, 2011

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.