ARBs

“ARB” stands for “angiotensin II receptor blocker” or “angiotensin II receptor inhibitor.” ARBs are typically used to treat high blood pressure, congestive heart failure, kidney damage caused by diabetes, chronic kidney disease, and even scleroderma (a skin condition).

How They Work

ARBs are alternatives to ACE inhibitors. They work by blocking angiotensin II receptors, allowing blood vessels to dilate and blood pressure to decrease. Basically, angiotensin is a chemical that causes arteries to constrict. To perform this action, angiotensin must find a specific receptor. ARBs make it impossible for angiotensin to constrict blood vessels by blocking this receptor. This means that ARBs don’t actively cause blood vessels to relax. Rather, they prevent the uptake of a chemical which would cause blood vessels to tense.

Relaxed blood vessels help supply adequate blood and oxygen to the heart, which helps it to work efficiently. When arteries are constricted or narrowed, blood is under more pressure because it’s being forced to move through a smaller space than it normally would be.

Common ARBs include:

  • candesartan (Atacand)
  • eprosartan mesylate (Teveten)
  • irbesarten (Avapro)
  • losartin potassium (Cozaar)
  • telmisartan (Micardis)
  • valsartan (Diovan)

ARBs are usually prescribed in once-daily doses. However, more frequent dosing schedules are recommended for some specific ARBs, including losartan, candesartan, and eprosartan.

Who Needs Them

You may be prescribed ARBs if you:

  • have had a heart attack
  • have coronary artery disease
  • have high blood pressure that hasn’t responded well to ACE inhibitors
  • have had many side effects from ACE inhibitors

Many patients experience a chronic cough when using ACE inhibitors. ARBs were specifically developed to avoid this side effect. Consequently, chronic cough is a much less common side effect of ARBs.

Benefits

ARBs can decrease risk of heart attack, stroke, or death from a cardiac event. Most physicians will ask you to try an ACE inhibitor first. If it isn’t suitable for you, doesn’t decrease your symptoms, or has many side effects, they may recommend an ARB. Studies have shown that taking both ACE inhibitors and ARBs provides no additional benefit over taking just one medication.

Side Effects and Risks

Side effects of ARBs include:

  • headache
  • fainting
  • dizziness
  • nasal congestion
  • diarrhea
  • back pain
  • leg pain

In rare cases, some people taking an ARB have experienced allergic reactions, liver failure, kidney failure, angioedema (tissue swelling), and decreased white blood cell counts. Another, less common side effect is arrhythmia, which is caused by elevated blood-potassium levels that affect how the heart beats.

These medications aren’t recommended for pregnant women or women who plan to become pregnant. Talk to your doctor if side effects are particularly troublesome or if you’re not sure whether the medication is improving your condition.

Controversy

In July 2010, a meta-analysis of several clinical trials showed an increase in cancer risk in patients taking an ARB. However, in June 2011, further research and analysis of dozens of research studies conducted by the FDA showed that there’s no increased risk of developing cancer while taking an ARB. The initial report compiled data from five clinical trials and the FDA’s farther-reaching analysis included more than 30 studies. It’s now commonly thought that ARBs don’t increase a patient’s risk of developing cancer.

It’s important to weigh your physician’s advice, which takes into account your unique health concerns. The doctor’s office should be your first stop if you have concerns about medications you’re taking or if you’re unsure whether the medication is working for you.