What Are Angiotensin II Receptor Blockers (ARBs)?

Reviewed by: HU Medical Review Board | Last reviewed: March 2022 | Last updated: October 2022

Angiotensin II receptor blockers (ARBs) are a type of vasodilator, a drug that widens blood vessels to lower blood pressure, improve blood flow, and decrease the workload on the heart.1-3 They do this by blocking angiotensin II, a hormone in the body that acts as a vasoconstrictor, causing the blood vessels to narrow (constrict).2-3 This helps improve blood flow and reduces the pooling of blood in the body.

Why are they prescribed?

They are prescribed for people with systolic heart failure (HF) caused by left ventricular dysfunction. ARBs reduce the pressure that the heart has to pump against, thereby easing the workload of the heart. This helps to improve symptoms and help people to feel better and live longer lives. ARBs have many of the same benefits as ACE inhibitors, they affect the hormones that regulate fluids, particularly the salt and water balance of the body.2 They help these fluids to be eliminated through urine which lowers blood pressure. ARBs may be prescribed for people who cannot take ACE inhibitors due to a cough.2

ARBs are recommended for people with systolic HF who have symptoms and for those who are asymptomatic (without symptoms). There are side effects to this medication that is similar to ACE inhibitors. Your provider will check blood tests about a week after starting this medication or after dose changes. People with elevated potassium levels, those who have had previous adverse reactions to ARBs, or who are pregnant should not take these drugs.

Additionally, because they lower blood pressure, ARBs may not be the right type of medication for people who already have very low blood pressure. Similarly, these drugs can alter blood flow through the kidneys and may decrease kidney function in people with certain kinds of kidney problems caused by narrowed blood vessels (renal artery stenosis).2

Treatment goals

Treatment goals of ARBs include improvement in heart function or delayed progression of heart failure, symptom relief, decreased risk of hospitalization for heart failure, and decreased risk of death.

Commonly prescribed ARBs include:3

  • Atacand® (candesartan)
  • Avapro® (irbesartan)
  • Benicar® (olmesartan)
  • Cozaar® (losartan)
  • Diovan® (valsartan)
  • Edarbi® (azilsartan)
  • Micardis® (telmisartan)
  • Teveten® (eprosartan)

Side effects

ARBs are generally well tolerated. Common side effects of ARBs include dizziness, elevated potassium levels (hyperkalemia), and lowered blood pressure.1 ARBS may have limited drug interactions with other medicines you are taking. Be sure to mention to your provider any medications, vitamins, supplements, or over the counter products you take before starting an ARB.2

As with most heart failure medications, your provider will generally order regular blood tests to evaluate its effectiveness and any side effects; especially potassium levels and kidney function.2 It is important to take all medicines as prescribed. This will improve the effectiveness of the medication and may reduce any complications. If you have difficulty taking your medications, do not stop on your own, contact your healthcare team for assistance.

If you have trouble breathing, swelling in your face, lips, tongue or throat, or sudden chest pain call 911 or other emergency services or go directly to an emergency room.

These are not all the possible side effects of ARBs. Patients should talk to their doctor about what to expect with treatment with ARBs.

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