Angiotensin II Receptor Blockers (ARBs)

What are angiotensin II receptor blockers?

Angiotensin II receptor blockers (ARBs) are a class of medications that treat high blood pressure and other conditions like heart failure and kidney disease. They block a hormone (angiotensin II) from narrowing your blood vessels. ARBs are oral medications (you take them by mouth).

Healthcare providers prescribe ARBs for:

• Congestive heart failure to help your heart pump more blood to your body
• Fatty liver disease to prevent inflammation in your liver
• Heart attack to prevent one or limit heart damage after one
• High blood pressure to open up blood vessels so blood can pass through more easily
• Kidney disease to slow kidney damage, especially related to diabetes
• Stroke prevention to open blood vessels, allowing blood clots to move through without causing a stroke

Examples of ARBs

Medications that end in “-sartan” are ARBs. They include:

• Azilsartan medoxomil (Edarbi®)
• Candesartan (Atacand®)
• Eprosartan mesylate (Teveten®)
• Irbesartan (Avapro®)
• Losartan (Cozaar®) – the most commonly prescribed ARB
• Olmesartan (Benicar®)
• Telmisartan (Micardis®)
• Valsartan (Diovan® and Prexxartan®)

How do angiotensin II receptor blockers work?

Angiotensin II is a hormone that triggers increased blood volume, blood pressure and salt levels.

When your body has too much angiotensin II, you start to retain fluids. Excess fluid retention causes your blood pressure to go up. High blood pressure causes the blood vessels to contract or become narrow.

For angiotensin II to work, it needs another protein (receptor) to bind to. ARBs block these receptor proteins so the hormone can’t bind to them and constrict your blood vessels. This allows your blood vessels to relax and stay open. Blood then flows freely and without excessive force.

What are the side effects of ARBs?

Side effects of ARBs can include:

• Dizziness
• Fatigue
• Headache
• Swelling of your face and tongue

In rare cases, ARBs affect blood flow to your kidneys. This problem is more likely to occur if you already have renal artery disease. You’ll have occasional blood tests to check your kidney function.

How long will I need to take this medication?

High blood pressure often returns when you stop taking medication for it. You may need to take ARBs or another blood pressure medicine for life.

What’s the difference between ACE inhibitors and ARBs?

Angiotensin-converting enzyme (ACE) inhibitors and ARBS both reduce the effect of angiotensin. But they do so in different ways. ACE inhibitors decrease the amount of angiotensin your body makes, rather than blocking its receptors.

A common side effect of ACE inhibitors is a dry cough. Healthcare providers often prescribe ARBs in place of ACE inhibitors if this side effect develops.

Is it safe to take other medicines with ARBs?

When you’re taking blood pressure medicine, you should always check with your healthcare provider before taking over-the-counter (OTC) medicines or supplements. Some medicines for allergies, coughs and colds can increase your blood pressure. So can NSAIDs. This defeats the purpose of the ARB.

ARBs may raise your potassium levels. You shouldn’t take potassium supplements or potassium-sparing diuretics with them unless directed by your provider with careful monitoring. High potassium can cause an irregular heartbeat and other heart problems.

Should I avoid certain foods or drinks when taking ARBs?

If you’re taking an ARB and following a sodium-controlled diet, you should avoid salt substitutes that contain potassium chloride.

Regular, heavy alcohol use can worsen high blood pressure. But binge drinking may lower it too much, causing you to faint. If you drink alcohol, aim for minimal to moderate consumption.

Is it safe to take ARBs during pregnancy?

No. Medicines that lower angiotensin levels, like ARBs and ACE inhibitors, can cause serious complications during pregnancy. The medications increase the risk of:

• Birth defects
• High potassium levels
• Kidney failure
• Low blood pressure
• Stillbirth

If you have high blood pressure before pregnancy, your healthcare provider will prescribe a different medicine that’s safe for you and the developing fetus.

Is an ARB a diuretic?

ARBs aren’t diuretics (“water pills”). But your healthcare provider may prescribe a combination pill that contains an ARB and a thiazide diuretic. Thiazide diuretics are usually the first-line treatment for high blood pressure.