Angiotensin II receptor blockers (ARBs) are typically used to treat high blood pressure, heart failure, and chronic kidney disease (CKD). They may also be prescribed following a heart attack. Your doctor may suggest treatment with ARBs instead of angiotensin-converting enzyme (ACE) inhibitors, another group of hypertension medications.

According to the Centers for Disease Control and Prevention (CDC), high blood pressure affects one in every three American adults. Only 54 percent of people with the condition have it under control. If your blood pressure is high all the time, it can damage your heart and lead to other health problems. ARBs may help you to control your blood pressure.

Blood vessels supply blood and oxygen to the heart. This constant supply helps the heart function. Angiotensin II is a hormone made by our body, and it tightens the muscles of our blood vessels. Angiotensin II also contributes to salt and water retention in our bodies. Increased salt in the body and tightened blood vessels may cause our blood pressure to rise. High blood pressure harms blood vessels.

Both ARBs and ACE inhibitors act on angiotensin II. But while ACE inhibitors limit the formation of angiotensin II, ARBs block certain receptors of angiotensin II. These receptors, known as AT1 receptors, are found in the heart, blood vessels, and kidneys.

When blood vessels tighten, they become narrow. This puts blood under greater pressure as it’s forced to move through a smaller-than-normal space. When ARBs block angiotensin II, this reduces the tightening of blood vessels. Blood pressure is then lowered.

Drugs with names ending in “sartan” are ARBs. Common ones include:

You may find ARBs combined with another drug such as hydrochlorthiazide. This is a diuretic drug that causes you to pass urine more often. It also helps to lower your blood pressure. Examples of these combination drugs include hydrochlorothiazide-valsartan (Diovan HCT) and hydrochlorothiazide-losartan (Hyzaar).

All ARBs can be used to treat high blood pressure. However, specific ARBs may be recommended for other medical conditions, according to the American Journal of Cardiovascular Drugs. For example, valsartan is suggested for heart failure and following a heart attack. Losartan may be best suited for heart failure, kidney damage related to diabetes, and stroke prevention.

You may be prescribed ARBs if you have:

Most people take ARBs in once-daily doses in the morning. However, your doctor may also prescribe a twice-daily dose. ARBs don’t have to be taken in the morning.

Some people may experience a chronic cough when they take ACE inhibitors, but ARBs don’t usually have this side effect. This is one of the reasons ARBs are often used instead of ACE inhibitors.

ARBs can decrease your risk of heart attack, stroke, or death from a cardiac event.

If you have kidney disease, ARBs may be one of the more effective treatments for high blood pressure. Some animal and human studies have also shown that ARBs may help protect against cognitive decline.

Most doctors will ask you to try an ACE inhibitor first. If it isn’t suitable for you, they may recommend an ARB. Your doctor will likely prescribe either an ACE inhibitor or an ARB, but not both at the same time.

Side effects of ARBs include:

In rare cases, some people taking an ARB may have:

Some drugs may not work well with ARBs. Taking ARBs and ACE inhibitors together should be avoided as this may increase the risk of low blood pressure, kidney damage, and high potassium levels. Painkillers such as ibruprofen (Advil) and naproxen (Aleve, Naprosyn) may also interact with ARBs to affect your potassium levels. Learn more about drug interactions.

ARBs aren’t recommended for those who are pregnant or plan to become pregnant. There’s also some evidence that ARBs should be used with caution in older adults. Talk to your doctor if side effects are particularly troublesome or if you aren’t sure whether the medication is helping you.

In July 2010, a meta-analysis of several clinical trials showed an increased cancer risk in people taking ARBs. In June 2011, further research by the U.S. Food and Drug Administration (FDA) indicated no increased risk of developing cancer while taking an ARB. The earlier report included data from five clinical trials, while the FDA’s analysis included more than 30 studies.

More recently, studies published in 2014 and 2016 also suggest that there’s no increased risk of cancer in people taking ARBs. A study published in 2017 indicated that ARBs may actually be helpful for people with prostate cancer. At this time, the FDA states that treatment with an ARB medication doesn’t increase the risk of cancer.

There’s some evidence that people on ACE inhibitors are less prone to myocardial infarction (MI) and fatal heart and cardiovascular events than people who take ARBs. However, a report from a 2013 meta-analysis showed that ARBs are a good option for reducing the risk of cardiovascular deaths, MI, and stroke in people without heart failure. Valsartan and telmisartan have been found effective in reducing the risk of fatal MI and cardiovascular events.

Bear in mind that your body may respond differently than other people’s to any medication. If you have side effects from your medication, tell your doctor immediately. Talk with them, weigh your options, and then decide on the best treatment plan for you.