Beta blockers: what they are, what they do and side effects hers (2023)

Medically examined byDr. Patrick Carroll, MD

Written by our editorial team

Last updated on 03/02/2020

When you find yourself in a stressful or tense situation, your body has a natural fight-or-flight response that causes your heart to beat faster than normal. Beta blockers are a class of drugs that prevent the stress hormones that contribute to your body's fight-or-flight response from affecting your heart.

Most beta-blockers are designed to treat heart conditions such as high blood pressure, an irregular heartbeat, or a high risk of heart attack. They are also used to treat anxiety disorders, hyperthyroidism, tremors, and diseases like glaucoma.

Below we have explained in more detail what beta blockers are and what they do to your body when you use them. We also explained how beta blockers can be useful to treat anxiety and calm your nerves in difficult, stressful situations.

What are beta blockers?

Also known as beta-blockers, beta-blockers are drugs that block the effects of adrenaline or epinephrine — as well as other stress hormones like norepinephrine — on your heart.

Adrenaline and norepinephrine are used by your body to activate your musclesfight-or-flight mechanism, designed to protect you in a dangerous situation.

Normally, a stressful situation causes your body to increasingly release stress hormones, including adrenaline, resulting in a noticeably faster heartbeat. You may also notice your hands shaking and sweating and your voice becoming unsteady and weak.

Many people also experience dizziness - another physical effect of a surge in your body's adrenaline levels. This surge in adrenaline—and its noticeable effects—can cause you to panic under pressure.

Beta blockers reduce the effects of adrenaline on your heart and make it easier for your heart to relax in the presence of stress hormones. Instead of a rapid heartbeat, your heart beats at a normal pace, which limits the physical effects of adrenaline on your body.

There are numerous beta-blocker drugs. Most beta-blockers specifically target the heart, while others may also target the lungs and blood vessels. beta blockerscan also workto increase the effects of another class of medicines known as ACE inhibitors, which work by reducing your body's release of angiotensin, a hormone that can constrict your blood vessels.

What do beta blockers do?

Beta blockers are used to treat various diseases. Most beta-blockers are designed to treat heart conditions such as high blood pressure and an irregular heartbeat (atrial fibrillation), both of which can contribute to putting excessive strain on the heart.

By reducing the workload on the heart muscles, beta-blockers can make heart attacks and other serious health problems less likely — which is why they're often prescribed to people with these conditions.

Many doctors also prescribeBeta blockers for anxiety. By blocking the effects of stress hormones like adrenaline on your heart, beta-blockers can block the physical effects of anxiety on your body, such as: B. sweating, a fast heartbeat or dizziness.

When using beta-blockers for anxiety, it's important to understand that they don't treat the psychological causes of anxiety itself. Instead, they just make it easier for you to deal with your body's physical response to anxiety.

Some beta-blockers are also used to treat hyperthyroidism, which can contribute to excessive weight loss, tremors, trouble sleeping, nervousness, and other symptoms.

In addition to treating heart disease and reducing the physical effects of anxiety, beta blockers may have other health benefits.

For example, some are beta blockersassociated with reduced bone mineral lossin people with high blood pressure who are at risk for conditions such as osteoporosis and bone resorption compared to calcium channel blockers.

Beta blockers have been used since the 1960s, but today there are several beta blockers on the market, many of which are actively used to treat heart conditions and anxiety. Some of the most commonly used beta blockers are:

• Acebutolol

• Atenolol

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• Bisoprolol

• Carteolol

• Esmolol

• Metoprolol

• Nadolol

• Nebivolol

• Propranolol

What are side effects of beta blockers?

Like almost all medications, beta blockers can have side effects. Most side effects of beta blockers are fairly mild. It's also possible for beta blockers to interact with other medications and cause more serious, more serious side effects.

The vast majority of people who use beta blockers do not experience any side effects. Overall, beta blockers are safe and very effective, with a low risk of side effects when used as directed by your doctor.

The most common side effects of beta blockers are:

• Fatigue. Because beta blockers cause your heart rate to drop, it's common to feel a slight decrease in energy. Some people taking beta-blockers feel tired after starting treatment because of the drug's effects on the heart.
  If you feel tired after using a beta-blocker, it's best to talk to your doctor. Most of the time, this side effect can be avoided by adjusting your dosage or using a different type of beta-blocker medication.

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• weight gain. Some beta-blockers, especially older drugs like metoprolol and atenolol, can contribute to weight gain. While there's no consensus as to why this happens, it's thought to be related to fluid retention or the drug's effects on your metabolism.
  Most of the time, weight gain from beta blockers is fairly mild. Expect to gain a pound or two, if any. This weight gain can often be reversed by switching to a different beta blocker.
  

• Cold feet and hands. Beta blockers can potentially make your hands and feet feel cold due to their effects on your blood flow. Like many other beta-blocker side effects, this can often be avoided by adjusting the dosage or switching medications.
  

• Nausea, dizziness and lightheadedness. It's fairly common to feel slightly dizzy and light-headed after using beta-blockers, especially for the first few times. This side effect is usually temporary and goes away after using beta-blockers for several days.

There are also some less common side effects of beta blockers. These include:

• Slow heartbeat. Beta blockers are designed to relieve cardiovascular stress by giving you a slower heartbeat. If you take too large a dose of your beta-blocker medication, you may experience bradycardia, or an abnormally slow heartbeat.
  If your waking resting heart rate is below 50 beats per minute after taking a beta-blocker, contact your doctor. This side effect is most common when usingcalcium channel blockersat the same time as beta-blockers used to treat high blood pressure.
  

• Higher cholesterol and triglyceride levels. Some beta-blockers can cause a decrease in your high-density lipoprotein (HDL or "good cholesterol") levels and an increase in triglycerides.
  This side effect is often temporary and may reverse over time. Overall, beta-blockers are effective in treating heart disease and should not be avoided because of the possibility of changes in your cholesterol levels.
  

• Asthma cases.Although the science is not fully settled here, some beta-blockers have been linked to an increased risk of asthma attacks in people with severe asthma.
  This side effect is most commonly documented with older medications. This is less common with newer beta-blockers, most of which are safe for people with mild to moderate asthma.
  

• Cramps. Although it's uncommon, some people experience cramps -- particularly in the abdominal muscles -- while using beta-blockers.
  

• Depression. As with asthma attacks, the science surrounding beta-blockers and depression is not fully understood. A small percentage of people using beta-blockers experience depression and memory loss, although this may not be caused by the drug.

Because beta-blockers affect your heart rate, they can also affect your life in ways unrelated to anxiety and heart problems:

• Interaction with stimulants. It's recommended to avoid stimulants like caffeine while using beta-blockers, as caffeine can increase your heart rate, anxiety symptoms, and blood pressure, and counteract the effects of beta-blockers.
  

• impact on training. After taking a beta-blocker, your maximum heart rate is lower than normal. This means you may have less endurance during exercise, especially if you're doing cardiovascular exercise like running, biking, walking, or rowing.
  

• Consumption of foods rich in sodium. Eating foods high in sodium — like fast food — can increase your blood pressure and put extra pressure on your heart. If you're prescribed a beta-blocker for heart problems, it's best to avoid eating foods high in sodium.
  

• Consumption of foods rich in potassium. Because beta-blockers affect your body's ability to process potassium, it's also recommended that you avoid foods high in potassium if you're prescribed a beta-blocker for heart problems or anxiety.

Overall, beta blockers are a safe, reliable, and effective drug. Most people who take beta blockers experience few or no side effects, especially with the newer drugs used today.

Selective vs. non-selective beta-blockers

There are two main types of beta-blocker drugs: selective beta-blockers and non-selective beta-blockers.

Selective beta blockers are specifically designed to block thisβ1 receptors, which are mainly in the heart. Because the action of these beta blockers is more specific, they are usually safe to use if you have diabetes.

Common selective beta-blockers include acebutolol, atenolol, bisoprolol, betaxolol, bevantolol, celiprolol, metoprolol, esmolol, and nebivolol.

Because selective beta-blockers only affect β1 receptors, which are concentrated in heart tissue, they tend to be used to treat heart disease and are not a popular treatment option for anxiety.

Non-selective beta blockers are designed to block the β1, β2 and β3 receptors. This means that they not only target the beta receptors in the heart, but also affect the veins, liver, pancreas and a number of other parts of the body.

Common nonselective beta-blockers include alprenolol, carteolol, oxprenolol, propranolol, and sotalol. Nonselective beta-blockers can be used not only to treat certain heart conditions, but also to treat somephysical effects of fear.

Unlike selective beta blockers, nonselective beta blockers are not considered safe if you have diabetes.

Learn more about beta blockers

Beta blockers are among the most commonly used medications in the world, prescribed for heart disease, anxiety and more. Safe, easy to use and effective, they deliver fast and noticeable results that make them ideal for preventing chronic anxiety and panic attacks.

OurGuide to Propranololgoes into more detail on how one of the most commonly used beta-blocker drugs works, from its history to key benefits, potential side effects, drug interactions, and more.