Beta-blockers: What You Need to Know

Medically Reviewed By Alisha D. Sellers, BS Pharmacy, PharmD
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Beta-blockers are a group of drugs that mainly treat cardiovascular problems. This includes high blood pressure, congestive heart failure, and arrhythmias. Other uses include preventing migraine and treating glaucoma. This class has several potential drug interactions, including drugs that can increase or decrease their effects. Side effects may include dizziness and drowsiness

This article covers information about beta-blockers as a class. This includes their uses, interactions, and side effects.

How do beta-blockers work?

Pills organized in a heart shape
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The name “beta-blocker” explains how this class of drugs works. They block beta receptors on the surface of cells. There are three types of beta receptors:

  • Beta-1 (B1): These receptors are mainly on heart muscle cells.
  • Beta-2 (B2): These receptors are present in various organ systems. One of their main locations is the smooth muscle cells of the lungs and blood vessels.
  • Beta-3 (B3): These receptors are common on fat cells. They do not seem to be very clinically relevant at this point in time.

Beta-blockers stop certain chemicals from binding to these beta receptors. These chemicals include epinephrine (adrenaline) and norepinephrine. This class also goes by the names “beta-adrenergic blockers” and “beta-adrenergic antagonists.”

Epinephrine is the fight-or-flight hormone. It increases heart rate and blood pressure in response to stress.

When you block it from binding to beta receptors, you get the opposite effects. The heart rate slows, there is less stress on the heart, and blood pressure decreases. This is the main way beta-blockers treat cardiovascular problems. 

Decreased heart rate and blood pressure are good when they relieve stress on the heart. However, these vital signs can dip too low. If you take beta-blockers, your doctor will monitor your heart rate and blood pressure.

What conditions do beta-blockers treat?

The main use of beta-blockers is in treating cardiovascular conditions. However, their effects can be useful in treating other disorders.

Cardiovascular conditions

Cardiovascular indications for beta-blockers include:

  • Angina and coronary artery disease: By decreasing stress on the heart, beta-blockers reduce the amount of oxygen the heart needs. This relieves the chest pain of angina.
  • Arrhythmias: Beta-blockers reduce impulses that can lead to fast or irregular heartbeats.
  • Congestive heart failure: Beta-blockers reduce how hard the heart beats. They also relax blood vessels to decrease blood pressure. All of this makes it easier for the heart to beat. There is less stress on the heart, and it does not overwork to pump blood.
  • Heart attack: Beta-blockers can reduce the risk of a second heart attack. Such as in angina and coronary artery disease, beta-blockers take stress off your heart.  
  • High blood pressure: Blocking beta receptors will relax blood vessels and reduce blood pressure. However, they are not usually a first-line treatment for high blood pressure. Doctors may use them if other agents are not effective enough on their own.

Other conditions

Other reasons doctors may prescribe a beta-blocker include:

  • Anxiety: Beta-blockers can help calm some forms of anxiety. They decrease heart rate, flushing, and trembling that can occur with performance anxiety. This may help calm people down.
  • Essential tremor: Beta-blockers likely work to calm essential or familial tremors by blocking beta receptors on nerve cells.
  • Glaucoma: Topical beta-blockers in the form of eye drops can treat glaucoma. They work by decreasing the amount of fluid the eye produces. This decrease in fluid reduces pressure inside the eye.
  • Hyperthyroidism: Beta-blockers do not treat hyperthyroidism itself. However, they can relieve some of the symptoms, such as fast heart rate.
  • Migraine prevention: The way beta-blockers prevent migraine is not entirely clear. It may involve stabilizing blood vessels. It could also involve blocking beta receptors on nerve cells.

What are the types and drug names of beta-blockers?

There are two main types of beta-blockers.

Nonselective beta-blockers

Nonselective beta-blockers bind to both B1 and B2 receptors. Because they block B2 receptors, they can affect different organ systems. These beta-blockers include:

  • carvedilol (Coreg)
  • labetalol (Trandate)
  • propranolol (Inderal)
  • sotalol (Betapace)

Beta-1 selective beta-blockers

These beta-blockers only bind to B1 receptors, limiting their actions to the heart muscle. They include:

  • acebutolol (Sectral)
  • atenolol (Tenormin)
  • betaxolol (Kerlone)
  • bisoprolol (Zebeta)
  • esmolol (Brevibloc)
  • metoprolol (Lopressor, Toprol XL)
  • nebivolol (Bystolic)

How do you take beta-blockers?

How you take beta-blockers, including how much you take, varies with the drug. In general, beta-blockers are for once- or twice-daily dosing. Be sure to take your beta-blocker exactly as your doctor prescribes.

What are the side effects of beta-blockers?

All medications can cause side effects. Some are more common than others, and some are more serious than others. However, most people can take beta-blockers without significant side effects.

Common side effects

Some of the more common side effects of beta-blockers include:

It is also possible to have problems with sex drive or erections while taking a beta-blocker. 

What should you avoid when taking beta-blockers?

If you take a beta-blocker, it is wise to avoid or limit alcohol. Alcohol can reduce the effects beta-blockers have on the heart and blood vessels. Caffeine can also reduce the effects of beta-blockers.

What medications may interact with beta-blockers?

Several medications interact with beta-blockers, including:

  • antihistamines and other drugs that cause drowsiness
  • certain antidepressants
  • certain asthma drugs
  • cough and cold medications
  • other high blood pressure and heart drugs, which can increase the effect of beta-blockers

These problems, their timing, and their severity are variable.

Who should not take beta-blockers?

Some people need to be careful about taking beta-blockers. People with asthma or other lung problems need to take a beta-1 selective drug to help avoid breathing problems.

People with diabetes need to use caution with beta-blockers. Beta-blockers can mask the signs of low blood sugar, such as fast heart rate. Therefore, people with diabetes may need to adjust how — and how often — they check their blood sugar levels.

Some beta-blockers have very specific instructions about who cannot take them. These contraindications vary with the drug.

How do you stop taking beta-blockers?

You should not stop taking beta-blockers suddenly. Doing so can cause problems with your heart. Talk with your doctor before stopping a beta-blocker.

Summary

Beta-blockers are a class of drugs that mainly treat cardiovascular disorders. They have some additional uses, including preventing migraine and treating tremors.

Most people tolerate beta-blockers well. However, the class can have side effects, such as fatigue and dizziness.

Talk with your doctor about your medical history before starting a beta-blocker. People with breathing problems or diabetes need to use caution with this drug class.

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Medical Reviewer: Alisha D. Sellers, BS Pharmacy, PharmD
Last Review Date: 2022 May 31
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