What are beta blockers?

Beta blockers are a class of drugs that block beta-adrenergic substances such as adrenaline (epinephrine), a key agent in the “sympathetic” portion of the autonomic (involuntary) nervous system and activation of heart muscle. By blocking the action of the involuntary nervous system on the heart, beta blockers slow the heartbeat and relieve stress on the heart. These drugs are used for the treatment of irregular heart rhythms, chest pain, heart attack, hypertension, migraine headaches, social phobias, tremors, and glaucoma.

Common side effects of beta blockers are nausea, vomiting, abdominal cramps, diarrhea, and weight gain if you are taking medicine for diabetes (type 1 and type 2). There are other important side effects and serious adverse effects of this drug class that include, blurred vision, insomnia, hair loss, disorientation, central nervous system (CNS) effects, and serious heart problems. Beta blockers interact with several other drugs, for example, chlorpromazine (Thorazine), clonidine (Catapres), Phenobarbital, nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin, and diabetes medications, including insulin.

Examples of generic and brand names available for beta blockers in the U.S. include: acebutolol (Sectral), atenolol (Tenormin), bisoprolol (Zebeta), metoprolol (Lopressor, Lopressor LA, Toprol XL), nadolol (Corgard), timolol (Blocadren). Talk with your doctor, pharmacist, or other medical professional if you have questions about beta blockers.

If you notice other effects not listed above, contact your doctor or pharmacist. In the U.S. — call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada — call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the entire beta blockers consumer monograph >>