Beta Blocker Side Effects and Adverse Effects

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 >>

Beta blockers may cause:

• Diarrhea
• Stomach cramps
• Nausea
• Vomiting

Other important side effects include:

• Rash
• Blurred vision
• Disorientation
• Insomnia
• Hair loss
• Weakness
• Muscle cramps
• Fatigue

As an extension of their beneficial effect, they slow heart rate and reduce blood pressure, but they may cause adverse effects such as heart failure or heart block in patients with heart problems.

Beta blockers should not be withdrawn suddenly because sudden withdrawal may worsen angina (chest pain) and cause heart attacks, serious abnormal heart rhythms, or sudden death.

Central nervous system effects of beta blockers include:

• Headache
• Depression
• Confusion
• Dizziness
• Nightmares
• Hallucinations

Beta blockers that block β2 receptors may cause shortness of breath in asthmatics.

As with other drugs used for treating high blood pressure, sexual dysfunction may occur.

Beta blockers may cause low or high blood glucose and mask the symptoms of low blood glucose (hypoglycemia) in people with diabetes.

Other serious side effects of beta blockers include:

• Toxic epidermal necrolysis
• Raynaud's phenomenon
• Lupus erythematosus
• Bronchospasm
• Serious allergic reactions
• Erythema multiform
• Steven Johnson Syndrome
• Toxic epidermal necrolysis

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 >>

You may experience dizziness, lightheadedness, drowsiness, and blurred vision as your body adjusts to the medication. Use caution engaging in activities requiring alertness.

Because beta blockers may reduce blood circulation to the extremities, your hands and feet may be cold. Dress warmly.

Inform your doctor if you develop:

• easy bruising or bleeding,
• swollen hands or feet,
• confusion,
• depression,
• a sore throat.

Tell your doctor immediately if any of these unlikely but serious side effects occur: slow/irregular heartbeat.

In the unlikely event you have an allergic reaction to this drug, seek medical attention immediately. Symptoms of an allergic reaction include:

• rash,
• itching,
• swelling,
• dizziness,
• trouble breathing.

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 consumer beta blockers drug information >>