Atenolol is used with or without other medications to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. This medication is also used to treat chest pain (angina) and to improve survival after a heart attack.

Atenolol belongs to a class of drugs known as beta blockers. It works by blocking the action of certain natural chemicals in your body, such as epinephrine, on the heart and blood vessels. This effect lowers the heart rate, blood pressure, and strain on the heart.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for irregular heartbeat or alcohol withdrawal symptoms. It may also be used to reduce the risk of migraine headaches.

See also Warning section.

Take this medication by mouth with or without food as directed by your doctor, usually 1 to 2 times daily. The dosage is based on your medical condition and response to treatment.

Apple juice and orange juice may prevent your body from fully absorbing atenolol. It is best to avoid drinking apple/orange juice within 4 hours of taking atenolol, unless your doctor or pharmacist tells you otherwise.

Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time(s) each day. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick.

If this product is used for chest pain, it must be taken regularly to be effective. It should not be used to treat chest pain when it occurs. Use other medications (such as nitroglycerin placed under the tongue) to relieve chest pain as directed by your doctor.

It may take 1 to 2 weeks before you get the full benefit of this medication. Tell your doctor if your condition does not get better or if it gets worse (for example, your blood pressure readings remain high or increase, your chest pain occurs more often).

See also Warning and Precautions sections.

Dizziness, lightheadedness, tiredness, and nausea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

This drug may reduce blood flow to your hands and feet, causing them to feel cold. Smoking may worsen this effect. Dress warmly and avoid tobacco use.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain)
• very slow heartbeat
• fainting
• blue fingers/toes
• mental/mood changes (such as confusion, mood swings, depression)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking atenolol, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• certain types of heart rhythm problems (such as slow heartbeat, second- or third-degree atrioventricular block)
• breathing problems (such as asthma, chronic bronchitis, emphysema)
• blood circulation problems (such as Raynaud's disease, peripheral vascular disease)
• kidney disease
• heart failure
• serious allergic reactions including those needing treatment with epinephrine
• a certain muscle disease (myasthenia gravis)

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This product may prevent the fast/pounding heartbeat you would usually feel when your blood sugar level falls too low (hypoglycemia). The risk is higher if you have diabetes, or are vomiting, fasting, or not eating regularly. Other symptoms of low blood sugar level, such as dizziness and sweating, are not affected by this drug.

If you have diabetes, this product may make it harder to control your blood sugar levels. Check your blood sugar levels regularly as directed by your doctor. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. Your doctor may need to adjust your diabetes medication, exercise program, or diet.

Children may be at greater risk for low blood sugar (hypoglycemia) while using this drug, especially if they are vomiting or not eating regularly. To help prevent low blood sugar, make sure children eat regularly. If your child cannot eat regularly, is vomiting, or has symptoms of low blood sugar (such as sweating, shaking), tell the doctor right away.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using atenolol. Atenolol may harm an unborn baby. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

See also How To Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

A product that may interact with this drug is:

• fingolimod

Some products have ingredients that could raise your heart rate or blood pressure or worsen your heart failure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: very slow heartbeat, severe dizziness, severe weakness, fainting, trouble breathing.

Do not share this medication with others.

Lifestyle changes such as stress reduction programs, exercise and dietary changes may increase the effectiveness of this medicine. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.

Check your blood pressure and pulse (heart rate) regularly while taking this medication. Learn how to monitor your own blood pressure and pulse at home, and share the results with your doctor.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).