What is atenolol?

Atenolol (Tenormin) is in a group of drugs called beta-blockers. Beta-blockers affect the heart and circulation (blood flow through arteries and veins). 

Atenolol is used to treat angina (chest pain) and hypertension (high blood pressure). It is also used to treat or prevent heart attack. 

Atenolol may also be used for purposes other than those listed in this medication guide. 

Important information about atenolol 

Do not stop taking atenolol without first talking to your doctor. Stopping suddenly  may make your condition worse. 

If you need to have any type of surgery, you may need to temporarily stop using atenolol. Be sure the surgeon knows ahead of time that you are using atenolol. 

Atenolol can  cause side effects that may impair your thinking  or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol, which could increase drowsiness and dizziness while you are taking atenolol. 

Atenolol is only part of a complete program of treatment for hypertension that may also include diet, exercise, and weight control. Follow your diet, medication, and exercise routines very closely if you are being treated for hypertension. 

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of  your life. 

Store atenolol at room temperature away from moisture and heat. 

What should I discuss with my healthcare provider before taking atenolol? 

You should not use this medication if you are allergic to atenolol, or if you have certain heart conditions such as slow heartbeats, or heart block. 

Before taking atenolol, tell your doctor if you have: 

• asthma, bronchitis, emphysema; 
• diabetes;
• low blood pressure; 
• a heart problem such as heart block, sick sinus syndrome, slow heart rate, or congestive heart failure; 
• depression; 
• liver  or kidney disease; 
• a thyroid disorder; 
• myasthenia gravis; 
• pheochromocytoma; or 
• problems  with circulation (such as Raynaud's syndrome). 

• asthma, bronchitis, emphysema; 
• diabetes;
• low blood pressure; 
• a heart problem such as heart block, sick sinus syndrome, slow heart rate, or congestive heart failure; 
• depression;
• liver  or kidney disease; 
• a thyroid disorder; 
• myasthenia gravis; 
• pheochromocytoma; or 
• problems with circulation (such as Raynaud's syndrome). 

If  you have any of these conditions, you may need a dose adjustment or special tests  to safely  take this medication. 

FDA pregnancy category D. This medication can cause harm to an unborn baby. Do not use atenolol if you are pregnant. Tell  your doctor if you become pregnant during treatment. Use an effective form of birth control while you are using this medication. Atenolol can pass into breast milk  and may harm a nursing baby. Do not use this medication without telling  your doctor if  you are breast-feeding a baby. 

How should I take atenolol? 

• Take atenolol exactly as it was prescribed for you.  Do not take the medication in larger amounts  or for longer  than recommended by your doctor. Follow  the directions on your prescription label. 
• Take this medication with a  full glass of water. 
• Take  atenolol at the same time every day. 
• Do not skip doses or  stop taking atenolol without first talking to your doctor. Stopping suddenly may make your condition worse. 
• To be sure  this medication  is helping your condition, your blood pressure will need  to be checked on a regular basis. Do not miss any visits  to your doctor. 
• If you need to have any type  of surgery, tell the surgeon that you are  using atenolol. You  may need to briefly stop using atenolol before having surgery. 
• Atenolol is only part of a complete program of treatment  for hypertension that may also include diet, exercise, and weight control. Follow  your diet, medication, and exercise routines very closely if you are being treated  for hypertension. 
• If you  are being treated  for high blood pressure, keep using atenolol even if you feel fine. High blood pressure often has no symptoms. You may need to use blood pressure  medication for the rest  of your life.
• Store atenolol at room temperature away from moisture and heat. 

What happens if I miss a dose? 

Take the missed dose as soon as you remember. If  your next dose is less than 8 hours away, skip the missed dose and take the medicine  at the next regularly scheduled time. Do not take extra medicine to make up the missed dose. 

What happens if I overdose? 

Seek emergency medical attention if you think you have used too much  of this medicine. 

Overdose symptoms  may include uneven heartbeats, shortness of breath, bluish-colored fingernails, dizziness, weakness, fainting, or seizure (convulsions). 

What should I avoid while taking atenolol? 

Atenolol can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol, which could increase drowsiness and dizziness while you are taking atenolol. 

Atenolol side effects 

Get emergency medical help if you have any of these signs of an allergic reaction: hives;  difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects: 

• slow or uneven heartbeats; 
• feeling light-headed, fainting; 
• feeling short of breath, even with mild exertion; 
• swelling of your ankles or feet; 
• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing  of the skin  or eyes); 
• depression; or 
• cold feeling in your hands and feet. 

Less serious atenolol side effects may include: 

• decreased sex drive, impotence, or difficulty having an orgasm; 
• sleep problems (insomnia); 
• tired feeling;  or
• anxiety, nervousness.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual  or that is especially bothersome.

What other drugs will affect atenolol? 

Before taking atenolol, tell your doctor if you are using: 

• allergy treatments (or if you are undergoing allergy skin-testing); 
• amiodarone (Cordarone, Pacerone); 
• clonidine (Catapres); 
• digoxin (digitalis, Lanoxin); 
• disopyramide (Norpace); 
• guanabenz (Wytensin);
• an MAO inhibitor such as isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), or selegiline (Eldepryl, Emsam); 
• a diabetes medication such as insulin, glyburide (Diabeta, Micronase, Glynase), glipizide (Glucotrol), chlorpropamide (Diabinese), or metformin (Glucophage); 
• a heart medication such as nifedipine (Procardia, Adalat), reserpine (Serpasil), verapamil (Calan, Verelan, Isoptin), diltiazem (Cartia, Cardizem); 
• medicine for asthma or  other breathing disorders, such as albuterol (Ventolin, Proventil), bitolterol (Tornalate), metaproterenol (Alupent), pirbuterol (Maxair), terbutaline (Brethaire, Brethine, Bricanyl), and theophylline (Theo-Dur, Theolair); or 
• Cold medicines, stimulant medicines, or diet pills. 

If you are using any of these drugs, you may not  be able  to take atenolol, or  you may need dosage adjustments  or special tests during treatment. 

There may be other drugs not listed that can affect atenolol. Tell your  doctor about all the prescription and over-the-counter medications  you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling  your doctor.

Where can I get more information? 

Your pharmacist can provide more information about atenolol. 

What does my medication look like? 

Atenolol is available with a prescription under the brand name Tenormin. Other brand or generic forms may also be available.  Ask your pharmacist any questions you have about this medication, especially if it is new to you. 

• Tenormin 25 mg - round, flat, white, uncoated 
• Tenormin 50 mg - round, flat, white, uncoated 
• Tenormin 100 mg - round, flat, white, uncoated 
• Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment  of healthcare practitioners. The absence of a warning for a given drug or drug  combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects.