Written by Rachel Nall | Published on November 11, 2013
Medically Reviewed by George Krucik, MD, MBA on November 11, 2013

What Is Atenolol?

Generic Name: atenolol
Brand Name: Tenormin, Tenoretic (a combination of atenolol and chlorthalidone)

Atenolol belongs to a group of medications known as beta blockers. These medications improve blood flow and lower blood pressure. Atenolol is often prescribed with other blood pressure-reducing medications, such as thiazide diuretics (FDA, 2011).

Read the FDA description of Atenolol.

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What Does Atenolol Do?

Beta blockers are also called beta-adrenergic blocking agents. This means that atenolol blocks the action of the stress hormone epinephrine, which is also known as adrenaline. Epinephrine increases the body’s heart rate, raises blood pressure, and affects the body’s immune system response (Mayo Clinic, 2013).

Doctors prescribe atenolol to achieve one or more of the following effects: reduce a patient’s heart rate and cardiac output; reduce systolic and diastolic blood pressure (the top and bottom numbers of a blood pressure reading, respectively); and reduce orthostatic tachycardia, or the speed up of the heart rate when changing position from seated to standing or vice versa.

This information is a summary. Before starting this medication, discuss questions with your healthcare provider and make sure you understand dosage instructions.

What Should I Tell My Doctor Before Starting Atenolol?

Tell your doctor if you:

  • have a heart block that is greater than first degree
  • are breastfeeding
  • are pregnant or could possibly be pregnant: atenolol can cross the placental barrier and cause fetal injury, including the birth of infants that are small for gestational age
  • have asthma
  • have cardiogenic shock
  • have diabetes
  • have hyperthyroidism
  • have overt (symptomatic) cardiac failure: beta blockers like atenolol can depress the cardiac muscle’s ability to contract, which can lead to worsening heart failure
  • have renal conditions or impairment
  • have sinus bradycardia, a heart rhythm of less than 60 beats per minute that originates in the heart’s sinus node
  • have untreated pheochromocytoma

What Medications May Interact with Atenolol?

Always tell your physician about any prescription medications or herbal remedies you are taking.

Medications that can adversely interact with Atenolol include:

  • amiodarone (Cordarone)
  • calcium channel blockers, such as bepridil (Vascor)
  • clonidine (Catapres, Kapvay, or Nexiclon)
  • digitalis glycosides, such as digoxin or digitoxin (Lanoxine, Digitaline, Novo-Digoxin
  • disopyramide (Norpace, Rythmodan)
  • prostaglandin synthase inhibiting drugs, such as indomethacin (USAN)

Possible Side Effects of Atenolol

The following are severe and emergent side effects of these medications. Contact your medical provider immediately if you experience the following:

  • depression
  • a large, red rash
  • swelling of the hands, feet and ankles
  • symptoms associated with severe allergic reaction, such as fever and difficulty breathing
  • unusual weight gain

The following side effects may occur, but do not usually represent an emergency. Discuss with your doctor or healthcare professional if they continue or are bothersome.

  • cold hands
  • constipation
  • diarrhea
  • dizziness
  • headache
  • reduced sex drive
  • shortness of breath
  • unexplained fatigue

This list may not describe all possible side effects. Call your doctor or healthcare provider for advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Where Should I Keep Atenolol?

Atenolol should be stored at room temperature—somewhere between 68 degrees and 77 degrees Fahrenheit or 20 degrees to 25 degrees Celsius. Keep the medication tightly closed and in a light-resistant container.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

FDA WARNING: Atenolol carries a black box warning (meaning the medication has potentially lethal side effects) for its potential to cause chest pain exacerbation in patients with coronary artery disease, myocardial infarction, or ventricular arrhythmias when the medication is suddenly discontinued. Do not stop taking your medication unless your doctor instructs you to do so.

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Show Sources

●      Atenolol. (2010, July 1). MedlinePlus. Retrieved October 26, 2013, from
●      Atenolol. (July 2011). U.S. Food and Drug Administration. Retrieved October 26, 2013, from
●      Beta Blockers. (2010, December 16). Mayo Clinic. Retrieved October 26, 2013, from
●      Chronic Stress Puts Your Health at Risk. (2013, July 11). Mayo Clinic. Retrieved October 26, 2013, from

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