Atenolol has a black box warning. This is the most serious warning from the U.S. Food and Drug Administration (FDA). Though the medication can still be sold and used, a black box warning alerts doctors and patients to potentially dangerous problems.
Warning: Don’t stop taking atenolol suddenly. If you do, you may experience worse chest pain, a jump in blood pressure, or even have a heart attack. Stopping atenolol is not recommended. If you need to stop taking the drug, first talk to your doctor. Your dose should be gradually decreased under a doctor's supervision.
Asthma/chronic obstructive pulmonary disease (COPD):
At higher doses, atenolol can block different types of beta receptors found in breathing passages. Blocking these receptors can lead to narrowing of breathing passages, making asthma or COPD worse.
Atenolol may mask important signs of low blood sugar, including shaking and increased heart rate. Without these signals, it becomes more difficult to recognize dangerously low blood sugar levels.
If you have poor circulation in your feet and hands, you may have worse symptoms when taking atenolol. Atenolol reduces blood pressure, so you might not get as much blood to your hands and feet.
Atenolol is a prescription drug. It comes as a tablet you take by mouth. It’s also available in an intravenous (IV) form, which is only given by a healthcare provider.
Atenolol is available as the brand-name drug Tenormin. It’s also available as a generic drug. Generic drugs usually cost less. In some cases, they may not be available in every strength or form as the brand-name version.
Why it's used
Atenolol is used to:
- lower high blood pressure
- reduce chest pain
- after a heart attack, the drug reduces the amount of work your heart muscle has to do to push blood through your body.
How it works
Atenolol belongs to a class of drugs called beta blockers. A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.
Beta receptors are found on cells in the heart. When adrenaline activates a beta receptor, blood pressure and heart rate go up. Beta blockers prevent adrenaline from affecting beta receptors in blood vessels and the heart. This causes blood vessels to relax. By relaxing the vessels, beta blockers help to lower blood pressure and reduce chest pain.
Blood pressure is often raised because blood vessels are tightened. That puts a strain on the heart. It also increases the body's need for oxygen. Beta blockers help to lower heart rate and the heart's demand for oxygen.
Beta blockers don’t permanently change blood pressure and chest pain. Instead, they help to manage the symptoms.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.