Atenolol

Atenolol is approved for controlling high blood pressure, relieving symptoms of angina, and improving survival following a heart attack. It works by blocking a specific type of beta receptor, which causes the reverse effect of stress hormones -- decreasing heart rate and systolic and diastolic blood pressure, as well as the workload of the heart. Common side effects seen with this medication include tiredness, dizziness, and shortness of breath.
  

What Is Atenolol?

Atenolol (Tenormin®) is a prescription medicine that has been licensed to treat several conditions related to the heart and blood vessels. It is part of a class of drugs called beta blockers.
  

Approved Uses

Atenolol has been licensed to treat a number of conditions. These uses include:
 
However, the drug does not cure high blood pressure or angina.
 
Atenolol may also be recommended for other reasons, such as treatment of migraines or anxiety. It has not been approved for use in children.
 
(Click What Is Atenolol Used For? for more information, including possible off-label uses.)
 

Side Effects of Atenolol

As with any medicine, side effects can occur with atenolol.
 However, not everyone who takes it will experience problems. If side effects do occur, they are often minor and either require no treatment or are easily treated by you or your healthcare provider. Serious side effects are less common.
 
The most common side effects include:
 
(Click Atenolol Side Effects to learn more, including potentially serious side effects you should report to your healthcare provider.)
 
You can read about specific side effects in the following eMedTV articles:
 

What Should I Tell My Healthcare Provider?

You should talk with your healthcare provider prior to taking atenolol if you have:
 
Also, let your healthcare provider know if you:
 
In addition, tell your healthcare provider about all other medicines you may be currently taking, including prescription and non-prescription medicines, antacids, vitamins, and herbal supplements.
 
(Click Warnings and Precautions With Atenolol for more information, including information on who should not take the drug.)
  

How Does Atenolol Work?

Atenolol is part of a class of drugs called beta-adrenergic blocking agents, or beta blockers for short. As the name implies, beta blockers work by blocking beta receptors in the body. Beta receptors are located in a number of places within the body, including the heart and blood vessels. Adrenaline attaches to these receptors and causes certain reactions in the body, such as an increase in:
 
Atenolol helps to block a specific type of beta receptor called beta-1 receptors. By blocking beta-1 receptors, the medication causes the reverse effect of adrenaline. It decreases heart rate, systolic and diastolic blood pressure, and the workload of the heart. This means that the heart requires less blood and oxygen to work properly.
 
Atenolol is a beta-1 selective (or cardioselective) beta blocker. This means that it mostly blocks beta-1 receptors, especially at normal doses. However, it can block beta-2 receptors in the lungs to some extent, especially at higher dosages. This can lead to breathing problems, especially in people with asthma or similar conditions.
 

Clinical Effects

By lowering blood pressure, atenolol can decrease the risks that accompany long-term hypertension (see Effects of High Blood Pressure). By decreasing the workload of the heart, the drug can also decrease symptoms of angina, including chest pain. Finally, although the exact mechanism is not known, atenolol can increase the survival in people who have just suffered a heart attack.
 

When and How Do I Take It?

Some general considerations for when and how to take atenolol include the following:
 
  • Atenolol comes in a tablet form and is usually taken once a day. It can be taken with or without food.
     
  • The medication should be taken at the same time each day to maintain an even level in your blood.
     
  • For the drug to work properly, you have to take it as prescribed. Atenolol will not work if you stop taking it.
     
  • You should not stop taking atenolol without talking to your healthcare provider. Stopping it abruptly increases the risk of serious side effects (see Warnings and Precautions With Atenolol).
     

Atenolol Dosing Information

The dose of atenolol your healthcare provider recommends will vary, depending on a number of factors, including:
 
  • Your age
  • The medical condition being treated
  • Other medical conditions you may have
  • Other medications you may be currently taking.
     
As always, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
 
(Click Atenolol Dose for more information.)
 

Drug Interactions

Atenolol can potentially interact with a number of other medicines (see Drug Interactions With Atenolol for more information).
 

What If I Take an Overdose?

People who take too much atenolol may have overdose symptoms that could include but are not limited to:
 
If you happen to overdose on this drug, seek immediate medical attention.
 
(Click Atenolol Overdose for more information.)
 

How Should Atenolol Be Stored?

The medicine should be stored at room temperature in a dry place. The tablets should be kept in an airtight, light-resistant container.
 
Keep this and all other medications out of the reach of children.
 

What Should I Do If I Miss a Dose?

If you do not take your atenolol as scheduled, take your missed dose as soon as you remember. If it is almost time for your next scheduled dose, skip the missed one and continue with normal dosing. Do not take a double dose.
 

Is Generic Atenolol Available?

Atenolol is available as a generic medicine. It is manufactured by a number of different companies.
 
(Click Generic Atenolol for more information.)
 

Who Makes Atenolol?

The brand-name version of this medication (Tenormin) is made by IPR Pharmaceuticals, Inc., and is marketed and distributed by AstraZeneca Pharmaceuticals. Generic versions are made by various manufacturers.
 

Available Strengths

Atenolol comes in a number of strengths, including:
 
  • 25 mg
  • 50 mg
  • 100 mg.
 
Add this article to your Favorites     Email this article     Print
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;