Atenolol

💊 What is Atenolol used for?

• •Treatment of high blood pressure (hypertension), to lower blood pressure
• •Treatment of angina pectoris (chest pain caused by reduced blood flow to the heart)
• •Use in the hospital for people with definite or suspected acute myocardial infarction (heart attack), given as an intravenous injection and then as tablets

How it works

The label describes atenolol as a synthetic beta 1-selective (cardioselective) blocker. It works by blocking certain receptors that respond to adrenaline-type signals, which is part of how it lowers blood pressure and helps the heart. The label says it is blood pressure reduction that largely accounts for the reduced risk of stroke and heart attack seen in studies.

How it is usually taken

• •Atenolol is taken by mouth as a tablet. The label describes dosing once a day for high blood pressure and angina. For high blood pressure, it may be used alone or together with other blood pressure medicines, including diuretics (water pills). The label says the full effect is usually seen within one to two weeks. Follow the exact instructions from your prescriber or pharmacist.

Comes as

• •25 mg tablets
• •50 mg tablets
• •100 mg tablets
• •Intravenous (IV) injection, used in the hospital for acute heart attack

⚠️ Atenolol side effects

🛑 Who should not take Atenolol, and who should be careful

The label says not to take it if

• 🚨You have sinus bradycardia (a slow heart rhythm from the heart's natural pacemaker).
• 🚨You have heart block greater than first degree.
• 🚨You have cardiogenic shock.
• 🚨You have overt cardiac failure.
• 🚨You have had a hypersensitivity (allergic reaction) to atenolol or any of the product's ingredients.

Tell your doctor before taking it if

• •Do not stop atenolol suddenly without talking to your doctor. The label advises people with coronary artery disease against abrupt discontinuation. When stopping is planned, the label says the patient should be carefully watched and advised to limit physical activity.
• •Tell your doctor if you have heart failure, a slow heart rate, heart block, or heart valve or rhythm problems.
• •Tell your doctor if you have asthma or other bronchospastic disease. The label says people with this condition should, in general, not take beta-blockers. It may be used with caution in some cases, and the lowest possible dose should be used.
• •Tell your doctor if you have diabetes or are at risk of low blood sugar. The label says beta-blockers can hide early warning signs such as a fast heartbeat.
• •Tell your doctor if you have an overactive thyroid (thyrotoxicosis). The label says atenolol may mask some signs of this condition.
• •Tell your surgeon or anesthesia team that you take atenolol. The label says it should not usually be stopped before major surgery, and the heart's reduced ability to respond may add risk during anesthesia.
• •Tell your doctor if you have had a severe allergic reaction. The label says people with a history of anaphylactic reactions may have a more severe reaction while taking beta-blockers.
• •Tell your doctor if you are pregnant, planning pregnancy, or breastfeeding.

🔀 Atenolol with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •Catecholamine-depleting drugs, such as reserpine: may add to blood pressure lowering and slow heart rate. The label says to watch closely for low blood pressure or a very slow heart rate.
• •Calcium channel blockers, such as verapamil or diltiazem: may cause slow heart rate, heart block, or a rise in left ventricular pressure.
• •Disopyramide (an antiarrhythmic): the label reports severe slow heart rate, stopping of the heart, and heart failure when used with beta-blockers.
• •Amiodarone (an antiarrhythmic): may add to the slowing effect on the heart.
• •Clonidine: beta-blockers may make rebound high blood pressure worse when clonidine is withdrawn. The label gives specific timing for stopping one and starting the other.
• •Prostaglandin synthase inhibitors, such as indomethacin: may reduce the blood pressure-lowering effect of beta-blockers.
• •Digitalis glycosides (heart medicines such as digoxin): both can slow the heart and may increase the risk of a slow heart rate.
• •Aspirin: the label says studies have not shown a clinical interaction in the heart attack setting, but information is limited.
• •Insulin or other diabetes medicines: beta-blockers may increase the risk of severe or prolonged low blood sugar and may hide warning signs.

Alcohol and food

The label does not say.

🤰 Atenolol in pregnancy and breastfeeding

Pregnancy

The label says caution should be used when atenolol is given during pregnancy. The label excerpt refers to a separate pregnancy and fetal injury warning, which is not included in the text provided. Talk with your prescriber about your situation.

Breastfeeding

The label says atenolol passes into human breast milk and that caution should be used when it is given to a nursing woman. It reports clinically significant slow heart rate in breastfed infants. Premature infants or infants with impaired kidney function may be more likely to have side effects. The label also says newborns of mothers taking atenolol at delivery or while breastfeeding may be at risk of low blood sugar and slow heart rate.

🗓️ Storage, missed doses and taking too much

Storage

The label says to store atenolol tablets at 20° to 25°C (68° to 77°F), at controlled room temperature. Keep this and all medicines out of the reach of children.

If a dose is missed

The label does not say.

If too much is taken

The label describes overdoses in which patients survived large acute doses, and one death after a very large intake. The main reported symptoms are extreme tiredness (lethargy), trouble with breathing control, wheezing, a pause in the heartbeat (sinus pause), and a very slow heart rate. Other effects that may occur with beta-blocker overdose include heart failure, low blood pressure, bronchospasm, and low blood sugar. The label says treatment may include removing unabsorbed drug and that atenolol can be removed from the circulation by hemodialysis. Seek emergency care right away if an overdose is suspected.

🗒️ Questions to ask about Atenolol

• Is atenolol the right medicine for my blood pressure or heart condition?
• How long will it take before I notice that it is working?
• What should I do if I feel dizzy, faint, or unusually tired?
• Should I check my blood sugar more often, since atenolol may hide the warning signs of low blood sugar?
• What should I do if I miss a dose, and what is the plan if I need to stop the medicine?
• Are any of my other medicines, such as calcium channel blockers or clonidine, a concern with atenolol?
• Are there any activities I should limit while I am taking atenolol?

❓ Atenolol: frequently asked questions