10 Atenolol Side Effects You Should Know About

Atenolol (Tenormin) is a commonly prescribed beta blocker medication. It’s approved to treat health conditions such as chest pain (angina) and to lower the risk of death after a heart attack. It’s also approved for treating high blood pressure, though it’s not usually a first-choice option..

Beta blockers like atenolol can cause a number of side effects, ranging from slowed heart rate and dizziness to erectile dysfunction. Fortunately, some of these tend to improve as your body gets used to atenolol. But certain atenolol side effects can sometimes become more serious.

Atenolol side effects at a glance

Atenolol side effects can range from mild to severe. Mild side effects tend to resolve on their own and can be treated at home. More serious side effects may need to be treated by a healthcare professional.

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Common atenolol side effects include:

• Slowed heart rate

• Low blood pressure

• Dizziness

• Fatigue

• Erectile dysfunction (ED)

• Cold hands and feet

• Diarrhea

• Nausea

• Vivid dreams or nightmares

• Masking symptoms of low blood glucose (sugar)

Rare but serious atenolol side effects include:

• Heart rhythm problems

• Heart block

Atenolol also has a boxed warning, the FDA’s strictest warning for medications. It cautions against stopping atenolol abruptly, which can cause chest pain, irregular heartbeats, and even a heart attack. If you need to stop taking atenolol for any reason, including for side effects, talk to your prescriber first. They will help you safely stop atenolol by lowering the dose slowly over time.

Some atenolol side effects may be more likely if you take it with interacting medications. Because of this, make sure your prescriber and pharmacist have your current medication list for review. They can check for these interactions in advance.

Below, we’ll review more details about 10 notable atenolol side effects.

EXPERT PICKS: WHAT TO READ NEXT

• Beta blocker list: Atenolol is one of many available beta blockers. Learn how it compares to other medications in its class.

• What to expect: When starting atenolol, it’s good to have an idea of what to expect. Here’s how long atenolol takes to lower your heart rate, how long it lasts, and more.

• Stay consistent: Stopping atenolol abruptly can be dangerous. Read more about why you shouldn’t stop taking your blood pressure medication without a healthcare professional’s OK.

1. Slowed heart rate

You may notice that your heart beat is slower after starting atenolol. This is an expected effect of the medication. That’s because beta blockers like atenolol work by slowing your heart rate. This prevents your heart from having to work as hard.

In most cases, having a slower heart rate because of atenolol doesn’t cause problems. But you may find it more difficult to exercise or walk up stairs.

It’s also possible for your heart rate to slow down too much (called bradycardia). If this happens, you may experience symptoms such as shortness of breath, chest pain, or fainting. Let your healthcare team know if these symptoms develop while you’re taking atenolol.

2. Low blood pressure

Beta blockers, including atenolol, can lower your blood pressure. Usually, this is an intended effect of the medication. Lowering your blood pressure (if it’s high) can help improve your heart health.

But sometimes your blood pressure can drop too low (a condition called hypotension). Symptoms can include lightheadedness, dizziness, and fatigue. These symptoms are also possible when you first start taking atenolol, even if your blood pressure isn’t too low. But they’ll usually resolve after a few days, as your body gets used to the medication.

You might notice low blood pressure symptoms when you stand up from sitting or lying down. This is called orthostatic hypotension. If this happens, be sure to move slowly when you stand up, and sit or lie back down if you feel dizzy.

Your healthcare team may have you monitor your blood pressure at home while you’re taking atenolol. Let them know if your blood pressure is dropping too low, or if you’re experiencing bothersome or worsening symptoms. You may need to switch to a different dose of atenolol or make other medication adjustments.

3. Dizziness

Dizziness is a common side effect of atenolol. It can be caused by having a slower heart rate or lower blood pressure. Usually, dizziness should improve on its own as your body adjusts to taking atenolol.

When starting atenolol, be careful when driving or doing other activities where dizziness can be dangerous. After any dizziness from the treatment has subsided, you can cautiously resume these activities with your prescriber’s approval.

If your dizziness doesn’t go away, or if it becomes bothersome, let your healthcare team know. You may need a different dose of atenolol. They may also suggest taking your dose in the evening so that you’re not as dizzy during the day.

4. Fatigue

Feeling tired, weak, or fatigued is common when taking atenolol. Like dizziness, this side effect usually happens because of a slowed heart rate or lower blood pressure. It can take several weeks after starting atenolol for your body to adjust and for the fatigue to lessen.

Your healthcare team may recommend being cautious with physical activity when you start atenolol so that you don’t tire yourself out. Getting plenty of sleep, eating a heart-healthy diet, and staying hydrated can also help reduce fatigue — and provide heart-related benefits.

But if your fatigue doesn’t go away or if it starts interfering with your quality of life, let your prescriber know. They may need to adjust your atenolol dose.

5. Erectile dysfunction

Beta blockers like atenolol are some of the most common medications to cause ED. ED from beta blockers is thought to happen because of reduced blood flow to the penis. This makes it more difficult to have an erection.

Other medications for blood pressure and heart conditions may be less likely to cause ED. But switching treatments isn’t always possible. If you notice problems with ED, talk with your prescriber. They can recommend next steps for improving your symptoms.

6. Diarrhea

Although it’s a less common side effect, some people taking beta blockers like atenolol report experiencing diarrhea. However, diarrhea has many possible causes. And for many people it’s not actually being caused by the beta blocker.

But if you start experiencing diarrhea, avoiding fatty, fried, or spicy foods that can worsen diarrhea may help. If needed, your prescriber may suggest an over-the-counter medication for relief.

If your diarrhea is bothersome, gets worse, or is accompanied by other symptoms, let your healthcare team know. It could be caused by an infection or health condition that needs further medical care.

7. Nausea

Nausea is a possible side effect of atenolol. It is generally mild and usually resolves on its own. However, there are a few things you can do to manage nausea in the meantime.

Atenolol can be taken with or without food. But if you’ve been taking it on an empty stomach, try taking your dose with food to reduce nausea. Avoiding spicy or greasy foods may also help.

If your nausea isn’t going away or if it becomes severe, talk to your healthcare team. They can help determine whether atenolol is responsible for your symptoms.

8. Cold hands or feet

Another possible atenolol side effect is cold hands or feet. There can be several different reasons that you feel cold, including some health conditions and other medications. But beta blockers like atenolol seem to cause cold hands and feet (also known as your “extremities”) because they can reduce blood flow to these parts of the body.

While this side effect isn’t common, it can be bothersome. If your symptoms don’t go away after a few days, or if they are getting worse, talk to your prescriber. They may suggest changing your dose or gradually stopping the medication.

9. Masking symptoms of low blood glucose

Hypoglycemia, which is a common concern for people living with diabetes, is when your blood glucose drops too low. If left untreated, hypoglycemia can be life-threatening. So it’s important to recognize the symptoms and treat it right away.

Common hypoglycemia symptoms include a fast heartbeat and shakiness. However, beta blockers like atenolol can mask (or hide) these symptoms. But one hypoglycemia symptom that isn’t masked by beta blockers is sweating. So if you notice you’re sweating more than usual, it’s a good idea to check your blood glucose if you have diabetes. Be sure to have fast sources of glucose on hand to help treat hypoglycemia if it happens.

10. Heart block

Heart block is a life-threatening condition where your heart can slow down significantly or stop entirely. It can happen because of disruptions in the electrical system that helps your heart pump properly. Because beta blockers like atenolol slow down the heart, it’s possible for them to cause heart block.

Symptoms of heart block include chest pain, fainting, and shortness of breath. Dizziness and feeling your heart beat in an unusual way can also happen. If you’re at higher risk for heart rhythm problems like heart block, your prescriber may monitor your heartbeat more closely. If you experience symptoms of heart block, get emergency medical care right away.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

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