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Atenolol (Tenormin): 9 FAQs Inc. Dosage, Side Effects, and Stopping Safely

Answers to the most common questions about Atenolol

Atenolol, sold under the brand name Tenormin, belongs to a class of drugs known as beta-blockers. Atenolol, like many other beta-blockers, is typically used to treat hypertension. It is often used to treat other heart or cardiovascular conditions as well, such as arrhythmia, migraines, and chest pain. With nearly 20 million prescriptions annually, atenolol is consistently one of the most prescribed medications in the US.

The content on this page is provided for informational purposes only. If you have any questions or concerns about your treatment, you should talk to your doctor, pharmacist, or healthcare professional. This is particularly important if you are taking multiple medications or have any existing medical conditions.

  1. How does atenolol work?
  2. How long does it take atenolol to work?
  3. When should you take atenolol?
  4. How do you safely stop taking atenolol?
  5. How long does atenolol stay in your system?
  6. What are the side effects of atenolol?
  7. What is the right atenolol dosage for me?
  8. Can I drink alcohol while taking atenolol?
  9. What is the difference between atenolol and metoprolol?

1. How does atenolol work?

Atenolol works similarly to other beta-blockers, working to slow down your heart rate. Through a slowed heart rate and by changing how the heart responds to nerve impulses, atenolol enables the heart to pump blood easier. Even though atenolol is used to treat migraines, it's exact mechanism is unknown. Atenolol may help to reduce activity in the visual cortex, a part of the brain where migraines begin. However, reduced migraines may also be a result of atenolol’s ability to relax blood vessels.

2. How long does it take atenolol to work?

Patients prescribed atenolol often wonder how long it will take before they begin to see positive results. Fortunately, atenolol typically begins reducing blood pressure within about 3 hours of taking it. Despite the fast-acting nature of the drug, patients likely will not experience the full effects until they’ve been taking it consistently for around 2 weeks.

3. When should you take atenolol?

The right time to take atenolol may vary between patients and can depend on how many doses you need to take each day. If you are taking only one dose per day, your doctor may recommend that you take atenolol before bed. This is because it may cause dizziness. After you understand how atenolol affects you personally you may wish to take your dose in the morning. If you are taking two doses per day, your doctor will likely recommend taking one in the morning when you wake up and once before bed.

4. How do you safely stop taking atenolol?

It is not recommended that you stop taking atenolol without weaning off. If you need to stop taking atenolol you must speak with your doctor. Your doctor will then likely put together a plan to gradually decrease your dosage so you can stop safely. Stopping abruptly can have serious consequences and may worsen the condition it was being used to treat. The exact reductions in dosage may be specific to individuals, therefore it is impossible to provide a more specific answer about how to wean off the drug.

5. How long does atenolol stay in your system?

The length of time that atenolol remains in the body can vary between patients. The half-life of atenolol is between 6 and 7 hours. This means that half of the drug will leave the patient's system during this period. However, it takes several half-lives before the medication can be eliminated, for most patients 1 to 2 days. Even though atenolol may remain in the system for up to 2 days, the antihypertensive effects last for only 24 hours.

6. What are the side effects of atenolol?

Atenolol can potentially cause side effects ranging from mild to severe. The list below includes some of the most common side effects but is not a complete list. Mild side effects may go away after a few days or weeks of consistent medication-taking, but if they persist or worsen you should speak with your doctor.

Common side effects:

Serious side effects:

  • Worsening chest pain
  • Clamminess in hands or feet
  • Passing out or feeling as though you might
  • Shortness of breath
  • Unexpected weight gain
  • Uneven heart rate

In some rare cases, patients can experience allergic reactions. Seek emergency medical care if you experience any of the following symptoms after taking atenolol.

  • Skin rash
  • Wheezing
  • Tightness in the throat or chest
  • Difficulty talking or breathing
  • Swelling of the face, lips, tongue, or throat

Atenolol should be used with caution by people with diabetes because it may mask hypoglycemia. Discuss your maintenance dosage with your doctor if you are diabetic and taking atenolol.

7. What is the right atenolol dosage for me?

The proper dosage of atenolol will vary between patients and is based on several factors. You should always follow your doctor’s instructions or the directions on the label. The following information refers to typical doses for adult patients.

Treating hypertension – The standard dose for patients with hypertension is 50mg daily, with the option to increase to 100mg daily if necessary. If patients receive atenolol orally, the dosage may be between 25-50mg daily.

Treating migraines – The standard dose for patients with migraines is 25-100mg taken twice daily.

Treating arrhythmia – The standard dose for patients with arrhythmia is 50-100mg taken orally, once daily.

Treating chest pain – The standard dose for patients with chest pain begins with 50mg taken orally each day. However, after a week of treatment, this may be increased to between 100-200mg daily.

8. Can I drink alcohol while taking atenolol?

Atenolol and alcohol do not directly interact. However, a common side effect of atenolol is dizziness, which may be made substantially worse by consuming alcohol. For that reason, patients should avoid drinking alcohol. If you plan to drink anyways, you should speak with your doctor first and wait until you better understand how atenolol affects you.

9. What is the difference between atenolol and metoprolol?

Atenolol and metoprolol are both beta-blockers and are used to treat many of the same conditions, so many patients wonder about the differences. The differences between the two are mostly minor. The most notable difference though is that metoprolol is typically more effective at treating hypertension and has been shown to decrease mortality at a higher rate than atenolol. For this reason, many doctors may prescribe metoprolol first, and switch patients to atenolol if it isn’t effective. One other noteworthy difference is that atenolol is available only as an immediate-release tablet, where metoprolol is available as an immediate release, extended-release, injectable solution, and oral powder.


The content on this page is provided for informational purposes only. If you have any questions or concerns about your treatment, you should talk to your doctor, pharmacist, or healthcare professional. This is particularly important if you are taking multiple medications or have any existing medical conditions.

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