Tenormin (atenolol) is a prescription drug that’s used to treat high blood pressure, angina, and heart attack. The drug comes as a tablet. It’s usually taken once per day.

Tenormin is used in adults to treat:

The active ingredient in Tenormin is atenolol. An active ingredient is what makes a drug work. Tenormin belongs to a group of drugs called beta-blockers.

This article describes the dosages of Tenormin, as well as its strengths and how to take it. To learn more about Tenormin, see this in-depth article.

The table below highlights the basics of Tenormin’s dosage. All doses are listed in milligrams (mg).

IndicationInitial dosageDose increase and intervalMaximum dosage
high blood pressure50 mg once per dayAfter 1 or 2 weeks, increase to 100 mg once per day100 mg once per day
angina due to narrowed arteries50 mg once per day

After 1 week, increase to 100 mg once per day200 mg once per day
heart attack50 mg twice dailyAfter the first two doses, 100 mg once per day or 50 mg twice daily for at least 7 days100 mg once per day or 50 mg twcie daily

Keep reading for more details about Tenormin’s dosage.

What are Tenormin’s forms?

Tenormin is available as an oral tablet.

What strengths does Tenormin come in?

Tenormin comes in three strengths:

  • 25 mg
  • 50 mg
  • 100 mg

What are the usual dosages of Tenormin?

Your doctor will likely start you on a low dosage and adjust it over time to reach the right amount for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.

The information below describes dosages that are commonly used or recommended. But be sure to take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs.

Dosage for high blood pressure

The typical Tenormin dosage for adults with high blood pressure condition is 50–100 mg once per day.

Doctors typically start with 50 mg once per day. After 1 or 2 weeks, if blood pressure remains high, doctors may increase the dose to 100 mg once per day.

The maximum dosage for treating high blood pressure is 100 mg once per day.

Dosage for stable angina due to narrowed arteries

For angina (a type of chest pain) due to narrowed arteries in adults, the typical dosage of Tenormin is 50–100 mg once per day. Doctors usually prescribe 50 mg once per day to start. If angina symptoms don’t improve after 1 week, doctors may increase the dosage to 100 mg once per day.

The maximum dosage for angina due to narrowed arteries is 200 mg once per day.

Dosage for heart attack

The typical Tenormin dosage for patients after a heart attack is 50 mg twice daily or 100 mg once daily for at least seven days. It may be appropriate to continue Tenormin long term.

If any major side effects, such as low heart rate or low blood pressure occur, doctors may stop prescribing Tenormin.

Is Tenormin used long term?

Yes, Tenormin is usually used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.

Dosage adjustments

People with kidney problems may require lower doses of Tenormin. Throughout treatment, doctors assess kidney function to make sure the person is removing enough Tenormin.

A drop in kidney function may cause the amount of Tenormin to increase in the body, which can lead to an increase in the side effects of the drug.

The dosage of Tenormin you’re prescribed may depend on several factors. These include:

  • the type and severity of the condition you’re using the drug to treat
  • your age
  • other conditions you may have (see the “Dosage adjustments” section above)

Tenormin is available as an oral tablet. If you have trouble swallowing tablets, see this article for tips on how to take this form of medication.

For information on the expiration, storage, and disposal of Tenormin, talk with your doctor or pharmacist.

Accessible drug containers and labels

Some pharmacies provide medication labels that:

  • have large print
  • use braille
  • feature a code you can scan with a smartphone to change the text to audio

Your doctor or pharmacist may be able to recommend pharmacies that offer these accessibility features if your current pharmacy doesn’t.

Let your pharmacist know if you have trouble opening medication bottles. They may have tips to help, or they may be able to supply Tenormin in an easy-open container.

If you miss a dose of Tenormin, take it as soon as you remember. But if it’s almost time for your next dose, skip the missed dose and take your next dose at its usual time. If you’re not sure whether you should take a missed dose, talk with your doctor or pharmacist.

If you need help remembering to take your dose of Tenormin on time, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.

Do not take more Tenormin than your doctor prescribes, as this can lead to harmful effects.

Symptoms of overdose

Symptoms caused by an overdose can include:

What to do in case you take too much Tenormin

Call your doctor right away if you think you’ve taken too much Tenormin. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

Below are answers to some commonly asked questions about Tenormin’s dosage.

How long does it take for Tenormin to start working?

Tenormin starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. It may take up to 1–2 weeks to see the full blood pressure lowering effects.

Its long-term effects may take longer to start working. But your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

If you have other questions about what to expect from your Tenormin treatment, talk with your doctor.

Can Tenormin be used for anxiety? If so, what’s the dosage?

Tenormin is not approved for treating anxiety. But in some cases, your doctor may prescribe it off-label for this use. (With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for.)

Because Tenormin isn’t approved for anxiety, the drug manufacturer doesn’t provide recommended dosages for this use. Your doctor will prescribe the dosage that’s right for you.

To learn more about your treatment options for anxiety, including Tenormin, talk with your doctor.

Do older adults need to take a lower dose of Tenormin?

In general, doctors will start older adults on lower doses of Tenormin. Older adults may need lower doses because their bodies get rid of the drug slower than younger adults.

If you’re concerned about your Tenormin dosage, talk with your doctor.

The sections above describe the usual dosages provided by the manufacturer. If your doctor recommends Tenormin for you, they’ll prescribe the dosage that’s right for you.

Remember, you should not change your dosage of Tenormin without your doctor’s recommendation. Only take Tenormin exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.

Here are some examples of questions you may want to ask your doctor:

  • How does my dosage change if I need to take other drugs to manage my blood pressure?
  • What dosage of Tenormin is safe if I have diabetes?

To learn more about Tenormin, see this article:

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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 another 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.