Lopressor (metoprolol tartrate) is a brand-name drug prescribed for heart conditions, including high blood pressure and chest pain in adults. Lopressor comes as an oral tablet that’s typically taken once or twice per day.

Lopressor belongs to a drug class called beta-blockers. Lopressor is available in a generic version called metoprolol.

Keep reading for specific information about the dosage of Lopressor, including its strengths and how to take the medication. For a comprehensive look at Lopressor, including details about its uses, see this article.

Note: This article describes typical dosages for Lopressor provided by the drug’s manufacturer. When taking Lopressor, always follow the dosage your doctor prescribes.

Read below for recommended dosages of Lopressor and other details about the drug.

Lopressor form

Lopressor comes as an oral tablet.

Lopressor strengths

Lopressor comes in two strengths: 50 milligrams (mg) and 100 mg

Typical dosages

Typically, your doctor will start treatment with a low dosage. They may call this your “starting dosage.” Then they’ll adjust it over time to reach the amount that’s right for you. They may refer to this as your “maintenance dosage.” Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that doctors commonly prescribe or recommend. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Note: To manage the following conditions, your doctor may prescribe other medications along with Lopressor. For more information, talk with your doctor.

Dosage for hypertension (high blood pressure)

The recommended starting dosage of Lopressor for high blood pressure is 100 mg per day. To achieve this dose, your doctor may prescribe 100 mg once per day or 50 mg twice per day.

The typical dosage range for this condition is 100–450 mg per day. However, always take the dosage your doctor prescribes.

Dosage for chest pain

The typical starting dosage of Lopressor for stable angina (a type of chest pain) is 50 mg twice per day.

The typical dosage range for this use is 100–400 mg per day. However, always take the dosage your doctor prescribes.

Dosage for recent heart attack

Lopressor is prescribed to reduce the risk of death in people who recently had (or may have had) a heart attack. Lopressor treatment typically starts in the hospital with intravenous (IV) injections of the generic version — metoprolol tartrate.* Then, your doctor will switch to Lopressor tablets. Your starting dosage depends on how your body responds to IV metoprolol tartrate.

The typical starting dosage is one 50-mg Lopressor tablet every 6 hours for 48 hours. In some cases, doctors start with 25 mg every 6 hours.† The typical maintenance dosage is 100 mg twice per day.

* Metoprolol tartrate is the active drug in Lopressor. The generic version comes as oral forms and as a liquid solution for IV injection.
† For a 25-mg dose, the 50-mg tablet is split in half.

Long-term treatment

Lopressor is meant to be taken as a long-term treatment. If you and your doctor determine that Lopressor is safe and effective for you, you’ll likely take it long term.

Here are some frequently asked questions about Lopressor and dosage.

Is Lopressor available as an IV? Is the dosage similar to the tablet?

No, the brand-name drug Lopressor isn’t available as an intravenous (IV) injection. Lopressor comes as an oral tablet. However, the generic version called metoprolol tartrate (the active drug in Lopressor) comes as an IV injection. It also comes in oral forms. The dosage of metoprolol tartrate IV injection is different from Lopressor tablet.

Lopressor treatment for a heart attack typically starts in a hospital with IV injections of metoprolol tartrate. The typical dosage is three 5-mg injections, given 2 minutes apart. Then treatment typically switches to an oral form of the medication. For details about Lopressor’s dosage, see the “Lopressor dosage” section above.

If you’d like to know more about metoprolol tartrate IV injections, talk with your doctor.

Can Lopressor be used for AFib? If so, what is the dosage?

Yes, Lopressor may be prescribed off-label for atrial fibrillation (AFib). With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for. AFib is a type of arrhythmia, or irregular heart rhythm. If your doctor recommends the drug, they’ll prescribe the right dosage for you.

Lopressor is approved by the Food and Drug Administration (FDA) to treat high blood pressure and stable angina (a type of chest pain). It’s also approved to reduce the risk of death in people who recently had (or may have had) a heart attack. The FDA hasn’t approved Lopressor for AFib.

If you have questions about Lopressor and AFib, talk with your doctor. They can advise you on AFib medications and whether Lopressor will be effective for your condition.

The Lopressor dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re taking Lopressor to treat
  • how your body responds to Lopressor
  • other medical conditions you may have

Dosage adjustments

If you have liver problems, your doctor may lower your dosage of Lopressor. For example, they may prescribe a lower dosage to start. Then they’ll slowly increase it to the amount that’s right for you.

Talk with your doctor for more information if you have questions about your dosage.

Lopressor comes as an oral tablet that you swallow. You should take Lopressor with food.

If your doctor prescribes a 25-milligrams (mg) dose, you’ll cut a 50-mg tablet in half. Then, you’ll swallow half of one 50-mg tablet as your dose. Your doctor or pharmacist can show you how to cut the tablet properly.

It’s best to take your dose around the same time each day. This helps maintain a steady level of the drug in your body so it can work effectively.

If you have difficulty swallowing tablets, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.


Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Lopressor in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Lopressor, take the dose as soon as you remember. But if it’s almost time for your next dose, skip the missed one. Then take your next dose at the usual time.

Do not double up your next dose to make up for the missed one. Doing so may increase your risk of side effects from Lopressor. To learn about Lopressor’s side effects, see this article.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.

If you take more Lopressor than your doctor prescribes, you may develop harmful effects. To learn about side effects of Lopressor, see this article.

It’s important that you do not take more Lopressor than your doctor advises.

Symptoms of an overdose

Overdose symptoms of Lopressor can include:

If you take more than the recommended amount of Lopressor

Call your doctor right away if you believe you’ve taken too much Lopressor. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Lopressor for you, they’ll prescribe the dosage that’s right for you.

If you have questions about the dosage of Lopressor that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Lopressor. These additional articles might be helpful:

  • More about Lopressor. For information about other aspects of Lopressor, refer to this article.
  • Side effects. To learn about side effects of Lopressor, see this article. You can also look at the Lopressor prescribing information.
  • Drug comparison. Find out how Lopressor compares with Toprol XL.
  • Interactions. For details about what Lopressor interacts with, see this article.
  • Details about your condition. For details about the conditions Lopressor treats, see our cardiovascular health hub.

Disclaimer: Medical News Today 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.