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Baloxavir Marboxil

pronounced as ba lox' a" veer mar box' el

Why is this medication prescribed?

Baloxavir marboxil is used to treat some types of influenza infection ('flu') in adults and children 5 years and older who have had symptoms of the flu for no longer than 2 days and who are otherwise healthy or are at high risk for developing influenza-related complications. Baloxavir marboxil is also used to treat some types of flu in adults and children 12 years and older who have had symptoms of the flu for no longer than 2 days and who are at high risk for developing influenza-related complications. It is also used to prevent some types of flu in adults and children 5 years and older when they have spent time with someone who has the flu. Baloxavir marboxil is in a class of medications called polymerase acidic endonuclease inhibitors. It works by stopping the spread of the flu virus in the body. Baloxavir marboxil helps to shorten the time that flu symptoms such as a stuffy or runny nose, sore throat, cough, muscle or joint aches, tiredness, headache, fever, and chills last. Baloxavir marboxil will not prevent bacterial infections, which may occur as a complication of the flu.

How should this medicine be used?

Baloxavir marboxil comes as a tablet and a suspension (liquid) to take by mouth. It is usually taken as a one-time dose with or without food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take baloxavir marboxil exactly as directed.

Do not take baloxavir marboxil along with dairy products such as milk or yogurt or with calcium-fortified drinks.

If you are taking the suspension, gently swirl the suspension well before use to mix the medication evenly; do not shake the bottle(s). Use an oral syringe provided by your pharmacist to measure the correct amount of liquid needed for your dose. Your total dose may require less than one bottle, one bottle, or 2 bottles of the suspension. Do not take more or less of it other than prescribed by your doctor. Do not mix the suspension with any other liquid or with soft food.

If you feel worse or develop new symptoms while taking baloxavir marboxil or if your flu symptoms do not start to get better, call your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking baloxavir marboxil,

  • tell your doctor and pharmacist if you are allergic to baloxavir marboxil, any other medications, or any of the ingredients in baloxavir marboxil tablets or suspension. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • do not take antacids or laxatives containing magnesium, aluminum, or calcium, calcium supplements, iron products, or vitamin or mineral supplements containing calcium, iron, zinc or selenium with baloxavir marboxil.
  • tell your doctor if you are pregnant or are breastfeeding.
  • tell your doctor if you have recently received or are scheduled to receive any vaccines.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What side effects can this medication cause?

Baloxavir marboxil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • vomiting
  • diarrhea
  • nausea

Some side effects with baloxavir marboxil can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • difficulty breathing or swelling of the face or throat
  • swelling of the arms, hands, feet, and legs
  • hives or itching
  • new red skin lesion or bump

Baloxavir marboxil may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

Keep all appointments with your doctor.

Do not let anyone else take your medication.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Xofluza®
Last Revised - 10/15/2022