Generic name: baloxavir marboxil [ ba-LOX-a-vir-mar-BOX-il ]
Drug class: Miscellaneous antivirals

Medically reviewed by Judith Stewart, BPharm. Last updated on Sep 25, 2023.

What is Xofluza?

Xofluza is used to treat flu symptoms caused by the influenza virus in people who have had symptoms for no more than 48 hours. Baloxavir marboxil will not treat the common cold.

Xofluza is also used to prevent flu symptoms in people who have been in contact with someone who has the flu.

Xofluza is for adults and children at least 5 years old and weighing at least 44 pounds (20 kilograms).

Xofluza should not be used in place of getting a yearly flu shot. The Centers for Disease Control and Prevention recommends an annual flu shot to help protect you each year from new strains of influenza virus.

Warnings

Xofluza may contain inactive ingredients, which can cause allergic reactions or other problems.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use Xofluza if you are allergic to baloxavir marboxil.

Tell your doctor if you are pregnant or plan to become pregnant. Having influenza during pregnancy can cause severe complications that could harm both mother and baby. The benefit of treating influenza may outweigh any risks to the baby.

The Centers for Disease Control and Prevention recommends that pregnant women get a flu shot during any trimester of pregnancy to protect themselves and their newborn babies from flu.

Tell your doctor if you are breastfeeding.

How should I take Xofluza?

Take Xofluza exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Xofluza is usually given as a single dose to be taken at one time. This medicine will be provided either as tablets or a liquid (oral suspension) that is mixed by a healthcare professional.

Xofluza doses are based on weight. Follow all dosing instructions carefully, and do not share this medicine with another person.

Take Xofluza when you first notice flu symptoms (fever, chills, muscle aches, sore throat, runny or stuffy nose). This medicine may not be effective if you have been sick for longer than 48 hours.

If you are taking Xofluza to prevent flu symptoms, take your dose as soon as possible after you've been in contact with someone who has the flu.

You may take Xofluza with or without food.

Do not take this medicine with dairy products such as milk or yogurt, or with calcium-fortified juice.

Also avoid taking Xofluza with a laxative, antacid, or vitamin/mineral supplement that contains aluminum, calcium, magnesium, iron, selenium, or zinc.

Call your doctor if your symptoms do not improve, or if they get worse.

Store tablets in the blister pack at room temperature, away from moisture and heat. You must use the liquid within 10 hours after it was mixed.

Dosing information

Usual Adult Dose for Influenza:

20 kg to less than 80 kg: 40 mg orally once as a single dose
At least 80 kg: 80 mg orally once as a single dose

Use:
-For the treatment of acute uncomplicated influenza in patients symptomatic for no more than 48 hours who are otherwise healthy or at high risk of developing influenza-related complications

Usual Adult Dose for Influenza Prophylaxis:

20 kg to less than 80 kg: 40 mg orally once as a single dose
At least 80 kg: 80 mg orally once as a single dose

Use:
-For postexposure prophylaxis of influenza after contact with an individual who has influenza

Usual Pediatric Dose for Influenza:

5 years or older:
-Less than 20 kg: 2 mg/kg orally once as a single dose
-20 kg to less than 80 kg: 40 mg orally once as a single dose
-At least 80 kg: 80 mg orally once as a single dose

Use:
-For the treatment of acute uncomplicated influenza in patients who have been symptomatic for no more than 48 hours and who are otherwise healthy adults and pediatric patients 5 years of age and older, or adults and pediatric patients 12 years of age and older who are at high-risk of developing influenza-related complications

Usual Pediatric Dose for Influenza Prophylaxis:

5 years or older:
-Less than 20 kg: 2 mg/kg orally once as a single dose
-20 kg to less than 80 kg: 40 mg orally once as a single dose
-At least 80 kg: 80 mg orally once as a single dose

Use:
-For postexposure prophylaxis of influenza in patients 5 years of age and older after contact with an individual who has influenza

What happens if I miss a dose?

Xofluza is used as a single dose and does not have a daily dosing schedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid after taking Xofluza?

Ask your doctor before getting a "live" flu vaccine (such as nasal FluMist). Baloxavir marboxil may interfere with the drug action of FluMist, making the vaccine less effective.

Xofluza side effects

Get emergency medical help if you have signs of an allergic reaction to Xofluza: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Common Xofluza side effects in adults and adolescents may include:

• cough, chest congestion;

• nausea, diarrhea;

• headache; or

• runny or stuffy nose.

Common Xofluza side effects in children 5-12 years of age may include:

• vomiting; or

• diarrhea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Xofluza?

Other drugs may interact with baloxavir marboxil, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Frequently asked questions

• What is the difference between Xofluza and Tamiflu?
• How long does it take for Xofluza to work?

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Xofluza only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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