Baloxavir marboxil is an antiviral medication used to treat the flu (influenza) if your symptoms started less than 48 hours ago. It helps make the symptoms (such as stuffy nose, cough, sore throat, fever/chills, aches, tiredness) less severe and may shorten the recovery time by 1 to 2 days. Baloxavir marboxil works by stopping the flu virus from growing. It will not treat other kinds of infection besides the flu virus.

This medication may also be used to prevent the flu if you have been exposed to someone who already has the flu (such as a sick household member) or if there is a flu outbreak in the community. Talk to your doctor for more details.

This medication should not be used in children younger than 5 since it may not be effective.

Baloxavir marboxil is not a substitute for the flu vaccine. (See also Notes section.)

Read the Patient Information Leaflet if available from your pharmacist before you take baloxavir marboxil. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually a single dose. The dosage is based on your weight.

For the best effect, take this medication at least 4 hours before or 2 hours after taking other products that contain aluminum, iron, zinc, selenium, calcium, or magnesium. These products may make this medication not work well. Some examples include antacids, vitamins/minerals, dairy products (such as milk, yogurt), and calcium-enriched juice.

Other kinds of infections may have symptoms like flu or can occur along with flu. These infections may need different kinds of treatment. Tell your doctor if you develop new symptoms during or after treatment, or if your condition does not get better, or if it gets worse.

Baloxavir marboxil usually has very few side effects. If you have any unusual effects, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking baloxavir marboxil, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Tell your doctor if you have received flu vaccine in the nose within 2 weeks before treatment with this medication. This medication may lower your protection from flu vaccine given in the nose. After treatment with this medication, talk with your doctor or pharmacist before receiving flu vaccine.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

This medication is not a substitute for the flu vaccine. Consult your doctor about the risks and important benefits of receiving a yearly flu shot to lower your chances of getting the flu.

Not applicable.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.