Baloxavir Marboxil Side Effects

Medically reviewed by Drugs.com. Last updated on Aug 7, 2024.

Applies to baloxavir marboxil: oral tablet.

Precautions

It is very important that your doctor check your or your child's progress after treatment to make sure that the infection is cleared up completely, and to allow your doctor to check for any unwanted effects.

If your or your child's symptoms do not improve or if they become worse, check with your doctor.

This medicine may cause serious allergic reactions, including anaphylaxis, angioedema, or certain skin conditions, which can be life-threatening and require immediate medical attention. Call your doctor right away if you or your child have a rash, itching, blistering, peeling, or loosening of the skin, fever or chills, large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs, trouble breathing or swallowing, or any swelling of your hands, face, mouth, or throat while you are using this medicine.

This medicine is not a substitute for an annual flu shot. It also will not keep you or your child from getting a bacterial infection that starts with flu-like symptoms.

Serious side effects of baloxavir marboxil

Along with its needed effects, baloxavir marboxil may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking baloxavir marboxil:

Other side effects of baloxavir marboxil

Some side effects of baloxavir marboxil may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to baloxavir marboxil: oral granule for reconstitution, oral tablet.

Dermatologic adverse events

• Postmarketing reports: Angioedema (swelling of face, eyelids, tongue, and lips), rash, urticaria, erythema multiforme^[Ref]

Gastrointestinal

• Common (1% to 10%): Diarrhea, nausea
• Postmarketing reports: Vomiting, hematochezia, bloody diarrhea, melena, colitis, ischemic colitis^[Ref]

Nausea was reported in 6% of elderly subjects compared to 1% of younger subjects (aged 18 to 64 years).^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylactic reactions, anaphylactic shock, anaphylactoid reactions, anaphylaxis, hypersensitivity reactions^[Ref]

Nervous system

• Common (1% to 10%): Headache^[Ref]

Psychiatric

• Postmarketing reports: Delirium, abnormal behavior, hallucinations

Respiratory

• Common (1% to 10%): Bronchitis, sinusitis, nasopharyngitis
• Frequency not reported: Dysphonia^[Ref]

See also:

Frequently asked questions

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

Further information

Baloxavir marboxil side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer