Key points
- Baloxavir marboxil is a prescription flu antiviral drug given as a pill by mouth for treatment of flu or post exposure prevention.
- Baloxavir is approved for children ages 5 to 12 years who do not have chronic medical conditions for all people ages 12 years and older.
- Baloxavir works differently than other currently recommended flu antiviral drugs, which are neuraminidase inhibitors (oseltamivir, zanamivr, and peramivir).
An Overview of Baloxavir Marboxil
Baloxavir marboxil (trade name Xofluza®) is an influenza (flu) antiviral drug given as a pill in a single dose by mouth that was approved on October 24, 2018, by the U.S. Food and Drug Administration (FDA).
Patient Profile for Baloxavir Marboxil
Baloxavir is currently approved by the FDA for treatment of flu in children aged 5 years to less than 12 years who do not have any chronic medical conditions, and for all people aged 12 years and older. Baloxavir also is approved by the FDA for post-exposure prophylaxis of flu in people aged 5 years and older. CDC does not recommend use of baloxavir in pregnant people, breastfeeding people, outpatients with complicated or progressive illness, severely immunosuppressed people, or hospitalized patients because of the lack of information on use of baloxavir for these groups to date.
Administering Baloxavir Marboxil
Baloxavir is available as an oral tablet (20mg, 40mg, or 80mg) and given in a single dose by mouth.
Other Available Antiviral Drugs for Flu
In the United States, there are four FDA-approved antiviral drugs recommended by CDC this season:
- Oseltamivir (available as a generic version or under the trade name Tamiflu®)
- Zanamivir (trade name Relenza®)
- Peramivir (trade name Rapivab®)
- Baloxavir (trade name Xofluza®)
Finding Antiviral Drugs for Flu Treatment
Antiviral drugs for flu treatment are not sold over the counter. You can only get them from a pharmacy if you have a prescription from your doctor or health care provider.
Reasons Behind New Flu Antiviral Medications
Baloxavir works differently than the other currently recommended flu antiviral drugs, which are neuraminidase inhibitors (oseltamivir, zanamivr and peramivir). Given how frequently flu viruses change and the potential for flu viruses to develop resistance or reduced susceptibility to one or more flu antiviral drugs, it is good to have more options for treating flu. For example, flu viruses that are resistant to oseltamivir should still be susceptible to baloxavir.
Understanding Antiviral Resistance with Baloxavir
Reduced susceptibility and antiviral resistance mean, respectively, that a flu virus has changed in such a way that antiviral drugs are less effective or not effective at all in treating or preventing illnesses with that flu virus. Flu viruses can develop reduced susceptibility or resistance to one or more antiviral drugs, including baloxavir. In randomized clinical trials, there was evidence of development of reduced susceptibility in some patients treated with baloxavir.
CDC's Approach to Testing Antiviral Resistance to Baloxavir
CDC's Influenza Division has taken specific actions in the laboratory to incorporate the antiviral drug baloxavir into routine virologic surveillance. This includes the creation and validation of assays to determine baloxavir susceptibility, and training of laboratorians to conduct baloxavir susceptibility testing.