The flu season is upon us and it is vital that clinicians understand the recommendations for prescribing influenza antiviral medications.

Antiviral treatment can be considered for any previously healthy, symptomatic outpatient not at high risk for flu complications, who is diagnosed with confirmed or suspected influenza, on the basis of clinical judgment, if treatment can be initiated within 48 hours of illness onset.

Studies show that flu antiviral drugs work best for treatments when they are started within 48 hours of illness onset. However, starting them later can still be helpful, especially if the sick person has a high-risk health condition or is very sick from flu (for example, hospitalized patients).

 It is important to know that antiviral treatment is recommended as early as possible for any patient with confirmed or suspected flu who:

• is hospitalized;*
• has severe, complicated, or progressive illness; * or
• is at higher risk for influenza complications.

*Note: Oral oseltamivir is the recommended antiviral for patients with severe, complicated, or progressive illness who are not hospitalized, and for hospitalized influenza patients.

The following are current recommendations for the 2019-2020 flu season:

• For outpatients with acute uncomplicated flu, oral oseltamivir, inhaled zanamivir, intravenous peramivir, or oral baloxavir may be used for treatment.
• For patients with severe or complicated illness with suspected or confirmed flu (e.g., pneumonia, or exacerbation of underlying chronic medical condition) who are not hospitalized, antiviral treatment with oral or enterically-administered oseltamivir is recommended as soon as possible.
• Pregnant women are recommended to receive the same antiviral dosing as non-pregnant people. Oral oseltamivir is preferred for the treatment of pregnant women. 

The decision about starting antiviral treatment should not wait for laboratory confirmation of influenza. Starting the antiviral as close to the onset of illness is recommended. By delaying the start of antivirals, you are risking a decrease in the greatest benefit. We know that the best protection against flu is vaccination, the history of vaccination should not rule out the possibility of influenza virus infection or delay the treatment with antivirals.

CDC has issued an excellent clinical guidance summary that can be found here.

Thank you to Alyssa Strouse, MPH, Adult and Adolescent Immunization Coordinator at the Michigan Dept. of Health and Human Services for partnering with MINAPNAP in promoting vaccination/preventing communicable diseases and for providing this very important information.