Antiviral Guidance for Influenza

Antiviral drugs are an adjunct to, not a substitute for, vaccination for preventing and controlling influenza.

Table of Contents

Antiviral drug recommendations

MDPH recommends the use of neuraminidase inhibitors listed below: 

  • Oseltamivir (Tamiflu®) 
  • Zanamivir (Relenza®) 
  • Peramivir (Rapivab®) 
  • Baloxavir (Xofluza®)

Prompt empiric antiviral treatment

Clinical judgment is an important factor in treatment decisions for patients presenting with influenza-like illness. Prompt empiric antiviral treatment with influenza antiviral medications is recommended while results of definitive diagnostic tests are pending, or if diagnostic testing is not possible, for patients with clinically suspected influenza illness who have: 

  • Illness requiring hospitalization 
  • Progressive, severe, or complicated illness, regardless of previous health status, and/or  
  • Increased risk for severe disease. 

Antiviral treatment, when clinically indicated, should not be delayed, pending definitive laboratory confirmation of influenza. Influenza antiviral medications are most effective when initiated within the first two days of illness, but these medications may also provide benefits for severely ill patients when initiated even after two days. Guidance on use of antivirals may change depending upon resistance data. 

Consult CDC’s latest recommendations on antiviral use.

Antiviral agents for outbreaks

Antiviral chemoprophylaxis should be considered following identification of any laboratory-confirmed case of influenza or when three or more residents have influenza-like illness (e.g., fever with cough and/or sore throat) in a facility or area of the facility. 

Administered to all residents 

When antiviral agents are used for outbreak control, they should be administered to all residents regardless of immunization status. Priority should be given to residents living on the same unit or floor as an ill resident. 

Ordering Antiviral Agents 

Pre-approved medication orders, or plans to obtain physician’s orders on short notice, should be in place to ensure that chemoprophylaxis can be started as soon as possible. 


The antiviral dose for each resident is determined based on age, renal function, liver function, and other pertinent characteristics. 

Continual treatment 

The drugs should be continued for a minimum of two weeks and continue for at least seven days after the last known case was identified. 

Chemoprophylaxis for variant flu strains 

All staff, regardless of vaccination status, should be offered chemoprophylaxis if there are any indications that the outbreak is caused by a variant strain of influenza that is not covered by the vaccine. 

All unvaccinated staff should be re-offered influenza vaccine 

They should also be offered chemoprophylaxis if they care for persons at high risk for complications. 

Additional Information 

Additional information can be found on the CDC’s guidance concerning control of influenza in LTCFs page. 

Clinicians should be alert to changes in antiviral recommendations that might occur as additional antiviral resistance data becomes available. For more information visit the CDC’s Influenza Antiviral Medications: Summary for Clinicians.   

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