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What You Should Know About Flu Antiviral Drugs

Note: The Food and Drug Administration (FDA) approved a new influenza antiviral drug, baloxavir marboxil (trade name Xofluza®), on October 24, 2018. Content on this website is being updated to reflect the most recent guidance. More information about baloxavir marboxil [594 KB, 13 pages] is available.



Can the flu be treated?

Yes. There are prescription medications called “antiviral drugs” that can be used to treat flu illness.

What are antiviral drugs?

Antiviral drugs are prescription medicines (pills, liquid, an inhaled powder, or an intravenous solution) that fight against the flu virus in your body. Antiviral drugs are not sold over-the-counter. You can only get them if you have a prescription from your doctor or health care provider. Antiviral drugs are different from antibiotics, which fight against bacterial infections.

What should I do if I think I have the flu?

If you get the flu, antiviral drugs are a treatment option. Check with your doctor promptly if you are at high risk of serious flu complications (Full list of high risk factors) and you develop flu symptoms. Flu signs and symptoms can include feeling feverish or having a fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Your doctor may prescribe antiviral drugs to treat your flu illness.

Should I still get a flu vaccine?

Yes. Antiviral drugs are not a substitute for getting a flu vaccine. While flu vaccine can vary in how well it works, a flu vaccine is the first and best way to prevent seasonal flu. Antiviral drugs are a second line of defense to treat the flu (including seasonal flu and variant flu viruses) if you get sick.

What are the benefits of antiviral drugs?

When treatment is started within two days of becoming sick with flu symptoms, antiviral drugs can lessen symptoms and shorten the time you are sick by about one day. They may reduce the risk of complications such as ear infections in children, and pneumonia and hospitalizations in adults.  For people at high risk of serious flu complications, early treatment with an antiviral drug can mean the difference between having milder illness instead of more severe illness that might require a hospital stay.  For adults hospitalized with flu illness, early antiviral treatment can reduce their risk of death.

What are the possible side effects of antiviral drugs?

The most common reported side effects of antiviral drugs for flu are nausea and vomiting. Other less common side effects also have been reported. Your doctor can give you more information about these drugs or you can check the Food and Drug Administration (FDA) website for specific information about an antiviral drug, including the manufacturer’s package insert.

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When should antiviral drugs be taken for treatment?

Studies show that flu antiviral drugs work best for treatment when they are started within two days of getting sick. However, starting them later can still be beneficial, especially if the sick person is at high risk of serious flu complications or is in the hospital with more severe illness.  Follow instructions for taking these drugs.

What antiviral drugs are recommended this flu season?

There are three FDA-approved antiviral drugs recommended by CDC to treat flu this season.

  • oseltamivir (available as a generic version or under the trade name Tamiflu®),
  • zanamivir (trade name Relenza®), and
  • peramivir (trade name Rapivab®).

Generic oseltamivir and Tamiflu® are available as a pill or liquid suspension and are FDA approved for early treatment of flu in people 14 days old and older. Relenza® is a powder that is inhaled and approved for early treatment of flu in people 7 years of age and older. (Note: Relenza® is not recommended for people with breathing problems like asthma or COPD.) Rapivab® is given intravenously by a health care provider and is approved for early treatment of flu in people 2 years of age and older.

How long should antiviral drugs be taken?

To treat the flu, oseltamivir and zanamivir are usually prescribed to be taken twice daily for 5 days, although people hospitalized with the flu may need antiviral treatment for longer than 5 days. Peramivir is given one time intravenously over a period of 15 to 30 minutes.

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Can children take antiviral drugs?

Yes. Oseltamivir is recommended by the CDC and American Academy of Pediatrics (AAP) for early treatment of flu in people of any age, and for the prevention of flu (i.e., prophylaxis) in people 3 months of age and older. Zanamivir is recommended for early treatment of flu in people 7 years of age and older, and for the prevention of flu in people 5 years of age and older. Peramivir is recommended for early treatment in people 2 years of age and older.

If your child’s provider prescribes oseltamivir capsules for your child and your child cannot swallow capsules, the prescribed capsules may be opened, mixed with a thick sweetened liquid, and given that way. Learn more here.

Can pregnant women take antiviral drugs?

Yes. Oral oseltamivir is recommended for treatment of pregnant women with flu because compared to other recommended antiviral medications it has the most studies available to suggest that it is safe and beneficial during pregnancy.

Who should take antiviral drugs?

It’s very important that flu antiviral drugs are started as soon as possible to treat hospitalized flu patients, people who are very sick with the flu but who do not need to be hospitalized, and people who are at high risk of serious flu complications based on their age or health if they develop flu symptoms. Although other people with mild illness who are not at high risk of flu complications may also be treated early with antiviral drugs by their doctor, most people who are otherwise healthy and get the flu do not need to be treated with antiviral drugs.

Following is a list of all the health and age factors that are known to increase a person’s risk of getting serious complications from the flu:
  • Asthma
  • Neurological and neurodevelopmental conditions
  • Blood disorders (such as sickle cell disease)
  • Chronic lung disease (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis)
  • Endocrine disorders (such as diabetes mellitus)
  • Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
  • Kidney disorders
  • Liver disorders
  • Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)
  • People who are obese with a body mass index [BMI] of 40 or higher
  • People younger than 19 years of age on long-term aspirin therapy
  • People with a weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids)

Other people at high risk from the flu:

  • Adults 65 years and older
  • Children younger than 5 years old, but especially children younger than 2 years old
  • Pregnant women and women up to 2 weeks after the end of pregnancy
  • American Indians and Alaska Natives
  • People who live in nursing homes and other long-term care facilities

Additional Resources

What You Should Know, Flu Antiviral Drugs

What You Should Know About Influenza (Flu) Antiviral Drugs

Fact Sheet [202 KB, 2 Pages]


Influenza Round Table: Take Three Influenza Round Table: Take Three [Streaming, 2 min 20 sec]
Dr. Joe Bresee describes how to keep from getting seasonal flu and spreading it to others by taking these three steps.

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