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Influenza (Flu) Antiviral Drugs and Related Information

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Note: Information provided may change and should not be used as a substitute for individual evaluation by a health care provider, or as the primary means of diagnosing influenza or determining treatment.

Illustration of Magnified VirusIntroduction   

The term influenza refers to illness caused by influenza virus. This is commonly called the flu, but many different illnesses cause flu-like symptoms such as fever, chills, aches and pains, cough, and sore throat. Influenza can cause different illness patterns, ranging from mild common cold symptoms, to typical flu, to life-threatening pneumonia, bacterial infections and other complications.

There are a number of drugs approved by FDA for the treatment and prevention of influenza but they are not a substitute for yearly vaccination. Yearly vaccination is the primary means of preventing and controlling influenza.

Antibiotics are used to treat illnesses caused by bacteria like strep throat, tuberculosis and many types of pneumonia. Antibiotics do not treat viral illnesses like flu, colds, and most sore throats.

Influenza Vaccine Information

  • Seasonal Flu Vaccine. Information from Center for Biologics Evaluation and Research (CBER) about Seasonal Influenza Vaccine.
  • Questions about Vaccines. Information from Center for Biologics Evaluation and Research (CBER) on general vaccine topics, including influenza vaccines.
  • Seasonal Flu. Comprehensive flu information for consumers and healthcare professionals from the Centers for Disease Control and Prevention (CDC).
  • Influenza Vaccine. Consumer information from the CDC containing basic vaccine questions and answers. 

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Use of Antiviral Medications to Treat Influenza

Outbreaks of influenza occur every year and typically reach epidemic levels at some part of the season. Usually, uncomplicated influenza gets better with or without treatment but may cause substantial discomfort and limit activities while it lasts.

Many people with uncomplicated influenza use over-the-counter medicines, get rest, and take plenty of fluids to lessen their symptoms. Antiviral drugs available by prescription can reduce the time it takes for symptoms to improve, and are used in selected situations to reduce the chance of illness in people exposed to influenza. Prompt medical evaluation is important for early treatment of influenza as the antiviral drugs may provide the most benefit for patients who initiate therapy within 48 hours of symptom onset.

Complications of influenza can include bacterial infections, viral pneumonia, and cardiac and other organ system abnormalities. People with chronic medical conditions (including obesity), children younger than 5 years old (and especially children less than 2 years old), patients 65 years and older, residents of long-term care facilities, Native Americans and Alaska Natives and pregnant women may be at increased risk for complications.

Complications of influenza, and other illnesses that resemble influenza, may require different treatment and, in some cases, urgent medical attention. Antiviral drugs do not eliminate the risk of complications. Some complications can be life-threatening. There have been reports of people with other types of infections that got worse because they were treated only for influenza and not for the other infections. Influenza viruses can become resistant to specific anti-influenza antiviral drugs, and all of these drugs have side effects. If you experience new symptoms during treatment or your symptoms persist or get worse during treatment, see your health care professional.

Many other diseases, including rapidly progressive bloodstream infections, may start with symptoms that resemble influenza, and may need to be considered in treatment decisions. Laboratory tests can help detect influenza. However, a negative test does not always rule out the possibility of an influenza infection, and positive tests do not exclude the possibility of other illnesses or take the place of clinical evaluation.  

If a new variety of influenza is transmitted rapidly it can cause widespread illness known as a pandemic. Depending on the strain of influenza, antiviral drugs may not work to the same extent. The government stockpiles antiviral drugs, and develops recommendations about their use as part of pandemic preparations.

For more information and public health recommendations about circulating influenza virus go to Flu.gov or to the CDC and WHO websites. 

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FDA Approved Drugs for Influenza

There are three FDA-approved influenza antiviral drugs recommended by CDC for use against recently circulating influenza viruses.

Two older drugs, amantadine (generic) and rimantadine (Flumadine and generic) historically have been approved for treatment and prevention of influenza A. But many strains of influenza, including the 2009 H1N1 influenza, are now resistant to these drugs. CDC has not recommended the use of these drugs for recently circulating influenza viruses, although recommendations could change if there were future re-emergence of specific virus strains with susceptibility patterns favoring such use.

Clinical Trials

Clinical trials evaluate the safety and efficacy of unapproved products or new uses for approved products. Information about open clinical trials can be found at ClinicalTrials.gov.

Resources for Drug Product Information

Information about expanded access regulations, other aspects of drug development and review, and resources about the approval status of drugs and formulations can be found at:

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Drug Shortage Reports

  • When shortage reports occur, check the FDA Drug Shortages web page for updated information.  

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Contacts for More Information

  • Information on availability of influenza vaccine:
    Food and Drug Administration
    Center for Biologics Evaluation and Research
    Office of Communication, Training & Manufacturers Assistance
    800-835-4709 or 240-402-8010
  • Information on drugs used to treat influenza:
    Food and Drug Administration
    Center for Drug Evaluation and Research
    Drug Information Line
    888-info-FDA or 301-827-4573.  Fax: 301-827-4577
  • Information on influenza prevention and control:
    Centers for Disease Control and Prevention
    Public Inquiries Office
    800-311-3435 or 404-639-3311.  Fax: 770-488-4995
    800-CDC-INFO (800-232-4636) TTY: (888) 232-6348

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