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Content on this page was developed during the 2009-2010 H1N1 pandemic and has not been updated.

  • The H1N1 virus that caused that pandemic is now a regular human flu virus and continues to circulate seasonally worldwide.
  • The English language content on this website is being archived for historic and reference purposes only.
  • For current, updated information on seasonal flu, including information about H1N1, see the CDC Seasonal Flu website.

Quick Facts for the Public on Antiviral Treatments for 2009 H1N1

Questions to Ask Your Doctor

Here are a few questions to consider asking your health care provider about flu antivirals

  • Do I need antiviral treatment if I have flu symptoms?
  • When should I call back if I don’t feel better?
  • What do I do if my child is prescribed oseltamivir and can’t swallow capsules? Click here for instructions on how to open capsules and mix the medicine with liquids.

Treatment Is Important for High Risk Groups

People in high risk groups should talk to their health care provider as soon as possible if they think they may have the flu because they have a greater chance of getting serious flu complications than other persons. Flu antiviral drugs can make you feel better, shorten the time you are sick, and prevent serious flu complications, especially if treatment is begun within 2 days of getting sick. Flu antiviral drugs must be prescribed by a physician.

Don’t Delay Treatment

If your doctor prescribed Tamiflu® (oseltamivir) or Relenza® (zanamivir) for you, don’t delay filling the prescription, and start taking the medication as soon as you get it. This way you will get the most benefit. It’s very important that antiviral drugs be started as soon as possible for the flu, ideally within 2 days of getting sick.

Don’t Confuse Tamiflu® (oseltamivir) with Theraflu®

Tamiflu® is the brand name and oseltamivir is the generic name of a prescription antiviral drug used to treat the flu and should not be confused with Theraflu®, which is an over-the-counter medication. Antiviral drugs are not sold over-the-counter. You can only get them if you have a prescription from your health care provider.

Side Effects of Flu Antiviral Drugs

The most common side effects of oseltamivir (Tamiflu®) are nausea and vomiting, which can also be symptoms of the flu. Nausea and vomiting can be minimized by taking the medication with food. The most common side effects of zanamivir (Relenza®) are dizziness, sinusitis, runny or stuffy nose, cough, diarrhea, nausea, or headache, also symptoms that can be due to the flu. Zanamivir may also cause wheezing and trouble breathing in people with lung disease; therefore, persons with a history of asthma or another lung disease should not be prescribed zanamivir.

Treatment May Be Needed Even if Test Results are Negative

Your health care provider may diagnose you with flu based on your symptoms and their clinical judgment or they may choose to use an influenza diagnostic test. Health care providers can use rapid flu tests (15 minutes or less) to test a specimen from your nose or throat in their offices. Unfortunately, these tests are less than perfect in telling who really has the flu. Therefore, you could still have the flu, even though your rapid flu test result is negative. Health care providers may prescribe antivirals if they suspect flu, even if the rapid flu test is negative.

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