How Do Influenza Antivirals Help Ease Flu Symptoms?

Discover what these medications do + why they don't replace the flu shot
woman on the couch sick with flu

With the concern of COVID-19 mixing with flu season this fall and winter, experts are concerned about the spread of both illnesses. But one key difference between the flu and COVID-19 is that there are vaccines to prevent flu.

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There will never be a replacement for getting your annual flu shot, but there are a variety of antiviral medications that medical experts can use when someone has the flu or is suspected to have the flu.

These medications are called antiviral drugs and are only available from a doctor. Influenza antivirals are used to lessen flu symptoms and can shorten the amount of time someone is sick.

“All influenza antivirals work by reducing how much the flu virus reproduces in your body,” says infectious disease specialist Susan Rehm, MD.

But, just because influenza antiviral medications are available doesn’t mean you should rely on a pill to knock the flu out of your system, she cautions. Your annual flu shot is still your best defense against the flu.

Why is the flu such a big deal?

Influenza can be a deadly illness for anyone.

“People at the extremes of age and those with underlying conditions are at even higher risk of complications and death,” says Dr. Rehm. “62,000 Americans lost their lives during the 2019-2020 flu season, and over half a million people were hospitalized.”

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The majority of those flu deaths involved people aged 65 and older or who were at high risk.  

You’re considered high risk when you:

  • Are younger than 2 years of age or older than 65.
  • Have a chronic condition, such as heart, lung, kidney or neurologic disease or diabetes.
  • Are immunosuppressed.
  • Are a pregnant woman.
  • Are obese.
  • Live in a chronic care facility, such as a nursing home.

If you’re at high risk of flu complications, it’s important that you call your healthcare provider at the first signs of illness.

How do you know you have the flu and not a cold?

It’s tough to tell the difference between symptoms of a cold and symptoms of the flu. The word F.A.C.T.S. — Fever, Aches, Chills, Tiredness, Sudden onset — can help you remember what symptoms are more common with the flu.

“The flu can make you feel like you’ve been hit by a truck, with muscle aches and/or a headache,” Dr. Rehm explains. “Colds come on more gradually, and are more likely to cause a stuffy and runny nose.”

How can you tell the difference between the flu and COVID-19?

Symptoms of influenza and COVID-19 can be very similar. Your doctor may recommend that you be tested for both viruses, especially if you’re high risk for complications. Influenza antiviral medications are not active against COVID-19.

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How many flu antivirals are available?

Many antivirals have been used to treat flu over the years, but doctors currently rely on four main ones. To treat influenza, doctors can prescribe:

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

All of these antiviral medications work best when given soon after symptoms start. Contact your doctor if you think you might have influenza or COVID-19 and you are at high risk for complications.

How do influenza antivirals help with the flu?

They work best when taken within 48 hours of the onset of flu symptoms. Antivirals may reduce your symptoms’ duration by about one day and reduce the amount of virus in your system. If your infection comes under control more quickly you may be less likely to develop complications and less likely to spread it to other people.

Antivirals are good precautions, but not a substitute for the flu shot

“It’s important for doctors to have a variety of medicines on reserve for people at high risk of complications, and for times when there is a vaccine mismatch or a new strain of influenza emerges,” says Dr. Rehm. “But I can’t emphasize enough that vaccination is the mainstay of prevention.”

Everyone 6 months of age and older should get the flu vaccine — every single year.

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