Will the Newest Antiviral Help to Ease Your Flu Symptoms?

Discover what it does (and why it doesn't replace a flu shot)

For the first time in 20 years, the U.S. Food and Drug Administration has approved a drug to treat early flu: baloxavir marboxil, or Xofluza®. Doctors are already armed with antivirals to fight flu. So how is this one different?

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“All antivirals work by reducing how much the flu virus reproduces in your body,” says infectious disease specialist Susan Rehm, MD. “Baloxavir marboxil is more convenient to take, works in a different way than the older influenza antiviral medications, and may be active against rare, resistant strains of flu.”

This 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 the best defense against flu.

Why is the flu such a big deal?

“Influenza is a deadly illness for those at high risk, including those at the extremes of age,” says Dr. Rehm. “Nearly 80,000 Americans lost their lives during the 2017-2018 flu season, and nearly a million people  were hospitalized.”

Eighty to 90 percent of those flu deaths involved people aged 65 and older. And an exceptionally high number of children — 183 — lost their lives during the last flu season.

How do antivirals help? They work best when taken within 48 hours of the onset of flu symptoms. Antivirals, which are prescribed by your doctor, will reduce your symptoms’ duration by about one day.

But flu symptoms typically last for two or more days, so you can still become very ill — and expose people around you, including those at high risk.

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How many antivirals are available?

Many antivirals have been used to treat flu over the years, but doctors currently rely on just three.

“There aren’t a lot of flu strains resistant to these drugs, as is the case with the other antivirals,” explains Dr. Rehm. Each year, the flu virus morphs into new strains, which are resistant to the older drugs.

With the new drug, doctors now have four options to shorten the duration of your flu:

  • Baloxavir marboxil (Xofluza®): One pill, taken in a single dose, for ages 12 and up.
  • Oseltamivir (Tamiflu®): Pills, taken twice a day for five days or once a day for 10 days, for ages 1 and up.
  • Peramivir (Rapivab®): Intravenous (IV) medicine, given as a single dose in the hospital, for ages 2 and up.
  • Zanamivir (Relenza®): Inhaled medicine, given twice a day for five days, for ages 7 and up.

How do you know you have 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 and Tiredness of Sudden onset — can help you remember which symptoms are more common with 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.”

When should you call your doctor about the flu?

If you are at high risk of flu complications, call your healthcare provider promptly at the first signs of flu. You’re considered at high risk when you:

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A new antiviral is a good precaution

“It’s good for doctors to have a variety of medicines in reserve for times when there is a vaccine mismatch or a new strain of influenza emerges,” says Dr. Rehm.

For example, sometimes the World Health Organization’s predictions of the three to four key flu strains to include in the yearly flu vaccine are off.

While baloxavir marboxil seems to more quickly lower the amount of flu virus in the body within the first 72 hours, research is needed to confirm whether this would impact the spread of flu.

“I can’t emphasize enough that vaccination is the mainstay of prevention,” she says. “Everyone 6 months of age and older should get the flu vaccine — every year.”

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