What You Should Know About Flu Antiviral Drugs

a doctor holding pills and a prescription

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Can flu be treated?

Yes. There are prescription medications called “antiviral drugs” that can be used to treat flu illness. CDC recommends prompt treatment for people who have flu infection or suspected flu infection and who are at high risk of serious flu complications, such as people with asthma, diabetes (including gestational diabetes), or heart disease.

What are antiviral drugs?

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

What should I do if I think I am sick with flu?

If you get sick with flu, antiviral drugs are a treatment option. Check with your doctor promptly if you are at high risk of serious flu complications (see box below for the 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 best way to help prevent seasonal flu and its potentially serious complications. Antiviral drugs are a second line of defense that can be used to treat flu (including seasonal flu and variant flu viruses) if you get sick.

What are the benefits of antiviral drugs?

Antiviral treatment works best when started soon after flu illness begins. When treatment is started within two days of becoming sick with flu symptoms, antiviral drugs can lessen fever and flu symptoms, and shorten the time you are sick by about one day. They also may reduce the risk of complications such as ear infections in children, respiratory complications requiring antibiotics, and hospitalization in adults. For people at high risk of serious flu complications, early treatment with an antiviral drug can mean having milder illness instead of more severe illness that might require a hospital stay. For adults hospitalized with flu illness, some studies have reported that early antiviral treatment can reduce their risk of death.

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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 four FDA-approved antiviral drugs recommended by CDC to treat flu this season.

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

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 and older. Zanamivir is a powder that is inhaled and approved for early treatment of flu in people 7 years and older. (Note: Zanamivir (trade name Relenza®) is administered using an inhaler device and is not recommended for people with breathing problems like asthma or COPD.) Peramivir is given intravenously by a health care provider and is approved for early treatment of flu in people 2 years and older. Baloxavir is a pill given as a single dose by mouth and is approved for early treatment of flu in people 12 years and older. (Note: Baloxavir (trade name Xofluza®) is not recommended for pregnant women, breastfeeding mothers, outpatients with complicated or progressive illness, or hospitalized patients because there is no information about use of baloxavir in these patients.)

How long should antiviral drugs be taken?

Duration of treatment varies depending on the antiviral drug prescribed. Oseltamivir and zanamivir are usually prescribed to be taken twice daily for 5 days, although people hospitalized with flu may need antiviral treatment for longer than 5 days. Peramivir is given one time intravenously over a period of 15 to 30 minutes. Baloxavir is given as a single oral dose.

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What are the possible side effects of antiviral drugs?

Side effects vary for each medication. The most common side effects for oseltamivir are nausea and vomiting. Zanamivir can cause bronchospasm, and peramivir can cause diarrhea. Other less common side effects also have been reported. Your health care provider can give you more information about these drugs or you can check the Food and Drug Administration (FDA) website for specific information about antiviral drugs, including the manufacturer’s package insert.

Children and Flu Antiviral Drugs

Parents, if your child gets sick with flu, antiviral drugs offer a safe and effective treatment option. For treatment, influenza antiviral drugs should ideally be started within 2 days after becoming sick and taken for 5 days.

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Can children take antiviral drugs?

Yes. Oseltamivir is recommended by CDC and the 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 and older. Zanamivir is recommended for early treatment of flu in people 7 years and older, and for the prevention of flu in people 5 years and older. Peramivir is recommended for early treatment in people 2 years and older. Baloxavir is recommended for early treatment of flu in people 12 years and older.

If your child’s health care 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. Baloxavir is not recommended for pregnant women or breastfeeding mothers, as there are no available efficacy or safety data.

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 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 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 flu:

Asthma
Neurologic and neurodevelopment 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- or salicylate-containing medications.
People with a weakened immune system due to disease (such as people with HIV or AIDS, or some cancers such as leukemia) or medications (such as those receiving chemotherapy or radiation treatment for cancer, or persons with chronic conditions requiring chronic corticosteroids or other drugs that suppress the immune system)

Other people at high risk from flu:

Adults 65 years and older
Children younger than 2 years old1
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
1 Although all children younger than 5 years old are considered at high risk for serious flu complications, the highest risk is for those younger than 2 years old, with the highest hospitalization and death rates among infants younger than 6 months old.

Additional Resources

What You Should Know, Flu Antiviral Drugs

What You Should Know About Influenza (Flu) Antiviral Drugs

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Treating Influenza (Flu)

Fact Sheet [308 KB, 2 Pages, 8.5″ x 11″]

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.