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Antiviral Medicines to Treat the Flu

Antiviral Medicines to Treat the Flu

This article is for people who have influenza ("the flu"), or anyone who's interested in learning more about treating the flu. The goal of this activity is to help people engage in shared decision-making with their doctor about antiviral medicines to treat the flu.

You will learn about:

  • What the flu is and who can get it

  • Complications that can happen from the flu and who is at a higher risk

  • Antiviral medicines to treat the flu

  • Possible side effects of antivirals

  • Questions to ask your doctor

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What Is the Flu?

Influenza -- or the flu -- is a respiratory illness caused by a number of viruses that can infect your nose, throat, and lungs. There are 2 main types of flu viruses -- types A and B -- that frequently spread during flu season, but flu viruses often change and new strains can develop regularly.

The flu is mainly spread by droplets containing the virus that form when someone who's infected talks, coughs, or sneezes. The flu can be spread to others before you even know you're sick, and for up to 7 days after. Some people -- including children and those with weakened immune systems -- can spread it even longer.

Flu Symptoms

Flu symptoms usually appear about 2 days (or 1 to 4 days) after being exposed to and infected with the flu.

They can range from mild to severe and include:

  • Fatigue (tiredness), weakness

  • Fever, chills, sweating

  • Headache

  • Sore throat

  • Runny or stuffy nose

  • Dry cough

  • Trouble breathing

  • Muscle or body aches

  • Eye pain

  • Vomiting, diarrhea

How Sick Can You Get From the Flu?

Anyone can get the flu. Many people can treat it themselves at home with the flu clearing up on its own. But for others, the flu can make them sick enough to be in the hospital (hospitalization) and can even be deadly.

Complications (additional problems) from the flu can happen to anyone, but people at a higher risk include:

  • Adults 65 and older

  • Children younger than 5

  • Pregnant women

  • People with certain health conditions, such as obesity, asthma, diabetes, heart disease, or a weakened immune system

Complications From the Flu

Complications from the flu can include:

  • Asthma flare-ups

  • Ear and sinus infections

  • Heart problems

  • Bronchitis -- inflammation (swelling) of the airways in your lungs

  • Pneumonia -- an infection that causes inflammation of the air sacs (alveoli) in your lungs

  • Acute respiratory distress syndrome (ARDS) that happens when fluid builds up in the alveoli

  • Worsening of certain chronic (long-term) health conditions, such as asthma and diabetes

When to Call Your Doctor

If you are at a higher risk of complications and have symptoms, or think you've been exposed to the flu, it's recommended that you contact your doctor. There are prescription medicines to treat the flu that may shorten how long you're sick for and help prevent complications.

If you have any of these symptoms with the flu, call your doctor or get medical attention right away:

  • Trouble breathing

  • Blue lips

  • Dizziness

  • Chest pain

  • Severe weakness or muscle pain

  • Seizures

  • Worsening of a chronic health condition

Is It the Flu or COVID-19?

The flu and COVID-19 share some of the same symptoms, but they are caused by different viruses, can affect people differently, and are treated differently.

Compared to the flu, with COVID-19 you may:

  • Lose your sense of taste or smell

  • Get symptoms 2 to 14 days after exposure

  • Have different complications

You can have the flu and COVID-19 separately, or at the same time. Getting vaccines; covering your mouth and nose when you cough, sneeze, or blow your nose; washing your hands; cleaning surfaces; and social distancing can help prevent the spread.

If you have symptoms or think you've been exposed to the flu and/or COVID-19, contact your doctor about getting tested.

Treating the Flu With Antivirals

Antivirals are prescription medicines that can help treat the flu. They work by preventing flu viruses inside your body from infecting healthy cells.

If started within 2 days of flu symptoms, antivirals may lower fever, lessen symptoms, and shorten how long you're sick for. They may also reduce the risk of certain complications and result in milder illness, instead of a more severe illness that might need hospitalization.

If you have the flu or think you have it, and are at a higher risk of complications, it's recommended that you get treated quickly.

Approved Antivirals for the Flu

While antivirals work best when started within 2 days of getting sick, starting them later can still help, especially if you're at a higher risk for complications.

Antivirals currently approved to treat the flu include:

  • Baloxavir marboxil (Xofluza®)

  • Oseltamivir phosphate (Tamiflu®)

  • Peramivir (Rapivab®)

  • Zanamivir (Relenza®)

Possible Side Effects

All medicines can have side effects. Some common ones that may happen with antivirals to treat the flu can include:

  • Nausea, vomiting, diarrhea

  • Headache, dizziness

  • Fever, chills

  • Bronchospasm (tightening of the airways in your lungs)

  • Sinus inflammation

  • Joint pain or inflammation

Not all side effects are listed here. Ask your doctor for a full list and when you should call them or seek medical attention because of side effects.

Questions to Ask Your Doctor

Questions you can ask your doctor about the flu and treatment with antivirals can include:

  • What symptoms of the flu should I look for?

  • Am I at a higher risk of complications from the flu?

  • When should I contact you if I think I have the flu or have been exposed to it?

  • What antivirals are available to treat the flu, when's the best time to take them, and what are their side effects?

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You have successfully completed the program Antiviral Medicines to Treat the Flu.

View Additional Materials on this topic that you may find useful:

People at High Risk for Flu Complications

Flu Antiviral Medicines

Influenza Antiviral Medications

What You Should Know About Flu Antiviral Drugs

Authors and Disclosures

Clinician Reviewer

Karen Badal, MD, MPH

Senior Medical Education Director, Medscape, LLC.

Disclosure: Karen Badal, MD, MPH, has disclosed the following relevant financial relationships:Owns stock, stock options or bonds from: Kallyope, Inc.


Anita A. Galdieri, PharmD, RPh

Associate Director, Content Development. Medscape, LLC.

Disclosure: Anita A. Galdieri, PharmD, RPh, has disclosed no relevant financial relationships.


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