Flu Antiviral Medications

Just as flu shots can help prevent the flu (influenza), antiviral medications can help reduce how long you have the flu. This is important, especially if you are in a high-risk group.

At Banner Health, your health and well-being are our top priority. We’re here to help you understand how antivirals can tackle the flu virus and help you recover faster.

What are influenza antiviral medicines?

Flu antiviral drugs are prescription medications (pills, liquid, inhaled powder or intravenous (IV)) designed to fight against the flu in your body. They work by blocking the virus from multiplying and spreading, which can shorten how long you are sick and lower the risk of complications.

What antivirals can you take for the flu?

There are currently four Food and Drug Administration (FDA)-approved antiviral drugs that used to treat the flu.

The most prescribed antivirals for the flu are neuraminidase inhibitors. They work by blocking the neuraminidase enzyme, which is needed for the flu virus to replicate. Some examples include:

• Oseltamivir phosphate (Tamiflu): This antiviral comes in pill or liquid form and can be used by adults and children as young as two weeks old. It is the first choice for treating the flu in pregnant people and children.
• Zanamivir (Relenza): This antiviral is available as an inhaler and is used by adults and children ages 7 and older. It is not recommended for people with breathing problems like asthma or chronic obstructive pulmonary disease (COPD).
• Peramivir (Rapivab): This antiviral is given through an IV and is suitable for adults and children over 6 months.

Another type of antiviral drug works by targeting a different part of the flu virus’ replication process:

• Baloxavir marboxil (Xofluza): This antiviral comes in pill  form and is a single dose treatment for  children aged 5 years to less than 12 years who do not have any chronic medical conditions, and for all people aged 12 years and older. This medication is not currently recommended for pregnant people or while breastfeeding.

What are the benefits of flu antiviral medications?

Taking antivirals early can shorten the length of the flu by about one day and help you feel better sooner.

They may also lower the risk of severe complications (such as pneumonia, ear infections and hospitalization), especially if you are at high risk for complications.

Antivirals can also help reduce the amount of virus being produced within your body, helping limit the spread of the virus to family members, friends, coworkers and your community.

Who should take flu antiviral medication?

Flu antiviral medications are prescribed by your health care provider and are used to treat flu symptoms. They work best when taken within 48 hours (about two days) of getting sick.

Flu antivirals are recommended for the following groups:

• People at high risk for complications: This includes children under 5 years old, adults over 65, pregnant people, people with chronic diseases like asthma or lung disease and/or those with weakened immune systems.
• People with severe flu symptoms: Contact your health care provider immediately if you experience severe symptoms like difficulty breathing, chest or belly pain, dizziness or confusion.

Can antivirals prevent the flu?

In addition to treating the flu, some antivirals can also be used for flu prevention. However, they are only recommended in certain situations. Getting an annual flu shot is still the best way to protect yourself and your loved ones.

Your provider may recommend antivirals for prevention if you:

• Are high risk but can’t receive the flu vaccine.
• Are high risk and someone in your home exposed you to the flu virus.
• Care for or live with someone who is in a high-risk group and you have been exposed to the flu.
• Work in a hospital or long-term care facility where the flu has been detected.

Do flu antiviral medications have side effects?

According to the Centers for Disease Control and Prevention (CDC), side effects can vary for each of the antiviral medications:

• Oseltamivir (Tamiflu): Common side effects include nausea and vomiting. Headache and pain are also possible. Talk to your health care provider if you have kidney problems before taking this medication.
• Zanamivir (Relenza): Side effects aren’t common but may include dizziness or a runny nose. It can also narrow the airways into the lungs. This is why it is not recommended for individuals with asthma, COPD and other lung disease.
• Peramivir (Rapibav): A common side effect is diarrhea. It may also cause changes to certain blood tests, such as blood sugar and white blood cell counts. Talk to your health care provider if you have kidney problems before taking this medication.
• Baloxavir marboxil (Xofluza): Common side effects include diarrhea, cough, nausea, sinusitis, and headache.  More severe side effects may include trouble breathing, skin rash, and dizziness or lightheadedness.

Other less common side effects have been reported. Your health care provider will determine which medicine is right for you.

Can I take an antibiotic to treat and prevent the flu?

No, antibiotics only cure bacterial infections. They will not kill cold or flu viruses.

Antiviral drugs for flu only work to treat the flu and are different from other antiviral drugs used to treat other viruses, such as COVID-19.

Emergency symptoms of the flu that you shouldn’t ignore

If you or a loved one have the following symptoms, call your provider immediately:

• Difficulty breathing
• Intense or ongoing chest or belly pain
• Dizziness
• Confusion
• Severe or repeated vomiting and/or diarrhea
• Coughing up blood
• Drowsiness, difficulty waking up or unresponsiveness

Learn more about seeking medical care for the flu.

It’s not too late to get vaccinated

While flu antivirals help treat the flu, the best way to stop the flu is to get a flu shot. That’s because several flu strains circulate each season.

The flu shot boosts your defense against these strains, even if you’ve already had one of them this year. This can help limit how sick you get if you get the flu again.

Learn more about flu vaccination and common myths and facts about flu shots.