Xofluza is a brand-name prescription medication. It’s FDA-approved for use in adults and children ages 12 years and older to:

  • Treat influenza. Xofluza is approved to treat influenza (the flu) that doesn’t require treatment in the hospital. It’s used in people who’ve had flu symptoms for up to 48 hours and who are either:
    • healthy, with no risk factors for complications from the flu, or
    • have a high risk for developing complications from the flu, such as pneumonia
  • Prevent influenza. Xofluza is approved to prevent the flu in people who’ve had contact with someone who’s known to have the flu.

For more information about how Xofluza is used to treat or prevent the flu, see the “Xofluza uses” section below.

Drug details

Xofluza contains the active drug baloxavir marboxil. It’s a type of drug called an antiviral. Xofluza stops the flu virus from multiplying inside your body. Depending on how you’re using the drug, Xofluza help you recover from the flu faster than usual or help prevent you from getting sick with the flu.

Xofluza comes as:

  • Tablets. These are taken by mouth and are available in two strengths: 20 milligrams (mg) and 40 mg.
  • Granules that are made into a solution. Xofluza solution is taken by mouth and is available in one strength: 40 mg/20 mL.

Xofluza is taken as a single, one-time dose for the flu. To treat the flu, you should take Xofluza within 48 hours of when your flu symptoms start. And to prevent the flu, you should take Xofluza as soon as possible after you’ve had contact with someone who has the flu.

FDA approval

Xofluza was first approved to treat influenza in 2018. It’s the first single-dose antiviral treatment for flu that’s taken by mouth. Then in November 2020, the FDA approved Xofluza to prevent the flu.

Effectiveness

For details about the effectiveness of Xofluza in treating or preventing the flu, see the “Xofluza uses” section.

Xofluza is available only as a brand-name medication. It’s not currently available in generic form.

A generic drug is an exact copy of the active drug in a brand-name medication. Generics usually cost less than brand-name drugs.

Xofluza is taken as a single, one-time dose that’s based on your body weight. The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Xofluza comes as:

  • Tablets. These are taken by mouth and are available in two strengths: 20 mg and 40 mg.
  • Granules that are made into a solution. Xofluza solution is taken by mouth and is available in one strength: 40 mg/20 mL.

Note: Your pharmacist will mix Xofluza granules into a solution before dispensing the drug to you. It’s important that you take the solution within 10 hours after it’s been mixed. This is because it doesn’t contain any preservatives, so it’s meant to be taken shortly after it’s made.

Dosage for treating or preventing the flu

The recommended dosage of Xofluza is the same for either treating or preventing influenza (the flu). Dosages for Xofluza tablets and Xofluza solution are described below. With either form of the drug, you should take a single dose of Xofluza:

  • within 48 hours of when your flu symptoms start, or
  • as soon as possible after you’re in contact with someone who has the flu

Dosage for Xofluza tablets

The recommended dosing instructions of Xofluza tablets for adults and children ages 12 years and older are as follows:

  • people who weigh less than 80 kilograms (kg), or about 176 pounds (lb), should take a single dose of 40 mg (two 20-mg tablets)
  • people who weigh 80 kg (176 lb) or more should take a single dose of 80 mg (two 40-mg tablets)

Dosage for Xofluza solution

The recommended dosing instructions of Xofluza solution for adults and children ages 12 years and older are as follows:

  • people who weigh less than 80 kilograms (about 176 pounds) should take a single dose of 40 mg (one 40 mg/20 mL-bottle)
  • people who weigh 80 kilograms or more should take a single dose of 80 mg (two 40 mg/20 mL-bottles)

Pediatric dosage

Xofluza is not approved for children under 12 years old. For children ages 12 years and older, see the recommended dosing instructions above.

What if I miss a dose?

Xofluza is taken as a single, one-time dose. It’s not meant to be taken every day.

Will I need to use this drug long term?

No, Xofluza is meant to be used as a one-time treatment for either treating or preventing the flu.

As with all medications, the cost of Xofluza can vary. To find current prices for Xofluza in your area, check out GoodRx.com.

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

It’s possible that you may have to pay for part or all of the cost of Xofluza. This could happen if your insurance doesn’t completely cover the cost, if you have a copay or coinsurance, or if you don’t have health insurance. In that case, you’ll need to decide whether shortening your symptoms by about a day is worth the cost.

Before approving coverage for Xofluza, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Xofluza, contact your insurance company.

Financial assistance

If you need financial support to pay for Xofluza, help is available. Genentech, the manufacturer of Xofluza, offers a coupon for the medication. For more information and to find out if you’re eligible for support, call 855-XOFLUZA (855-963-5892) or visit the coupon website.

Generic version

Xofluza is not available in a generic form. A generic drug is an exact copy of the active drug in a brand-name medication. Generics tend to cost less than brand-name drugs.

Xofluza can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Xofluza. These lists do not include all possible side effects.

For more information on the possible side effects of Xofluza, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs they have approved. If you would like to report to the FDA a side effect you’ve had with Xofluza, you can do so through MedWatch.

Mild side effects

Mild side effects of Xofluza can include*:

  • diarrhea
  • bronchitis(swelling of the airways)
  • nausea
  • sinusitis (swelling in your sinuses)
  • headache

These side effects can also be symptoms of the flu.

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Xofluza. To learn about other mild side effects, talk with your doctor or pharmacist, or visit Xofluza’s Medication Guide.
† For more information on this side effect, see “Side effect details” below.

Serious side effects

Serious side effects from Xofluza aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects, explained below in “Side effect details,” include:

Side effects in children

Xofluza is only approved to treat flu in children ages 12 years and older. Side effects in this age group are similar to side effects in adults, as described above and below.

How long do Xofluza side effects last?

If you have side effects after taking Xofluza, these typically go away within a few days or a couple of weeks. However, if your side effects don’t go away or if they become more severe, talk with your doctor or pharmacist.

Side effect details

You may wonder how often certain side effects occur with this drug or whether certain side effects pertain to it. Here’s some detail on certain side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Xofluza. It’s not known how often this occurred in clinical trials.

Symptoms of a mild allergic reaction can include:

  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • skin rash, including erythema multiforme (red patches or blisters, often on the soles of your feet or the palms of your hands)
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Xofluza. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Diarrhea

Diarrhea is a possible side effect of taking Xofluza. Diarrhea can also be a symptom of the flu in some people (mainly in children).

Diarrhea was the most common side effect reported in clinical studies of Xofluza. In these studies, diarrhea occurred in:

  • 3% of people who took Xofluza
  • 4% of people who took placebo (a treatment containing no active drug)

If you have diarrhea after taking Xofluza, drink plenty of fluids to avoid dehydration (low fluid levels). This is especially important if you also have a fever with the flu. Try sipping water or other clear fluids regularly throughout the day.

Sports drinks, broths, or oral rehydration solutions can all help replace lost fluids and electrolytes. Oral rehydration solutions provide an optimal mixture of fluids, sugar, and electrolytes. They come in various forms, including powders that you mix with water, ready-to-drink solutions, and popsicles. You can buy them from drugstores, grocery stores, or online.

Bronchitis

Some people may have bronchitis after taking Xofluza. Bronchitis can also be a complication of the flu.

Bronchitis is swelling in the large airways in your lungs. It causes symptoms such as a cough, sore throat, chest tightness, shortness of breath, and a fever.

In clinical studies of Xofluza, bronchitis occurred in:

  • 3% of people who took Xofluza
  • 4% of people who took placebo

If you have symptoms of bronchitis, these can typically be relieved with over-the-counter (OTC) medications, such as cough medications and pain relievers. However, if your symptoms don’t start to improve within a few days after taking Xofluza, talk with your doctor or pharmacist.

Hallucinations

Hallucinations (seeing or hearing things that aren’t really there) have been reported in some people taking Xofluza. Other psychiatric effects, such as delirium and abnormal behavior, have also been reported.

These side effects weren’t reported in clinical studies of the drug. However, they’ve been reported since Xofluza has been on the market. It’s not known how often these side effects occur, and it’s not known if they’re caused by Xofluza.

Hallucinations, delirium, and abnormal behavior have also been reported in people taking other antivirals to treat flu. However, these symptoms can also be caused by the flu. It’s not known if taking antivirals raises the risk for getting psychiatric symptoms with the flu.

If you have hallucinations after taking Xofluza, talk with your doctor.

Sleep problems (not a known side effect)

Sleep problems haven’t been reported with Xofluza. The drug doesn’t make you sleepy or cause insomnia (trouble sleeping). However, some people have reported sleep problems with other flu treatments.

If you have trouble sleeping after taking Xofluza, talk with your doctor about possible causes.

You may wonder how Xofluza compares with other medications that are prescribed for similar uses. Here we look at how Xofluza and Tamiflu are alike and different.

Ingredients

Xofluza contains the active drug baloxavir marboxil. Tamiflu contains the active drug oseltamivir.

Uses

Xofluza and Tamiflu to treat influenza (the flu) that doesn’t require treatment in the hospital. They’re used for people who’ve had flu symptoms for up to 48 hours. Xofluza is approved for use in adults and in children ages 12 years and older. Tamiflu is approved for use in adults and in children ages 2 weeks and older.

In addition, both Xofluza and Tamiflu are approved to prevent flu. For this use, Xofluza can be used in adults and children ages 12 years and older who have had contact with someone who has the flu. And Tamiflu can be used in adults and children ages 1 year and older.

Drug forms and administration

Xofluza comes as tablets and an oral solution that you take by mouth as a single, one-time dose.

Tamiflu is also taken by mouth. It comes as a capsule and as a liquid suspension (powder that’s mixed with water). Tamiflu is taken twice a day for 5 days to treat the flu.

Side effects and risks

Xofluza and Tamiflu have some similar side effects and others that vary. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each drug, or with both Xofluza and Tamiflu (when taken individually). These side effects can also be symptoms of the flu.

  • Can occur with Xofluza:
    • diarrhea
  • Can occur with Tamiflu:
    • vomiting
    • general body pain
  • Can occur with both Xofluza and Tamiflu:
    • nausea
    • headache

Serious side effects

These lists contain examples of serious side effects that can occur with Xofluza, with Tamiflu, or with both drugs (when taken individually).

Effectiveness

The use of Xofluza and Tamiflu in treating the flu has been directly compared in clinical studies. These studies found Xofluza and Tamiflu to be similarly effective for shortening the recovery time from flu symptoms. There wasn’t a significant difference in how quickly flu symptoms were relieved when the drugs were compared with each other.

Costs

According to estimates on GoodRx.com, Xofluza and Tamiflu generally cost about the same. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Xofluza and Tamiflu are both brand-name drugs. There’s currently no generic form of Xofluza, but generic forms of Tamiflu are available under the name oseltamivir. Brand-name medications usually cost more than generics.

Here are answers to some frequently asked questions about Xofluza.

How long are you contagious after taking Xofluza?

Taking Xofluza helps your body to fight off the influenza (flu) virus, but it won’t stop you from being contagious (able to transmit the flu virus to other people). The flu virus is highly contagious. It’s easily transferred in droplets you breathe out, especially through coughing, sneezing, and talking.

You can pass the flu virus to other people for about 5 to 7 days after you first get symptoms, even if you take Xofluza. Some people, such as those with a weak immune system, may continue transferring the virus for longer than 5 to 7 days.

To avoid transmitting the flu virus to other people:

  • if possible, stay at home and away from other people while you have symptoms
  • regularly wash your hands with soap and water
  • cover your nose and mouth with a tissue when coughing or sneezing, then put the tissue in the trash

How fast does Xofluza work?

Xofluza starts working against the flu virus within 4 hours of when you take a dose.

In people treating the flu, the majority feel better about 2 days after taking it. If you don’t start to feel better about 2 days after taking Xofluza, or if your symptoms get worse, call your doctor.

Can Xofluza cause a yeast infection?

No, Xofluza is not known to cause yeast infections.

Yeast infections can sometimes be caused by antibiotic drugs. That’s because antibiotics can kill healthy bacteria found in your body, allowing other germs like yeast to increase in numbers. However, antiviral drugs like Xofluza don’t kill bacteria, so they’re not known to cause yeast infections.

Can you take Xofluza twice?

It depends. You shouldn’t take Xofluza twice to treat the same bout of flu. However, your doctor might prescribe it twice if you get the flu twice in one season or if you get the flu again the next year.

If you’ve taken Xofluza to treat the flu but your symptoms don’t improve after about 2 days or they get worse, see your doctor. Your doctor may suggest a different antiviral, but they won’t prescribe a second dose of Xofluza.

This is because flu viruses can sometimes become resistant to antiviral drugs, including Xofluza. Drug resistance is when a virus or other germ is no longer treatable with a certain drug. In rare cases, a flu virus can become resistant to Xofluza, and the drug won’t be as effective at treating it. Therefore, taking a second dose of Xofluza wouldn’t help treat ongoing flu symptoms.

Worsening flu symptoms could also be caused by flu complications, such as pneumonia, or other infections. (Taking Xofluza doesn’t eliminate the risk of getting complications from the flu.) In these cases, the complications or other infections may need additional treatment. They won’t be helped by taking a second dose of Xofluza.

However, if you get the flu twice in one season, your doctor might prescribe Xofluza again. This will depend on recommendations from the Centers for Disease Control and Prevention (CDC).

The CDC tracks flu activity in the United States. It determines which strains of flu viruses are currently circulating and if they’re likely to be resistant to certain antivirals. If strains of flu viruses that are resistant to Xofluza are circulating, your doctor will likely recommend a different antiviral.

You’re unlikely to get the flu twice in one season. However, it could happen, because different strains of flu viruses can be circulating at the same time. You’re more likely to get the flu twice in one season if you haven’t had a flu vaccine.

Your doctor may also prescribe Xofluza more than once to prevent the flu if you’re exposed to someone with the flu on more than one occasion. This will depend on recommendations from the CDC. If strains of flu viruses that are resistant to Xofluza are circulating, your doctor will likely recommend an antiviral other than Xofluza. (With resistance, the virus won’t respond to the drug like usual.)

If you have additional questions about taking Xofluza more than once, talk with your doctor or someone at your local public health department.

Can I take Xofluza more than 48 hours after my first flu symptoms appear?

No, you shouldn’t take Xofluza if it’s been more than 48 hours since your first flu symptoms appeared. For treating the flu, the drug was only studied in people who had shown symptoms for no more than 48 hours. Therefore, it isn’t known how safe or effective the drug is in people who’ve had symptoms for longer than that.

If you’ve had symptoms of flu for more than 48 hours, call your doctor or visit an urgent care center. Even if Xofluza isn’t right for you, they may recommend another treatment for any symptoms you may have. They’ll also make sure your flu isn’t serious or in need of treatment in a hospital.

Is it OK to get a flu vaccine and Xofluza at the same time?

It depends on the type of flu vaccine you receive. There are two types of flu vaccine: the nasal spray and the injected flu vaccine (flu shot). The nasal spray flu vaccine contains live but weakened forms of flu viruses. The flu shot contains inactivated (non-live) flu viruses.

Xofluza hasn’t been studied with any flu vaccines. However, Xofluza is an antiviral drug that kills live flu viruses. Therefore, if you take Xofluza at the same time as getting the nasal spray flu vaccine, Xofluza could kill live viruses in the vaccine. This means Xofluza could make the nasal vaccine less effective at protecting you against the flu.

On the other hand, Xofluza is unlikely to affect how the flu shot works because it doesn’t contain live viruses.

If you want to get a flu vaccine at the same time as Xofluza, talk with your doctor about your options. Getting a flu vaccine is still the best way to protect yourself from the flu.

Will I be able to consume dairy or calcium during my Xofluza treatment?

You should not take Xofluza with dairy products or calcium-fortified drinks, or with other medications that contain calcium. This is because minerals such as calcium can prevent your body from absorbing Xofluza as well. In animal studies, this effect was seen when Xofluza was taken with calcium (along with magnesium and aluminum).

However, animal studies don’t always predict what will happen in humans, and this effect hasn’t been studied in humans. But to be safe, the drug’s manufacturer recommends avoiding products containing these minerals when you take your Xofluza dose.

If you have questions about consuming dairy products or calcium with Xofluza, talk with your doctor.

Xofluza is used to treat or prevent influenza (the flu). When used to treat the flu, the drug helps your body recover more quickly that it would without treatment. However, you might want to take OTC medications to help relieve your symptoms while Xofluza is working. Below are lists of examples of OTC drugs that may be used with Xofluza.

Examples of drugs that reduce body aches, headache, sore throat, and fever include:

  • acetaminophen (Tylenol)
  • ibuprofen (Motrin, Advil)
  • naproxen (Aleve)

Examples of drugs that relieve a blocked or stuffy nose and sinuses include:

  • pseudoephedrine (Sudafed)
  • phenylephrine
  • oxymetazoline

Examples of drugs that ease coughing include:

  • guaifenesin (Mucinex)
  • dextromethorphan (Delsym or Robitussin)

Many OTC flu medications contain a combination of several of the drug ingredients listed above. As with prescription medications, not all OTC medications are a good fit for everyone. To make sure an OTC medication is safe for you, check the label or talk with your doctor.

You can talk with your pharmacist about remedies that can help your symptoms. However, while you have the flu, it’s best to either call the pharmacist for advice or send someone else to the drugstore for you. This helps you avoid spreading the infection.

It’s important not to take more than the recommended dosage of OTC medications. In addition, don’t take more than one medication containing the same active ingredient. Talk with your doctor or pharmacist if you have questions about which drugs you can take with Xofluza.

Xofluza is not known to interact with alcohol. However, drinking alcohol while you have influenza (the flu) isn’t recommended. Doing so can worsen flu symptoms like headache and nausea.

You should take Xofluza according to your doctor or healthcare provider’s instructions.

When to take

To treat the flu, you should take Xofluza within 48 hours after your flu symptoms begin. And to prevent the flu, you should take Xofluza as soon as possible after being exposed to someone with the flu.

Note: If you’re taking Xofluza solution, it’s important that you take the solution within 10 hours after it’s been mixed. (Your pharmacist will mix the solution together before dispensing it to you.) This is because the solution doesn’t contain any preservatives, so it’s meant to be taken shortly after it’s made.

Taking Xofluza with food

You can take Xofluza either with or without food. However, don’t take Xofluza with dairy products, such as milk, yogurt, or cheese. In addition, don’t take it with calcium-fortified drinks, such as fruit juice with added calcium.

Can Xofluza be crushed, split, or chewed?

No, Xofluza shouldn’t be crushed, split, or chewed. These tablets should be swallowed whole. Talk with your doctor or pharmacist if you have trouble swallowing Xofluza tablets.

It’s not known if Xofluza is safe to take during pregnancy. The drug hasn’t been studied in pregnant women. In animal studies, Xofluza didn’t have any negative effects on fetuses exposed to the drug. However, animal studies don’t always predict what will happen in humans.

Due to the lack of safety information, the Centers for Disease Control and Prevention (CDC) does not recommend Xofluza for women who are pregnant.

However, the CDC does recommend that pregnant women take certain other antiviral drugs to treat flu. That’s because pregnant women have a higher risk for developing complications from the flu, such as pneumonia.

If you’re pregnant or planning a pregnancy, talk with your doctor about your options available for treating or preventing the flu.

It’s not known if Xofluza is safe to take during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Xofluza.

For more information about taking Xofluza during pregnancy, see the “Xofluza and pregnancy” section above.

It’s not known if Xofluza passes into breast milk or if it can affect your body’s production of breast milk. Xofluza hasn’t been studied in women who are breastfeeding.

The Centers for Disease Control and Prevention (CDC) does not recommend Xofluza for treating or preventing flu in women who are breastfeeding.

If you’re breastfeeding or plan to breastfeed, talk with your doctor about your options for treating or preventing the flu.

Xofluza can interact with several other medications. It can also interact with certain supplements as well as certain foods.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Xofluza and other medications

Below is a list of medications that can interact with Xofluza. This list does not contain all drugs that may interact with Xofluza.

Before taking Xofluza, talk with your doctor and pharmacist. Tell them about all prescription, OTC, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Xofluza and certain antacids

Xofluza shouldn’t be taken with certain antacids, which are used to treat indigestion (upset stomach) or heartburn. Taking Xofluza with antacids that contain calcium, magnesium, aluminum, or bismuth can prevent Xofluza from being absorbed into your body as well. This can make Xofluza less effective at treating or preventing the flu.

Examples of antacids that can make Xofluza less effective include:

  • calcium carbonate (Alka-Seltzer, Tums)
  • aluminum hydroxide / magnesium hydroxide / simethcone (Maalox, Mylanta)
  • calcium hydroxide / magnesium hydroxide (Rolaids)
  • bismuth subsalicylate (Pepto-Bismol)
  • magnesium sulfate / sodium hydrogen carbonate / citric acid (Andrews original salts)

You should avoid taking these antacids before or after your Xofluza dose. Because you’ll only take one dose of Xofluza, you can start taking the antacids again the next day.

Xofluza and certain laxatives

Laxatives are used to treat constipation. Taking Xofluza with certain laxatives that contain magnesium can prevent Xofluza from being absorbed into your body as well. This can make Xofluza less effective at treating or preventing the flu. Therefore, you shouldn’t take Xofluza at the same time as these laxatives.

Examples of laxatives that can make Xofluza less effective include:

You should avoid taking these laxatives before or after your Xofluza dose. Because you’ll only take one dose of Xofluza, you can start taking the laxatives again the next day.

Xofluza and herbs and supplements

Taking Xofluza with certain supplements can prevent Xofluza from being absorbed into your body as well. This can make Xofluza less effective at treating or preventing the flu.

Examples of supplements that can make Xofluza less effective include:

  • calcium
  • iron
  • magnesium
  • selenium
  • zinc

Don’t take Xofluza at the same time as supplements containing any of the ingredients listed above. You should avoid taking these supplements before or after your Xofluza dose. Because you’ll only take one dose of Xofluza, you can start taking the supplements again the next day.

Xofluza and foods

Xofluza can interact with certain foods and drinks.

Xofluza and dairy products

Taking Xofluza with dairy products can prevent Xofluza from being absorbed into your body as well. This can make Xofluza less effective at treating or preventing the flu. You shouldn’t take Xofluza at the same time as dairy products, including:

  • milk
  • cream
  • yogurt
  • cheese

You should avoid consuming dairy before or after your Xofluza dose. Because you’ll only take one dose of Xofluza, you can start consuming dairy again the next day.

There aren’t any other foods that have been specifically reported to interact with Xofluza. If you have any questions about eating certain other foods with Xofluza, talk with your doctor.

Xofluza and calcium-fortified drinks

Taking Xofluza with calcium-fortified drinks (which contain added calcium) can prevent Xofluza from being absorbed into your body as well. This can make Xofluza less effective at treating or preventing the flu. An example of a calcium-fortified drink is fruit juice with added calcium.

You should avoid calcium-fortified drinks before or after your Xofluza dose. Because you’ll only take one dose of Xofluza, you can have these drinks again starting the next day.

Xofluza and flu vaccines

There are two types of flu vaccines. The nasal spray flu vaccine contains live but weakened forms of flu viruses. The flu shot contains inactivated (non-live) forms of flu viruses.

Xofluza hasn’t been studied with flu vaccines. However, Xofluza is an antiviral drug that kills live flu virus. Getting a nasal spray flu vaccine (such as FluMist) within 17 days after taking Xofluza could kill the virus in the vaccine. This could make the nasal vaccine less effective at protecting you against the flu.

On the other hand, Xofluza is unlikely to affect how the flu shot works, because the flu shot doesn’t contain a live virus. If you want to get a flu vaccine at the same time as Xofluza, talk with your doctor about your options. Getting a flu vaccine is still the best way to protect yourself from the flu.

If you’ve recently had a flu vaccine, talk with your doctor about whether Xofluza is likely to make the vaccine less effective. They may recommend that you get another flu vaccine after taking Xofluza.

If you’re supposed to get a flu vaccine after taking Xofluza, talk with your doctor about the best time to have it and which type is recommended for you.

The Food and Drug Administration (FDA) approves prescription drugs, such as Xofluza, to treat certain conditions. Xofluza may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Xofluza for flu

Xofluza is FDA-approved to treat and prevent influenza (the flu) in certain people. Specifically, the drug is approved for use in adults and children ages 12 years and older to:

  • Treat influenza. Xofluza is approved to treat influenza (the flu) that doesn’t require treatment in the hospital. It’s used in people who’ve had flu symptoms for up to 48 hours and who are either:
    • healthy, with no risk factors for complications from the flu, or
    • high risk for developing complications from the flu, such as pneumonia
  • Prevent influenza. Xofluza is approved to prevent the flu in people who’ve had contact with someone who’s known to have the flu.

Xofluza is a type of drug called an antiviral. It stops the flu virus from multiplying inside your body and can help you recover from the infection faster. Xofluza is taken as a single, one-time dose to treat or prevent the flu.

Note: Xofluza may work better for certain types of influenza. Your doctor will recommend if Xofluza is a good option for the type of flu you have or may have been exposed to.

About the flu

Flu is a contagious condition that’s caused by the influenza virus. After contracting the flu virus, the infection affects your nose, lungs, and throat.

It’s transferred through coughing, sneezing, talking, and breathing. Symptoms of flu come on suddenly and can include fever, chills, body aches and pains, cough, and severe fatigue (lack of energy).

Your doctor may prescribe Xofluza if you have a high risk for developing complications from the flu. These complications can include trouble breathing, pneumonia, dehydration (low fluid levels), or worsening of an existing health condition. Flu complications often need to be treated in the hospital.

People with a high risk for developing complications from the flu include:

Effectiveness for treating flu

Xofluza has been shown to be effective at shortening the length of time people have the flu. In clinical studies, flu symptoms were relieved an average of 26 to 29 hours faster in people who took Xofluza than in people who took a placebo. (A placebo is a treatment containing no active drug).

In these studies, the average length of time it took for flu symptoms to be relieved was varied slightly in different groups of people. For example:

  • Of adults ages 20 to 64 years who took Xofluza and who were generally healthy other than having the flu, at least half had their flu symptoms relieved within 50 hours. In comparison, at least half of those taking a placebo had their flu symptoms relieved within 78 hours.
  • Of people ages 12 years and older who took Xofluza and who were generally healthy other than having the flu, at least half had their flu symptoms relieved within 54 hours. In comparison, at least half of those taking a placebo had their flu symptoms relieved within 80 hours.
  • Of people ages 12 years and older who had a high risk for flu complications (such as pneumonia) and who took Xofluza, at least half had their flu symptoms relieved within 73 hours. In comparison, at least half of those taking a placebo had their flu symptoms relieved within 102 hours.

Effectiveness for preventing flu

In a clinical study, Xofluza helped to prevent flu in people exposed to others with the flu. In the study, people who enrolled were exposed to other people who’d had the flu for up to 48 hours. And the enrolled people had lived with the person with the flu for longer than 48 hours.

Some of the enrolled people took Xofluza, while other enrolled people took a placebo (treatment with no active drug). Over the 10-day study, flu with fever and at least one respiratory symptom was seen in:

  • 1% of people taking Xofluza
  • 13% of people taking the placebo

The Centers for Disease Control and Prevention (CDC) tracks flu activity in the United States. It determines which strains of the flu virus are currently circulating and if they’re likely to be resistant to certain antivirals. Your doctor will typically only prescribe Xofluza if it’s recommended by the CDC for the current flu season.

Off-label uses for Xofluza

In addition to the use listed above, Xofluza may be used off-label for other purposes. Off-label drug use is when a drug that’s approved for one or more uses is prescribed for a different one that’s not approved. Below is an example of an off-label use for Xofluza.

Xofluza for flu in children ages 1 year and older (under review)

Xofluza is not currently FDA-approved for children younger than 12 years old. However, recent clinical studies have found Xofluza to be effective for both treating and preventing flu in children ages 1 year to less than 12 years.

In one clinical study, Xofluza and oseltamivir (Tamiflu) were found to be similarly effective for treating flu in children who were generally healthy other than having the flu. (Oseltamivir is another antiviral for flu that’s approved for use in children.)

In the study:

  • in children who took Xofluza, flu symptoms improved in an average of 138 hours
  • in children who took oseltamivir, flu symptoms improved in an average of 150 hours

In another clinical study, Xofluza was found to be effective for preventing flu in children living in the same house as someone diagnosed with the flu. The children were given either a single dose of Xofluza or a placebo (treatment containing no active drug). Over the next 10 days:

  • 4.2% of children who took Xofluza developed the flu
  • 15.5% of children who took placebo developed the flu

Based on these results, the manufacturer Xofluza has applied for FDA approval of Xofluza for both treating and preventing flu in children ages 1 to less than 12 years. These uses are currently being evaluated by the FDA, and a decision should be made by the end of 2020.

Xofluza and children

Xofluza is not FDA-approved for children younger than 12 years old. However, it’s currently being evaluated by the FDA for both treating and preventing flu in children ages 1 to less than 12 years. See the section above to learn more.

Xofluza is FDA-approved to treat and prevent influenza (the flu) in people ages 12 years and older who meet certain conditions. For more information, see the “Xofluza uses” section above.

What happens with the flu

Flu is caused by the influenza virus. There are two main types of influenza virus: type A and type B. There are various different strains of these viruses that circulate each year.

The flu virus infects your nose, throat, and lungs and is spread through coughing, sneezing, talking, and breathing. The virus typically causes flu symptoms within 1 to 4 days of someone becoming infected. Without treatment, flu symptoms can last for a week or longer. For some people, the flu can lead to serious complications, such as pneumonia.

What Xofluza does

Xofluza is an antiviral drug that kills the flu virus. It can kill type A and type B flu viruses.

Xofluza contains the active drug baloxavir marboxil. Xofluza works by blocking the action of a protein called endonuclease. Flu viruses use this protein to replicate (makes copies of themselves).

Xofluza blocks a different protein than do other drugs used for the flu. By blocking this protein, Xofluza stops the flu virus from replicating. This allows your immune system to fight off the virus. If you’re sick with the flu, Xofluza helps you recover from flu symptoms about a day faster than you would typically recover with no treatment.

Having drugs available that work differently on the flu is useful, because flu strains change every year. And, like other viruses, the flu can develop resistance to the medications used to treat it. Drug resistance is when a virus or other germ is no longer treatable with a certain drug.

Because Xofluza works differently than other medications do on the flu, it may work against flu strains that other drugs aren’t effective against.

How long does it take to work?

Xofluza starts working against the flu virus within 4 hours of when you take a dose.

In people treating the flu, the majority feel better about 2 days after taking it. This is about 1 day faster than if you don’t take an antiviral drug.

If you don’t start to feel better about 2 days after taking Xofluza, or if your symptoms get worse, call your doctor.

How long does Xofluza stay in your system?

Xofluza takes about 16 days to be removed from your body.

Other drugs are available that can treat or prevent influenza (the flu). Some may be a better fit for you than others. If you’re interested in finding an alternative to Xofluza, talk with your doctor. They can tell you about other medications that may work well for you.

Alternatives for treating the flu

Examples of other drugs that may be used to treat influenza infection include:

Alternatives for preventing the flu

Examples of other drugs that may be used to prevent influenza infection include:

* The Centers for Disease Control and Prevention (CDC) recommends the flu vaccine as the most effective way to prevent the flu. The CDC encourages every person age 6 months and older to get a flu shot each year. If you have questions about whether the flu vaccine is right for you, talk with your doctor.
† Xofluza can interact with certain forms of flu vaccine. For more information, see “Xofluza and flu vaccines” in the “Xofluza interactions” section above.

Xofluza and Relenza are prescribed for similar uses. Here we look at how these drugs are alike and different.

Ingredients

Xofluza contains the active drug baloxavir marboxil. Relenza contains the active drug zanamivir.

Uses

Xofluza and Relenza are both FDA-approved to treat influenza (the flu) that doesn’t require treatment in the hospital. They’re used in people who’ve had flu symptoms for up to 48 hours. Xofluza is approved for use in adults and in children ages 12 years and older. Relenza is approved for use in adults and in children ages 7 years and older.

In addition, both Xofluza and Relenza are approved to prevent flu. For this use, Xofluza can be used in adults and children ages 12 years and older who have had contact with someone who has the flu. And Relenza can be used in adults and children ages 5 year and older.

Drug forms and administration

Xofluza comes as tablets and an oral solution that you take by mouth as a single, one-time dose.

Relenza comes as a powder that you breathe in through an inhaler device called a Diskhaler. It’s taken twice a day for 5 days to treat the flu.

Side effects and risks

Xofluza and Relenza can cause some similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each drug, or with both Xofluza and Relenza (when taken individually). These side effects can also be symptoms of the flu.

  • Can occur with Xofluza:
    • few unique mild side effects
  • Can occur with Relenza:
    • dizziness
  • Can occur with both Xofluza and Relenza:
    • nausea
    • headache
    • diarrhea

Serious side effects

These lists contain examples of serious side effects that can occur with Xofluza, with Relenza, or with both drugs (when taken individually).

  • Can occur with Xofluza:
    • few unique serious side effects
  • Can occur with Relenza:
    • bronchospasm (narrowing of the airways that causes trouble breathing)
  • Can occur with both Xofluza and Relenza:

Effectiveness

These drugs haven’t been directly compared in clinical studies. However, studies have found both Xofluza and Relenza to be effective for treating the flu.

A recent review of studies indirectly compared the effectiveness of Xofluza and Relenza. The review suggests that Xofluza may improve flu symptoms faster than Relenza. However, the review only included studies involving people who were generally healthy other than having the flu. It didn’t include studies involving people at risk for flu complications, such as pneumonia.

Both Xofluza and Relenza are recommended by the Centers for Disease Control and Prevention (CDC) for treating flu. Talk with your doctor about which drug is the best fit for you.

Costs

According to estimates on GoodRx.com, Xofluza costs more than Relenza. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Xofluza and Relenza are both brand-name drugs. There are currently no generic forms of either drug. Brand-name medications usually cost more than generics.

This drug comes with some precautions. Before taking Xofluza, talk with your doctor about your health history. Xofluza may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Allergic reaction. If you’ve had an allergic reaction to Xofluza or any of its ingredients, you shouldn’t take Xofluza. Ask your doctor about other medications that may be a better option for you.
  • Pregnancy. Xofluza is not recommended for pregnant women. For more information, see the “Xofluza and pregnancy” section above.
  • Breastfeeding. Xofluza is not recommended for women who are breastfeeding. For more information, see the “Xofluza and breastfeeding” section above.

Note: For more information about the potential negative effects of Xofluza, see the “Xofluza side effects” section above.

Do not use more Xofluza than your doctor recommends. For some drugs, doing so may lead to unwanted side effects or overdose.

What to do in case you take too much Xofluza

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.

When you get Xofluza from the pharmacy, the pharmacist will add an expiration date to the label on the packet. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the FDA is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication. Avoid storing this medication in areas where it could get damp or wet, such as bathrooms.

Storing Xofluza tablets

Xofluza tablets should be stored at a room temperature of 68°F to 77°F (20°C to 25°C). The tablets should be stored in their blister packs away from light.

Storing Xofluza solution

Once your pharmacist has mixed the Xofluza solution, you should store it at a room temperature of 68°F to 77°F (20°C to 25°C). And you should take it within 10 hours after it’s been mixed. You’ll need to discard the solution if:

  • you haven’t taken it more than 10 hours after it was made
  • you’ve stored it at a temperature higher than 77°F (25°C)

Disposal

If you no longer need to take Xofluza and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Xofluza is FDA-approved for use in adults and in children ages 12 years and older to:

  • treat acute, uncomplicated influenza* in adults and in children ages 12 years and older. It can be used for people who have had influenza symptoms for no more than 48 hours, and
    • have a high risk of developing complications from influenza, or
    • are otherwise healthy
  • prevent influenza after known exposure to the virus

* Prescribing of influenza antivirals should be based on recommendations for the current flu season from the Centers for Disease Control and Prevention (CDC). These take into account the current viral strains in circulation and emergence of resistance to antivirals.

Administration

Xofluza comes as tablets and an oral solution. You should take it by mouth as a single dose either:

  • within 48 hours of flu symptoms starting
  • as soon as possible after exposure to influenza, preferably within 48 hours of first exposure

Mechanism of action

Xofluza contains the prodrug baloxavir marboxil. After oral administration, this is converted to the active drug baloxavir, an influenza antiviral. It works by inhibiting an influenza virus enzyme required for viral RNA transcription, called polymerase acidic protein. Baloxavir inhibits the endonuclease activity of this enzyme. It’s also known as a cap-dependent endonuclease inhibitor.

Xofluza interferes with viral RNA transcription and blocks replication of influenza A and B viruses.

Pharmacokinetics and metabolism

After single-dose oral administration, baloxavir reaches maximum plasma concentration in approximately 4 hours. It is approximately 93.5% bound to plasma proteins.

Baloxavir is primarily metabolized by UGT1A3 and CYP3A4, followed by excretion in the feces. The drug has an average elimination half-life of 79.1 hours.

The pharmacokinetics of baloxavir are not affected by mild to moderate renal or hepatic impairment. The drug hasn’t been studied in severe renal or hepatic impairment. There are no specific hepatic or renal dosing requirements.

Contraindications

Xofluza is contraindicated in people with known hypersensitivity to any of the ingredients.

Storage

Store Xofluza tablets at a room temperature of 68°F to 77°F (20°C to 25°C). The tablets are stable for short periods at 59°F to 86°F (15°C to 30°C).

Store Xofluza granules for oral solution at a room temperature of 68°F to 77°F (20°C to 25°C). The granules are stable for short periods at 59°F to 86°F (15°C to 30°C).

Once mixed into solution, store Xofluza oral solution at a room temperature of 68°F to 77°F (20°C to 25°C). The solution must be administered within 10 hours of preparation and must not be stored at temperatures greater than 77°F (25°C). If either occurs, the solution must be discarded.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.