How Does Xofluza Work? Plus, 5 More Xofluza FAQs
Key takeaways:
Xofluza (baloxavir marboxil) works by stopping the flu virus from replicating in the body. You only need one dose of Xofluza, but you need to take it within 48 hours (2 days) of feeling flu symptoms.
Xofluza starts working in about 4 hours, but it may take up to 2 days before your flu symptoms go away. In the meantime, it’s fine to take most over-the-counter flu medications with Xofluza if you need them.
There are many ways to save on Xofluza. If you’re eligible, a manufacturer savings card can help you get Xofluza for as little as $30 per dose.
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Table of contents
Xofluza (baloxavir marboxil) is a prescription medication that can help you feel better faster when you have the flu. It can also help you avoid getting the flu if you’ve recently been exposed to it. It’s safe for adults and children ages 5 years and older.
But how does Xofluza work? And how long does it take before you’ll start feeling better? Let’s review these and more commonly asked questions about Xofluza.
1. How does Xofluza work?
Xofluza contains the active ingredient baloxavir marboxil. It’s considered an endonuclease inhibitor medication. Endonuclease is an enzyme (protein) that helps the flu virus make copies of itself. These copies spread the flu infection in your body. Xofluza blocks this enzyme, preventing the flu virus from replicating and stopping the infection process.
Xofluza is most effective if taken within 48 hours (2 days) of the start of your flu symptoms — before the virus is widespread in your body. So it’s best to take your dose as soon as possible after flu symptoms appear.
2. How long does it take Xofluza to work?
Xofluza can start taking action against the flu virus within 4 hours of your dose. But it will likely take longer than that for you to start feeling better.
It’s likely your symptoms will gradually improve after you take Xofluza. In clinical studies, people reported mild or no flu symptoms about 2 days after their dose.
If it’s been 2 days or more and your symptoms aren’t improving or are getting worse, contact your healthcare provider. Sometimes the flu can lead to the development of other infections, including bacterial infections, that may need additional treatment with other medications.
3. How long does Xofluza stay in your system?
It takes a little over 2 weeks for your body to process and clear Xofluza. During this time, the medication will continue fighting your flu infection. That’s one of the reasons you only need to take one dose for Xofluza to work. And this makes it a more convenient option for a lot of people.
4. How often can you take Xofluza?
You should only take Xofluza once for each case of the flu you have or are exposed to. For instance, if you take Xofluza the day your flu symptoms start but you still don’t feel well a week later, you shouldn’t take another dose. But if you had the flu and used Xofluza to clear it up, and you get the flu again weeks or months later, you may be able to take Xofluza again.
Your healthcare provider can help decide if Xofluza is right for you.
5. Can you take Xofluza with OTC flu medications?
Yes. It’s fine to take Xofluza with over-the-counter (OTC) medications for your flu symptoms if you need them. This includes pain and fever relievers, such as Tylenol (acetaminophen) or Advil (ibuprofen). Medications for a stuffy nose and cough, such as Sudafed (pseudoephedrine) and Delsym (dextromethorphan) are also fine to take with Xofluza.
But you should avoid antacids, laxatives, or supplements that contain any of the following ingredients:
Calcium
Magnesium
Selenium
Aluminum
Zinc
These ingredients can bind to Xofluza and make it less effective. So you should avoid them the day you take your Xofluza dose. If you’ve already taken one of these ingredients, wait 4 to 5 hours before taking your Xofluza dose.
6. Is Xofluza safe to take if you’re pregnant?
Xofluza is not recommended if you’re pregnant or breastfeeding. There isn’t enough data to know if it’s safe. But that doesn’t mean you can’t get treatment. Tamiflu (oseltamivir) is the first-choice medication to treat the flu if you’re pregnant. It’s also considered safe to prevent the flu if you’re exposed to it while pregnant.
How to save on Xofluza
Xofluza is only available as a brand-name medication. If you have commercial insurance, you may be eligible to pay as little as $30 for Xofluza using a savings card from the manufacturer.
If you’re uninsured or underinsured, the same savings card can take up to $60 off the cost of your Xofluza prescription.
The bottom line
Xofluza (baloxavir marboxil) treats and prevents the flu in adults and children ages 5 years and older. It works by blocking the flu virus from making copies of itself. This helps stop the flu infection in your body. You only need one dose of Xofluza, but you should take it within 48 hours (2 days) after your symptoms start.
Xofluza starts working in about 4 hours, but it may take up to 2 days before your flu symptoms resolve. In the meantime, it’s fine to take most over-the-counter medications for flu symptoms with Xofluza if you need them.
You shouldn’t take Xofluza if you’re pregnant or breastfeeding. And you shouldn’t take more than one dose of Xofluza each time you’re exposed to or have the flu.
Why trust our experts?
References
Centers for Disease Control and Prevention. (2022). Influenza antiviral drug baloxavir marboxil.
Genentech, Inc. (2023). Xofluza - baloxavir marboxil tablet, film coated, and baloxavir marboxil granule, for solution [package insert].
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