Xofluza vs. Tamiflu for Flu: Differences and Similarities
Medically reviewed by Erika Prouty, PharmD
Xofluza (baloxavir marboxil) and Tamiflu (oseltamivir) are common prescription treatments for short, noncomplicated influenza (flu).
Both have similar purposes: they can treat an influenza infection or prevent one from occurring if you've been exposed to a sick person. However, they differ in their dosing and uses in different populations.
This article will cover the similarities and differences between Xofluza and Tamiflu, including who can take it, dosage, side effects, interactions, and which is more effective.
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Uses of Xofluza vs. Tamiflu
An antiviral medication, Xofluza is used to treat short and noncomplicated influenza or flu in adults and adolescents 12 and older. It can also help prevent the flu in adults and children 5 and older who have been exposed to another sick person.
It's best used when flu-like symptoms of fever, fatigue, or other symptoms are present for no more than 48 hours. This medication and others similar to it are used to treat the flu and should not be used in replacement for annual flu vaccines.
Tamiflu is an older medication than Xofluza. Like Xofluza, it can be used to treat acute flu infections, but unlike Tamiflu, it can be given to children as young as 2 weeks old, making it a better option for young children. Like Xofluza, it's most effective in treating the flu within 48 hours of the onset of symptoms.
Tamiflu can also be used to prevent influenza in children as young as 1 year who have been in contact with someone who is sick.
How Does Xofluza Work?
Xofluza is an influenza virus polymerase acidic endonuclease inhibitor.
Xofluza's active ingredient, baloxavir marboxil, is considered a prodrug, defined as an inactive product that develops into its active form once it is processed in the body to reach a therapeutic effect.
This happens because of the high amount of water in human bodies. The water in your body helps break up this medication into an active drug form. Once the drug becomes active, it begins to attack and break down the virus by blocking the proteins that help the flu multiply in the body. This slows the progression of the illness, reducing your time being sick, and eventually eliminates the virus quicker and more efficiently.
How Does Tamiflu Work?
Tamiflu is an influenza neuraminidase inhibitor (NAI). It binds to and blocks neuraminidase enzymes, which are present in influenza viruses. By doing this, Tamiflu reduces the viral load and the length of time infected.
Its active ingredient or generic version (oseltamivir phosphate) is also a prodrug. It works by undergoing a chemical breakdown similar to Xofluza. Once this medication is released into the body, it converts to its active form and blocks the influenza virus from releasing more viral particles into your system.
Is Xofluza or Tamiflu More Effective?
Research has shown that Xofluza, compared to Tamiflu, can be more effective in reducing household influenza transmission.
More clinical information has shown that Xofluza may be a more effective antiviral than Tamiflu in treating influenza and interfering with the progression of a pandemic or severe flu season. For one, Xofluza is a simple onetime dose, which is easier to complete than Tamiflu's five-day course of treatment or a 10-day course for prevention. Xofluza prevents the virus's spread more efficiently.
Because of Tamiflu's favorable safety profile in pregnant people, it is generally the preferred antiviral to treat flu during pregnancy. There is limited data on Xofluza's use during pregnancy.
Dosage: Xofluza vs. Tamiflu
Just a single dose of Xofluza is usually needed compared to Tamiflu, which requires 10 or more doses. This makes Xofluza a more appealing option overall.
Below is the recommended dosing for Xofluza and Tamiflu referred to in milligrams (mg), mg per milliliters (mg/mL), and mg per kilograms of body weight (mg/kg).
| Xofluza | Tamiflu |
Available Strengths | Tablets: 40 mg and 80 mg; Suspension: 40 mg/20 mL, 80 mg/40 mL, or 2 mg/kg | Capsules: 30 mg, 45 mg, and 75 mg Suspension: 360 mg in powder form |
Recommended dosing | Weight-based dosing (refer to dosing below) | Treatment: 75 mg twice daily for five days; Prophylaxis: 75 mg once daily for 10 days |
Available generically | No | Yes |
Dosing in Children | Less than 20 kg (44lbs): 2 mg/kg; 20–79 kg (44–176 pounds): Single 40 mg dose; 80 kg (176 pounds) or more: Single dose of 80 mg | Children ages 1 to 12: based on weight twice daily for 5 days (treatment) or 10 days (prevention); adolescents and adults: refer to the above recommended doses |
Side Effects: What to Expect with Xofluza and Tamiflu
As with most medications, Xofluza and Tamiflu come with potential side effects. You may or may not experience side effects when taking either of these drugs.
Common side effects associated Xofluza include:
Diarrhea
Headache
Nausea
Bronchitis
Sinusitis
Tamiflu’s common side effects include:
Nausea
Vomiting
Headache
These are the most commonly reported side effects associated with these medications. However, this list does not include all possible side effects that could occur.
Side effects can make it difficult to continue taking your full treatment course. Over-the-counter (OTC) therapies can help you manage some of these milder side effects. For example, you can take Advil and Motrin (ibuprofen) or Tylenol (acetaminophen) for headaches.
It's recommended not to use these medications if you are allergic to any of their components.
Drug Interactions
Xofluza may interact with the following:
It is essential to avoid these interactions as this is a onetime dose medication. Taking any of the above could reduce how well Xofluza works.
One interaction that can affect both Xofluza and Tamiflu is with live vaccines. These may lose effectiveness if given two weeks before or 48 hours after administration of an antiviral.
Talk to your healthcare provider when prescribed an antiviral if you are potentially getting a new vaccine.
Summary
Both Xofluza and Tamiflu are effective and commonly prescribed medications for the flu. Which medication you take may depend on different factors, such as age or pregnancy status.
It is important that you notify your primary healthcare provider of the duration of your illness to maximize this medication's effectiveness in reducing your fever, symptoms, and the amount of time you will be ill. You'll need to start treatment within 48 hours of symptom onset for the most optimal results.
Frequently Asked Questions
How quickly do Xofluza and Tamiflu work?
Because Xofluza is given as a onetime dose, this medication may work more quickly than Tamiflu. Tamiflu is a 10-pill regimen and can take five to 10 days for treatment and any sign of improvement. Xofluza has shown improvement and flu relief in a little over four days (50 to 54 hours) after the onetime dose.
Can you take Xofluza or Tamiflu for COVID-19?
These medications are approved for use specifically for the influenza virus and should not be used with other COVID-19 antiviral medications, as this may do more harm than good. Some common COVID-19 medications include:
Paxlovid (nirmatrelvir and ritonavir)
Do I need to take Xofluza or Tamiflu with food?
Both of these medications can be taken with or without food.
The author would like to recognize and thank Jaycob Mathew Peña for contributing to this article.
Read the original article on Verywell Health.
