Baloxavir Marboxil
Baloxavir marboxil is an antiviral ingredient in Xofluza used to treat influenza (the flu) and to prevent influenza after close contact with someone who has it.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 2 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Baloxavir Marboxil: Patient Information Guide
A plain-language walkthrough of Baloxavir Marboxil — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Baloxavir marboxil is the active ingredient in Xofluza, an antiviral used for influenza (flu) treatment and prevention in people 5 years of age and older.
- Treatment of acute uncomplicated influenza: Xofluza treats flu in patients 5 years and older who have been symptomatic for no more than 48 hours — including both otherwise healthy individuals and those at high risk of flu complications.
- Post-exposure prophylaxis (prevention after exposure): Xofluza can help prevent flu in people 5 years and older who have had close contact with someone who has influenza.
- Xofluza is not indicated in children under 5 years of age due to a higher rate of the virus developing resistance in that age group.
- Influenza viruses change over time, and resistance or changes in the virus could reduce Xofluza's benefit. Prescribers consider current flu strain information when recommending it.
⚙️How it works▾
Baloxavir marboxil is a prodrug — your body converts it into its active form, baloxavir, after swallowing. Baloxavir works by blocking an enzyme called PA endonuclease, which the influenza virus depends on to copy its genetic material and spread. By shutting down this enzyme, baloxavir stops the virus from replicating in your body.
Because this mechanism is different from older antivirals like oseltamivir (Tamiflu), baloxavir offers a distinct approach to fighting the flu. However, resistance can develop, particularly in younger children under 5, which is why Xofluza is not approved for that age group.
💊How it's taken▾
Xofluza is taken as a single oral dose — one time only. It can be taken with or without food, but should not be taken alongside dairy products, calcium-fortified beverages, antacids, or supplements containing calcium, iron, magnesium, selenium, or zinc, as these can reduce the drug's absorption. The dose is based on body weight.
- For flu treatment: take as soon as possible, and within 48 hours of symptom onset.
- For prevention after exposure: take as soon as possible after contact with an infected person.
- Xofluza comes as tablets (for those who can swallow them) and as an oral suspension in packets or bottles (for those who cannot, or who need enteral/tube administration).
🤒Side effects — in detail▾
Most people tolerate Xofluza well with a single dose. The most commonly reported side effects include:
- Diarrhea
- Nausea
- Vomiting (reported more often in children ages 5 to under 12)
- Headache
- Bronchitis
- Sinusitis
Seek emergency care immediately if you notice signs of a serious allergic reaction — such as hives, swelling of your face or throat, trouble breathing, or a spreading rash. These reactions, while rare, have been reported with Xofluza.
⚠️Warnings & precautions▾
- Serious allergic reactions: Anaphylaxis (a severe, life-threatening allergic reaction), hives, swelling, and serious skin reactions have been reported. Stop taking Xofluza and get emergency help right away if any of these occur. Do not take Xofluza if you have ever had an allergic reaction to it.
- Not for children under 5: Xofluza is not approved for children younger than 5 years old. In clinical trials, the flu virus developed resistance to baloxavir much more often in this age group than in older children or adults.
- Does not treat bacterial infections: Xofluza only works against influenza viruses. Serious bacterial infections can develop alongside or after the flu — contact your doctor if symptoms worsen or new ones appear, because Xofluza will not address a bacterial cause.
🔀What it interacts with▾
A few important interactions to know about before taking Xofluza:
- Dairy products and calcium-fortified drinks: Calcium can bind to baloxavir and significantly reduce the amount of drug your body absorbs — avoid these around the time of your dose.
- Antacids, laxatives, and supplements containing calcium, iron, magnesium, selenium, or zinc: These minerals can similarly reduce Xofluza's absorption and effectiveness — avoid them at the same time.
- Live nasal-spray flu vaccine (LAIV): Xofluza, like other antivirals, may interfere with the live virus in the nasal vaccine and reduce its effectiveness. Talk to your doctor about timing if both are needed.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Allergy history: Do not take Xofluza if you have ever had an allergic reaction to baloxavir marboxil or any of its ingredients.
- Children under 5: Xofluza is not approved for this age group due to a higher rate of resistance developing in the virus.
- Pregnancy: There are no well-controlled human studies. Influenza itself carries serious risks during pregnancy. Discuss the benefits and risks with your doctor.
- Breastfeeding: It is not known whether baloxavir passes into human breast milk. Talk to your doctor before taking Xofluza while breastfeeding.
- Severe kidney or liver disease: The effects of Xofluza have not been fully studied in people with severe kidney or liver impairment. Let your doctor know about any significant kidney or liver problems.
🚑If you take too much▾
There is no specific antidote if someone takes too much Xofluza. Treatment focuses on supportive care — monitoring vital signs and watching how the person feels. Because baloxavir binds tightly to proteins in the blood, dialysis is unlikely to remove a meaningful amount of the drug from the body.
📡Pharmacodynamics — effects in the body▾
At twice the exposure expected from the recommended dose, Xofluza did not prolong the QTc interval (an electrical measurement of heart rhythm), which is reassuring from a cardiac safety standpoint. When dosed by weight as recommended in patients 5 years and older, the relationship between the amount of drug in the body and how quickly flu symptoms resolve is flat — meaning higher exposures don't appear to provide added benefit once the recommended dose is given.
🔬Pharmacokinetics — how your body processes it▾
Baloxavir marboxil is a prodrug that is almost completely converted to its active form, baloxavir, after you take it by mouth. Blood levels typically peak around 4 hours after the dose. The drug has a long apparent half-life of about 79 hours, which is why a single dose is enough. Baloxavir is primarily broken down by an enzyme called UGT1A3, with CYP3A4 playing a secondary role, and most of the drug is eliminated through the feces. Taking Xofluza with a moderate-fat meal reduces absorption noticeably, which is why timing around foods and mineral supplements matters.
📦How to store it▾
Store tablets in their blister package at 20°C to 25°C (68°F to 77°F); excursions are permitted between 15°C and 30°C (59°F to 86°F) . Store granules (bottles) at 20°C to 25°C (68°F to 77°F) and keep in the original bottle; excursions are permitted between 15°C and 30°C (59°F and…
📄 Written from Baloxavir Marboxil’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Baloxavir Marboxil
17 supplements and herbal products have documented interactions with Baloxavir Marboxil in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Baloxavir Marboxil — the kind of thing our pharmacy team would talk through with you at the counter.
Does Xofluza really work with just one dose? ▾
Can I eat normally when I take Xofluza? ▾
What side effects should I expect? ▾
Can my child take Xofluza? ▾
Is it safe to take Xofluza during pregnancy? ▾
Does Xofluza replace my flu shot? ▾
Is Baloxavir Marboxil available over the counter? ▾
When was Baloxavir Marboxil first available? ▾
Who makes Baloxavir Marboxil? ▾
💬 Answers drafted from Baloxavir Marboxil’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Baloxavir Marboxil comes
Baloxavir Marboxil is available in 3 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Xofluza tablets are used to treat acute uncomplicated influenza in patients 5 years and older who have had symptoms for no more than 48 hours.
- Xofluza tablets are used for post-exposure prophylaxis of influenza in patients 5 years and older.
- Xofluza tablet dosing is weight-based: one tablet strength for patients 20 kg to under 80 kg, and a higher-strength tablet for patients 80 kg or more.
- Xofluza tablets are taken as a single oral dose, with or without food.
- Take your Xofluza tablet as soon as possible after flu symptom onset, and no later than 48 hours after symptoms begin.
- Do not take Xofluza tablets at the same time as dairy products, calcium-fortified drinks, antacids, or supplements with calcium, iron, magnesium, selenium, or zinc.
- Follow your prescriber's instructions for the correct tablet strength based on your weight.
Oral solution
How this form is used
- Xofluza oral solution is for patients who are unable to swallow tablets or who require enteral administration.
- Xofluza oral solution is used to treat acute uncomplicated influenza in patients 5 years and older.
- Xofluza oral solution is used for post-exposure prophylaxis of influenza in patients 5 years and older.
- Xofluza oral solution is taken as a single dose; the dose is based on body weight.
- Take Xofluza oral solution as soon as possible after flu symptoms start, and within 48 hours of symptom onset.
- Avoid taking Xofluza oral solution with dairy products, calcium-fortified beverages, antacids, or supplements containing calcium, iron, magnesium, selenium, or zinc.
Oral suspension
How this form is used
- Xofluza oral suspension is intended for patients who are unable to swallow tablets, or those who require enteral (feeding tube) administration.
- Xofluza oral suspension is used to treat acute uncomplicated influenza in patients 5 years and older, including children who cannot swallow tablets.
- Xofluza oral suspension is used for post-exposure prophylaxis of influenza in patients 5 years and older.
- Xofluza oral suspension (bottle) must be reconstituted by a healthcare provider before dispensing, and the full dose must be taken within 10 hours of preparation.
- Xofluza oral suspension is taken as a single dose; use the oral syringe provided to measure the correct amount based on your weight.
- Xofluza oral suspension can also be given through an enteral feeding tube that is 4 French or larger, with water flushes before and after.
- Do not take Xofluza oral suspension at the same time as dairy products, calcium-fortified drinks, antacids, or supplements with calcium, iron, magnesium, selenium, or zinc.
📊 Baloxavir Marboxil across the U.S. market
How Baloxavir Marboxil appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Baloxavir Marboxil is used
A general measure of how commonly Baloxavir Marboxil is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Baloxavir Marboxil is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Baloxavir Marboxil prescribed? Of the 1,596 medications we measure, Baloxavir Marboxil ranks #809 by Medicaid prescriptions — more than 49% of them.
Utilization by Baloxavir Marboxil product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
baloxavir marboxil 40 MG Oral Tablet Most dispensed
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2100008
baloxavir marboxil 80 MG Oral Tablet
Summed across the 1 of 5 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2536740
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Baloxavir Marboxil, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 2 of 7 listed Baloxavir Marboxil NDCs with Medicaid activity.
🔍 Compare Baloxavir Marboxil products
A representative set of FDA-listed product records for Baloxavir Marboxil — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Oral solution | ||||
| 40 mg/20 mL | Oral | Genentech, Inc. × 2 listings | NDA | View NDC → |
| 40 mg/mL | Oral | Genentech, Inc. | NDA | View NDC → |
| 💊Oral suspension | ||||
| 30 mg | Oral | Genentech, Inc. | NDA | View NDC → |
| 40 mg | Oral | Genentech, Inc. | NDA | View NDC → |
| 20 g/kg | — | Shionogi Pharma Co., Ltd | DRUG FOR FURTHER PROCESSING | View NDC → |
| 💊Tablet | ||||
| 20 mg | Oral | A-S Medication Solutions | NDA | Find on DailyMed ↗ |
| 40 mg | Oral | A-S Medication Solutions | NDA | Find on DailyMed ↗ |
| 40 mg | — | F. Hoffmann-La Roche Ltd | DRUG FOR FURTHER PROCESSING | View NDC → |
| 80 mg | — | F. Hoffmann-La Roche Ltd | DRUG FOR FURTHER PROCESSING | View NDC → |
| 40 mg | Oral | Genentech, Inc. × 3 listings | NDA | View NDC → |
| 80 mg | Oral | Genentech, Inc. × 3 listings | NDA | View NDC → |
| 20 mg | — | Shionogi Pharma Co., Ltd. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 40 mg | — | Shionogi Pharma Co., Ltd. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 80 mg | — | Shionogi Pharma Co., Ltd. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 80 mg | Oral | Sportpharm LLC | NDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Evonik Corporation | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | MSN Laboratories Private Limited | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Shionogi Pharma Co., Ltd. | BULK INGREDIENT | View NDC → |
Showing 23 of 23 products — FDA National Drug Code Directory. See every product, package size and price: browse all 23 Baloxavir Marboxil NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Baloxavir Marboxil — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Baloxavir Marboxil in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Baloxavir Marboxil went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2099995 2 dose forms · 5 strengths
-
Dose form (SCDF) Granules for Oral Suspension RxCUI 2467536In current FDA listings -
Dose form (SCDF) Oral Tablet RxCUI 2099999In current FDA listings
Look up RxCUI 2099995 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Baloxavir Marboxil is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Baloxavir Marboxil belongs to the Other antivirals class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 2 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Genentech, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.