For Patients and Caregivers

About the Flu

Recognize and Treat the Flu Promptly With an Antiviral*

There are serious risks associated with the flu7,11

Most patients who get the flu recover in 3 to 14 days, but influenza can cause complications that could be life threatening. For high-risk patients, dangers of the flu are even greater and can lead to serious complications, make chronic health problems worse, or even cause death.

During the 2024 to 2025 flu season in the United States, the CDC estimated that influenza was associated with up to12:

47-82 MILLION
FLU ILLNESSES

610,000-1,300,000
HOSPITALIZATIONS

27,000-130,000
DEATHS

 

Flu vaccines are widely available and play an essential role in flu prevention. However, they are not always used or may not always be effective, leaving people at risk.13

 

Treat the Flu Immediately

XOFLUZA® (baloxavir marboxil) Serious Disease Icon

The flu is a serious, contagious disease that impacts people of all ages and ethnicities. To make matters more serious, some symptoms of the flu can be quite similar to and/or overlap with the typical symptoms of COVID-19 and the common cold.11,14-19

SYMPTOMS FLU COVID-19 COMMON COLD
Incubation Period 1-4 days Varies Varies, but usually under 2 days
Symptom Onset Sudden Varies Gradual
Fever Common Common Rare
Chills Common Common Uncommon
Cough Common Common Common
Fatigue Common Common Sometimes
Sneezing Sometimes Rare Common
Nasal Congestion/Stuffy and/or Runny Nose Sometimes Common Common
New Loss of Taste/Sense of Smell Rare Common Rare
Diarrhea Common Common Rare
Body Aches Common Common Slight
Sore Throat Sometimes Common Common
Headache Common Common Rare
Shortness of Breath Common Common Not Reported/Rare

Although a single-dose of XOFLUZA does not treat COVID-19 or the common cold, coinfection with the flu and COVID-19 is possible. If the flu is confirmed or suspected, consider prescribing a flu antiviral immediately, regardless of COVID-19 infection.1,20

Influenza antivirals have been shown to shorten the duration of flu symptoms.21

The CDC Recommends Treating the Flu Empirically With an Antiviral21

When there is a clinical diagnosis of flu or suspected flu, the CDC recommends treating flu patients at high risk of developing complications empirically with an antiviral flu treatment. Empiric antiviral treatment is also recommended for non–high-risk outpatients with suspected influenza based on clinical judgment, including without an office visit, in communities where influenza is circulating. The CDC has included XOFLUZA among its list of antiviral medications recommended for the flu.21†

*Treating with single-dose XOFLUZA promptly (within 48 hours of symptom onset) can help alleviate flu symptoms in appropriate patients.1

 

†Source: Centers for Disease Control and Prevention (CDC). The CDC does not endorse private products, services, or enterprises. The content provided is for informational purposes only. Find the latest at CDC.gov.

 

XOFLUZA® (baloxavir marboxil) Single Dose Icon

Act After Exposure

Patients can reduce their risk of contracting the flu after exposure to an infected household member by taking single-dose XOFLUZA.1

Post-exposure prophylaxis efficacy >

Important Safety Information & Indication

Indication

XOFLUZA is an influenza virus polymerase acidic (PA) endonuclease inhibitor indicated for:

  • Treatment of acute uncomplicated influenza in patients 5 years of age and older who have been symptomatic for no more than 48 hours and who are otherwise healthy or at high risk of developing influenza-related complications.
  • Post-exposure prophylaxis (PEP) of influenza in patients 5 years of age and older following contact with an individual who has influenza.

 

Limitations of Use
Influenza viruses change over time, and factors such as the virus type or subtype, emergence of resistance, or changes in viral virulence could diminish the clinical benefit of antiviral drugs. Consider available information on drug susceptibility patterns for circulating influenza virus strains when deciding whether to use XOFLUZA.

Important Safety Information

Contraindications
XOFLUZA is contraindicated in patients with a history of hypersensitivity to baloxavir marboxil or any of its ingredients. Serious allergic reactions have included anaphylaxis, angioedema, urticaria, and erythema multiforme.

 

Warnings and Precautions

Hypersensitivity: Cases of anaphylaxis, urticaria, angioedema, and erythema multiforme have been reported in postmarketing experience with XOFLUZA. Appropriate treatment should be instituted if an allergic-like reaction occurs or is suspected.
 

Increased Incidence of Treatment-Emergent Resistance in Patients Less Than 5 Years of Age: XOFLUZA is not indicated in patients less than 5 years of age due to increased incidence of treatment-emergent resistance in this age group. In clinical trials, the incidence of virus with treatment-emergent substitutions associated with reduced susceptibility to baloxavir (resistance) was higher in pediatric subjects younger than 5 years of age (40%, 38/96) than in pediatric subjects ≥5 years to <12 years of age (16%, 19/117) or subjects ≥12 years of age (7%, 60/842). The potential for transmission of resistant strains in the community has not been determined.
 

Risk of bacterial infections: There is no evidence of the efficacy of XOFLUZA in any illness caused by pathogens other than influenza viruses. Serious bacterial infections may begin with influenza-like symptoms or may coexist with, or occur as, a complication of influenza. XOFLUZA has not been shown to prevent such complications. Prescribers should be alert to potential secondary bacterial infections and treat them as appropriate.

 

Adverse Reactions

  • The most common adverse reactions (≥1%) in adult and adolescent patients (≥12 years of age) in clinical studies for acute uncomplicated influenza were diarrhea (3%), bronchitis (3%), nausea (2%), sinusitis (2%), and headache (1%).
  • The most frequently reported adverse reactions (≥5%) in pediatric patients (5 to <12 years of age) in clinical studies for acute uncomplicated influenza were vomiting (5%) and diarrhea (5%).
  • The safety profile reported in a clinical study for post-exposure prophylaxis was similar in pediatric patients ages 5 to <12 years old as that reported in adults and adolescents 12 years of age and older.

 

Drug Interactions

Polyvalent cations: Coadministration with polyvalent cation-containing products may decrease plasma concentrations of baloxavir, which may reduce XOFLUZA efficacy. Avoid coadministration of XOFLUZA with dairy products, calcium-fortified beverages, polyvalent cation-containing laxatives, antacids, or oral supplements (e.g., calcium, iron, magnesium, selenium, or zinc).

 

Vaccines: The concurrent use of XOFLUZA with intranasal live attenuated influenza vaccine (LAIV) has not been evaluated. Concurrent administration of antiviral drugs may inhibit viral replication of LAIV and, thereby, decrease the effectiveness of LAIV vaccination. Interactions between inactivated influenza vaccines and XOFLUZA have not been evaluated.


For additional Important Safety Information, please see the XOFLUZA full Prescribing Information.

You are encouraged to report side effects to Genentech by calling 1-888-835-2555 or to the FDA by visiting www.fda.gov/medwatch or calling 1-800-FDA-1088.

    • XOFLUZA. Prescribing information. Genentech USA, Inc.

      XOFLUZA. Prescribing information. Genentech USA, Inc.

    • Baker J, Block SL, Matharu B, et al. Baloxavir marboxil single-dose treatment in influenza-infected children: a randomized, double-blind, active controlled phase 3 safety and efficacy trial (miniSTONE-2). Pediatr Infect Dis J. 2020;39(8):700-705. doi:10.1097/INF.0000000000002747

      Baker J, Block SL, Matharu B, et al. Baloxavir marboxil single-dose treatment in influenza-infected children: a randomized, double-blind, active controlled phase 3 safety and efficacy trial (miniSTONE-2). Pediatr Infect Dis J. 2020;39(8):700-705. doi:10.1097/INF.0000000000002747

    • TAMIFLU. Prescribing information. Genentech USA, Inc.; 2019.

      TAMIFLU. Prescribing information. Genentech USA, Inc.; 2019.

    • Hayden FG, Sugaya N, Hirotsu N, et al; Baloxavir Marboxil Investigators Group. Baloxavir marboxil for uncomplicated influenza in adults and adolescents. N Engl J Med. 2018;379(10):913-923.

      Hayden FG, Sugaya N, Hirotsu N, et al; Baloxavir Marboxil Investigators Group. Baloxavir marboxil for uncomplicated influenza in adults and adolescents. N Engl J Med. 2018;379(10):913-923.

    • Ison MG, Portsmouth S, Yoshida Y, et al. Early treatment with baloxavir marboxil in high-risk adolescent and adult outpatients with uncomplicated influenza (CAPSTONE-2): a randomised, placebo-controlled, phase 3 trial. Lancet Infect Dis. 2020;20(10):1204-1214. doi:10.1016/S1473-3099(20)30004-9

      Ison MG, Portsmouth S, Yoshida Y, et al. Early treatment with baloxavir marboxil in high-risk adolescent and adult outpatients with uncomplicated influenza (CAPSTONE-2): a randomised, placebo-controlled, phase 3 trial. Lancet Infect Dis. 2020;20(10):1204-1214. doi:10.1016/S1473-3099(20)30004-9

    • Ison MG, Portsmouth S, Yoshida Y, et al. Early treatment with baloxavir marboxil in high-risk adolescent and adult outpatients with uncomplicated influenza (CAPSTONE-2): a randomised, placebo-controlled, phase 3 trial. Lancet Infect Dis. 2020;20(10)(suppl):1-63. doi:10.1016/S1473-3099(20)30004-9

      Ison MG, Portsmouth S, Yoshida Y, et al. Early treatment with baloxavir marboxil in high-risk adolescent and adult outpatients with uncomplicated influenza (CAPSTONE-2): a randomised, placebo-controlled, phase 3 trial. Lancet Infect Dis. 2020;20(10)(suppl):1-63. doi:10.1016/S1473-3099(20)30004-9

    • Incalzi RA, Consoli A, Lopalco P, et al. Influenza vaccination for elderly, vulnerable and high-risk subjects: a narrative review and expert opinion. Intern Emerg Med. 2024;19(3):619-640.

      Incalzi RA, Consoli A, Lopalco P, et al. Influenza vaccination for elderly, vulnerable and high-risk subjects: a narrative review and expert opinion. Intern Emerg Med. 2024;19(3):619-640.

    • Green WD, Beck MA. Obesity impairs the adaptive immune response to influenza virus. Ann Am Thorac Soc. 2017;14(suppl 5):S406-S409.

      Green WD, Beck MA. Obesity impairs the adaptive immune response to influenza virus. Ann Am Thorac Soc. 2017;14(suppl 5):S406-S409.

    • United States Census Bureau. Caplan Z, Rabe M. The older population: 2020. May 2023. Accessed July 30, 2025. https://www2.census.gov/library/publications/decennial/2020/census-briefs/c2020br-07.pdf

      United States Census Bureau. Caplan Z, Rabe M. The older population: 2020. May 2023. Accessed July 30, 2025. https://www2.census.gov/library/publications/decennial/2020/census-briefs/c2020br-07.pdf

    • Ikematsu H, Hayden FG, Kawaguchi K, et al. Baloxavir marboxil for prophylaxis against influenza in household contacts. N Engl J Med. 2020;383(4):309-320. doi:10.1056/NEJMoa1915341

      Ikematsu H, Hayden FG, Kawaguchi K, et al. Baloxavir marboxil for prophylaxis against influenza in household contacts. N Engl J Med. 2020;383(4):309-320. doi:10.1056/NEJMoa1915341

    • Clinical signs and symptoms of influenza. Centers for Disease Control and Prevention. Last reviewed August 8, 2024. Accessed July 30, 2025.
      https://www.cdc.gov/flu/hcp/clinical-signs/index.html

      Clinical signs and symptoms of influenza. Centers for Disease Control and Prevention. Last reviewed August 8, 2024. Accessed July 30, 2025.
      https://www.cdc.gov/flu/hcp/clinical-signs/index.html

    • Estimated US flu disease burden. Centers for Disease Control and Prevention. Last reviewed May 9, 2025. Accessed July 30, 2025. https://www.cdc.gov/flu-burden/php/data-vis/2024-2025.html

      Estimated US flu disease burden. Centers for Disease Control and Prevention. Last reviewed May 9, 2025. Accessed July 30, 2025. https://www.cdc.gov/flu-burden/php/data-vis/2024-2025.html

    • Preventing seasonal flu. Centers for Disease Control and Prevention. Last reviewed August 26, 2024. Accessed July 30, 2025. https://www.cdc.gov/flu/prevention/

      Preventing seasonal flu. Centers for Disease Control and Prevention. Last reviewed August 26, 2024. Accessed July 30, 2025. https://www.cdc.gov/flu/prevention/

    • Symptoms of COVID-19. Centers for disease Control and Prevention. Last reviewed March 10, 2025. Accessed July 30, 2025. https://www.cdc.gov/covid/signs-symptoms/

      Symptoms of COVID-19. Centers for disease Control and Prevention. Last reviewed March 10, 2025. Accessed July 30, 2025. https://www.cdc.gov/covid/signs-symptoms/

    • Allan GM, Arroll B. Prevention and treatment of the common cold: making sense of the evidence. CMAJ. 2014;186(3):190-199. doi:10.1503/cmaj.121442

      Allan GM, Arroll B. Prevention and treatment of the common cold: making sense of the evidence. CMAJ. 2014;186(3):190-199. doi:10.1503/cmaj.121442

    • Cold versus the flu. Centers for Disease Control and Prevention. Last reviewed August 8, 2024. Accessed July 30, 2025. https://www.cdc.gov/flu/about/coldflu.html

      Cold versus the flu. Centers for Disease Control and Prevention. Last reviewed August 8, 2024. Accessed July 30, 2025. https://www.cdc.gov/flu/about/coldflu.html

    • Is it flu, COVID-19, allergies or a cold? National Institutes of Health. Last reviewed January 2022. Accessed July 30, 2025. https://newsinhealth.nih.gov/2022/01/it-flu-covid-19-allergies-or-cold

      Is it flu, COVID-19, allergies or a cold? National Institutes of Health. Last reviewed January 2022. Accessed July 30, 2025. https://newsinhealth.nih.gov/2022/01/it-flu-covid-19-allergies-or-cold

    • About adenovirus. Symptoms. Centers for Disease Control and Prevention. Last reviewed November 1, 2024. Accessed July 30, 2025. https://www.cdc.gov/adenovirus/about/index.html

      About adenovirus. Symptoms. Centers for Disease Control and Prevention. Last reviewed November 1, 2024. Accessed July 30, 2025. https://www.cdc.gov/adenovirus/about/index.html

    • Is it a cold, the flu, or COVID-19? National Institute on Aging. Last reviewed June 5, 2025. Accessed July 30, 2025. https://www.nia.nih.gov/health/covid-19/it-cold-flu-or-covid-19

      Is it a cold, the flu, or COVID-19? National Institute on Aging. Last reviewed June 5, 2025. Accessed July 30, 2025. https://www.nia.nih.gov/health/covid-19/it-cold-flu-or-covid-19

    • COVID-19 Treatment Guidelines Panel. Coronavirus Disease 2019 (COVID-19) Treatment Guidelines. National Institutes of Health. Updated February 29, 2024. Accessed July 30, 2025. https://www.ncbi.nlm.nih.gov/books/NBK570371/pdf/Bookshelf_NBK570371.pdf

      COVID-19 Treatment Guidelines Panel. Coronavirus Disease 2019 (COVID-19) Treatment Guidelines. National Institutes of Health. Updated February 29, 2024. Accessed July 30, 2025. https://www.ncbi.nlm.nih.gov/books/NBK570371/pdf/Bookshelf_NBK570371.pdf

    • Influenza antiviral medications: summary for clinicians. Centers for Disease Control and Prevention. Last reviewed December 8, 2023. Accessed July 30, 2025. https://www.cdc.gov/flu/hcp/antivirals/summary-clinicians.html

      Influenza antiviral medications: summary for clinicians. Centers for Disease Control and Prevention. Last reviewed December 8, 2023. Accessed July 30, 2025. https://www.cdc.gov/flu/hcp/antivirals/summary-clinicians.html

    • Emerging infectious diseases: influenza A(H1N1)pdm09 virus with reduced susceptibility to baloxavir, Japan, 2024. Centers for Disease Control and Prevention. May 2025. Accessed July 30,2025. https://wwwnc.cdc.gov/eid/article/31/5/24-1123_article

      Emerging infectious diseases: influenza A(H1N1)pdm09 virus with reduced susceptibility to baloxavir, Japan, 2024. Centers for Disease Control and Prevention. May 2025. Accessed July 30,2025. https://wwwnc.cdc.gov/eid/article/31/5/24-1123_article

    • Samji T. Influenza A: understanding the viral life cycle. Yale J Biol Med. 2009;82(4):153-159.

      Samji T. Influenza A: understanding the viral life cycle. Yale J Biol Med. 2009;82(4):153-159.

    • De Clercq E, Li G. Approved antiviral drugs over the past 50 years. Clin Microbiol Rev. 2016;29(3):695-747.

      De Clercq E, Li G. Approved antiviral drugs over the past 50 years. Clin Microbiol Rev. 2016;29(3):695-747.

    • Fiore AE, Fry A, Shay D, Gubareva L, Bresee JS, Uyeki TM. Antiviral agents for the treatment and chemoprophylaxis of influenza—recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2011;60(1):1-24.

      Fiore AE, Fry A, Shay D, Gubareva L, Bresee JS, Uyeki TM. Antiviral agents for the treatment and chemoprophylaxis of influenza—recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2011;60(1):1-24.

    • von Itzstein M. The war against influenza: discovery and development of sialidase inhibitors. Nat Rev Drug Discov. 2007;6(12):967-974. doi:10.1038/nrd2400

      von Itzstein M. The war against influenza: discovery and development of sialidase inhibitors. Nat Rev Drug Discov. 2007;6(12):967-974. doi:10.1038/nrd2400

    • von Itzstein M. The war against influenza: discovery and development of sialidase inhibitors. Nat Rev Drug Discov. 2007;6(12):967-974. doi:10.1038/nrd2400

      von Itzstein M. The war against influenza: discovery and development of sialidase inhibitors. Nat Rev Drug Discov. 2007;6(12):967-974. doi:10.1038/nrd2400