Pharmacy Phriday #9: Xofluza (Baloxavir marboxil) for Influenza

Contributor: Rachael Duncan, PharmD BCPS

Educational Pearls:

• According to the Department of Public Health and Environment who puts out a weekly report on the influenza virus in Colorado, there appears to be less influenza in Colorado than previous years
• A milder influenza outbreak is likely due to mask wearing and social distancing practices
• There have only been 22 hospitalizations for influenza in Colorado since the start of the flu season back in September and 0 outbreaks in long-term care facilities
• Xofluza (baloxavir marboxil) is an antiviral PA endonuclease inhibitor and was approved by the FDA in 2018 for uncomplicated influenza in patients 12 years and older that have been symptomatic for less than 48 hours
• Patient's getting Xofluza must be otherwise healthy or at risk of developing influenza-related complications
• Due to limited data, Xofluza would not be a good option for those that are inpatient or critically ill and is best utilized for patients who are being seen in the emergency department and will be sent home
• Currently Xofluza is not approved for complicated patients, pregnant patients or those that are breast-feeding which limits its use
• When compared with Tamiflu in phase 3 studies, Xofluza was superior to placebo and similar to Tamiflu in shortening the duration of illness
• Xofluza is a single dose that is weight based and appears to be very well tolerated with some adverse effects including headache, nausea and diarrhea
• Xofluza showed a quicker recovery compared to Tamiflu by 8 hours which could be related to its one-time dosing
• Cost is a limiting factor for the use of Xofluza. Tamiflu costs around $25 where as Xofluza (only available as brand name currently) is $156 at the cheapest
• Pharmacists are still encouraging everyone to get their influenza vaccines despite less influenza cases this year

References:

Cdphe.colorado.gov. 2021. Influenza (flu) | Department of Public Health & Environment. [online] Available at:

Ison, M., Portsmouth, S., Yoshida, Y., Shishido, T., Mitchener, M., Tsuchiya, K., Uehara, T. and Hayden, F., 2020. Early treatment with baloxavir marboxil in high-risk adolescent and adult outpatients with uncomplicated influenza (CAPSTONE-2): a randomised, placebo-controlled, phase 3 trial. The Lancet Infectious Diseases, 20(10), pp.1204-1214.

Hayden, F., Sugaya, N., Hirotsu, N., Lee, N., de Jong, M., Hurt, A., Ishida, T., Sekino, H., Yamada, K., Portsmouth, S., Kawaguchi, K., Shishido, T., Arai, M., Tsuchiya, K., Uehara, T. and Watanabe, A., 2018. Baloxavir Marboxil for Uncomplicated Influenza in Adults and Adolescents. New England Journal of Medicine, 379(10), pp.913-923.

Summarized by Emily Mack OMSIII

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