Patient-Oriented Evidence That Matters

Baloxavir Reduces Symptom Duration Similar to Oseltamivir, Primarily Within 24 Hours of Symptom Onset


Am Fam Physician. 2019 Dec 15;100(12):online.

Clinical Question

Is baloxavir (Xofluza) a safe and effective for treatment of influenza?

Bottom Line

Baloxavir has similar efficacy to oseltamivir (Tamiflu) (33-hour reduction in duration of symptoms compared with placebo) and, like oseltamivir, is most effective when given within 24 hours of the onset of symptoms. If given 24 to 48 hours after symptom onset, symptom duration was reduced by only 13 hours (which is almost identical to what we found in our meta-analysis of oseltamivir [Fam Pract. 2013;30(2):125–133]). It does not seem worth the extra cost in the United States: $160 for baloxavir vs. $50 for oseltamivir (www.goodrx.com). There are no data regarding the effect on complications or mortality, nor any data for patients younger than 12 years, older than 64 years, or with serious comorbidities. The major advantages of baloxavir over oseltamivir for those who choose to use it are convenience because it is a single dose and fewer adverse drug reactions (number needed to treat = 25). (Level of Evidence = 1b)


Baloxavir inhibits polymerase acidic protein, which is involved in viral replication. This report summarizes the results of a phase two (dose-ranging) trial and a phase three trial comparing baloxavir with oseltamivir and placebo (baloxavir is now U.S. Food and Drug Administration approved). We will focus on the phase three trial, which recruited patients 12 to 64 years with an influenza-like illness for less than 48 hours. The authors randomized patients 20 to 64 years of age into one of three groups in a 2:2:1 ratio: baloxavir in a single dose (40 mg for patients weighing less than 80 kg [176 lbs] and 80 mg for patients weighing at least 80 kg); oseltamivir, 75 mg twice daily for five days; or matching placebos. The patients 12 to 19 years of age were randomized in a 2:1 ratio to baloxavir or placebo. Influenza-like illness was defined as the presence of fever 100.4°F (38°C) or higher, at least one respiratory symptom that was moderately severe, and at

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

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This series is coordinated by Sumi Sexton, MD, editor-in-chief.

A collection of POEMs published in AFP is available at https://www.aafp.org/afp/poems.



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