[Photo of baloxavir marboxyl (Xofluza)]
Photo source: Fierce Pharma
- Baloxavir marboxyl (Xofluza) is a polymerase acidic endonuclease inhibitor that is active against the influenza virus
- Interferes with viral RNA polymerase complex that is necessary for viral gene transcription, which inhibits influenza virus replication
- Has activity versus influenza A and influenza B
- Viral resistance has been found due to amino acid substitutions in the polymerase acidic protein
- As seasonal flu strains in circulation may vary, beware this may impact the utility of baloxavir marboxyl
- FDA-approved on October 24th of 2018 for treatment of uncomplicated influenza in patients 12 years or greater who have been symptomatic for no more than 48 hours
- Available oral only
- Body weight 40kg – 80kg: 40mg x1
- Body weight > 80kg: 80mg x1
- Avoid co-administration with cations (e.g., calcium, iron, magnesium, zinc)
- No dose-adjustment listed for renal or hepatic impairment, but it has not been studied in severe renal or hepatic impairment
- May impact effectiveness of live attenuated influenza vaccines
- The most common side effects reported are: diarrhea, bronchitis, nasopharyngitis, headache, and nausea
- The ISMP August 2019 Acute Care Medication Alert Newsletter listed concerning post-market adverse event data, including 382 reports of which all but 14 had a serious or fatal outcome. They noted 50 cases of anaphylactic shock, 7 of which were fatal and all were reported by a healthcare professional.
- Anticipated to cost $150 per course (regardless of dose)
- Approximately $100 more than a course of oseltamivir
- Xofluza Package Insert
- Xofluza FDA Approval Press Release
- Baloxavir Marboxil for Uncomplicated Influenza in Adults and Adolescents. NEJM 2018.
- A Step Forward in the Treatment of Influenza. NEJM 2018.
- Sixty seconds on . . . baloxavir. BMJ 2018.
- New flu drug offers convenience, fast activity, and a novel mechanism – but at a cost. NEJM Journal Watch: HIV and ID Observations 2018.