II. Indications
-
Influenza (A or B)
- Alternative to Oseltamivir (Tamiflu) in non-severe Influenza
- Indicated in Non-hospitalized patients with risk factors (e.g. diabetes, heart disease)
- Age >= 5 years old and symptoms <=48 hours
- Oseltamivir is recommended instead in severe cases
III. Mechanism
- Cap-dependent endonuclease inhibitor
- Some RNA Viruses (including Influenza) replicate via cap snatching
- Virus extracts first 15-20 of host RNA residues which is used as 5' cap on virus RNA
- Virus RNA Polymerase has endonuclease functionality used in cap snatching
IV. Dosing
- Costs $150 in 2022 (contrast with $25 to $40 for 5 days of Tamiflu)
- One single oral dose for over age 12 years
- Weight 88 to 176 lb (40 to 80 kg)
- Give 40 mg (two 20 mg tablets)
- Weight >176 lb (>80 kg)
- Give 80 mg (two 40 mg tablets)
- Weight 88 to 176 lb (40 to 80 kg)
V. Efficacy
- May shorten Influenza symptoms by up to 1 day if started within 48 hours (similar to Oseltamivir)
- No evidence for benefit in high risk patients (under age 2, over age 65, pregnancy) to prevent complications
- Appears effective for Influenza Prophlaxis (but not FDA approved for prophylaxis as of 2020)
- Single dose after household exposure may prevent up to 1 case in 9 contacts
- Ikematsu (2020) N Engl J Med 383:309-20 [PubMed]
VI. Adverse Effects (in 1-3% of patients)
VII. Drug Interactions
VIII. Resources
- Baloxavir Marboxil (DailyMed)
IX. References
- (2023) Presc Lett 30(11): 62-3
- (2020) Presc Lett 27(10): 55-6
- (2018) Presc Lett 25(12): 67
- Erlich (2019) Am Fam Physician 100(12): 776-7 [PubMed]
Images: Related links to external sites (from Bing)
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