Baloxavir marboxil
XOFLUZA
Pronunciation: ba-lox-a-veer-mar-BOX-el (zoe-FLOO-za)
“Ball locks a virus (in) Marble box”
What it isProdrug of an influenza cap-dependent endonuclease inhibitor; uncomplicated influenza.
Why this oneA single oral administration completes treatment, unlike multiday neuraminidase-inhibitor regimens.
What limits itResistance can emerge during therapy, especially in children; polyvalent cations reduce absorption.
FDA-approved for
- influenza (2018)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Influenza — treatment or post-exposure prophylaxis | ≥5 y, 20 to <80 kg | 40 mg single dose | 40 mg x1 | 40 mg once |
| Influenza — treatment or post-exposure prophylaxis | ≥80 kg | 80 mg single dose | 80 mg x1 | 80 mg once |
| Influenza — treatment or post-exposure prophylaxis | Peds 15 to <20 kg (suspension packets) | 30 mg single dose | 30 mg x1 | 30 mg once |
| Influenza — treatment or post-exposure prophylaxis | Peds <20 kg (oral suspension bottle) | 2 mg/kg single dose | 2 mg/kg x1 | weight-based |
Renal Undefined
Hepatic Undefined
Single-dose regimen; not indicated in patients <5 years (treatment-emergent resistance)
Instructions
- Single dose; take within 48 h of symptom onset or exposure
- May take with or without food
- Avoid dairy, calcium-fortified beverages, antacids, laxatives, or polyvalent cation supplements (Ca, Fe, Mg, Se, Zn)
Available strengths
- tab 40, 80 mg
- susp 2 mg/mL
- susp 30, 40 mg/packet
- sol 40 mg/20 mL
Cautions
- Hypersensitivity (anaphylaxis, angioedema, urticaria, erythema multiforme)
- Increased treatment-emergent resistance in patients <5 years — not indicated
- Does not prevent secondary bacterial infections
Adverse reactions
- Diarrhea (3%)
- Bronchitis (3%)
- Nausea (2%)
- Sinusitis (2%), headache (1%)
- Peds: vomiting and diarrhea (5%)
Pregnancy No adequate human data; no adverse developmental effects in animals
Lactation No human data; baloxavir present in rat milk
Cost
Generic entry2041 est.
NO BOXED WARNINGS
Principal riskResistance emerges readily, especially in children
Classes and tags
Clinical profile
Legacy pregnancy categoryNot assigned — PLLR-era drug
Defining liabilityAgent-specific renal, hepatic, hematologic, metabolic and drug-interaction toxicity.
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