Baloxavir marboxil

Administration

• Type: Antiviral
• Dosage Forms: 20 mg, 40 mg tab
• Routes of Administration: PO
• Common Trade Names: Xofluza

Indications

• Influenza

Adult Dosing

• 40-79.9 kg: 40 mg PO x1
  • Start within 48 hours of symptom onset
  • Avoid co-administration with dairy products, calcium supplements
• >80 mg: 80 mg PO x1
  • Start within 48 hours of symptom onset
  • Avoid co-administration with dairy products, calcium supplements

Pediatric Dosing

• Approved for use in pediatric patients 12 and older
• 40-79.9 kg: 40 mg PO x1
  • Start within 48 hours of symptom onset
  • Avoid co-administration with dairy products, calcium supplements
• >80 mg: 80 mg PO x1
  • Start within 48 hours of symptom onset
  • Avoid co-administration with dairy products, calcium supplements

Special Populations

• Pregnancy Category: Not assigned (insufficient data)
• Lactation risk: Avoid use while breastfeeding

Renal Dosing

• Adult and Pediatric:
  • CrCl>50: no adjustment
  • CrCl<50 or HD/PD: not defined

Hepatic Dosing

• Adult and Pediatric:
  • Child-Pugh Class A or B: no adjustment
  • Child-Pugh Class C: not defined

Contraindications

• Allergy to class/drug
• Pregnancy
• Breastfeeding

Adverse Reactions

Serious

• Anaphylaxis
• Angioedema
• Erythema multiforme
• Urticaria

Common

• Nausea (Especially in older patients)

Pharmacology

• Half-life: 79.1 hours
• Metabolism: liver (CYP450)
• Excretion: Feces (predominant), urine

Mechanism of Action

• Inhibits viral polymerase acidic protein endonuclease activity, which inhibits viral replications

Comments

Only approved for patients >12 years old and >40kg in weight, no current safety data exists for pregnancy and breastfeeding. More expensive but one time dosing. Genentech, its creator, states a recent phase III trial has shown it to be effective for prophylaxis but not currently FDA indicated for this.

See Also

• Influenza
• Antiviral
• Tamiflu/Oseltamivir