From the Guidelines
Baloxavir should be dosed as a single oral dose, with the dosage dependent on body weight: 2 mg/kg for individuals less than 20 kg, 40 mg for those weighing 20-80 kg, and 80 mg for those weighing more than 80 kg, as recommended in the 2024 Pediatrics study 1. The dosing of baloxavir is based on its pharmacokinetics and efficacy in treating influenza.
- For individuals less than 20 kg, the dose is 2 mg/kg as a single dose.
- For those weighing 20-80 kg, the dose is 40 mg as a single dose.
- For those weighing more than 80 kg, the dose is 80 mg as a single dose. It is essential to note that baloxavir should be taken within 48 hours of symptom onset for maximum effectiveness, as it works by inhibiting the cap-dependent endonuclease enzyme needed for viral replication, as stated in the study 1. Some key considerations for baloxavir administration include:
- It should be taken with or without food.
- It should not be taken with products containing calcium, iron, magnesium, selenium, or zinc, as these can reduce absorption, as mentioned in the study 1.
- Patients should be advised that even after taking baloxavir, they remain contagious and should continue respiratory hygiene practices. The single-dose regimen of baloxavir may improve treatment adherence compared to other antiviral medications like oseltamivir, which requires multiple doses over 5 days, as seen in the comparison of treatment regimens in the study 1.
From the FDA Drug Label
2.2 Recommended Dosage Treatment of Acute Uncomplicated Influenza or Post-Exposure Prophylaxis in Adults, and Pediatric Patients (5 Years of Age and Older) XOFLUZA should be taken as a single dose as soon as possible and within 48 hours of influenza symptom onset for treatment of acute uncomplicated influenza or following contact with an individual who has influenza The recommended dosage of XOFLUZA in patients 5 years of age or older is a single weight-based dose displayed in Tables 1 and 2 Table 1 Recommended XOFLUZA Tablet Dosage in Adults and Pediatric Patients 5 Years of Age and Older Patient Body Weight (kg) | Recommended Single Oral Dose (Tablets) 20 kg to less than 80 kg | One 40 mg tablet At least 80 kg | One 80 mg tablet Table 2 Recommended XOFLUZA for Oral Suspension Dosage in Adults and Pediatric Patients 5 Years of Age and Older Patient Body Weight (kg) | Recommended Single Oral Dose*, † (For Oral Suspension) Less than 20 kg | 2 mg/kg taken as a single dose 20 kg to less than 80 kg | 40 mg (20 mL) taken as a single dose At least 80 kg | 80 mg (40 mL‡) taken as a single dose
The recommended dosage of Baloxavir is a single weight-based dose. For patients weighing 20 kg to less than 80 kg, the recommended dose is one 40 mg tablet or 40 mg (20 mL) of oral suspension. For patients weighing at least 80 kg, the recommended dose is one 80 mg tablet or 80 mg (40 mL) of oral suspension. For patients weighing less than 20 kg, the recommended dose is 2 mg/kg of oral suspension 2.
From the Research
Baloxavir Dose Information
- The dose of baloxavir is administered orally as a single-dose of 40 mg or 80 mg, depending on body weight 3.
- No dosage adjustment is needed in patients with mild-to-moderate hepatic or renal impairment 3.
Clinical Efficacy and Safety
- Baloxavir has been proven safe and effective in the treatment of acute uncomplicated influenza in patients 12 years of age and older when administered within 48 hours of symptom onset 3.
- Baloxavir was associated with the lowest risk of influenza-related complications and the lowest risk of total adverse events compared with placebo 4.
- The most common adverse reactions associated with baloxavir were diarrhea, bronchitis, nausea, nasopharyngitis, and headache 3.
Comparison with Other Antiviral Agents
- Zanamivir was associated with the shortest time to alleviation of influenza symptoms, while baloxavir was associated with reduced rate of influenza-related complications 4.
- Baloxavir had a significantly faster time to hypoxia resolution compared with oseltamivir in hospitalized patients with influenza A 5.
Special Populations
- Baloxavir can be effective in treating oseltamivir-resistant influenza A/H1pdm09 in immunocompromised patients, but clinical experience is limited 6.
- A combination of zanamivir and baloxavir-marboxil was effective in controlling influenza virus replication and clearing HCoV-OC43 in a hematopoietic stem cell transplant recipient 7.