What is the treatment for Influenza B in a 9-year-old child?

From the Guidelines

For a 9-year-old with influenza B, treatment with oseltamivir is recommended, with a dosage of 60 mg twice daily for 5 days, as this has been shown to reduce the duration of illness and the risk of complications, as supported by the 2019 Pediatrics study 1. The treatment should be started as soon as possible after illness onset, without waiting for a definitive influenza test result, as early therapy provides the best outcomes.

• The dosage may vary based on the child's exact weight, with the following guidelines:
  • 15–23 kg (33–51 lb): 45 mg, twice daily
  • 23–40 kg (51–88 lb): 60 mg, twice daily

  • 40 kg (88 lb): 75 mg, twice daily

• Supportive care is equally important and includes rest, plenty of fluids to prevent dehydration, and acetaminophen or ibuprofen for fever and discomfort (follow age-appropriate dosing on the package) 1.
• It is essential to monitor for warning signs like difficulty breathing, bluish lips, chest pain, severe headache, or worsening symptoms, which require immediate medical attention.
• Antiviral treatment works by inhibiting viral replication, potentially shortening illness duration by 1-2 days and reducing complications, as shown in a meta-analysis of 5 new RCTs that included 1598 children with laboratory-confirmed influenza 1.
• Even healthy children can benefit from treatment, as influenza can cause serious complications in pediatric patients, and the risk of otitis media was 34% lower in children treated with oseltamivir, as reported in the 2019 Pediatrics study 1.

From the FDA Drug Label

The safety and efficacy of oseltamivir phosphate for the treatment of influenza in pediatric patients 2 weeks old to 17 years of age has been established [see Dosage and Administration (2.2), Clinical Pharmacology (12.3), and Clinical Studies (14. 1)] and is based on: 1 year to 12 years of age: Safety and efficacy in pediatric patients 1 year to 12 years of age was supported by results of one double-blind, placebo-controlled trial in 452 pediatric patients with influenza in whom oseltamivir phosphate 2 mg per kg twice daily or placebo was administered within 48 hours of symptom onset

The oseltamivir phosphate can be used for the treatment of influenza in a 9-year-old patient, as the safety and efficacy have been established for pediatric patients 1 year to 12 years of age. The recommended dosage is 2 mg per kg twice daily. 2

From the Research

Influenza B Treatment in 9-Year-Olds

• The treatment of influenza B in 9-year-olds can involve the use of oseltamivir, a neuraminidase inhibitor that has been shown to be effective in reducing the duration and severity of influenza symptoms 3, 4, 5.
• Oseltamivir has been studied in children with influenza, including a liquid formulation that has been shown to be effective in treating children with influenza 3.
• In one study, a 9-year-old female with severe influenza B infection requiring organ replacement therapy was treated with oral and intravenous oseltamivir, with plasma oseltamivir carboxylate concentrations remaining stable initially, but only regular administration of 100 mg resulting in virus load decline and clinical improvement 6.
• Another study found that oseltamivir treatment was effective in decreasing viral load in children with influenza B virus infection, with no major decrease in viral susceptibility to oseltamivir observed during or after treatment 7.
• The dosage of oseltamivir for children is typically 2 mg/kg twice daily for 5 days, although this may vary depending on the specific circumstances of the patient 3, 6.
• Oseltamivir is generally well-tolerated in children, with nausea and vomiting being the most commonly reported adverse events 3, 4, 5.