Is a 1‑liter dose of oseltamivir appropriate for a child weighing 26.2 kg?

Is a 1-liter dose of oseltamivir appropriate for a child weighing 26.2 kg?

No, a 1-liter dose is absolutely not appropriate and would represent a massive, potentially fatal overdose—the correct dose for a 26.2 kg child is 60 mg (10 mL of oral suspension) twice daily for treatment, not 1 liter.

Correct Dosing for This Child

For a child weighing 26.2 kg, the appropriate oseltamivir dose is 60 mg twice daily for 5 days (or 60 mg once daily for prophylaxis). 1, 2, 3

• This child falls into the >23 kg to 40 kg weight category, which requires 60 mg twice daily for treatment. 1, 2, 3
• Using the 6 mg/mL oral suspension formulation, this translates to 10 mL per dose, administered twice daily (approximately 12 hours apart). 1, 2, 3
• The total daily dose is 120 mg (20 mL), and the total 5-day treatment course is 600 mg (100 mL total volume). 2, 3

Understanding the Magnitude of the Error

A "1-liter dose" would represent:

• 6,000 mg of oseltamivir (if using the 6 mg/mL suspension), which is 50 times the correct daily dose and 10 times the entire 5-day treatment course. 3
• This would constitute a severe overdose with unpredictable but potentially life-threatening consequences including severe gastrointestinal toxicity, neuropsychiatric effects, and renal complications. 4

Weight-Based Dosing Algorithm for Children

The correct pediatric dosing framework follows strict weight-based categories: 1, 2, 3

• ≤15 kg: 30 mg (5 mL) twice daily
• >15 to 23 kg: 45 mg (7.5 mL) twice daily
• >23 to 40 kg: 60 mg (10 mL) twice daily ← This child (26.2 kg) falls here
• >40 kg: 75 mg (12.5 mL) twice daily

Administration Details

• Oseltamivir should be administered with food to significantly reduce gastrointestinal side effects (nausea and vomiting occur in approximately 10-15% of patients). 2, 5, 4
• Treatment should be initiated within 48 hours of symptom onset for maximum benefit, though should not be withheld in high-risk or hospitalized children presenting beyond this window. 2, 5
• The standard treatment duration is 5 days. 1, 2, 3
• For prophylaxis (prevention after exposure), the same weight-based dose is given once daily for 10 days instead of twice daily. 1, 2, 3

Critical Pitfall to Avoid

Never confuse milliliters (mL) with liters (L)—this represents a 1,000-fold error that would be catastrophic. 3 The oral suspension comes in bottles that are reconstituted to provide a final concentration of 6 mg/mL, and typical pediatric doses range from 5 mL to 12.5 mL per dose, never approaching liter quantities. 1, 2, 3

Dispensing Guidance

For a 5-day treatment course at 60 mg twice daily (10 mL per dose):

• Total volume needed: 100 mL (10 mL × 2 doses/day × 5 days)
• Number of bottles to dispense: 2 bottles of the commercially available oral suspension 1, 3
• An appropriate oral dosing syringe that accurately measures 10 mL should be provided with the medication. 3