Oseltamivir Dosing for a 98-Pound Male Child
For a 98-pound (44.5 kg) male child with normal renal function, the recommended dose of liquid Tamiflu is 75 mg (12.5 mL of the 6 mg/mL oral suspension) twice daily for 5 days for treatment, or 75 mg (12.5 mL) once daily for 10 days for prophylaxis. 1, 2
Weight-Based Dosing Algorithm
Since this child weighs 98 pounds (44.5 kg), he falls into the >40 kg weight category, which requires the adult dose regardless of age. 1, 2, 3
The weight-based dosing tiers are:
- ≤15 kg (≤33 lb): 30 mg twice daily
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 1, 2, 3
Liquid Formulation Dosing
The oral suspension concentration is 6 mg/mL after reconstitution. 2, 3
For the 75 mg dose, administer 12.5 mL of the oral suspension twice daily for treatment (or once daily for prophylaxis). 3
Treatment vs. Prophylaxis Distinction
- Treatment regimen: 75 mg (12.5 mL) twice daily for 5 days, initiated within 48 hours of symptom onset 1, 3
- Prophylaxis regimen: 75 mg (12.5 mL) once daily for 10 days, started within 48 hours of exposure 1, 3
Critical pitfall: Never confuse treatment dosing (twice daily) with prophylaxis dosing (once daily), as this leads to either underdosing treatment or overdosing prophylaxis. 1
Administration Recommendations
Administer oseltamivir with food to significantly reduce gastrointestinal side effects (nausea and vomiting), which occur in approximately 10-15% of patients. 1, 2, 3 Taking the medication with meals improves tolerability without affecting efficacy. 1
Timing Considerations
Treatment must be initiated within 48 hours of symptom onset for maximum benefit, reducing illness duration by 1-1.5 days. 1, 3 Earlier initiation is associated with faster symptom resolution. 4
Renal Function Verification
Confirm normal renal function before using standard dosing. If creatinine clearance is 10-30 mL/min, reduce the dose to 75 mg once daily (instead of twice daily) for treatment. 1, 3 However, this is unlikely to be relevant in a healthy child.