Tamiflu Dosage for a 5-Year-Old Child
For a 5-year-old child, Tamiflu (oseltamivir) dosing is weight-based: children weighing ≤15 kg receive 30 mg twice daily, those >15-23 kg receive 45 mg twice daily, and those >23-40 kg receive 60 mg twice daily, all for 5 days of treatment. 1, 2
Weight-Based Dosing Algorithm
The key to proper dosing is determining the child's current weight and matching it to the appropriate dose tier:
- ≤15 kg (≤33 lb): 30 mg twice daily = 5 mL of oral suspension twice daily 1, 2
- >15-23 kg (>33-51 lb): 45 mg twice daily = 7.5 mL of oral suspension twice daily 1, 2
- >23-40 kg (>51-88 lb): 60 mg twice daily = 10 mL of oral suspension twice daily 1, 2
Most 5-year-old children typically fall into the 15-23 kg weight range, making 45 mg twice daily (7.5 mL) the most common dose for this age group. 1, 3
Treatment Duration and Timing
- Duration: 5 days of treatment regardless of weight category 1, 2
- Timing: Initiate treatment within 48 hours of symptom onset for maximum effectiveness 4, 2
- Administration: Can be given with or without food, though taking with meals may reduce gastrointestinal side effects like nausea and vomiting 1, 2
Formulation Options
The oral suspension (6 mg/mL concentration) is the preferred formulation for children who cannot swallow capsules. 3, 2 If capsules are used and the child can swallow them, the 30 mg or 45 mg capsule strengths correspond to the weight-based doses above. 1, 2
Prophylaxis Dosing (If Applicable)
If prescribing for influenza prevention rather than treatment, use the same weight-based doses but once daily instead of twice daily for 10 days following exposure to an infected individual. 1, 3
Critical Pitfalls to Avoid
- Do not underdose: Children eliminate oseltamivir faster than adults, requiring weight-based dosing rather than age-based dosing to achieve therapeutic drug levels. 5
- Do not delay treatment: Efficacy decreases significantly if treatment is not started within 48 hours of symptom onset. 2, 6
- Check renal function: If the child has renal impairment (creatinine clearance 10-30 mL/min), reduce the dose to once daily instead of twice daily. 1, 4
- Verify the weight: Always use current weight, not estimated or historical weight, as dosing errors are common when weight is approximated. 3