Tamiflu Dosing for a 5-Year-Old Weighing 16.1 kg
For a 5-year-old child weighing 16.1 kg, the recommended dose of Tamiflu (oseltamivir) is 45 mg twice daily for treatment (5 days) or 45 mg once daily for prophylaxis (10 days). 1
Weight-Based Dosing Algorithm
This child falls into the >15 kg to ≤23 kg weight category, which determines the appropriate dose 1, 2:
- Treatment dose: 45 mg (7.5 mL of 6 mg/mL oral suspension) twice daily for 5 days 1, 2
- Prophylaxis dose: 45 mg (7.5 mL of 6 mg/mL oral suspension) once daily for 10 days after exposure 1, 2
The dosing categories for children ≥12 months are 1, 2:
- ≤15 kg: 30 mg per dose
15 kg to 23 kg: 45 mg per dose (this patient)
23 kg to 40 kg: 60 mg per dose
40 kg: 75 mg per dose
Critical Pitfall to Avoid
Do not use the 30 mg dose for this patient. At 16.1 kg, this child exceeds the 15 kg threshold and must receive 45 mg, not 30 mg 3. Using the lower dose would result in subtherapeutic concentrations and reduced efficacy 4.
Administration Details
- Formulation: Use the oral suspension (6 mg/mL concentration) with 7.5 mL per dose 1, 2
- Timing: Administer with food to reduce gastrointestinal side effects (nausea, vomiting) 1, 2
- Measurement: Use a calibrated oral dosing syringe that accurately measures 7.5 mL 2
- Treatment initiation: Begin within 48 hours of symptom onset for maximum benefit 1, 2
Dispensing Requirements
For a 5-day treatment course at 45 mg twice daily, dispense 2 bottles of the oral suspension 2. Each bottle contains 60 mL when reconstituted, and the patient requires 75 mL total (7.5 mL × 10 doses) 2.
Common Adverse Effects
Monitor for gastrointestinal symptoms including nausea, vomiting, headache, and skin reactions 1. These are typically mild and transient, particularly when oseltamivir is taken with food 1, 2.