Tamiflu Dosing for a 35 lb Child
For a child weighing 35 pounds (approximately 16 kg), the recommended dose of Tamiflu (oseltamivir) is 45 mg twice daily for 5 days for treatment, or 45 mg once daily for 10 days for prophylaxis. 1
Weight-Based Dosing Rationale
A 35-pound child falls into the >15 kg to 23 kg weight category (35 pounds = 15.9 kg), which requires 45 mg per dose according to American Academy of Pediatrics guidelines. 1, 2
The weight-based dosing categories for children ≥1 year are stratified as follows:
- ≤15 kg (≤33 lb): 30 mg per dose 1
- >15-23 kg (33-51 lb): 45 mg per dose 1, 2
- >23-40 kg (>51-88 lb): 60 mg per dose 1
- >40 kg (>88 lb): 75 mg per dose 1
Administration Details
For treatment of influenza: Give 45 mg twice daily for 5 days, ideally initiated within 48 hours of symptom onset. 1, 3
For prophylaxis: Give 45 mg once daily for 10 days following close contact with an infected individual. 1, 2
The 45 mg dose can be administered as:
- 7.5 mL of oral suspension (6 mg/mL concentration) 1, 2
- One 45 mg capsule (if the child can swallow capsules) 1, 3
Key Administration Recommendations
Administer with food to improve gastrointestinal tolerability and reduce nausea/vomiting, which occur in approximately 10% of patients. 4, 2, 5
No renal dose adjustment is needed unless the child has significant renal impairment (creatinine clearance <30 mL/min). 4, 5
Common Pitfalls to Avoid
Do not round down to 30 mg simply because the child is close to 33 pounds—once the child exceeds 15 kg (33 lb), the dose increases to 45 mg. 1
Do not delay treatment beyond 48 hours of symptom onset, as efficacy decreases significantly with later initiation. 3, 6
Ensure accurate weight measurement in kilograms, as dosing errors commonly occur from incorrect pound-to-kilogram conversions (35 lb ÷ 2.2 = 15.9 kg). 1