Liquid Amoxicillin Dosing for a 6-Year-Old Weighing 34.9 kg
For a 6-year-old child weighing 34.9 kg requiring liquid amoxicillin, the dose depends critically on the indication and severity of infection. For most common infections (ear, nose, throat, skin, genitourinary), the standard dose is 875 mg (25 mg/kg) twice daily for mild-moderate infections or 1570 mg (45 mg/kg) twice daily for severe infections or lower respiratory tract infections 1.
Practical Dosing by Indication
For Mild-Moderate Infections (Ear/Nose/Throat, Skin, Genitourinary)
- Standard dose: 875 mg twice daily (every 12 hours)
- Using 250 mg/5 mL suspension: 17.5 mL twice daily
- This equals approximately 25 mg/kg/day
For Severe Infections or Lower Respiratory Tract Infections
- High dose: 1570 mg twice daily (every 12 hours)
- Using 250 mg/5 mL suspension: 31.4 mL twice daily
- This equals 45 mg/kg/day 1
For Pneumococcal Infections (Community-Acquired Pneumonia)
- High-dose amoxicillin: 1570-1745 mg twice daily
- This provides 45-50 mg/kg/dose twice daily
- Using 250 mg/5 mL suspension: 31.4-34.9 mL twice daily
- Guideline recommendation: 90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses 2, 3
For Group A Streptococcal Infections
- Moderate dose: 875-1310 mg twice daily
- This provides 50-75 mg/kg/day in 2 doses
- Using 250 mg/5 mL suspension: 17.5-26.2 mL twice daily 2, 3
Critical Considerations
Important caveat: At 34.9 kg, this child is approaching the weight where many clinicians inappropriately cap doses at "adult maximums." Recent evidence shows that larger children systematically receive lower mg/kg doses than recommended, with most children >60 kg receiving <40 mg/kg/day 4. Do not artificially cap the dose at adult maximums (typically 1500-1750 mg/day) if the calculated weight-based dose exceeds this - the child should receive the full weight-based dose for optimal treatment.
Suspension preparation: The 250 mg/5 mL suspension must be shaken vigorously before each use. After reconstitution, it remains stable for 14 days (refrigeration preferred but not required) 1.
Dosing frequency matters: For pneumococcal infections requiring high-dose therapy, twice-daily dosing (every 12 hours) is preferred over three-times-daily dosing for the same total daily dose, as it improves adherence while maintaining efficacy 2, 3.
Duration: Continue treatment for minimum 48-72 hours beyond symptom resolution. For streptococcal infections, treat for at least 10 days to prevent acute rheumatic fever 1.