Augmentin Dosing for a 4-Year-Old Child Weighing 15 kg at 45 mg/kg/dose
For a 4-year-old child weighing 15 kg requiring 45 mg/kg/dose of Augmentin (amoxicillin component), the calculated dose is 675 mg per dose, administered every 12 hours. 1
Dose Calculation
- Total daily dose: 45 mg/kg/day × 15 kg = 675 mg per dose (when given twice daily) 1
- Dosing interval: Every 12 hours (twice daily) 1
- Total daily amoxicillin: 1,350 mg/day 1
Practical Formulation Selection
Since this child weighs less than 40 kg, pediatric weight-based dosing applies rather than adult fixed-dose tablets 2, 1. The FDA label specifies that for severe infections or lower respiratory tract infections in children, the recommended dose is 45 mg/kg/day divided every 12 hours 1.
Available Formulations:
- Oral suspension 250 mg/5 mL: Give 13.5 mL per dose (provides 675 mg amoxicillin) 1
- Oral suspension 125 mg/5 mL: Give 27 mL per dose (provides 675 mg amoxicillin) 1
The 250 mg/5 mL suspension is preferred as it requires a smaller volume (13.5 mL vs 27 mL), improving palatability and adherence. 1
Clinical Context for 45 mg/kg/dose Regimen
The 45 mg/kg/day dosing (divided every 12 hours) is specifically indicated for 1:
- Severe ear/nose/throat infections
- Severe skin/skin structure infections
- All lower respiratory tract infections (regardless of severity)
- Infections caused by bacteria with intermediate susceptibility to amoxicillin
This high-dose regimen was developed to address drug-resistant Streptococcus pneumoniae and beta-lactamase-producing organisms 3, 4.
Administration Instructions
- Timing: Administer at the start of meals to minimize gastrointestinal intolerance 1
- Mixing options: Can be mixed with formula, milk, fruit juice, water, or cold drinks if needed; must be consumed immediately after mixing 1
- Shake well: Always shake oral suspension vigorously before each dose 1
- Storage: Refrigeration is preferable but not required; discard unused suspension after 14 days 1
Treatment Duration
- Minimum duration: Continue for 48-72 hours beyond symptom resolution or bacterial eradication 1
- Streptococcal infections: Treat for at least 10 days to prevent acute rheumatic fever 1
- Complex infections: May require several weeks of therapy with clinical/bacteriological follow-up for months after cessation 1
Maximum Daily Dose Consideration
The calculated dose of 1,350 mg/day is well below the maximum pediatric dose of 4,000 mg/day of amoxicillin 5. This provides a safety margin while achieving therapeutic levels for resistant organisms 3, 4.
Critical Pitfalls to Avoid
- Do not use adult fixed-dose tablets (e.g., 875 mg) in children under 40 kg; weight-based liquid formulations ensure accurate dosing 2, 1
- Do not underdose: The 45 mg/kg/day regimen (not 25 mg/kg/day) is required for severe infections and lower respiratory tract infections 1
- Do not confuse total daily dose with per-dose amount: 45 mg/kg/day means 22.5 mg/kg per dose when given twice daily, but the FDA label expresses this as "45 mg/kg/day in divided doses every 12 hours" 1
- Verify renal function: No dose adjustment is needed for normal renal function, but severe renal impairment (GFR <30 mL/min) requires dosing modifications 1