Augmentin (Amoxicillin/Clavulanate) Liquid Dosing for Pediatric Patients
For children ≥3 months old, the standard dose is calculated based on weight and infection severity, then converted to mL using the specific suspension concentration prescribed (125 mg/5 mL, 200 mg/5 mL, 250 mg/5 mL, or 400 mg/5 mL). 1
Dosing Algorithm by Age and Infection Severity
Infants <3 months old:
- Dose: 30 mg/kg/day of amoxicillin component divided every 12 hours 1
- Formulation: Use only the 125 mg/5 mL suspension (experience with 200 mg/5 mL is limited in this age group) 1
- Example: A 5 kg infant would receive 150 mg/day ÷ 2 = 75 mg per dose = 3 mL of 125 mg/5 mL suspension twice daily
Children ≥3 months old:
For severe infections (otitis media, sinusitis, lower respiratory tract infections):
- Every 12-hour regimen (preferred): 45 mg/kg/day divided every 12 hours 1
- Use 200 mg/5 mL or 400 mg/5 mL suspension 1
- Every 8-hour regimen: 40 mg/kg/day divided every 8 hours 1
- Use 125 mg/5 mL or 250 mg/5 mL suspension 1
For less severe infections:
- Every 12-hour regimen (preferred): 25 mg/kg/day divided every 12 hours 1
- Every 8-hour regimen: 20 mg/kg/day divided every 8 hours 1
For high-resistance areas or treatment failures:
- High-dose regimen: 90 mg/kg/day of amoxicillin component divided every 12 hours 2, 3
- This provides 14:1 ratio of amoxicillin to clavulanate (Augmentin ES-600) 4
Converting mg Dose to mL Volume
After calculating the mg dose based on weight and indication, convert to mL using the prescribed suspension concentration:
- 125 mg/5 mL suspension: Divide mg dose by 25 to get mL
- 200 mg/5 mL suspension: Divide mg dose by 40 to get mL
- 250 mg/5 mL suspension: Divide mg dose by 50 to get mL
- 400 mg/5 mL suspension: Divide mg dose by 80 to get mL
Example calculation: A 15 kg child with otitis media using the every 12-hour regimen:
- 45 mg/kg/day × 15 kg = 675 mg/day
- 675 mg ÷ 2 doses = 337.5 mg per dose
- Using 400 mg/5 mL suspension: 337.5 ÷ 80 = 4.2 mL per dose
Dose Rounding Considerations
Penicillins can be rounded by up to 15% for ease of home administration 5. For the example above, 4.2 mL could reasonably be rounded to 4 mL (within 5% rounding) or remain at 4.2 mL depending on infection severity and resistance concerns.
Critical Caveats
- The every 12-hour regimen is preferred over every 8-hour dosing because it significantly reduces diarrhea incidence 1, 6
- Different suspension concentrations are NOT interchangeable—always verify which concentration is dispensed before calculating mL dose 1
- Children ≥40 kg should receive adult dosing, not weight-based pediatric dosing 1
- Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects 1
- Reassess within 48-72 hours if no clinical improvement occurs 2, 3