Augmentin (Amoxicillin-Clavulanate) Liquid Dosing
For pediatric patients aged 3 months and older, use 45 mg/kg/day of the amoxicillin component divided into 2 doses for mild-to-moderate infections, or 90 mg/kg/day with 6.4 mg/kg/day of clavulanate divided into 2 doses for severe infections or when resistant organisms are suspected. 1, 2
Standard Dosing by Severity
Mild-to-Moderate Infections
- 45 mg/kg/day of amoxicillin component divided every 12 hours (twice daily) 1, 3
- Alternative: 40 mg/kg/day divided every 8 hours (three times daily) 3
- Maximum single dose: 2 grams regardless of weight 2
Severe Infections or High-Risk Situations
- 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate divided every 12 hours (twice daily) 1, 2
- This high-dose regimen provides a 14:1 ratio of amoxicillin to clavulanate 1, 4
- Maximum single dose: 2 grams 2
When to Use High-Dose Therapy
Use the 90 mg/kg/day regimen when any of these risk factors are present:
- Age younger than 2 years 1, 2
- Daycare attendance 1, 2
- Recent antimicrobial use within the past 30 days 1, 2
- Moderate-to-severe illness 1, 2
- Geographic areas with high prevalence (>10%) of penicillin-resistant Streptococcus pneumoniae 1, 2
- Incomplete Haemophilus influenzae type b vaccination (less than 3 injections) 2
Critical pitfall: Using standard doses when high-dose therapy is indicated leads to treatment failure with resistant organisms 2. The higher amoxicillin dose is specifically needed to overcome resistance in S. pneumoniae 1, and serum levels increase linearly with dose while adverse effects remain similar between lower and higher doses 1, 2.
Infants Under 3 Months
- Maximum 30 mg/kg/day divided every 12 hours 3
- This lower dose accounts for incompletely developed renal function affecting amoxicillin elimination 3
- No dosing recommendations exist for infants with impaired renal function 3
Duration of Therapy
- 7-10 days for most infections 1
- 10 days minimum for Streptococcus pyogenes infections to prevent acute rheumatic fever 3
- Continue for 48-72 hours beyond resolution of symptoms or evidence of bacterial eradication 3
Preparation and Administration
- Reconstitute powder with water per bottle instructions (see FDA label for specific volumes) 3
- Shake well before each use 3
- Administer at the start of a meal to minimize gastrointestinal intolerance 3
- Refrigeration is preferable but not required 3
- Discard unused suspension after 14 days 3
Tolerability Considerations
Twice-daily dosing produces equivalent efficacy to three-times-daily dosing but shows a trend toward better compliance and lower incidence of diarrhea 5. The most common adverse effect is mild diarrhea, which occurs less frequently with twice-daily versus three-times-daily administration 6, 5. The high-dose formulation (90/6.4 mg/kg/day) demonstrates similar tolerability to conventional twice-daily formulations 6, 7.