High-Dose Augmentin Dosing for a 64.3 kg Child with Acute Otitis Media
For this 64.3 kg child with acute otitis media, the high-dose Augmentin regimen is 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate (14:1 ratio), divided into 2 doses daily, which calculates to approximately 2,893 mg amoxicillin twice daily (5,786 mg total daily) with 206 mg clavulanate twice daily.
Dosing Calculation and Rationale
The American Academy of Pediatrics guidelines explicitly recommend high-dose amoxicillin-clavulanate at 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in a 14:1 ratio, given in 2 divided doses 1. This formulation is specifically designed to be less likely to cause diarrhea than other amoxicillin-clavulanate preparations while maintaining efficacy against resistant pathogens.
For your 64.3 kg patient:
- Amoxicillin component: 90 mg/kg/day × 64.3 kg = 5,787 mg/day ÷ 2 doses = ~2,893 mg per dose
- Clavulanate component: 6.4 mg/kg/day × 64.3 kg = 411 mg/day ÷ 2 doses = ~206 mg per dose
When High-Dose Augmentin is Indicated
High-dose amoxicillin-clavulanate should be used as first-line therapy in children with AOM who have 1:
- Taken amoxicillin in the previous 30 days
- Concurrent purulent conjunctivitis (otitis-conjunctivitis syndrome)
- Need for coverage against β-lactamase-producing H. influenzae and M. catarrhalis
Clinical Efficacy Evidence
The FDA-approved Augmentin ES-600 formulation (90/6.4 mg/kg/day) demonstrated superior bacteriologic eradication rates in clinical trials 2:
- 98.4% eradication of all S. pneumoniae strains
- 100% eradication of penicillin-resistant S. pneumoniae with MIC = 2 mcg/mL
- 85.7% eradication of highly resistant S. pneumoniae with MIC = 4 mcg/mL
- 92.6% eradication of H. influenzae
Clinical success rates at 2-4 days post-therapy ranged from 78.6% to 89.1% depending on pathogen resistance patterns 2.
Important Practical Considerations
Formulation Availability
Since this child weighs 64.3 kg (well above typical pediatric weights), standard adult Augmentin tablets may not provide the correct 14:1 ratio needed for high-dose therapy. The ES-600 powder formulation provides the appropriate ratio but is typically used in younger children. You may need to use:
- Multiple tablets of appropriate strength to achieve the target dose
- Consultation with pharmacy to ensure the 14:1 ratio is maintained
Duration of Therapy
Treat for 10 days as recommended by guidelines 1 and supported by FDA clinical trials 2.
Common Pitfall to Avoid
Do not use standard-dose Augmentin formulations (such as 875/125 mg tablets) for high-dose therapy, as these provide a 7:1 ratio rather than the required 14:1 ratio. The 14:1 ratio specifically reduces diarrhea incidence while maintaining efficacy 1.
Tolerability
Protocol-defined diarrhea occurred in approximately 11-13% of children receiving the high-dose formulation, which was not significantly different from standard-dose comparators 2. The 14:1 ratio formulation causes less gastrointestinal upset than older 4:1 or 7:1 formulations 1.
Alternative if High-Dose Augmentin Fails
If the patient fails to respond after 48-72 hours of high-dose amoxicillin-clavulanate, guidelines recommend ceftriaxone 50 mg/kg IM or IV daily for 3 days 1.