Augmentin Dosing for 56 lb Child with Ear Infection
For a 56 lb (25 kg) child with acute otitis media, prescribe high-dose amoxicillin-clavulanate (Augmentin) at 90 mg/kg/day of the amoxicillin component, divided into two doses, which equals approximately 1,125 mg of amoxicillin twice daily (2,250 mg total daily dose) for 10 days.
Specific Dosing Calculation
For this 25 kg child:
- Standard high-dose regimen: 90 mg/kg/day ÷ 2 doses = 45 mg/kg per dose
- Per dose: 45 mg/kg × 25 kg = 1,125 mg amoxicillin per dose
- Frequency: Every 12 hours (twice daily)
- Duration: 10 days 1, 2
Formulation Selection
Use Augmentin ES-600 suspension if available, which provides the optimal 14:1 ratio of amoxicillin to clavulanate (90 mg/6.4 mg per kg/day). For this 25 kg child, this translates to 9.4 mL twice daily of the ES-600 suspension 2.
Alternatively, you can use standard Augmentin 600 mg/42.9 mg per 5 mL suspension, adjusting volume to achieve the target amoxicillin dose.
Rationale for High-Dose Therapy
The high-dose regimen (90 mg/kg/day vs. standard 40-45 mg/kg/day) is specifically recommended for:
- Penicillin-resistant Streptococcus pneumoniae: The high-dose formulation achieves eradication rates of 98.4% for all pneumococcal strains and 85.7% even for highly resistant strains (penicillin MIC ≥4 mcg/mL) 2
- β-lactamase-producing Haemophilus influenzae: Eradication rate of 92.6% 2
- Recent antibiotic exposure: If the child received amoxicillin in the past 30 days 1
- Recurrent or persistent otitis media 1, 3
Clinical Evidence Supporting This Approach
Multiple high-quality studies demonstrate superior outcomes with high-dose amoxicillin-clavulanate:
- Clinical success rates of 89.1% at 2-4 days post-therapy for all pneumococcal infections 2
- Treatment failure rates as low as 5.4% with amoxicillin-based therapy 4
- Significantly better bacteriologic eradication (83% vs. 49%) compared to azithromycin 5
- Lower treatment failure rates compared to other antibiotics including cefdinir and azithromycin 6
Administration Instructions
- Timing: Give at the start of meals to minimize gastrointestinal side effects and enhance clavulanate absorption 2
- Storage: Refrigerate reconstituted suspension; stable for 10 days 2
- Shake well before each dose
Expected Side Effects
The most common adverse events with high-dose formulation include:
- Diarrhea: 11-13% (protocol-defined diarrhea) 2, 7
- Diaper rash/contact dermatitis: 6% 2
- Vomiting: 6.5-6.9% 2
Important: The twice-daily high-dose formulation (90/6.4 mg/kg/day) causes significantly less diarrhea than the older three-times-daily formulation (40/10 mg/kg/day), with rates of 9.6% vs. 26.7% respectively 8.
When to Reassess
- Clinical improvement expected within 48-72 hours 9
- If no improvement or worsening after 48-72 hours, consider:
- Tympanocentesis for culture if skilled
- Switch to ceftriaxone 50 mg/kg IM/IV daily for 3 days 1
- Infectious disease consultation for multidrug-resistant organisms
Why Not Other Antibiotics?
Amoxicillin-clavulanate remains superior to alternatives:
- vs. Azithromycin: Better bacteriologic eradication (83% vs. 49%, P=0.001) and clinical outcomes 5
- vs. Cefdinir: Higher clinical cure rates (85.5% vs. 69.7%, P<0.01) 10
- vs. Plain amoxicillin: Necessary when β-lactamase-producing organisms suspected, though recent data show amoxicillin alone still effective in 94.6% of cases 4
This dosing provides optimal coverage for resistant pathogens while maintaining an acceptable side effect profile, supported by both FDA labeling 2 and current AAP guidelines 1.