Augmentin Dosing for a 2-Year-Old with Bilateral Acute Otitis Media
For a 2-year-old child weighing 11.4 kg with bilateral acute otitis media, give high-dose Augmentin at 90 mg/kg/day of the amoxicillin component divided into 2 doses, which equals approximately 513 mg twice daily (approximately 5.7 mL of the 400 mg/5 mL suspension twice daily) for 10 days. 1, 2
Rationale for High-Dose Regimen
Children under 2 years of age with AOM require antibiotic therapy and specifically warrant high-dose amoxicillin-clavulanate. 3, 2 The high-dose formulation (90 mg/kg/day with 6.4 mg/kg/day clavulanate in 2 divided doses) provides a 14:1 ratio that achieves middle ear fluid concentrations adequate to overcome penicillin-resistant Streptococcus pneumoniae and β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. 1, 2, 4
Key Risk Factors Present in This Patient:
- Age <2 years - This alone mandates high-dose therapy 2
- Bilateral disease - Increases severity and resistance risk 2
Specific Dosing Calculation
For an 11.4 kg child:
- Total daily dose: 11.4 kg × 90 mg/kg = 1,026 mg/day of amoxicillin component 1
- Per dose: 513 mg twice daily 1
- Volume using 400 mg/5 mL suspension: approximately 6.4 mL twice daily 5
- Alternative using 200 mg/5 mL suspension: approximately 12.8 mL twice daily 5
The 400 mg/5 mL (ES-600) formulation is preferred as it delivers the high-dose regimen in smaller volumes, improving compliance. 1, 4
Treatment Duration and Monitoring
- Duration: Complete a full 10-day course 1, 2, 4
- Expected response: Clinical improvement should occur within 48-72 hours 1, 6
- Reassessment: If no improvement or worsening after 48-72 hours, reevaluate for treatment failure, complications, or alternative diagnoses 1, 2
Critical Dosing Considerations
Do not use standard-dose regimens (45 mg/kg/day) in children under 2 years with AOM. 2 Standard dosing fails to achieve adequate middle ear fluid concentrations against penicillin-resistant S. pneumoniae (MIC ≥2 mg/L), which are increasingly prevalent. 4, 7 Research demonstrates that amoxicillin 40 mg/kg/day is inadequate to eradicate resistant pneumococci, particularly during viral coinfection, and 75-90 mg/kg/day is necessary. 7
The high-dose formulation (90/6.4 mg/kg/day) eradicated penicillin-resistant S. pneumoniae with MICs of 2-4 mg/L in clinical trials, with clinical response rates of 76-95%. 4, 8
Common Pitfalls to Avoid
- Verify suspension concentration before dispensing - The 400 mg/5 mL and 200 mg/5 mL suspensions are NOT interchangeable with standard formulations 5
- Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet - They contain different clavulanate ratios 5
- Twice-daily dosing reduces diarrhea compared to three-times-daily regimens while maintaining equivalent efficacy 5, 9
- Complete the full 10-day course even if symptoms improve earlier, as shorter courses increase recurrence rates 1, 2
Adverse Effects
The most common adverse effect is mild diarrhea, which occurs less frequently with twice-daily dosing (6-31% depending on formulation). 2, 4 The high-dose formulation shows similar tolerability to conventional doses. 4 Serious adverse events are rare (3.6% in large postmarketing studies). 4