Amoxicillin-Clavulanate Dosing for 10-Year-Old with AOM and Perforation
For this 84 lb (38 kg) 10-year-old girl with acute otitis media and perforation, prescribe high-dose amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate (14:1 ratio) divided into 2 doses, which equals approximately 1,710 mg amoxicillin with 121 mg clavulanate twice daily (total daily: 3,420 mg/242 mg). 1, 2
Rationale for High-Dose Amoxicillin-Clavulanate
Perforation indicates more severe disease requiring broader coverage beyond standard amoxicillin, specifically targeting β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis that may be present in complicated AOM 1
The 14:1 ratio formulation (90 mg/kg amoxicillin with 6.4 mg/kg clavulanate) provides adequate coverage for penicillin-resistant Streptococcus pneumoniae while minimizing gastrointestinal side effects compared to other amoxicillin-clavulanate ratios 1, 2
High-dose amoxicillin achieves middle ear fluid concentrations exceeding the minimum inhibitory concentration for approximately 87% of S. pneumoniae isolates, including intermediately resistant strains 1, 3
Specific Dosing Calculation
Weight conversion: 84 lbs = 38.2 kg
Amoxicillin component: 90 mg/kg/day × 38.2 kg = 3,438 mg/day ÷ 2 doses = 1,719 mg per dose (round to 1,710 mg for practical dosing)
Clavulanate component: 6.4 mg/kg/day × 38.2 kg = 244 mg/day ÷ 2 doses = 122 mg per dose (round to 121 mg)
Practical prescription: Augmentin ES-600 suspension (600 mg amoxicillin/42.9 mg clavulanate per 5 mL) at approximately 14 mL twice daily, OR use combination of tablets to achieve target dose 1, 2, 4
Treatment Duration and Monitoring
Treat for 10 days given the patient's age and presence of perforation, which indicates more severe disease 3, 2
Clinical improvement should be evident within 48-72 hours; if no improvement occurs, reassess for treatment failure and consider switching to ceftriaxone (50 mg IM or IV for 3 days) 1, 2
The presence of perforation does not change the antibiotic choice but reinforces the need for high-dose therapy and close follow-up 1
Important Clinical Caveats
The 14:1 ratio is critical - older formulations with higher clavulanate ratios (7:1 or 4:1) cause significantly more diarrhea and should be avoided 1, 2
Diarrhea occurs in approximately 14-17% of patients on twice-daily high-dose amoxicillin-clavulanate, compared to 34% with three-times-daily dosing 4, 5
If the patient had received amoxicillin in the previous 30 days (which you should verify), this further supports the choice of amoxicillin-clavulanate over amoxicillin alone 1, 6
Do not use standard-dose amoxicillin (45 mg/kg/day) for this patient - the perforation indicates need for high-dose therapy with β-lactamase coverage 1
Address pain management concurrently with antibiotics, as symptom relief is important regardless of antibiotic choice 3