Amoxicillin Dosing for Otitis Media
High-dose amoxicillin at 80-90 mg/kg/day divided into 2 doses is the recommended first-line treatment for acute otitis media in children. 1, 2, 3
Standard Dosing Regimen
- Administer 80-90 mg/kg/day divided into 2 doses for most pediatric patients with acute otitis media 1, 2, 3
- This high-dose regimen achieves middle ear fluid concentrations that exceed the minimum inhibitory concentration (MIC) for intermediately resistant Streptococcus pneumoniae (penicillin MICs 0.12-1.0 μg/mL) and many highly resistant serotypes (penicillin MICs ≥2 μg/mL) for a longer duration of the dosing interval 4, 2
- Approximately 87% of S. pneumoniae isolates are susceptible to high-dose amoxicillin, compared to only 83% for standard-dose (40 mg/kg/day) therapy 4, 2
- Twice-daily dosing is as effective as three-times-daily administration and improves adherence by reducing scheduling difficulties for caregivers 5, 6
Treatment Duration by Age
- Children under 2 years: treat for 10 days 2
- Children over 2 years with uncomplicated disease: 5-7 days is sufficient 3
When to Use Amoxicillin-Clavulanate Instead
Switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in a 14:1 ratio, divided into 2 doses) in these specific situations: 1, 2, 3
- Child received amoxicillin within the previous 30 days
- Concurrent purulent conjunctivitis is present
- Coverage for β-lactamase-producing Haemophilus influenzae or Moraxella catarrhalis is specifically desired
- The 14:1 ratio formulation causes less diarrhea than other amoxicillin-clavulanate preparations 4, 2
Treatment Failure Management
- Reassess at 48-72 hours if symptoms fail to improve 2, 3
- If treatment fails after 48-72 hours on amoxicillin, switch to amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate) 1, 2, 3
- Alternative: ceftriaxone 50 mg IM or IV for 3 days 1
Important Clinical Caveats
- Pain management should be addressed concurrently during the first 24 hours, regardless of antibiotic choice 2, 3
- For obese children, there is controversy about maximum dosing: some experts cap the dose at the standard adult maximum of 1500 mg/day, while others recommend continuing weight-based dosing up to 80-90 mg/kg/day 7
- High-dose amoxicillin provides no additional benefit over standard-dose in children at low risk for antibiotic-resistant bacteria, but given the difficulty in predicting resistance patterns clinically, high-dose remains the standard recommendation 8
- Clinical improvement should be evident within 48-72 hours; lack of improvement warrants diagnostic reassessment 2, 3