Amoxicillin Dosing for Pediatric Otitis Media
For a pediatric patient weighing 58.8 lbs (26.7 kg) with acute otitis media, prescribe amoxicillin 80-90 mg/kg/day divided into two daily doses, which equals approximately 1,070-1,200 mg twice daily (2,140-2,400 mg total daily dose). 1
Weight Conversion and Dose Calculation
- Patient weight: 58.8 lbs = 26.7 kg
- High-dose amoxicillin: 80-90 mg/kg/day 1
- Calculated dose range: 2,136-2,403 mg/day
- Practical dosing: Give 1,000-1,200 mg twice daily 1
Rationale for High-Dose Therapy
High-dose amoxicillin (80-90 mg/kg/day) is the first-line treatment for acute otitis media in children, particularly when drug-resistant Streptococcus pneumoniae is a concern. 1
When to Use High-Dose vs. Standard-Dose:
Use high-dose amoxicillin (80-90 mg/kg/day) if the patient has: 1
- Age younger than 2 years
- Attendance at child care
- Recent antibiotic use within the past 30 days
- Moderate to severe illness presentation
- Geographic area with >10% penicillin-nonsusceptible S. pneumoniae
Standard-dose amoxicillin (45 mg/kg/day) may be considered only for: 1
- Children ≥2 years old
- Mild to moderate illness
- No child care attendance
- No antibiotics in the past 4 weeks
- Low community resistance rates
Dosing Schedule and Duration
- Divide total daily dose into 2 equal doses given every 12 hours 1
- Duration: 10 days of therapy 1
- Maximum single dose: 2 g 1
Clinical Efficacy Evidence
High-dose amoxicillin achieves middle ear fluid concentrations adequate to overcome resistance in S. pneumoniae with altered penicillin-binding proteins. 1, 2 Research demonstrates that high-dose amoxicillin (80 mg/kg/day) eradicates 92% of S. pneumoniae isolates, including penicillin-nonsusceptible strains with MICs ≤2 mg/L. 2
Reassessment and Treatment Failure
Reassess the patient if symptoms worsen or fail to improve within 48-72 hours. 1
If Treatment Fails:
Switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses). 1 This provides coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, which account for the majority of amoxicillin failures. 2
Important Clinical Considerations
- Beta-lactamase-producing organisms (H. influenzae, M. catarrhalis) are the predominant pathogens in amoxicillin treatment failures 2
- Viral coinfection may reduce amoxicillin middle ear fluid penetration and efficacy 3
- Pain management should be addressed regardless of antibiotic use, especially during the first 24 hours 1