Amoxicillin Dosing for Acute Otitis Media in a 40.37 kg Child
For a 40.37 kg child with acute otitis media, prescribe amoxicillin 875 mg tablets twice daily (every 12 hours) for 5-10 days.
Dosing Rationale
The WHO guideline recommends 40 mg/kg/day divided twice daily for acute otitis media 1. For this 40.37 kg child:
- Calculated dose: 40 mg/kg/day × 40.37 kg = 1,614.8 mg/day
- Divided twice daily = approximately 807 mg per dose
However, the FDA-approved amoxicillin dosing for children weighing ≥40 kg follows adult dosing regimens 2. For ear/nose/throat infections of mild to moderate severity, the standard adult dose is 500 mg every 12 hours or 250 mg every 8 hours. For severe infections, the dose is 875 mg every 12 hours or 500 mg every 8 hours 2.
Recommended Tablet Strength
Use 875 mg tablets, given twice daily. This provides:
- Total daily dose: 1,750 mg/day
- Per-kg dose: 43.3 mg/kg/day
This slightly exceeds the WHO recommendation but remains within FDA-approved dosing for children ≥40 kg and aligns with high-dose amoxicillin recommendations for areas with drug-resistant Streptococcus pneumoniae 3.
Alternative Considerations
If high-dose therapy is not deemed necessary (low local resistance patterns), 500 mg tablets twice daily is acceptable 2, providing:
- Total daily dose: 1,000 mg/day
- Per-kg dose: 24.8 mg/kg/day
However, this falls below the WHO-recommended 40 mg/kg/day for otitis media 1.
Duration of Therapy
- 5 days is adequate for uncomplicated AOM in children ≥2 years per WHO guidelines 1
- 10 days remains common practice and is FDA-approved 2
- Recent evidence suggests shorter durations (5-7 days) are equally effective with less antibiotic exposure 4
Important Caveats
- Take at the start of meals to minimize gastrointestinal intolerance 2
- If the child has received antibiotics in the past 30 days, has concurrent conjunctivitis, or you suspect β-lactamase-producing organisms, consider amoxicillin-clavulanate (90 mg/kg/day amoxicillin component) instead 3
- Children in daycare settings have higher rates of drug-resistant pneumococcus and may benefit from high-dose therapy 5
- Treatment failure rates with standard amoxicillin remain low (5-6%) even with β-lactamase-producing bacteria present 6