What is the recommended dose of amoxicillin (amoxicillin) for a child with otitis media weighing 51.3 kg?

Amoxicillin Dosing for Otitis Media in a 51.3 kg Child

For a child weighing 51.3 kg with otitis media, the recommended dose of amoxicillin is 40 mg/kg/day divided into two doses (approximately 1000 mg twice daily) for 5 days. 1

Dosing Calculation and Rationale

The appropriate dosing for this child can be determined as follows:

• Standard dose amoxicillin for otitis media: 40 mg/kg/day 1
• For a 51.3 kg child: 51.3 kg × 40 mg/kg/day = 2,052 mg/day
• Divided into two doses: approximately 1,000 mg twice daily

Factors to Consider:

1. Weight-based dosing: At 51.3 kg, this child is approaching adult weight (≥40 kg), so adult dosing considerations may apply 2

2. Severity assessment:

   • For mild, uncomplicated otitis media: Standard-dose amoxicillin (40 mg/kg/day) is appropriate 1
   • For more severe infections or in areas with high prevalence of resistant organisms: High-dose amoxicillin (80-90 mg/kg/day) may be considered 1

Special Considerations

When to Use High-Dose Amoxicillin (80-90 mg/kg/day):

• In communities with high prevalence of nonsusceptible S. pneumoniae (>10%) 1
• For children who:
  • Are younger than 2 years
  • Attend childcare
  • Have received antibiotics within the previous 4-6 weeks
  • Have severe symptoms 1

If high-dose therapy is warranted, the calculation would be:

• 51.3 kg × 80-90 mg/kg/day = 4,104-4,617 mg/day
• Practically administered as 2,000 mg twice daily

Duration of Therapy

The recommended duration for otitis media treatment is 5 days 1. Some guidelines suggest 7-10 days depending on clinical response 1.

Alternative Options for Special Situations

If the patient has penicillin allergy or treatment failure occurs after 72 hours, consider:

• Cefpodoxime proxetil
• Cefuroxime axetil
• Cefdinir 1

For patients with immediate Type I hypersensitivity to β-lactams:

• Trimethoprim-sulfamethoxazole
• Azithromycin
• Clarithromycin 1

Common Pitfalls to Avoid

1. Underdosing: Using adult fixed doses rather than weight-based dosing in children can lead to treatment failure

2. Inappropriate high-dose use: Using high-dose amoxicillin when not indicated increases the risk of side effects without additional benefit 3

3. Failure to reassess: If no improvement is observed after 72 hours of therapy, reassessment and possible change in antibiotic therapy is warranted 1

4. Overlooking β-lactamase producers: In cases of treatment failure, consider that beta-lactamase-producing H. influenzae may be the causative organism, which would require amoxicillin-clavulanate instead 4

The standard dose of amoxicillin remains appropriate first-line therapy for uncomplicated otitis media in most communities, with high-dose regimens reserved for specific risk factors or areas with high resistance patterns.