What is the recommended dosage of amoxicillin (Amoxicillin) for the treatment of Acute Otitis Media (AOM)?

Amoxicillin Dosage for Acute Otitis Media (AOM)

High-dose amoxicillin at 80-90 mg/kg/day divided into two doses is the recommended first-line treatment for acute otitis media. 1

First-Line Treatment Options

• Standard recommendation: Amoxicillin 80-90 mg/kg/day divided into two doses for children
• Duration:
  • 10 days for children under 2 years or those with severe symptoms
  • 7 days for children 2-5 years with mild/moderate AOM
  • 5-7 days for children 6 years and older with mild/moderate symptoms 2, 1

Treatment Algorithm

Clinical Scenario	Recommended Treatment
First episode of AOM	High-dose amoxicillin (80-90 mg/kg/day in 2 divided doses)
Recent amoxicillin use (within 30 days)	Amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses)
Concurrent conjunctivitis	Amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses)
Treatment failure after 48-72 hours	Switch to amoxicillin-clavulanate or consider ceftriaxone

Rationale for High-Dose Amoxicillin

High-dose amoxicillin is preferred over standard-dose (40-45 mg/kg/day) because:

1. It achieves middle ear fluid levels that exceed the minimum inhibitory concentration (MIC) of intermediately resistant S. pneumoniae (penicillin MICs 0.12-1.0 μg/mL) and many highly resistant serotypes (penicillin MICs ≥2 μg/mL) 2

2. It demonstrates improved bacteriologic and clinical efficacy compared to regular dosing, particularly against resistant pneumococcal strains 2

3. Current US data indicate approximately 87% of S. pneumoniae isolates are susceptible to high-dose amoxicillin compared to 83% for regular-dose amoxicillin 2

Special Considerations

• Beta-lactamase producing organisms: For patients with recent amoxicillin use, concurrent conjunctivitis, or when coverage for M. catarrhalis is desired, use high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate) 2, 1

• Penicillin allergies:

  • Non-Type I allergies: Cefdinir (14 mg/kg/day), cefuroxime (30 mg/kg/day), or cefpodoxime (10 mg/kg/day)
  • Type I allergies: Macrolides (e.g., azithromycin) or clindamycin (30-40 mg/kg/day) 2, 1

• Dosing frequency: While the traditional recommendation is twice-daily dosing, research suggests that once or twice daily dosing of amoxicillin is comparable to three-times daily dosing in terms of clinical efficacy and compliance 3

Monitoring and Follow-up

• Assess response to therapy within 48-72 hours
• If no improvement occurs within this timeframe:
  1. Confirm diagnosis
  2. Switch to amoxicillin-clavulanate
  3. Consider referral to ENT specialist, especially with tympanic membrane perforation 1

Common Pitfalls to Avoid

1. Underdosing amoxicillin: Using standard-dose (40-45 mg/kg/day) instead of high-dose (80-90 mg/kg/day) may be inadequate for resistant S. pneumoniae, particularly during viral coinfection 4

2. Failure to recognize treatment failure: Not switching antibiotics when there's no improvement after 48-72 hours of treatment

3. Inappropriate observation strategy: Children under 2 years with bilateral AOM require immediate antibiotic therapy rather than observation 1

4. Inadequate treatment duration: Using shorter courses (5-7 days) in children under 2 years or those with severe symptoms instead of the recommended 10 days 2, 1

5. Not considering beta-lactamase producers: Failing to use amoxicillin-clavulanate when there's recent amoxicillin use or concurrent conjunctivitis 5

The evidence strongly supports high-dose amoxicillin as first-line therapy for AOM, with appropriate adjustments based on clinical factors and response to treatment.