What is the recommended dosage of amoxicillin (amoxicillin) for otitis media?

Amoxicillin Dosage for Otitis Media

For acute otitis media, high-dose amoxicillin at 80-90 mg/kg/day divided into two doses for children or 1500-3000 mg/day for adults is the recommended first-line treatment. 1

Dosing Recommendations

Children

• First-line therapy: Amoxicillin 80-90 mg/kg/day divided into two doses for 5 days 1
• This high-dose regimen provides excellent coverage against Streptococcus pneumoniae, including penicillin-resistant strains, and non-beta-lactamase producing Haemophilus influenzae
• Traditional WHO guidelines recommended a lower dose of 40 mg/kg twice daily for 5 days 2, but more recent evidence supports the higher dosing regimen

Adults

• First-line therapy: Amoxicillin 1500-3000 mg/day divided into two doses for 5 days 1
• Adult dosing should not exceed 3000 mg/day

Treatment Algorithm

Clinical Scenario	Recommended Treatment
First episode of AOM	Amoxicillin 80-90 mg/kg/day (if no amoxicillin use in past 30 days)
Recurrent AOM or recent amoxicillin use	Amoxicillin-clavulanate 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate
Treatment failure with amoxicillin-clavulanate	Consider ceftriaxone or specialist consultation

Dosing Frequency

• Twice-daily dosing is as effective as three-times-daily dosing and may improve compliance 3
• The conventional recommendation was three or four daily doses, but current evidence supports that once or twice daily dosing is equally effective 1, 3

Special Considerations

Penicillin Allergy

• For non-Type I allergies: Cefdinir, cefuroxime, or cefpodoxime 1
• For Type I allergies: Macrolides or clindamycin (7 mg/kg per dose three times daily, maximum 300 mg per dose, for 10 days) 1

Beta-lactamase Producing Organisms

• If beta-lactamase producing organisms are suspected (e.g., recent antibiotic use, daycare attendance):
  • Switch to amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate) 1
  • Beta-lactamase producing H. influenzae is the predominant pathogen in children failing high-dose amoxicillin therapy 4

Weight Considerations

• For obese children, there is debate about whether to cap the dose at adult levels
• Some clinicians prescribe the standard adult dose (1500 mg/day) when a child's weight-based dose would exceed this amount 5
• However, for optimal efficacy against resistant organisms, following the weight-based dosing (80-90 mg/kg/day) is recommended unless it would exceed 3000 mg/day 1

Duration of Therapy

• Standard duration is 5 days for uncomplicated cases 2, 1
• Longer duration (7-10 days) may be considered for severe cases or in children under 2 years of age with bilateral otitis media 1

Common Pitfalls

• Underdosing amoxicillin, particularly in areas with high prevalence of drug-resistant S. pneumoniae
• Not switching to a beta-lactamase stable drug when treatment fails
• Using standard-dose amoxicillin (40-45 mg/kg/day) which may be inadequate for resistant pneumococci 6, 4
• Not considering twice-daily dosing which may improve compliance while maintaining efficacy

High-dose amoxicillin remains the first-line treatment for acute otitis media due to its excellent efficacy against the most common pathogens, including penicillin-resistant S. pneumoniae, when used at appropriate doses.