Amoxicillin Dosing for Acute Otitis Media
For pediatric patients with acute otitis media, use high-dose amoxicillin at 80-90 mg/kg/day divided into 2 doses; for adults, use 1500-4000 mg/day divided into 2-3 doses. 1, 2
Pediatric Dosing
The standard first-line treatment is high-dose amoxicillin at 80-90 mg/kg/day divided into 2 doses for 5-10 days. 1, 2
Why High-Dose Therapy is Essential
- High-dose amoxicillin (80-90 mg/kg/day) achieves middle ear fluid concentrations that exceed the minimum inhibitory concentration (MIC) for resistant Streptococcus pneumoniae strains, which is critical given current resistance patterns 1, 2
- The older standard dose of 40 mg/kg/day is inadequate to effectively eradicate resistant S. pneumoniae, particularly during viral coinfection 3
- High-dose therapy provides 82% bacteriologic eradication compared to lower rates with standard dosing 1
When to Switch to Amoxicillin-Clavulanate
Switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses) in these specific situations: 1, 2
- Amoxicillin use within the previous 30 days
- Concurrent purulent conjunctivitis
- Treatment failure after 48-72 hours of amoxicillin therapy
- Need for coverage against beta-lactamase-producing H. influenzae and Moraxella catarrhalis
The rationale is that beta-lactamase-producing H. influenzae accounts for the majority of treatment failures with amoxicillin monotherapy 4
Adult Dosing
Standard-risk adults should receive 1500-4000 mg/day divided into 2-3 doses. 1
High-risk patients or those with recent antibiotic exposure (within 4-6 weeks) should receive the maximum dose of 4000 mg/day. 1
Treatment Duration and Monitoring
- Standard treatment duration is 5-10 days 1
- Reassess at 48-72 hours if no clinical improvement occurs 1, 2
- Treatment failure at 72 hours warrants switching to high-dose amoxicillin-clavulanate or ceftriaxone (50 mg IM or IV for 3 days in children) 1, 2
Penicillin Allergy Alternatives
For patients with non-Type I penicillin allergy: 1, 2
- Cefdinir: 14 mg/kg/day (pediatric) or 300 mg BID (adult)
- Cefuroxime: 30 mg/kg/day (pediatric) or 500 mg BID (adult)
- Cefpodoxime: 10 mg/kg/day (pediatric)
Important Caveats
- Amoxicillin remains the first-choice antibiotic per WHO and major guidelines, with amoxicillin-clavulanate as second choice 5
- Antibiotics are not needed in most cases of otitis media, and watchful waiting is reasonable unless the child is younger than 2 years with bilateral otitis media 5
- The predominant pathogens causing treatment failure are beta-lactamase-producing organisms, particularly H. influenzae 4