What is the recommended dosage of amoxicillin for treating acute otitis media (AOM) or an ear infection?

Amoxicillin Dosage for Acute Otitis Media (Ear Infection)

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

First-Line Treatment Recommendations

For Children:

• Dosage: 80-90 mg/kg/day divided into two doses
• Duration: 10 days (as recommended by the American Academy of Pediatrics) 1
• Formulation options: Oral suspension or chewable tablets (based on age/weight)

For Adults:

• Dosage: 1500-3000 mg/day (divided into two doses)
• For more severe infections: 875 mg every 12 hours or 500 mg every 8 hours 2

Treatment Algorithm

1. First episode of AOM with no recent antibiotic use:

   • High-dose amoxicillin (80-90 mg/kg/day for children)

2. For patients with recent amoxicillin use (within past 30 days), concurrent conjunctivitis, or when beta-lactamase coverage is needed:

   • Switch to amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate) 1

3. For treatment failure with amoxicillin after 72 hours:

   • Switch to high-dose amoxicillin-clavulanate
   • Alternative: ceftriaxone or specialist consultation 1

4. For penicillin allergy:

   • Adults: Respiratory fluoroquinolones (levofloxacin 750mg daily or moxifloxacin 400mg daily) 1
   • Alternative for adults: Doxycycline 100mg twice daily or clindamycin 300-450mg four times daily 1

Special Considerations

Age-Specific Recommendations:

• Children under 2 years with bilateral otitis media: Require immediate antibiotic therapy rather than observation 1
• Children weighing 40 kg or more: Should follow adult dosing recommendations 2
• Neonates and infants <12 weeks: 30 mg/kg/day divided every 12 hours (based on amoxicillin component) 2

Renal Impairment:

• Patients with glomerular filtration rate <30 mL/min should not receive the 875 mg/125 mg dose 2
• For GFR 10-30 mL/min: 500 mg/125 mg or 250 mg/125 mg every 12 hours
• For GFR <10 mL/min: 500 mg/125 mg or 250 mg/125 mg every 24 hours 2

Evidence Quality and Clinical Pearls

• The recommendation for high-dose amoxicillin is based on its excellent coverage against S. pneumoniae, which is a predominant pathogen in otitis media 1
• Clinical studies have shown that high-dose amoxicillin achieves bacteriologic eradication in 92% of S. pneumoniae cases 3
• The twice-daily dosing regimen is associated with significantly less diarrhea than three-times-daily dosing (14% vs 34%) 2

Common Pitfalls to Avoid

1. Underdosing amoxicillin: Standard doses (40-45 mg/kg/day) may be insufficient for areas with high prevalence of drug-resistant S. pneumoniae 4

2. Failing to switch antibiotics when appropriate: If no improvement is observed after 72 hours of therapy, consider switching antibiotics 1

3. Overlooking beta-lactamase producing organisms: Beta-lactamase-positive H. influenzae is a common cause of treatment failure with amoxicillin alone 3

4. Inappropriate duration: Shorter courses may be insufficient for complete eradication, while the American Academy of Pediatrics recommends a full 10-day course for children 1