What is the recommended amoxicillin dosage for an 11-year-old child weighing 23.5 kg with acute otitis media?

Amoxicillin Dosing for Acute Otitis Media in an 11-Year-Old, 23.5 kg Child

For this 11-year-old child weighing 23.5 kg with acute otitis media, prescribe amoxicillin 80–90 mg/kg/day divided into 2 doses for 5–7 days, which equals approximately 940–1060 mg twice daily (rounded to 1000 mg twice daily for practical dosing). 1

Dosing Calculation and Rationale

• High-dose amoxicillin (80–90 mg/kg/day) is the first-line treatment for acute otitis media due to its effectiveness against common pathogens including penicillin-resistant Streptococcus pneumoniae, safety profile, low cost, and narrow spectrum. 2, 1, 3

• For this 23.5 kg child:

  • 80 mg/kg/day = 1,880 mg/day (940 mg twice daily)
  • 90 mg/kg/day = 2,115 mg/day (1,057 mg twice daily)
  • Practical dosing: 1000 mg twice daily (approximately 85 mg/kg/day) 1

• The maximum single dose is 2 grams, which this child does not approach. 1

Treatment Duration by Age and Severity

• For children ≥6 years with mild-to-moderate symptoms, a 5–7 day course is appropriate. 1, 3

• If symptoms are severe (moderate-to-severe otalgia, otalgia ≥48 hours, or fever ≥39°C), extend treatment to 10 days. 1

• Children under 2 years require a full 10-day course regardless of severity, but this does not apply to an 11-year-old. 1

When to Use Amoxicillin-Clavulanate Instead

Switch to amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component + 6.4 mg/kg/day clavulanate, divided twice daily) if: 1, 3

• The child received amoxicillin within the previous 30 days
• Concurrent purulent conjunctivitis is present (suggests Haemophilus influenzae)
• History of recurrent AOM unresponsive to amoxicillin
• Attends daycare in areas with high prevalence of β-lactamase-producing organisms

Pain Management (Mandatory)

• Immediately initiate weight-based acetaminophen or ibuprofen regardless of antibiotic decision. 1

• Pain relief typically occurs within 24 hours from analgesics, whereas antibiotics provide no symptomatic benefit in the first 24 hours. 1

• Continue analgesics throughout the acute phase, as 30% of children still have pain after 3–7 days of antibiotic therapy. 1

Reassessment Protocol

• Re-evaluate at 48–72 hours if symptoms worsen or fail to improve. 1, 3

• If amoxicillin fails, switch to amoxicillin-clavulanate (90 mg/kg/day). 1

• If amoxicillin-clavulanate fails, administer intramuscular ceftriaxone 50 mg/kg once daily for 3 consecutive days (superior to single-dose regimen). 1

Penicillin Allergy Alternatives

For non-severe (non-IgE-mediated) penicillin allergy, use: 1

• Cefdinir 14 mg/kg/day once daily (preferred for convenience)
• Cefuroxime 30 mg/kg/day divided twice daily
• Cefpodoxime 10 mg/kg/day divided twice daily

Cross-reactivity between penicillins and second/third-generation cephalosporins is negligible (≈0.1%), making these safe alternatives. 1

Critical Pitfalls to Avoid

• Do not use macrolides (azithromycin, clarithromycin) as first-line therapy due to pneumococcal resistance exceeding 40% in the United States, with bacterial failure rates of 20–25%. 1, 3

• Do not use trimethoprim-sulfamethoxazole or erythromycin-sulfisoxazole for treatment failures due to substantial resistance. 1

• Isolated tympanic membrane redness without middle ear effusion does not constitute AOM and should not be treated with antibiotics. 1

• Antibiotics do not prevent complications like mastoiditis; 33–81% of mastoiditis cases had received prior antibiotics. 1

Post-Treatment Expectations

• Middle ear effusion persists in 60–70% of children at 2 weeks after successful treatment, declining to 40% at 1 month and 10–25% at 3 months. 1

• This post-AOM effusion (otitis media with effusion) requires monitoring but not additional antibiotics unless it persists >3 months with hearing loss. 1