What is the appropriate antibiotic choice and dosage for a 9‑year‑old child weighing 51.3 kg with uncomplicated acute otitis media?

Antibiotic Treatment for a 9-Year-Old with Acute Otitis Media

For this 9-year-old child weighing 51.35 kg with an ear infection, prescribe high-dose amoxicillin 4,000 mg per day (2,000 mg twice daily) for 5–7 days, along with immediate pain control using weight-appropriate ibuprofen or acetaminophen. 1

First-Line Antibiotic Selection and Dosing

• Amoxicillin is the reference treatment and antibiotic of choice for uncomplicated acute otitis media in children without penicillin allergy. 1, 2

• The recommended dose is 80–90 mg/kg/day divided into two doses given every 12 hours. 1, 2

  • For this 51.35 kg child: 80 mg/kg/day = 4,108 mg/day
  • Practical dosing: 2,000 mg twice daily (total 4,000 mg/day), which falls within the recommended range and stays below the maximum of 2 grams per dose. 2

• Treatment duration for children ≥6 years with mild-to-moderate symptoms is 5–7 days, which is equally effective as longer courses and reduces antibiotic exposure. 3, 2

  • If symptoms are severe (moderate-to-severe ear pain, fever ≥39°C, or pain >48 hours), extend to a full 10-day course. 3, 2

Immediate Pain Management

• Begin acetaminophen or ibuprofen immediately at the start of therapy to control ear pain, as antibiotics provide no symptomatic relief in the first 24 hours. 1, 2

• Continue analgesia throughout the acute phase regardless of antibiotic use. 2

When to Use Amoxicillin-Clavulanate Instead

Switch to amoxicillin-clavulanate (amoxicillin component 90 mg/kg/day) if any of the following apply: 1, 2

• The child received amoxicillin within the previous 30 days
• Concurrent purulent conjunctivitis is present (suggests Haemophilus influenzae)
• History of recurrent AOM unresponsive to amoxicillin
• High local prevalence of beta-lactamase-producing organisms

For this 51.35 kg child, amoxicillin-clavulanate dosing would be approximately 4,600 mg/day of the amoxicillin component, divided twice daily. 2

Treatment Failure Protocol

• Reassess at 48–72 hours if symptoms worsen or fail to improve. 1, 2

• If amoxicillin fails, upgrade to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component). 1

• If amoxicillin-clavulanate also fails, administer intramuscular ceftriaxone 50 mg/kg once daily for 3 consecutive days (approximately 2,500 mg daily for this child), as a 3-day course is superior to single-dose therapy. 3, 1, 2

Penicillin Allergy Alternatives

If the child has a non-severe penicillin allergy, use oral cephalosporins (cross-reactivity is <0.1%): 2

• Cefdinir 14 mg/kg/day once daily (preferred for convenience): approximately 720 mg daily
• Cefuroxime 30 mg/kg/day divided twice daily: approximately 1,540 mg daily
• Cefpodoxime 10 mg/kg/day divided twice daily: approximately 515 mg daily

Critical Pitfalls to Avoid

• Do not use azithromycin or other macrolides as first-line therapy, as pneumococcal macrolide resistance exceeds 40% in the United States, with bacterial failure rates of 20–25%. 2

• Avoid trimethoprim-sulfamethoxazole or erythromycin-sulfisoxazole for treatment failures, as pneumococcal resistance to these agents is substantial. 3, 2

• Do not prescribe antibiotics for isolated tympanic membrane redness without documented middle ear effusion, as this does not constitute acute otitis media. 2

• Routine follow-up visits at 10–14 days are unnecessary for uncomplicated cases that improve clinically. 1

Expected Post-Treatment Course

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

• This persistent effusion without acute symptoms represents otitis media with effusion (OME), not treatment failure, and requires only observation—not additional antibiotics. 3, 1, 2