What is the recommended dose of amoxicillin (amoxicillin) for a 2-year-old patient with otitis media (ear infection) weighing 30.4 pounds?

Amoxicillin Dosing for 2-Year-Old with Ear Infection (30.4 lbs)

For this 2-year-old child weighing 30.4 lbs (13.8 kg) with acute otitis media, prescribe amoxicillin 80-90 mg/kg/day divided into two doses, which equals approximately 550-620 mg twice daily (total daily dose 1100-1240 mg/day) for 10 days. 1, 2

Weight-Based Calculation

• Patient weight: 30.4 lbs = 13.8 kg 1
• Recommended dose: 80-90 mg/kg/day for acute otitis media 1, 2
• Total daily dose: 1104-1242 mg/day (13.8 kg × 80-90 mg/kg) 1
• Divided dosing: Give 552-621 mg twice daily (every 12 hours) 1, 2
• Practical prescription: Amoxicillin 600 mg twice daily is the most practical dose 1

Treatment Duration

• For children under 2 years: Treat for 10 days 1, 3
• This 2-year-old falls into the category where 10-day treatment is appropriate rather than shorter courses used in older children 1, 3

Why High-Dose Amoxicillin

• High-dose amoxicillin (80-90 mg/kg/day) is first-line therapy because it provides adequate coverage against drug-resistant Streptococcus pneumoniae, which is the most common bacterial pathogen in acute otitis media 1, 3
• The standard lower dose of 40 mg/kg/day is inadequate to eradicate resistant pneumococcal strains, particularly when viral coinfection is present 4, 5
• All S. pneumoniae isolates with amoxicillin MIC ≤2.0 mcg/mL are effectively treated with high-dose amoxicillin 5

Administration Instructions

• Give at the start of meals to minimize gastrointestinal intolerance 2
• Shake oral suspension well before each use 2
• Refrigeration is preferable but not required; discard unused suspension after 14 days 2

When to Switch Antibiotics

• Reassess after 48-72 hours if symptoms persist or worsen 1, 3
• Switch to amoxicillin-clavulanate (same amoxicillin dose with clavulanate 6.4 mg/kg/day) if treatment fails, as this covers beta-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis 1, 3
• The predominant pathogens in amoxicillin treatment failure are beta-lactamase-producing organisms, occurring in approximately 28% of cases 5

Critical Pitfalls to Avoid

• Do not underdose based on adult maximum doses: While some physicians cap amoxicillin at the standard adult dose of 1500 mg/day, the recommended pediatric dose of 80-90 mg/kg/day should be prescribed even if it exceeds this amount 6
• Do not prescribe antibiotics without adequate visualization of the tympanic membrane: Ensure proper diagnosis with pneumatic otoscopy showing bulging tympanic membrane or new-onset otorrhea 1, 3
• Do not use amoxicillin if the child received it within the past 30 days: In this case, start with high-dose amoxicillin-clavulanate instead 3, 1
• Address pain management: Prescribe analgesics (acetaminophen or ibuprofen) regardless of antibiotic use, as pain control is essential 3, 1

Special Considerations for This Age Group

• Children under 2 years with acute otitis media require immediate antibiotic treatment rather than watchful waiting, which may be appropriate for older children with non-severe disease 1, 3
• At 2 years old, this child is at the upper end of the age range where bilateral disease and severe symptoms are more common and benefit most from antibiotic therapy 3
• The number needed to treat (NNT) for clinical success in children under 2 years is approximately 3-4, meaning antibiotics provide substantial benefit in this age group 3