What is the recommended dosage of amoxicillin (amoxicillin) for a child?

Recommended Dosage of Amoxicillin for Children

The recommended dosage of amoxicillin for children depends on the specific condition being treated, with standard dosing ranging from 45-90 mg/kg/day divided into 2-3 doses daily, based on the severity of infection and suspected pathogen.

General Dosing Guidelines

• For children less than 40 kg, the FDA-approved dosing for mild to moderate infections is 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 1
• For severe infections or lower respiratory tract infections, the recommended dosage increases to 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours 1
• For children less than 12 weeks (3 months) of age, the maximum recommended dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 1

Condition-Specific Dosing

For Community-Acquired Pneumonia

• For presumed bacterial pneumonia in outpatient children under 5 years: 90 mg/kg/day in 2 doses 2
• For Streptococcus pneumoniae with MICs for penicillin <2.0 μg/mL: 90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses 2
• For Group A Streptococcus infections: 50-75 mg/kg/day in 2 doses 2
• For Haemophilus influenzae (β-lactamase negative): 75-100 mg/kg/day in 3 doses 2

For Skin and Soft Tissue Infections

• For mild to moderate skin infections in children ≥3 months and <40 kg: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 2

Dosing Frequency Considerations

• Traditional dosing has been three times daily, but evidence supports that twice-daily dosing can be equally effective and may improve compliance 3
• For common uncomplicated infections, amoxicillin can be given as 60 mg/kg/day in two divided doses 4
• For acute otitis media, twice-daily dosing shows comparable clinical outcomes to three-times-daily dosing 3

Special Considerations

• Higher doses (75-90 mg/kg/day) are recommended for acute otitis media, particularly during viral coinfection 5
• For children with renal impairment, dose adjustment is necessary. Children with GFR <30 mL/min should NOT receive the 875 mg dose 1
• Treatment duration should generally continue for 48-72 hours beyond symptom resolution 1
• For Streptococcus pyogenes infections, a minimum of 10 days of treatment is recommended to prevent acute rheumatic fever 1

Administration Guidelines

• Amoxicillin should be taken at the start of a meal to minimize gastrointestinal intolerance 1
• Oral suspension should be shaken well before using and can be placed directly on the child's tongue or mixed with formula, milk, fruit juice, or cold drinks 1
• Reconstituted suspension must be discarded after 14 days 1

Common Pitfalls to Avoid

• Underdosing amoxicillin when treating resistant organisms - current standard dosing recommendations may be inadequate for resistant Streptococcus pneumoniae 5
• Using age-based rather than weight-based dosing can lead to inappropriate dosing 4
• Not adjusting doses for children with renal impairment 1
• Stopping treatment too early - continue treatment for at least 48-72 hours after symptom resolution 1

By following these evidence-based dosing guidelines, clinicians can optimize treatment outcomes while minimizing the risk of adverse effects and antimicrobial resistance.