Pediatric Amoxicillin Dosing Recommendations
The recommended dose of amoxicillin for pediatric patients varies by indication, with standard dosing ranging from 45-90 mg/kg/day divided into 2-3 doses depending on infection severity and local resistance patterns. 1, 2
Standard Dosing by Age Group
Infants Less Than 12 Weeks (3 Months)
- Maximum recommended dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 2
- Treatment should continue for at least 48-72 hours after symptom resolution 2
Children 3 Months and Older (Weight < 40 kg)
- Mild to moderate infections: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 2
- Severe infections: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours 2
- Lower respiratory tract infections: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours regardless of severity 2
Dosing by Specific Indication
Respiratory Tract Infections
- Standard dose: 45 mg/kg/day in 2 doses for mild to moderate infections 1
- High-dose: 90 mg/kg/day in 2 doses for severe infections or in areas with high pneumococcal resistance 1, 3
- For acute otitis media, higher dosing (75-90 mg/kg/day) may be more effective, especially with viral coinfection 4
Group A Streptococcal Infections
Lyme Disease
- 50 mg/kg/day, with 25 mg/kg/dose given twice daily showing comparable efficacy to three-times-daily dosing for MICs up to 1 mg/L 5
Administration Considerations
- Administer at the start of a meal to minimize gastrointestinal intolerance 2
- For oral suspension, shake well before using and refrigerate after reconstitution 2
- Any unused portion must be discarded after 14 days 2
Treatment Duration
- Continue treatment for 48-72 hours beyond symptom resolution 2
- For Streptococcus pyogenes infections, minimum 10-day treatment to prevent acute rheumatic fever 2
- For respiratory infections, typical duration is 7-10 days 1
Special Considerations
Renal Impairment
- For GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours depending on infection severity 2
- For GFR <10 mL/min: 500 mg or 250 mg every 24 hours depending on infection severity 2
- Patients on hemodialysis require an additional dose during and at the end of dialysis 2
Dosing Frequency
- Twice-daily dosing may improve adherence compared to three-times-daily dosing with comparable efficacy 6, 7
- For community-acquired pneumonia, twice-daily dosing of amoxicillin showed non-inferiority to three-times-daily dosing 8
Common Adverse Effects
- Gastrointestinal disturbances (diarrhea, nausea, vomiting) 1
- Rash, urticaria, and other hypersensitivity reactions 1
Clinical Pearls
- Weight-based dosing is preferred over age-based dosing for accuracy 7
- Higher doses (90 mg/kg/day) may be necessary in areas with high pneumococcal resistance 1, 3
- For prescriptions, include daily dose, number of divided doses, duration of therapy, indication, and child's weight 7
- Recent research suggests that lower doses (35-50 mg/kg/day) may be as effective as higher doses (70-90 mg/kg/day) for community-acquired pneumonia 8