Amoxicillin Dosing for a 13 kg Child
For a 13 kg child, the recommended dose of amoxicillin is 45 mg/kg/day divided into two doses, which equals approximately 585 mg per day or 292.5 mg twice daily. 1
Dosing Algorithm Based on Infection Type
Standard Dosing for Mild to Moderate Infections
- Mild/Moderate Ear/Nose/Throat, Skin/Skin Structure, Genitourinary Tract Infections:
- 25 mg/kg/day divided every 12 hours (325 mg/day or 162.5 mg twice daily)
- OR 20 mg/kg/day divided every 8 hours (260 mg/day or 86.7 mg three times daily) 1
Higher Dosing for Severe Infections
Severe Ear/Nose/Throat, Skin/Skin Structure, Genitourinary Tract Infections:
- 45 mg/kg/day divided every 12 hours (585 mg/day or 292.5 mg twice daily)
- OR 40 mg/kg/day divided every 8 hours (520 mg/day or 173.3 mg three times daily) 1
Lower Respiratory Tract Infections (Mild/Moderate or Severe):
- 45 mg/kg/day divided every 12 hours (585 mg/day or 292.5 mg twice daily)
- OR 40 mg/kg/day divided every 8 hours (520 mg/day or 173.3 mg three times daily) 1
Special Considerations
For Suspected or Confirmed Streptococcus pneumoniae
For penicillin-susceptible S. pneumoniae (MICs <2.0 μg/mL):
- Oral amoxicillin: 90 mg/kg/day in 2 doses (585 mg twice daily) or 45 mg/kg/day in 3 doses (195 mg three times daily) 2
For penicillin-resistant S. pneumoniae (MICs ≥4.0 μg/mL):
- Higher doses or alternative antibiotics may be required 2
For Group A Streptococcus
- Amoxicillin: 50-75 mg/kg/day in 2 doses (325-487.5 mg twice daily) 2
Administration Guidelines
- Administer at the start of a meal to minimize gastrointestinal intolerance 1
- Continue treatment for 48-72 hours beyond symptom resolution 1
- For streptococcal infections, treat for a minimum of 10 days to prevent acute rheumatic fever 1
Dosing Frequency Considerations
- Twice-daily dosing (every 12 hours) has similar efficacy to three-times-daily dosing for most infections and may improve treatment adherence 3
- For acute otitis media, twice-daily dosing has shown comparable clinical outcomes to three-times-daily dosing with better adherence reported by caregivers 3
Important Cautions
- For children with viral co-infections, higher doses may be needed as amoxicillin penetration can be reduced in these cases 4
- Standard dosing of 40 mg/kg/day may be inadequate for resistant organisms; 75-90 mg/kg/day may be recommended for conditions like acute otitis media with suspected resistant pathogens 4
- For children with severe renal impairment (GFR 10-30 mL/min), dose adjustment is required 1
Suspension Preparation (If Applicable)
- Shake oral suspension well before using
- After reconstitution, the suspension can be administered directly or mixed with formula, milk, fruit juice, or water
- Any unused portion must be discarded after 14 days
- Refrigeration is preferable but not required 1