Amoxicillin Dosing for a 28kg Child
For a 28kg child, the recommended amoxicillin dose depends on the indication: for mild to moderate infections (ear, nose, throat, skin, genitourinary), give 700 mg every 12 hours (25 mg/kg/day divided twice daily); for severe infections or lower respiratory tract infections, give 1260 mg every 12 hours (45 mg/kg/day divided twice daily). 1
Standard Dosing Algorithm by Indication
Mild to Moderate Infections (Ear/Nose/Throat, Skin, Genitourinary)
- Dose: 25 mg/kg/day divided every 12 hours 1
- For 28kg child: 350 mg per dose, twice daily (total 700 mg/day)
- Alternative: 20 mg/kg/day divided every 8 hours (approximately 187 mg three times daily) 1
Severe Infections or Lower Respiratory Tract Infections
- Dose: 45 mg/kg/day divided every 12 hours 1
- For 28kg child: 630 mg per dose, twice daily (total 1260 mg/day)
- Alternative: 40 mg/kg/day divided every 8 hours (approximately 373 mg three times daily) 1
High-Dose Regimen for Resistant Organisms
- Dose: 90 mg/kg/day divided every 12 hours 2, 3
- For 28kg child: 1260 mg per dose, twice daily (total 2520 mg/day)
- Maximum daily dose: Do not exceed 4000 mg/day regardless of weight 3
When to Use High-Dose Therapy (90 mg/kg/day)
Use high-dose amoxicillin (90 mg/kg/day) for children with any of these risk factors: 2
- Age <2 years
- Daycare attendance
- Recent antibiotic use (within past 30 days)
- Geographic area with high prevalence (>10%) of penicillin-resistant Streptococcus pneumoniae
- Moderate to severe illness
- Incomplete Haemophilus influenzae type b vaccination
Treatment Duration
- Streptococcal infections: Minimum 10 days to prevent acute rheumatic fever 1
- Respiratory infections: 7-10 days for most infections; 10 days specifically for pneumonia 3
- General rule: Continue for minimum 48-72 hours beyond symptom resolution or evidence of bacterial eradication 1
When to Consider Amoxicillin-Clavulanate Instead
Switch to amoxicillin-clavulanate if: 2
- β-lactamase-producing organisms suspected (H. influenzae, M. catarrhalis)
- Recent antibiotic exposure within past 4-6 weeks
- Treatment failure with amoxicillin alone
- Recurrent or persistent infections
For amoxicillin-clavulanate in this 28kg child, the high-dose regimen would be 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses (1260 mg amoxicillin component per dose, twice daily). 2
Administration Considerations
- Timing: Give at the start of meals to minimize gastrointestinal intolerance 1
- Formulation: For oral suspension, ensure proper reconstitution and shake well before each use 1
- Storage: Refrigeration is preferable but not required; discard unused suspension after 14 days 1
Monitoring and Follow-Up
- Expected improvement: Clinical improvement should occur within 48-72 hours 2
- If no improvement: Reevaluate diagnosis, consider resistant organisms, atypical pathogens, or complications 2
- Adherence: Twice-daily dosing improves compliance compared to three-times-daily regimens 3
Common Pitfalls to Avoid
- Underdosing: Using 40 mg/kg/day when 90 mg/kg/day is indicated leads to treatment failure with resistant organisms 2
- Premature discontinuation: Complete the full course even if symptoms improve before completion 2
- Wrong indication: Most upper respiratory tract infections are viral and do not require antibiotics 2
- Renal impairment: This 28kg child exceeds 40kg threshold concerns, but if severe renal impairment exists (GFR <30 mL/min), dose adjustment is required 1