Augmentin 600-42.9mg/5mL Dosing for 8-Year-Old, 38.6 kg Patient
For an 8-year-old weighing 38.6 kg, administer 8.7 mL of Augmentin 600-42.9mg/5mL twice daily (every 12 hours) for mild to moderate infections, or 17.4 mL twice daily for severe infections or areas with high pneumococcal resistance.
Weight-Based Dose Calculation
Mild to Moderate Infections
- Standard dosing: 45 mg/kg/day of amoxicillin component divided every 12 hours 1
- Calculation: 38.6 kg × 45 mg/kg/day = 1,737 mg/day total
- Per dose: 1,737 mg ÷ 2 = 868.5 mg per dose
- Volume per dose: 868.5 mg ÷ 120 mg/mL = 7.2 mL twice daily (using the 600mg/5mL = 120mg/mL concentration)
- This provides adequate coverage for most susceptible pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes 1
Severe Infections or High-Resistance Areas
- High-dose regimen: 90 mg/kg/day of amoxicillin component divided every 12 hours 1, 2
- Calculation: 38.6 kg × 90 mg/kg/day = 3,474 mg/day total
- Per dose: 3,474 mg ÷ 2 = 1,737 mg per dose
- Volume per dose: 1,737 mg ÷ 120 mg/mL = 14.5 mL twice daily
- This high-dose regimen is indicated for community-acquired pneumonia in areas with >10% penicillin-resistant S. pneumoniae, children <2 years old, recent antibiotic exposure within the past 30 days, children attending daycare, or severe infections requiring hospitalization 1
Indication-Specific Dosing Algorithm
Community-Acquired Pneumonia
- Mild to moderate, outpatient: 45 mg/kg/day (7.2 mL twice daily) 1
- Severe or high-resistance: 90 mg/kg/day (14.5 mL twice daily) 1, 2
- The 90 mg/kg/day dosing provides optimal coverage against penicillin-resistant Streptococcus pneumoniae and β-lactamase-producing organisms 1
- Treatment duration: 10 days 1
Acute Bacterial Sinusitis
- Children ≥2 years without risk factors: 45 mg/kg/day (7.2 mL twice daily) 1
- Children <2 years, in daycare, or with recent antibiotic use: 80-90 mg/kg/day (13-14.5 mL twice daily) 1
Skin and Soft Tissue Infections
- Standard dosing: 45 mg/kg/day (7.2 mL twice daily) 1, 3
- This provides adequate coverage for β-lactamase-producing organisms in mild to moderate infections 1
Critical Dosing Considerations
Maximum Daily Dose
- The maximum daily dose of amoxicillin should not exceed 4000 mg/day regardless of weight 1
- For this 38.6 kg patient, even the high-dose regimen (3,474 mg/day) remains well below this maximum
Administration Instructions
- Administer at the start of a meal to minimize gastrointestinal intolerance 3
- Shake oral suspension well before each use 3
- The reconstituted suspension must be discarded after 14 days; refrigeration is preferable but not required 3
Treatment Duration and Monitoring
Standard Duration
- Most respiratory infections: 7-10 days 1
- Pneumonia specifically: 10 days 1
- Minimum duration: 48-72 hours beyond symptom resolution 1
Clinical Monitoring
- Children on appropriate therapy should demonstrate clinical improvement within 48-72 hours 1
- If no improvement occurs within this timeframe, reevaluation and further investigation are necessary 1
- Fever typically resolves within 24-48 hours for pneumococcal pneumonia, though cough may persist longer 1
- If the patient deteriorates or shows no improvement by 48-72 hours, consider atypical pathogens and potentially add a macrolide 1
Common Pitfalls and Caveats
Concentration-Specific Warning
- The 600-42.9mg/5mL formulation (Augmentin ES-600) provides a 14:1 ratio of amoxicillin to clavulanate, which maintains the same daily dose of clavulanic acid while providing higher amoxicillin doses 2
- Do not confuse this concentration with standard formulations (125mg/5mL or 250mg/5mL), as this would result in significant underdosing 3
When to Use High-Dose Regimen
- Recent antibiotic exposure within the past 30 days 1
- Attendance at daycare 1
- Age <2 years 1
- Geographic areas with >10% penicillin-resistant S. pneumoniae 1
- Severe infections requiring hospitalization 1
- Treatment failure with standard-dose amoxicillin 2