Augmentin Dosing for Community-Acquired Pneumonia in a 39.8-Pound Child
For a child weighing 39.8 pounds (18 kg) with community-acquired pneumonia, administer Augmentin at 90 mg/kg/day of the amoxicillin component divided into 2 doses, which equals 810 mg twice daily (1620 mg total daily dose). 1, 2
Weight-Based Calculation
- Child's weight: 39.8 pounds = 18 kg
- Recommended dose: 90 mg/kg/day of amoxicillin component 1, 2
- Total daily dose: 18 kg × 90 mg/kg = 1620 mg/day
- Divided into 2 doses: 810 mg twice daily 1, 2
Rationale for High-Dose Regimen
The 90 mg/kg/day dosing (rather than 45 mg/kg/day) is essential for community-acquired pneumonia to overcome potential pneumococcal resistance. 3, 1, 2 The Infectious Diseases Society of America specifically recommends this higher dose for CAP in children, as it achieves adequate pharmacodynamic parameters against Streptococcus pneumoniae with reduced penicillin susceptibility. 3, 2
- High-dose amoxicillin/clavulanate provides coverage for β-lactamase-producing Haemophilus influenzae while maintaining efficacy against resistant pneumococci 1, 4
- Underdosing with 40-45 mg/kg/day is a common and dangerous error that may lead to treatment failure 2, 5
Practical Formulation Selection
Use the Augmentin ES-600 formulation (600 mg amoxicillin/42.9 mg clavulanate per 5 mL) if available, as it is specifically designed for high-dose pediatric therapy. 4 For this 18 kg child:
- Dose per administration: 810 mg amoxicillin
- Volume using ES-600: Approximately 6.75 mL twice daily
- Alternatively, use standard Augmentin suspension (400 mg/5 mL or 600 mg/5 mL formulations) with appropriate volume adjustments 1
Treatment Duration and Monitoring
- Duration: 10 days for pneumonia 1, 5
- Reassessment: Evaluate clinical response at 48-72 hours; lack of improvement requires reevaluation for complications or alternative diagnoses 3, 2, 5
- Children on appropriate therapy should demonstrate clinical improvement (decreased fever, improved respiratory effort, increased activity) within 48-72 hours 1, 5
Critical Considerations
Add vancomycin (40-60 mg/kg/day IV) or clindamycin (40 mg/kg/day IV) if methicillin-resistant Staphylococcus aureus (MRSA) is suspected based on severe presentation, necrotizing infiltrates, empyema, or recent influenza infection. 3, 2
- For fully immunized children without MRSA risk factors, Augmentin monotherapy at 90 mg/kg/day is appropriate 3, 2
- For incompletely immunized children, Augmentin is preferred over amoxicillin alone due to β-lactamase-producing H. influenzae coverage 1, 6
Common Pitfalls to Avoid
- Do not use 45 mg/kg/day dosing for pneumonia – this is inadequate for CAP and only appropriate for mild otitis media 1, 2
- Do not divide into 3 doses – the 90 mg/kg/day regimen should be given twice daily for optimal pharmacodynamics 3, 1
- Do not use macrolides as monotherapy for presumed bacterial pneumonia in children under 5 years, as atypical pathogens are uncommon in this age group 2, 6
- For children ≥5 years with features suggesting atypical pneumonia (gradual onset, prominent cough, lack of toxicity), consider adding azithromycin to the β-lactam rather than switching 3, 2