Amoxicillin-Clavulanate Dosing for an 8 kg Child
For an 8 kg child, administer amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component divided into 2 doses, which equals 360 mg twice daily (720 mg total daily dose). 1, 2
Weight-Based Calculation
- The calculation is straightforward: 8 kg × 90 mg/kg/day = 720 mg total daily dose, administered as 360 mg every 12 hours. 1, 2
- Using a 400 mg/5 mL suspension (commonly available as Augmentin ES-600 or equivalent high-dose formulation), this translates to 4.5 mL twice daily. 1
Rationale for High-Dose Regimen
- The high-dose regimen (90 mg/kg/day) is the standard of care for most pediatric infections requiring amoxicillin-clavulanate, particularly for respiratory tract infections, acute otitis media, and community-acquired pneumonia. 1, 2
- This dosing achieves middle-ear and lung tissue concentrations sufficient to overcome penicillin-resistant Streptococcus pneumoniae with MICs up to 2–4 mg/L and provides coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. 2, 3, 4
- The high-dose formulation uses a 14:1 ratio of amoxicillin to clavulanate (90 mg/kg amoxicillin with 6.4 mg/kg clavulanate), which minimizes diarrhea compared to older formulations while maintaining efficacy. 2
Indication-Specific Considerations
Community-Acquired Pneumonia
- For presumed bacterial pneumonia in children under 5 years, the Infectious Diseases Society of America and Pediatric Infectious Diseases Society recommend 90 mg/kg/day in 2 divided doses for 10 days. 1, 2
Acute Otitis Media
- For children under 2 years with acute otitis media, the American Academy of Pediatrics recommends 90 mg/kg/day divided twice daily for 10 days, especially when recent antibiotic exposure (within 30 days), severe presentation, or daycare attendance is present. 2
Acute Bacterial Rhinosinusitis
- The American Academy of Otolaryngology-Head and Neck Surgery recommends 90 mg/kg/day divided twice daily for 10–14 days as first-line therapy. 2
Critical Dosing Considerations
- Maximum single dose is 2,000 mg per administration, though this is not relevant for an 8 kg child. 2
- Maximum daily dose is 4,000 mg, regardless of weight. 1
- The twice-daily dosing schedule improves adherence compared to three-times-daily regimens without compromising efficacy. 1, 5
Treatment Duration and Monitoring
- Standard treatment duration is 10 days for most respiratory infections, including pneumonia, acute otitis media, and sinusitis. 1, 2
- Clinical improvement should be evident within 48–72 hours; if no improvement or worsening occurs, reassess for resistant organisms, atypical pathogens, or complications. 1, 2
- Fever typically resolves within 24–48 hours for pneumococcal infections, though cough may persist longer. 1
Common Pitfalls to Avoid
- Do not use standard-dose formulations (45 mg/kg/day) when high-dose therapy is indicated, as this leads to treatment failure with resistant organisms. 2
- Verify the suspension concentration before dispensing—the high-dose formulation is typically 600 mg/5 mL (ES-600) or 400 mg/5 mL, not the older 125 mg/5 mL or 250 mg/5 mL formulations. 1, 2
- Do not underdose based on age-based tables; weight-based dosing is mandatory for children under 40 kg. 1
Adverse Effects
- The most common adverse effects are gastrointestinal disturbances, particularly diarrhea (occurring in approximately 25% of patients) and diaper dermatitis. 2
- The high-dose 14:1 formulation causes less diarrhea than older amoxicillin-clavulanate preparations while maintaining superior efficacy against resistant pathogens. 2
Alternative Regimens for Penicillin Allergy
- For non-anaphylactic penicillin allergy, second- or third-generation cephalosporins (cefdinir, cefuroxime) are appropriate alternatives. 1, 5
- For IgE-mediated (Type I) penicillin allergy, clindamycin (10–20 mg/kg/day divided into 3 doses) or azithromycin (12 mg/kg once daily for 5 days) may be used, though with inferior bacteriologic efficacy. 1