Amoxicillin Dosing for a 7-Year-Old with Presumed Bacterial CAP
For a 7-year-old child with presumed bacterial community-acquired pneumonia, administer amoxicillin 90 mg/kg/day divided into two doses (given every 12 hours), with a maximum daily dose of 4000 mg. 1
Calculating the Actual Dose
To determine the specific dose for your 7-year-old patient:
- Weigh the child accurately - this is critical for proper dosing
- Calculate total daily dose: Weight (kg) × 90 mg = total mg per day
- Divide by 2 for the individual dose given every 12 hours
- Cap at maximum: Do not exceed 2000 mg per dose (4000 mg/day total)
Practical Example:
- For a 25 kg child: 25 × 90 = 2250 mg/day → 1125 mg every 12 hours
- For a 30 kg child: 30 × 90 = 2700 mg/day → 1350 mg every 12 hours
- For a 50 kg child: 50 × 90 = 4500 mg/day → 2000 mg every 12 hours (capped at maximum)
Key Clinical Considerations
Age-specific guidance: The 2011 PIDS/IDSA guidelines specifically address children ≥5 years old, recommending 90 mg/kg/day in 2 doses with a maximum of 4 g/day for presumed bacterial CAP 1. The FDA labeling confirms this dosing for lower respiratory tract infections at 45 mg/kg/day divided every 12 hours for severe infections 2, though current guidelines favor the higher 90 mg/kg/day dose for pneumonia given evolving pneumococcal resistance patterns.
Critical pitfall to avoid: Research demonstrates that larger/older children frequently receive inadequate dosing because clinicians are reluctant to exceed "adult maximum doses" 3. A 7-year-old may weigh anywhere from 20-35 kg, and many will require doses that approach or reach the 2000 mg per dose maximum. Do not underdose based on arbitrary adult dose limits - use the weight-based calculation up to the 4000 mg/day maximum.
Administration Details
- Give with food to minimize gastrointestinal intolerance 2
- Duration: Minimum 5 days, continuing 48-72 hours beyond clinical improvement 1
- For Streptococcus pyogenes: Treat for minimum 10 days to prevent rheumatic fever 2
- Formulation options: Tablets, chewable tablets, or oral suspension depending on child's ability to swallow
When to Consider Alternatives
If the child has clinical, laboratory, or radiographic features suggesting atypical pneumonia (Mycoplasma or Chlamydophila), add a macrolide (azithromycin 10 mg/kg day 1, then 5 mg/kg days 2-5) to the amoxicillin regimen 1. However, for straightforward presumed bacterial CAP in a fully immunized 7-year-old, amoxicillin monotherapy at 90 mg/kg/day divided twice daily remains first-line.