Recommended Amoxicillin Dose for a 65-Pound Child with Suspected Pneumonia
For a 65-pound (29.5 kg) child with suspected community-acquired pneumonia, prescribe oral amoxicillin 90 mg/kg/day divided into 2 doses, which equals approximately 1,325 mg twice daily (total 2,650 mg/day). 1, 2
Dosing Calculation and Rationale
The high-dose regimen of 90 mg/kg/day is specifically designed to overcome penicillin-resistant Streptococcus pneumoniae, the most common bacterial cause of community-acquired pneumonia in children. 1, 2
For a 65-pound child (29.5 kg):
- 90 mg/kg/day × 29.5 kg = 2,655 mg/day
- Divided into 2 doses = 1,327.5 mg per dose (round to 1,325 mg twice daily for practical dosing) 1
Twice-daily dosing is preferred over three-times-daily dosing because it improves adherence and achieves superior pharmacokinetic profiles. 2
Age-Specific Considerations
For children under 5 years old, the standard recommendation is amoxicillin 90 mg/kg/day in 2 doses for presumed bacterial pneumonia. 1
For children 5 years and older, the same dose applies (90 mg/kg/day in 2 doses), with a maximum of 4 grams per day. 1, 2
Since the child's age is not specified but weighs 65 pounds, this dosing applies regardless of whether they fall into the preschool or school-age category. 1
Treatment Duration
Prescribe 5-7 days of amoxicillin for outpatient pneumonia, with reassessment if symptoms persist beyond 48-72 hours. 2
Recent evidence demonstrates that 3-day treatment is noninferior to 7-day treatment for uncomplicated community-acquired pneumonia, though cough resolution may be slightly faster with 7 days (10 days vs 12 days). 3, 4
When to Add Atypical Coverage
If the child has clinical features suggesting atypical pneumonia (e.g., gradual onset, prominent cough, minimal fever), add azithromycin 10 mg/kg on day 1 (maximum 500 mg), followed by 5 mg/kg/day once daily on days 2-5 (maximum 250 mg). 1, 2
For children 5 years and older with features that don't clearly distinguish bacterial from atypical pneumonia, a macrolide can be added to the β-lactam antibiotic for empiric therapy. 1
Alternative Regimens for Penicillin Allergy
For non-severe penicillin allergy: Consider amoxicillin-clavulanate 90 mg/kg/day (amoxicillin component) in 2 doses, maximum 4,000 mg/day. 1, 2
For true β-lactam allergy: Use levofloxacin (if growth maturity reached) or a macrolide alone. 1, 2
Critical Dosing Pitfalls to Avoid
Do not use the lower 45 mg/kg/day dose for community-acquired pneumonia—this dose is inadequate for resistant Streptococcus pneumoniae and is reserved for less severe infections like Group A Streptococcus pharyngitis. 1, 2
The absolute maximum limit for amoxicillin is 4,000 mg/day, regardless of weight, so this 65-pound child is well below that threshold. 2, 5
Ensure reassessment at 48-72 hours—if the child deteriorates or shows no improvement, further investigation and possible antibiotic change are warranted. 1