Pediatric Amoxicillin Dosage for an 80-Pound Child
For a pediatric patient weighing 80 pounds (approximately 36.3 kg), the recommended amoxicillin dosage is 45 mg/kg/day divided into 2 doses for mild to moderate infections, or up to 90 mg/kg/day divided into 2-3 doses for more severe infections. 1
Dosage Calculation
To determine the specific dosage for this patient:
For mild to moderate infections:
- 45 mg/kg/day × 36.3 kg = 1,633.5 mg/day
- Divided into 2 doses: approximately 800 mg twice daily
For severe infections:
- 90 mg/kg/day × 36.3 kg = 3,267 mg/day
- Divided into 2 doses: approximately 1,600 mg twice daily
- Or divided into 3 doses: approximately 1,100 mg three times daily
Dosing Based on Infection Type
The specific dosage depends on the type and severity of infection:
Respiratory Tract Infections
- For community-acquired pneumonia: 90 mg/kg/day in 2 doses 2
- For acute otitis media: 90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses 2
Skin/Skin Structure Infections
- Mild/Moderate: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 1
- Severe: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours 1
Important Clinical Considerations
Maximum daily dose: For children weighing near adult weight (as in this case), consider the standard adult maximum daily dose of 1,500-3,000 mg/day depending on infection severity 3
Dosing frequency: While traditionally prescribed three times daily, twice-daily dosing has been shown to be equally effective for most indications and may improve compliance 4
Penicillin resistance: In areas with high prevalence of penicillin-resistant Streptococcus pneumoniae, higher dosing (90 mg/kg/day) is recommended 2
Common Pitfalls to Avoid
Underdosing in larger children: Studies show that physicians often prescribe significantly lower-than-recommended amoxicillin doses for older or heavier children 3
Failing to adjust for local resistance patterns: Consider local antibiotic resistance patterns when determining appropriate dosage 5
Not considering alternative antibiotics for treatment failures: If treatment fails, particularly with beta-lactamase-producing organisms, switching to a beta-lactamase-stable drug is recommended 6
Overlooking the importance of compliance: Twice-daily dosing may improve adherence compared to three-times-daily regimens, especially for school-aged children 7, 4
For this 80-pound child, ensure the dose is appropriate for both weight and infection severity, while staying within safe maximum daily limits.