What is the maximum recommended dose of Augmentin (amoxicillin/clavulanate) for a child weighing 80 lb?

Maximum Augmentin Dose for 80-Pound Child

For a child weighing 80 pounds (36 kg), the maximum recommended dose of Augmentin is 90 mg/kg/day of the amoxicillin component, which equals 3,240 mg/day divided into two doses (1,620 mg twice daily), though this should not exceed the standard adult maximum of 2,000 mg per dose (4,000 mg/day total). 1

Dosing Framework

The appropriate Augmentin dose depends on the severity of infection and risk factors for resistant organisms:

Standard-Dose Regimen

• 45 mg/kg/day divided into 2 doses
• For 36 kg child: 1,620 mg/day (810 mg twice daily)
• Appropriate for mild-to-moderate infections in children ≥2 years without recent antibiotic exposure or daycare attendance 2

High-Dose Regimen

• 80-90 mg/kg/day of amoxicillin component divided into 2 doses
• For 36 kg child: 2,880-3,240 mg/day (1,440-1,620 mg twice daily)
• Maximum: 2,000 mg per dose (4,000 mg/day) 1
• Indicated for:
  • Moderate-to-severe infections
  • Age <2 years
  • Daycare attendance
  • Recent antibiotic use (within 30 days)
  • Geographic areas with high penicillin-resistant S. pneumoniae (>10%) 2, 3

Critical Dosing Considerations

The practical maximum for this 80-pound child is 2,000 mg twice daily (4,000 mg/day total), which represents the standard adult maximum dose. This is particularly relevant because:

• At 90 mg/kg/day, this child's calculated dose (3,240 mg/day) approaches but doesn't exceed adult dosing limits
• The FDA label for Augmentin ES-600 specifically addresses pediatric dosing up to 40 kg, with experience beyond this weight being limited 1
• Primary care physicians commonly prescribe lower-than-guideline doses in heavier children, often defaulting to adult maximum doses 4

Formulation-Specific Guidance

Augmentin ES-600 (High-Dose Suspension)

• Provides 600 mg amoxicillin/42.9 mg clavulanate per 5 mL
• Designed for 90 mg/kg/day dosing in two divided doses
• For 36 kg child: 10.8 mL twice daily (rounded to practical measurement)
• Only approved for children weighing <40 kg 1

Standard Augmentin Formulations

• Cannot substitute standard suspensions (200/28.5 or 400/57 mg per 5 mL) for ES-600 due to different clavulanate ratios 1
• Tablets may be more practical for this weight: 875 mg tablets twice daily for standard dosing, or two 1000 mg tablets twice daily for high-dose therapy (if child can swallow tablets)

Clinical Caveats

Important pitfalls to avoid:

1. Weight-based dosing in obesity: The 90 mg/kg recommendation was established before the obesity epidemic. When calculated doses exceed adult maximums, clinical judgment is required 4

2. Clavulanate-related diarrhea: Higher doses increase gastrointestinal side effects. The ES-600 formulation maintains lower clavulanate levels (6.4 mg/kg/day) while achieving high amoxicillin doses, reducing this risk 1, 5

3. Twice-daily vs. three-times-daily: Twice-daily dosing improves compliance and reduces diarrhea incidence without compromising efficacy 6

4. Storage stability: In hot climates, improper storage significantly degrades amoxicillin-clavulanate potency. Refrigeration after reconstitution is essential 7

Evidence Quality Note

The high-dose regimen (80-90 mg/kg/day) is strongly supported by pediatric infectious disease guidelines from both the American Academy of Pediatrics 2 and IDSA/PIDS 3, with FDA labeling providing explicit dosing parameters 1. Research demonstrates superior outcomes with high-dose therapy specifically in children <20 kg with bilateral infections 8, and pharmacodynamic modeling confirms adequate tissue penetration against resistant S. pneumoniae strains with MICs up to 4 mcg/mL 9.

For this 80-pound child, prescribe either 1,620 mg twice daily (standard dose) or up to 2,000 mg twice daily (high dose based on infection severity and risk factors), ensuring administration with food to enhance absorption and minimize gastrointestinal effects. 1