What is the appropriate Augmentin (amoxicillin + clavulanate) dose for a 7‑year‑old child weighing 38 kg?

Augmentin Dosing for a 38 kg, 7-Year-Old Child

For a 7-year-old child weighing 38 kg, the appropriate Augmentin dose depends on the infection severity: for mild-to-moderate infections (e.g., uncomplicated sinusitis, pharyngitis), prescribe 5 mL of the 250/62 suspension three times daily; for severe infections or suspected resistant pathogens, prescribe 10.5 mL of the ES-600 suspension (600 mg amoxicillin/42.9 mg clavulanate per 5 mL) twice daily to deliver 90 mg/kg/day of the amoxicillin component. 12

Standard-Dose Regimen for Mild-to-Moderate Infections

• For routine community-acquired infections (e.g., acute bacterial sinusitis without severe features, uncomplicated skin infections, or pharyngitis), the guideline-recommended dose is 5 mL of Augmentin 250/62 suspension three times daily, which provides approximately 40 mg/kg/day of amoxicillin. 1

• This dosing aligns with the pandemic influenza guideline table showing that children >6 years receive 5 mL of 250/62 suspension three times daily, and your patient at 38 kg falls into the >24 kg, over 7 years category. 1

• The 250/62 formulation contains 250 mg amoxicillin and 62.5 mg clavulanate per 5 mL, delivering approximately 750 mg amoxicillin and 187.5 mg clavulanate per day when given three times daily. 1

High-Dose Regimen for Severe Infections or Resistant Pathogens

• For severe acute bacterial sinusitis, acute otitis media with treatment failure, community-acquired pneumonia, or any infection requiring enhanced pneumococcal coverage, prescribe Augmentin ES-600 suspension at 90 mg/kg/day of the amoxicillin component divided every 12 hours. 32

• For a 38 kg child, this translates to 10.5 mL of ES-600 suspension (600 mg amoxicillin/42.9 mg clavulanate per 5 mL) administered twice daily, as specified in the FDA dosing table for children weighing 28 kg. 2

• This high-dose regimen is specifically designed to overcome resistance in Streptococcus pneumoniae with penicillin MIC >2 µg/mL and β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. 34

• The ES-600 formulation provides 1,710 mg amoxicillin and 122.4 mg clavulanate per day (approximately 45 mg/kg amoxicillin per dose), which achieves middle-ear and sinus fluid concentrations adequate to eradicate resistant pathogens. 22

Critical Formulation Differences

• Do not substitute the 200 mg/28.5 mg/5 mL or 400 mg/57 mg/5 mL suspensions for ES-600, as they contain different clavulanate concentrations and are not interchangeable. 2

• The ES-600 formulation contains 42.9 mg clavulanate per 5 mL, whereas the 250/62 suspension contains 62.5 mg per 5 mL—the higher clavulanate ratio in ES-600 is specifically engineered to inhibit β-lactamase while minimizing diarrhea. 25

Infection-Specific Guidance

Acute Bacterial Sinusitis

• For persistent purulent nasal discharge >10 days or worsening symptoms after initial improvement, use high-dose amoxicillin-clavulanate (80–90 mg/kg/day of amoxicillin) for 10–14 days. 63

• If the child has moderate-to-severe illness, attends daycare, or received antibiotics within the past 30 days, initiate high-dose therapy (ES-600 formulation) from the outset. 3

Community-Acquired Pneumonia

• For outpatient pneumonia in a child this age, standard amoxicillin 75–100 mg/kg/day divided three times daily is first-line; reserve Augmentin for suspected β-lactamase-producing pathogens or treatment failure. 4

• If atypical pathogens (Mycoplasma or Chlamydophila) are suspected in a child ≥3 years, add azithromycin 10 mg/kg on day 1, then 5 mg/kg daily on days 2–5 to the amoxicillin regimen. 4

Acute Otitis Media

• For uncomplicated AOM in a child ≥2 years without recent antibiotic exposure, standard-dose amoxicillin (45 mg/kg/day) is appropriate; escalate to high-dose amoxicillin-clavulanate (90 mg/kg/day) if no improvement after 48–72 hours. 3

• For severe AOM, age <2 years, daycare attendance, or recent antibiotic use, initiate high-dose amoxicillin-clavulanate (ES-600 formulation) from the start. 3

Administration and Monitoring

• Administer Augmentin at the start of a meal to minimize gastrointestinal intolerance and enhance clavulanate absorption. 2

• Shake the suspension vigorously before each dose; the reconstituted ES-600 suspension is stable for 10 days under refrigeration. 2

• Protocol-defined diarrhea (≥3 watery stools in one day or 2 watery stools per day for 2 consecutive days) occurs in approximately 13% of children on ES-600, compared to 27% on higher-clavulanate formulations. 25

• If diarrhea or diaper dermatitis develops, consider switching to a reduced-clavulanate formulation (80 mg amoxicillin/2.85 mg clavulanate per kg/day), which maintains efficacy while reducing gastrointestinal side effects by approximately 35%. 5

Common Prescribing Pitfalls

• Do not cap the dose at adult maximums (e.g., 875 mg twice daily) for children in higher weight categories; weight-based dosing must be used to ensure therapeutic exposure, especially for resistant organisms. 47

• Avoid underdosing in children >20 kg—studies show primary care physicians frequently prescribe significantly lower-than-recommended doses (mean 40.4 mg/kg/day versus target 80–90 mg/kg/day) in this weight range, leading to treatment failure. 7

• Do not use the standard 40/10 mg/kg/day three-times-daily regimen for severe infections; this older formulation has been superseded by the 90/6.4 mg/kg/day twice-daily ES-600 regimen, which provides equivalent efficacy with substantially less diarrhea. 8