What is the appropriate Augmentin (amoxicillin/clavulanate) dose for a 10-year-old child weighing 86 kg with a presumed bacterial oral infection (culture pending)?

Augmentin Dosing for a 10-Year-Old, 86 kg Child with Bacterial Oral Infection

For this 10-year-old weighing 86 kg with a presumed bacterial oral infection, dose Augmentin as an adult: 875 mg/125 mg twice daily for 7–10 days, because pediatric patients weighing ≥40 kg should receive adult dosing rather than weight-based calculations. 1

Why Adult Dosing Applies

• The FDA label explicitly states that pediatric patients weighing 40 kg or more should be dosed according to adult recommendations, not pediatric weight-based calculations. 1
• At 86 kg, this child is more than double the 40 kg threshold, making adult dosing both appropriate and necessary to avoid significant underdosing. 1
• Using pediatric weight-based calculations (e.g., 45–90 mg/kg/day) would result in doses far exceeding maximum safe limits and is not recommended for children ≥40 kg. 1

Recommended Regimen

• Standard dose: Augmentin 875 mg/125 mg orally twice daily (every 12 hours) for 7–10 days for moderate bacterial infections of the oral cavity. 1
• Severe infection alternative: If the infection is severe (high fever, extensive tissue involvement, systemic symptoms), consider 500 mg/125 mg three times daily (every 8 hours) instead. 1
• Administration: Give at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects. 1

Clinical Context for Oral Infections

• While the provided evidence focuses primarily on respiratory tract infections, Augmentin provides excellent coverage for the typical oral pathogens: Streptococcus species (including S. pyogenes), Staphylococcus aureus (methicillin-susceptible), and anaerobes. 2, 3
• The combination of amoxicillin with clavulanate covers β-lactamase-producing organisms that may be present in polymicrobial oral infections. 2
• Duration of 7–10 days is standard for most bacterial soft tissue and mucosal infections. 4

Reassessment Protocol

• At 48–72 hours: Expect clinical improvement (reduced pain, fever, swelling). If no improvement or worsening occurs, reassess the diagnosis and consider culture-directed therapy once results are available. 4
• If the patient cannot tolerate oral medication or shows signs of severe systemic infection (high fever, difficulty swallowing, airway compromise), consider IV therapy at 30 mg/kg every 8 hours (maximum 4000 mg/day amoxicillin component). 5

Critical Prescribing Considerations

• Verify the formulation: The 875 mg/125 mg tablet is the appropriate adult strength; do not substitute two 250 mg/125 mg tablets, as they contain the same amount of clavulanate and are not equivalent. 1
• Renal function: If this patient has any renal impairment (unlikely at age 10 but worth checking if risk factors exist), dose adjustment may be needed. For GFR <30 mL/min, reduce to 500 mg/125 mg every 12 hours. 1
• Common adverse effects: Diarrhea, nausea, and rash are the most frequent side effects; the twice-daily regimen causes less diarrhea than three-times-daily dosing. 4, 6

When Culture Results Return

• If cultures grow resistant organisms (e.g., MRSA), switch to clindamycin 300–450 mg three times daily based on susceptibility testing. 7
• If cultures are negative or show normal oral flora, consider stopping antibiotics and reassessing for non-bacterial causes (viral, fungal, autoimmune). 4