What is the recommended dose of Augmentin (amoxicillin-clavulanate) for a 12-year-old patient weighing 135 pounds with a suspected secondary bacterial infection following an allergic reaction to an insect bite?

Augmentin Dosing for a 12-Year-Old, 135-Pound Patient with Suspected Secondary Bacterial Infection Following Insect Bite

For this 12-year-old patient weighing 135 pounds (61.4 kg), the recommended dose is Augmentin 875/125 mg orally twice daily, as this patient meets the weight threshold (≥40 kg) for adult dosing. 1

Weight-Based Dosing Determination

• This patient weighs 135 pounds (61.4 kg), which exceeds 40 kg, the threshold at which pediatric patients should transition to adult dosing recommendations 1
• The FDA label explicitly states: "Pediatric patients weighing 40 kg or more should be dosed according to adult recommendations" 1

Recommended Regimen for Insect Bite with Secondary Bacterial Infection

The standard adult dose of Augmentin 875/125 mg twice daily is appropriate for this clinical scenario 2, 1:

• Dosing: 875 mg amoxicillin/125 mg clavulanate orally every 12 hours
• Duration: 3-5 days for preemptive therapy in patients with moderate injuries 2
• Administration: Should be taken at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 1

Clinical Context for Insect Bite Infections

The IDSA guidelines specifically recommend amoxicillin-clavulanate as first-line therapy for animal and insect bite wounds because it provides coverage against both aerobic and anaerobic bacteria 2:

• Preemptive antimicrobial therapy for 3-5 days is recommended for patients with moderate to severe injuries, especially to the hand or face, or those with resultant edema of the affected area 2
• Amoxicillin-clavulanate provides excellent coverage against Staphylococcus aureus, Streptococcus species, and anaerobes commonly found in skin infections following bites 2

Important Dosing Considerations

Do not substitute two 250/125 mg tablets for one 500/125 mg tablet, as both contain the same amount of clavulanic acid (125 mg), making them non-equivalent 1:

• The 250/125 mg and 500/125 mg tablets both contain 125 mg clavulanate, so doubling the 250 mg tablet would result in excessive clavulanate dosing 1
• For patients requiring higher respiratory tract infection coverage, the 875/125 mg formulation twice daily is preferred over 500/125 mg three times daily 1

Alternative Dosing if Lower Severity

If the infection is assessed as mild and the patient has not received recent antibiotics (past 4-6 weeks), the alternative would be 500/125 mg every 8 hours 1:

• However, given the context of a secondary bacterial infection following an allergic reaction to an insect bite with presumed edema, the higher dose (875/125 mg twice daily) is more appropriate 2

Monitoring and Follow-up

• Tetanus prophylaxis should be verified - patients without tetanus toxoid vaccination within 10 years should receive Tdap 2
• Reassess after 3-5 days - if no improvement or worsening occurs, consider alternative diagnoses or resistant organisms 2
• Watch for signs of systemic infection (fever >38°C, tachycardia, elevated WBC) that might warrant more aggressive therapy 2