What is the recommended dosage of coamoxiclav (amoxicillin/clavulanic acid) for a child with a dirty wound?

Recommended Dosage of Co-amoxiclav for Dirty Wounds in Children

For a child with a dirty wound requiring antibiotic prophylaxis or treatment, administer oral amoxicillin-clavulanate (co-amoxiclav) at 25 mg/kg/day of the amoxicillin component divided into 2 doses for mild infections, or 45 mg/kg/day divided into 2 doses for more contaminated wounds with higher infection risk. 1

Dosing Algorithm Based on Wound Severity

For Simple Dirty Wounds (Low-Risk)

• Standard dose: 25 mg/kg/day of the amoxicillin component divided into 2 doses orally 1
• This provides adequate coverage against common skin pathogens including Staphylococcus aureus and Streptococcus pyogenes 1
• Maximum single dose should not exceed 875 mg of amoxicillin component 2

For High-Risk Contaminated Wounds

• Higher dose: 45 mg/kg/day of the amoxicillin component divided into 2 or 3 doses 2
• Consider this dosing for wounds with:
  • Significant soil contamination
  • Delayed presentation (>6-8 hours)
  • Crush injury components
  • Involvement of deeper tissues 1

For Severe or Polymicrobial Infections

• If the wound shows signs of established infection with systemic symptoms (fever >38°C, tachycardia, spreading erythema), parenteral therapy may be required initially 1
• Intravenous dosing: 60-75 mg/kg/dose of the piperacillin component every 6 hours, or alternative broad-spectrum coverage as outlined for necrotizing infections 1

Maximum Dosing Considerations

The maximum daily dose is 90 mg/kg/day of the amoxicillin component (not to exceed 4000 mg/day total) for severe infections. 2 This higher dosing is typically reserved for resistant organisms or severe infections, not routine wound prophylaxis 2.

Duration of Therapy

• Standard duration: 5-7 days for established wound infections 1
• For prophylaxis after wound debridement: 3-5 days may be sufficient 1
• Clinical improvement should be evident within 48-72 hours; if not, reassess for resistant organisms or deeper infection 2

Important Clinical Caveats

Pathogen Coverage

Co-amoxiclav provides excellent coverage for the typical pathogens in dirty wounds, including beta-lactamase producing strains of Staphylococcus aureus, Streptococcus pyogenes, and anaerobes from soil contamination 1. However, it does not cover MRSA 1.

When to Consider Alternative Therapy

• If MRSA is suspected (prior colonization, local prevalence >10%, failure of initial therapy), add or switch to clindamycin 10-13 mg/kg/dose every 8 hours IV or 20 mg/kg/day orally in 3 divided doses 1
• For penicillin allergy with immediate hypersensitivity reactions, use clindamycin alone 1

Red Flags Requiring Surgical Consultation

Watch for signs suggesting necrotizing infection that would require immediate surgical debridement beyond antibiotics alone 1:

• Pain disproportionate to physical findings
• Rapid progression despite antibiotics
• Skin necrosis, bullae, or crepitus
• Systemic toxicity with altered mental status
• Hard, wooden feel to subcutaneous tissues 1

Practical Administration

The twice-daily dosing of co-amoxiclav improves adherence compared to three-times-daily regimens, with similar or better tolerability 2, 3. Gastrointestinal side effects (diarrhea, nausea) are the most common adverse events but are generally mild 2, 3.