What is the appropriate Augmentin (amoxicillin/clavulanate) dosing regimen for prophylaxis after a dog bite in an adult, including adjustments for children, renal impairment, severe infection, and penicillin allergy?

Augmentin Dosing for Dog Bite Prophylaxis

For dog bite prophylaxis in adults, prescribe amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days, particularly for high-risk wounds including hand/face injuries, puncture wounds, immunocompromised patients, or those with advanced liver disease or asplenia. 1

Adult Dosing

• Standard prophylactic dose: Amoxicillin-clavulanate 875/125 mg orally twice daily for 3-5 days 1
• Alternative dosing: 500/125 mg three times daily may be used 1
• Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects 2

Pediatric Dosing

For children ≥3 months: 1, 2

• High-risk infections (hand/face wounds, puncture wounds): 45 mg/kg/day (based on amoxicillin component) divided every 12 hours using 200 mg/5 mL or 400 mg/5 mL suspension 2
• Lower-risk infections: 25 mg/kg/day divided every 12 hours 2
• Infants <3 months: 30 mg/kg/day divided every 12 hours using 125 mg/5 mL suspension 2
• Children ≥40 kg: Use adult dosing 2

High-Risk Indications Requiring Prophylaxis

Preemptive antibiotic therapy for 3-5 days is strongly recommended for patients with: 1

• Immunocompromised status
• Asplenia
• Advanced liver disease
• Preexisting or resultant edema of affected area
• Moderate to severe injuries, especially to hand or face
• Injuries penetrating periosteum or joint capsule
• Puncture wounds 3, 4

Penicillin Allergy Alternatives

For penicillin-allergic patients: 1

• Doxycycline 100 mg twice daily (excellent activity against Pasteurella multocida; avoid in children <8 years) 1
• Moxifloxacin 400 mg daily (monotherapy with anaerobic coverage; avoid in children <18 years) 1
• Combination therapy: Trimethoprim-sulfamethoxazole 160-800 mg twice daily PLUS metronidazole 250-500 mg three times daily (covers aerobes and anaerobes respectively) 1

Renal Impairment Adjustments

The FDA label does not provide specific renal dosing adjustments for prophylactic use, but standard practice suggests: 2

• Extend dosing intervals for creatinine clearance <30 mL/min
• Consider alternative agents or consult pharmacy for specific adjustments

Treatment Duration and Clinical Pearls

• Prophylaxis duration: 3-5 days for high-risk wounds 1
• Established infection: 7-10 days minimum 1
• Complicated infections (osteomyelitis, septic arthritis): 4-6 weeks 1

Critical microbiologic considerations: Dog bite wounds contain an average of 5 bacterial species, with Pasteurella multocida isolated in 50% of cases, along with staphylococci, streptococci, and anaerobes (Bacteroides, Fusobacterium, Porphyromonas) 1. Amoxicillin-clavulanate provides optimal coverage for this polymicrobial flora 1.

Common Pitfalls to Avoid

• Do NOT substitute two 250/125 mg tablets for one 500/125 mg tablet—they contain the same amount of clavulanate (125 mg) but different amoxicillin doses 2
• Avoid monotherapy with: First-generation cephalosporins (cephalexin), clindamycin alone, or macrolides—all have poor activity against P. multocida 1
• Low-risk wounds presenting within 12-24 hours may not require prophylaxis if no high-risk features present, though evidence shows antibiotics reduce infection risk (relative risk 0.56) 1

Additional Considerations

• Rabies prophylaxis: Consult local health officials to determine need for postexposure vaccination 1
• Tetanus status: Update if indicated 3, 4
• Wound care: Copious irrigation with normal saline, debridement of devitalized tissue, and evaluation for neurovascular injury are essential adjuncts to antibiotic therapy 3, 4