What is the appropriate duration of amoxicillin/clavulanate (Augmentin) therapy for a cat‑scratch wound?

Duration of Augmentin for Cat Scratch Wounds

For a cat scratch or bite wound, amoxicillin-clavulanate (Augmentin) should be prescribed at 875/125 mg twice daily for 3-5 days for prophylaxis or 7-10 days for established infection. 1

Important Distinction: Cat Scratch Wound vs. Cat Scratch Disease

It is critical to differentiate between a traumatic cat scratch/bite wound and cat scratch disease (caused by Bartonella henselae):

• Cat scratch/bite wounds are treated with amoxicillin-clavulanate as outlined below 1
• Cat scratch disease (lymphadenopathy from Bartonella) requires azithromycin, not amoxicillin-clavulanate 1

Treatment Algorithm for Cat Scratch/Bite Wounds

For Prophylaxis (No Infection Present)

Prescribe amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days when: 1

• Wound is 9-24 hours old (strongest benefit demonstrated) 2
• Puncture wounds (highest infection risk, especially on hands) 3
• Full-thickness wounds 3
• Hand wounds (greatest infection risk from cat bites) 3, 4

Key Evidence: Prophylactic antibiotics show significant benefit for wounds presenting 9-24 hours after injury (P=0.023), but minimal benefit for wounds <9 hours old unless high-risk features present 2. Wound depth and type (puncture) are the most important infection risk factors 3.

For Established Infection

Prescribe amoxicillin-clavulanate 875/125 mg twice daily for 7-10 days when clinical infection is present 1

Dosing Specifics

• Adults: 875/125 mg orally twice daily 1
• Pediatric (≥3 months): 45 mg/kg/day divided twice daily (standard formulation) or 90 mg/kg/day divided twice daily (ES-600 formulation for resistant organisms) 5
• Administration: Take at the start of meals to minimize GI intolerance and enhance clavulanate absorption 5

Rationale for Amoxicillin-Clavulanate

Amoxicillin-clavulanate is the guideline-recommended first-line agent because: 1

• Covers Pasteurella multocida (isolated in >50% of cat bite wounds) 4
• Covers Staphylococcus aureus and Streptococcus species 1
• Covers anaerobes commonly present in oral flora 1
• β-lactamase inhibitor (clavulanate) extends coverage to β-lactamase-producing organisms 4

Common Pitfalls to Avoid

• Do not use amoxicillin-clavulanate for cat scratch disease (lymphadenopathy from Bartonella)—this requires azithromycin 1
• Do not skip prophylaxis for hand puncture wounds—these have the highest infection risk even if initially appearing minor 3, 4
• Do not prescribe prophylaxis for superficial "claw" scratches—these have minimal infection risk 3
• Ensure proper storage of reconstituted suspension (refrigerate, use within 10 days) 5
• Warn patients about diarrhea (occurs in 12-13% of patients)—usually resolves after completion but contact physician if severe or bloody 5

Alternative Agents (If Amoxicillin-Clavulanate Contraindicated)

• Doxycycline 100 mg twice daily: Excellent activity against P. multocida, though some streptococci resistant 1
• Moxifloxacin 400 mg daily: Monotherapy option with good anaerobic coverage 1