Treatment of Cat Bite Infection Not Responding to Augmentin
For cat bite infections not responding to amoxicillin-clavulanate (Augmentin), the next step should be switching to alternative antibiotics such as doxycycline, fluoroquinolones (ciprofloxacin or levofloxacin) with metronidazole, or intravenous options like ampicillin-sulbactam or piperacillin-tazobactam, along with wound reassessment and possible surgical intervention. 1, 2
Evaluation of Treatment Failure
When a cat bite infection fails to respond to Augmentin, consider:
Wound reassessment:
- Check for abscess formation, deep tissue involvement, or foreign bodies
- Evaluate for involvement of tendons, joints, or bone
- Look for signs of worsening infection (increasing erythema, swelling, pain)
Microbiology considerations:
- Standard cat bite infections contain Pasteurella multocida, Staphylococci, Streptococci, and anaerobes
- Treatment failure may indicate resistant organisms or unusual pathogens (like Mycobacterium chelonae) 3
- Consider wound culture and sensitivity testing to guide antibiotic therapy
Alternative Antibiotic Options
Oral alternatives:
- Doxycycline - excellent alternative for penicillin-allergic patients and provides good coverage against Pasteurella 2
- Fluoroquinolones (ciprofloxacin or levofloxacin) plus metronidazole for anaerobic coverage 1, 2
- Second/third-generation cephalosporins with anaerobic coverage 1
Intravenous options (for moderate to severe infections):
- Ampicillin-sulbactam
- Piperacillin-tazobactam
- Carbapenems (imipenem, meropenem, ertapenem)
- Ceftriaxone plus metronidazole 1, 2
Surgical Intervention
Consider surgical management if:
- Abscess has formed
- Deep structures are involved (tendons, joints, bones)
- Evidence of necrotic tissue
- Foreign body is suspected
Surgical approach includes:
- Thorough debridement of necrotic tissue
- Irrigation with sterile saline or dilute povidone-iodine solution
- Drainage of any purulent collections
- Removal of foreign bodies if present 2, 4
Special Considerations
Hand Infections
Cat bite infections of the hand warrant special attention as they:
- Have higher risk of treatment failure
- May involve tendons, joints, or bones
- Often require more aggressive treatment and possibly hospitalization 2, 5
Unusual Pathogens
Consider atypical organisms if standard treatment fails:
- Mycobacterium species (including M. chelonae) 3
- Bartonella henselae (cat scratch disease) 4
- Resistant staphylococci or streptococci
Follow-up and Monitoring
- Reassess within 24-48 hours of changing antibiotics
- Monitor for signs of improvement or deterioration
- Consider inflammatory markers to track response
- Extend antibiotic duration if improvement is slow 2
Indications for Hospitalization
Consider inpatient management if:
- Systemic symptoms (fever, chills)
- Significant hand involvement
- Immunocompromised patient
- Failed outpatient therapy
- Need for IV antibiotics or surgical intervention 2
Common Pitfalls
- Inadequate initial wound irrigation and debridement
- Failure to consider deep structure involvement
- Not obtaining cultures when initial therapy fails
- Overlooking unusual pathogens in non-responsive infections
- Insufficient duration of antibiotic therapy
- Delayed surgical intervention when indicated
Remember that cat bites have a higher infection rate than dog bites due to their sharp teeth causing deep puncture wounds that are difficult to clean and create an ideal environment for bacterial growth.