What is the recommended antibiotic regimen for acute cholecystitis?

Recommended Antibiotic Regimens for Acute Cholecystitis

For acute cholecystitis, piperacillin-tazobactam is the recommended first-line antibiotic for critically ill or immunocompromised patients, while amoxicillin-clavulanate is appropriate for stable, immunocompetent patients. 1

Patient Classification and Antibiotic Selection

Stable, Immunocompetent Patients

• Amoxicillin/Clavulanate 2g/0.2g every 8 hours is the first-line treatment for stable, immunocompetent patients 2, 1
• Alternative regimens include:
  • Ceftriaxone plus Metronidazole 2
  • Ticarcillin/Clavulanate (in stable patients) 2

Critically Ill or Immunocompromised Patients

• Piperacillin/Tazobactam 4g/0.5g every 6 hours or 16g/2g by continuous infusion is recommended for critically ill or immunocompromised patients 1, 3
• For patients with risk of ESBL-producing Enterobacterales, Ertapenem 1g every 24 hours is recommended 2, 1

Special Considerations

• Anaerobic coverage is not required unless a biliary-enteric anastomosis is present 2
• Coverage for enterococci is recommended only for healthcare-associated infections 2, 1
• MRSA coverage (vancomycin) should only be considered for patients with healthcare-associated infections who are known to be colonized or at risk due to prior treatment failure 2

Common Pathogens in Acute Cholecystitis

• Most frequently isolated organisms include gram-negative aerobes (Escherichia coli and Klebsiella pneumoniae) and anaerobes (especially Bacteroides fragilis) 2, 4
• Healthcare-associated infections are commonly caused by more resistant strains and may require broader spectrum antibiotics 2
• Recent studies show increasing rates of ciprofloxacin-resistant Enterobacteriales, which should be considered when selecting empiric therapy 4

Duration of Antibiotic Therapy

• For uncomplicated cholecystitis with early surgical intervention, one-shot prophylaxis is sufficient with no post-operative antibiotics 1, 5
• For complicated cholecystitis with adequate source control:
  • 4 days of antibiotic therapy for immunocompetent, non-critically ill patients 1
  • Up to 7 days for immunocompromised or critically ill patients 1
• Patients undergoing cholecystectomy for acute cholecystitis should have antimicrobial therapy discontinued within 24 hours unless there is evidence of infection outside the gallbladder wall 2, 5

Surgical Management Considerations

• Early laparoscopic cholecystectomy (within 7-10 days of symptom onset) is the treatment of choice for definitive management 6
• Microbiological cultures should be obtained in complicated cases to guide targeted antibiotic therapy 6, 7
• As soon as causative organisms have been identified, antibiotic therapy should be adjusted to a narrower spectrum antimicrobial agent based on sensitivity testing 7

Antibiotic Resistance Patterns

• The incidence of ciprofloxacin-resistant Enterobacteriales has shown a significant increasing trend in recent years 4
• Vancomycin-resistant E. faecium, carbapenem-resistant Enterobacteriales, and ESBL-producing Enterobacteriales have been recently observed in bile cultures 4
• Local resistance patterns should be considered when selecting empiric antibiotic therapy 7

Remember that source control through cholecystectomy remains a crucial component of infection management in grade I and II acute cholecystitis, and appropriate antibiotic selection should be based on patient factors, local resistance patterns, and severity of illness 4.