What are the recommended antibiotics for diverticulitis according to Australian guidelines?

Antibiotic Recommendations for Diverticulitis According to Australian Guidelines

For uncomplicated diverticulitis (WSES stage 0), antibiotics should be avoided in immunocompetent patients without systemic manifestations of infection. 1

Classification and Antibiotic Recommendations

Uncomplicated Diverticulitis (WSES Stage 0)

• No antibiotics recommended for immunocompetent patients without systemic manifestations 1, 2
• Observation with pain management (typically acetaminophen) and dietary modification with a clear liquid diet is sufficient 3

Localized Complicated Diverticulitis (WSES Stage 1a)

• Antibiotics recommended for patients with pericolic air bubbles or little pericolic fluid without abscess 1
• Recommended antibiotics:
  • Oral: Amoxicillin-clavulanic acid 4, 5
  • Alternative for penicillin allergy: Ciprofloxacin plus metronidazole 5

Complicated Diverticulitis

• Intravenous broad-spectrum antibiotics covering gram-negative bacilli and anaerobes 2
• Options include:
  • Piperacillin-tazobactam
  • Ceftriaxone plus metronidazole
  • Ciprofloxacin plus metronidazole
  • Ampicillin plus gentamicin plus metronidazole 2, 3

Special Considerations for Antibiotic Use

Antibiotics should be reserved for patients with:

• Systemic symptoms (persistent fever or chills)
• Increasing leukocytosis
• Age >80 years
• Pregnancy
• Immunocompromised status (receiving chemotherapy, high-dose steroids, or post-organ transplant)
• Chronic medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 2, 3

Treatment Duration and Setting

• Uncomplicated diverticulitis: 7-day course of oral antibiotics when indicated 4, 5
• Outpatient treatment is appropriate for patients who:
  • Can tolerate oral intake
  • Have no severe comorbidities
  • Have adequate family support 5
• Inpatient treatment with IV antibiotics indicated for patients who:
  • Cannot tolerate oral intake
  • Have significant comorbidities
  • Lack adequate family support 5
• Recent evidence shows oral antibiotics are as effective as IV antibiotics for uncomplicated diverticulitis in the outpatient setting 6

Important Clinical Considerations

• CT scan with IV contrast is the recommended first-line imaging modality with 98% sensitivity and 99% specificity 2
• Patients should be monitored for signs of treatment failure, which may include persistent fever, increasing pain, or worsening laboratory values
• Patients with diffuse peritonitis due to diverticular perforation require prompt emergency operation 2
• Follow-up colonoscopy 6-8 weeks after resolution is recommended to exclude colonic neoplasm if a high-quality examination has not been recently performed 2

Common Pitfalls to Avoid

• Overuse of antibiotics in uncomplicated diverticulitis where they may not be necessary
• Failure to recognize high-risk patients who should receive antibiotics despite having uncomplicated disease
• Inadequate follow-up to ensure resolution of symptoms and exclude underlying malignancy
• Inappropriate outpatient management of patients with suspected complicated diverticulitis, recent antibiotic use, unstable comorbid conditions, immunosuppression, or signs of sepsis 2