What is the recommended antibiotic treatment for colitis?

Antibiotic Treatment for Clostridium difficile Colitis

For antibiotic treatment of colitis, metronidazole 500 mg three times daily orally for 10 days is recommended as first-line therapy for non-severe Clostridium difficile colitis, while vancomycin 125 mg four times daily orally for 10 days is recommended for severe C. difficile colitis. 1, 2

Disease Severity Assessment

Severity assessment is crucial for appropriate antibiotic selection:

• Non-severe C. difficile colitis: Characterized by stool frequency < 4 times daily, no signs of severe colitis, and white blood cell count < 15 × 10^9/L 1, 3

• Severe C. difficile colitis: Characterized by one or more of the following 1:

  • Fever (core body temperature > 38.5°C)
  • Hemodynamic instability or signs of septic shock
  • Signs of peritonitis or ileus
  • Marked leukocytosis (leukocyte count > 15 × 10^9/L)
  • Elevated serum creatinine (>50% above baseline)
  • Elevated serum lactate
  • Pseudomembranous colitis on endoscopy 1

First-Line Treatment Recommendations

Non-Severe C. difficile Colitis

• Metronidazole 500 mg three times daily orally for 10 days (A-I) 1, 2
• Consider stopping the inducing antibiotic and observing clinical response for 48 hours in non-epidemic situations, but follow patients closely for deterioration 1

Severe C. difficile Colitis

• Vancomycin 125 mg four times daily orally for 10 days (A-I) 1, 2
• The use of oral metronidazole in severe CDI is strongly discouraged (D-I) 1
• Consider increasing vancomycin dosage to 500 mg four times daily for 10 days in severe cases (B-III) 1

When Oral Therapy Is Not Possible

• Non-severe: Metronidazole 500 mg three times daily intravenously for 10 days (A-III) 1
• Severe: Metronidazole 500 mg three times daily intravenously for 10 days (A-III) PLUS intracolonic vancomycin 500 mg in 100 mL of normal saline every 4–12 hours (C-III) and/or vancomycin 500 mg four times daily by nasogastric tube (C-III) 1

Treatment for Recurrent C. difficile Infection

First Recurrence

• Same treatment as initial episode based on severity 1

Second and Subsequent Recurrences

• Fidaxomicin 200 mg twice daily for 10 days (B-II) 1, 2
• OR Vancomycin 125 mg four times daily for 10 days followed by either:
  • Pulse strategy (e.g., a dose of 125 mg every 3 days for 3 weeks) (B-II) 1
  • Taper strategy (e.g., decreasing daily dose with 125 mg every 3 days) (B-II) 1

Multiple Recurrent CDI

• For multiple recurrent CDI unresponsive to repeated antibiotic treatment, fecal transplantation in combination with oral antibiotic treatment is strongly recommended (A-I) 1

Important Considerations

• Avoid antiperistaltic agents and opiates in C. difficile infection 1, 3
• Discontinue the inciting antibiotic if possible 1, 3
• Vancomycin capsules are FDA-approved for C. difficile-associated diarrhea and staphylococcal enterocolitis 4
• Monitor renal function in patients >65 years of age during and after treatment with vancomycin, as nephrotoxicity has been reported 4
• Vancomycin for colitis is for oral use only and is not systemically absorbed; parenteral administration is not effective for treatment of C. difficile-associated diarrhea 4

Surgical Considerations

Consider colectomy in any of the following situations 1:

• Perforation of the colon
• Systemic inflammation and deteriorating clinical condition not responding to antibiotic therapy
• Toxic megacolon or severe ileus
• Surgery should preferably be performed before colitis becomes very severe (before serum lactate exceeds 5.0 mmol/L) 1

Regional Variations in Practice

• While European and American guidelines have recently shifted toward recommending fidaxomicin as first-line treatment, with vancomycin as second choice, some national guidelines (e.g., Swiss Infectious Diseases Society) still recommend metronidazole as first-line treatment for patients without risk factors and with low probability of relapse 5