Treatment for Clostridioides difficile Infection (CDI)
For initial CDI episodes, oral vancomycin 125 mg four times daily for 10 days or fidaxomicin 200 mg twice daily for 10 days should be used as first-line therapy, with treatment selection based on disease severity. 1, 2
Initial Treatment Algorithm Based on Disease Severity
Non-severe CDI
- First-line options:
- Note: Metronidazole (500 mg three times daily for 10 days) is no longer recommended as first-line therapy for adults due to lower cure rates compared to vancomycin, especially in severe cases 1, 4
Severe CDI
Severe CDI is defined by one or more of:
Marked leukocytosis (WBC >15 × 10⁹/L)
Serum albumin <30 g/L
Serum creatinine ≥133 μmol/L or ≥1.5 times baseline 1
Treatment: Oral vancomycin 125 mg four times daily for 10 days 1
Fulminant CDI (life-threatening)
Signs include:
Hypotension or shock
Ileus
Toxic megacolon
Treatment:
When Oral Therapy Is Not Possible
- Intravenous metronidazole 500 mg three times daily for 10 days
- PLUS vancomycin 500 mg four times daily via nasogastric tube or as retention enema 1
Management of Recurrent CDI
First Recurrence
- Vancomycin 125 mg four times daily for 10 days (if metronidazole was used for initial episode) 1
- Fidaxomicin 200 mg twice daily for 10 days (if vancomycin was used for initial episode) 1, 2
- Consider vancomycin in a tapered and pulsed regimen (e.g., 125 mg four times daily for 10-14 days, then twice daily for 7 days, then once daily for 7 days, then every 2-3 days for 2-8 weeks) 1
Second or Subsequent Recurrences
- Vancomycin in a tapered and pulsed regimen 1, 2
- Vancomycin 125 mg four times daily for 10 days followed by rifaximin 400 mg three times daily for 20 days 1
- Fidaxomicin 200 mg twice daily for 10 days 1
- Fecal microbiota transplantation (FMT) after appropriate antibiotic treatments for at least 2 recurrences 1, 5
Special Considerations
Pediatric Patients
- For non-severe CDI in children: metronidazole or vancomycin (dosing based on weight) 1
- For severe CDI in children: vancomycin with or without IV metronidazole 1
Surgical Management
Colectomy should be considered in:
- Colonic perforation
- Systemic inflammation not responding to antibiotic therapy
- Toxic megacolon
- Severe ileus
Surgery is recommended before serum lactate exceeds 5.0 mmol/L to reduce mortality 1, 2
Prevention Strategies
- Implement antibiotic stewardship to reduce unnecessary antibiotic use 2
- Practice proper hand hygiene (soap and water preferred during outbreaks) 4
- Isolate patients with confirmed or suspected CDI 2
- Use gloves and gowns when caring for CDI patients 2
- Ensure thorough environmental cleaning and disinfection 2
Common Pitfalls to Avoid
Using metronidazole as first-line therapy: Recent guidelines no longer recommend metronidazole as first-line therapy due to inferior cure rates compared to vancomycin and fidaxomicin 4
Failing to recognize severe disease: Prompt identification of severe CDI is critical for appropriate treatment selection and improved outcomes 1
Repeated testing during the same episode: Testing within 7 days during the same episode rarely changes management and may lead to false positives 2
Using antiperistaltic agents: These can worsen symptoms and should be avoided 2
Delaying surgical consultation in fulminant cases: Early surgical consultation is essential in fulminant CDI as delayed intervention increases mortality 1, 2
The treatment landscape for CDI has evolved significantly, with vancomycin and fidaxomicin now preferred over metronidazole for initial episodes. For recurrent infections, tapered vancomycin regimens, fidaxomicin, or fecal microbiota transplantation offer the best chances for sustained cure and improved quality of life.