Treatment of C. difficile Infection

Initial Episode - Mild to Moderate CDI

The American College of Gastroenterology recommends oral vancomycin 125 mg four times daily for 10 days as the preferred treatment for first episodes of mild-moderate CDI, due to its superiority over metronidazole in clinical outcomes 1, 2
Fidaxomicin 200 mg orally twice daily for 10 days is an alternative option, particularly for patients at high risk for recurrence, such as the elderly or those with multiple comorbidities 1, 2
Metronidazole should be limited to initial mild-moderate episodes only and avoided for long-term therapy due to cumulative neurotoxicity risk, with a strength of evidence rated as high 3, 4

Oral vancomycin 125 mg four times daily for 10 days is considered superior to metronidazole in severe CDI, with high-quality evidence supporting its use 1
Higher vancomycin doses (up to 500 mg four times daily) have been used in fulminant cases, though evidence is limited and primarily based on case reports 1
Aggressive supportive care is essential, including IV fluid resuscitation, electrolyte replacement, and albumin supplementation for severe hypoalbuminemia, with a recommendation grade of strong 3, 2

For first recurrence of CDI, oral vancomycin 125 mg four times daily for 14 days or fidaxomicin 200 mg twice daily for 10 days is recommended, with fidaxomicin demonstrating lower recurrence rates compared to vancomycin 3, 4, 2
Metronidazole is not recommended for recurrent CDI due to lower sustained response rates and neurotoxicity concerns, with a strength of evidence rated as moderate to high 3, 4, 2

Oral vancomycin using a tapered and pulsed regimen is recommended for patients with multiple recurrences, though no randomized controlled trials (RCTs) exist for second or subsequent recurrences 3, 4, 2
Fecal microbiota transplantation (FMT) is highly effective for multiple recurrences, with 87-92% clinical resolution rates across studies, and a strength of evidence rated as high 5, 6, 1

Limited evidence supports probiotics as adjunctive treatment for first episodes in immunocompetent patients, with a strength of evidence rated as low to moderate 3, 2
Saccharomyces boulardii combined with high-dose vancomycin (2 g/day) reduced recurrence rates in one trial, though the evidence is primarily based on a single study 6
Probiotics are contraindicated in immunocompromised patients due to bacteremia/fungemia risk, with a strength of evidence rated as high 6

Discontinue the inciting antibiotic(s) as soon as clinically possible, with a recommendation grade of strong 1, 7
If continued antibiotics are necessary, switch to agents less associated with CDI, such as parenteral aminoglycosides, sulfonamides, macrolides, tetracyclines/tigecycline, with a strength of evidence rated as moderate 3, 7
Avoid high-risk antibiotics, such as clindamycin, third-generation cephalosporins, penicillins, fluoroquinolones, with a strength of evidence rated as high 7
Discontinue unnecessary proton pump inhibitors as part of stewardship practice, though no RCT data support mandatory discontinuation, with a strength of evidence rated as low 1, 8

The Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) provide a strong recommendation for Fecal Microbiota Transplantation (FMT) in patients with multiple recurrences who have failed appropriate antibiotic treatments 9
FMT demonstrates superior outcomes compared to additional antibiotic courses, with clinical resolution rates of 87-92% compared to 40-50% with antibiotics alone 9

The Taiwan guidelines recommend FMT for second and subsequent recurrences with strong evidence (Grade 1B) 10
Administer oral vancomycin 125 mg four times daily for 4-10 days as a lead-in before FMT, with a strength of evidence of Grade 1B 10
FMT can be delivered via colonoscopy or nasojejunal tube with similar efficacy, although the strength of evidence is not specified 11

The IDSA/SHEA guidelines note that vancomycin tapered and pulsed regimen is the most evidence-supported antibiotic approach for multiple recurrences, with a strength of evidence of Grade 1B 9
Vancomycin 125 mg every 6 hours × 10-14 days, then 125 mg every 12 hours × 7 days, then 125 mg every 24 hours × 7 days, then 125 mg every 48-72 hours × 2-8 weeks, with a strength of evidence of Grade 1B 12, 9

Stop all unnecessary antibiotics immediately if the patient is on any concurrent antimicrobials, as recommended by the IDSA/SHEA guidelines with a strength of evidence of Grade 1B 9
Discontinue proton pump inhibitors if not absolutely required, as they are associated with CDI recurrence, with a strength of evidence of Grade 2B 12

Watch for warning signs requiring escalation, including WBC ≥25,000 or rising, lactate ≥5 mmol/L, ileus, toxic megacolon, or peritoneal signs, as recommended by the IDSA/SHEA guidelines with a strength of evidence of Grade 1B 9
If severe features develop, add IV metronidazole 500 mg every 8 hours to oral vancomycin and consider surgical consultation, with a strength of evidence of Grade 1B 9