Treatment of Clostridioides difficile (C. diff) and Escherichia coli (E. coli) Infections
For C. difficile infections, oral vancomycin 125 mg four times daily for 10 days is the first-line treatment for all cases regardless of severity, with metronidazole 500 mg three times daily for 10 days as an alternative only for non-severe cases. 1, 2
Treatment of C. difficile Infection Based on Severity
Non-severe C. difficile Infection
- Metronidazole 500 mg orally three times daily for 10 days can be used for initial non-severe episodes 3, 1
- Vancomycin 125 mg orally four times daily for 10 days is recommended for all cases and is superior to metronidazole in clinical outcomes 1, 2
- Fidaxomicin 200 mg orally twice daily for 10 days is an effective alternative with lower recurrence rates 1, 4
Severe C. difficile Infection
- Vancomycin 125 mg orally four times daily for 10 days is the treatment of choice 1, 2
- Criteria for severe CDI include: WBC >15 × 10^9/L, serum albumin <30 g/L, or rise in serum creatinine ≥1.5 times baseline 2, 5
- Avoid metronidazole for severe cases due to lower efficacy 1
Fulminant C. difficile Infection
- Vancomycin 500 mg orally four times daily plus intravenous metronidazole 500 mg three times daily 1
- When oral therapy is impossible, use intravenous metronidazole 500 mg three times daily plus intracolonic vancomycin 500 mg in 100 mL of normal saline every 4-12 hours and/or vancomycin 500 mg four times daily by nasogastric tube 3
- Early surgical consultation for patients with systemic toxicity, perforation, or toxic megacolon 3, 5
Treatment of Recurrent C. difficile Infection
- First recurrence: Treat as a first episode based on severity, preferably with vancomycin or fidaxomicin 1, 2
- Second or subsequent recurrences: Vancomycin 125 mg orally four times daily for at least 10 days, followed by a tapered and pulsed regimen 1, 2
- Fidaxomicin 200 mg twice daily for 10 days may be particularly useful for patients at high risk for recurrence 3, 1
- Fecal microbiota transplantation (FMT) is effective for multiple recurrences that have failed appropriate antibiotic treatments 3
- Bezlotoxumab (monoclonal antibody against C. diff toxin B) may prevent recurrences, particularly in high-risk patients 3, 2
Important Considerations for C. difficile Management
- Discontinue the inciting antibiotic as soon as possible to reduce recurrence risk 1, 2
- Avoid antiperistaltic agents and opiates as they may mask symptoms and worsen disease 5
- Implement strict infection control measures including hand hygiene with soap and water (not alcohol-based sanitizers) 1, 5
- Consider surgical intervention for perforation, systemic inflammation not responding to antibiotics, toxic megacolon, or severe ileus 3, 5
Treatment of E. coli Infections
- Treatment depends on the type of E. coli infection (urinary tract, gastrointestinal, systemic) and local resistance patterns
- For uncomplicated urinary tract infections: trimethoprim-sulfamethoxazole, nitrofurantoin, or fosfomycin are first-line options
- For complicated urinary tract infections or systemic infections: fluoroquinolones, third-generation cephalosporins, or carbapenems based on susceptibility
- For enterotoxigenic E. coli (traveler's diarrhea): azithromycin or rifaximin
- For Shiga toxin-producing E. coli: supportive care only, as antibiotics may increase the risk of hemolytic uremic syndrome
Pitfalls to Avoid
- Don't use metronidazole for severe or recurrent C. difficile infections due to lower efficacy and potential neurotoxicity with repeated courses 1, 2
- Don't delay treatment for severe C. difficile infection while awaiting diagnostic confirmation 5
- Don't use alcohol-based hand sanitizers for C. difficile infection control, as they don't kill spores 5
- Don't continue the inciting antibiotic if clinically possible 2
- Don't use antibiotics for Shiga toxin-producing E. coli infections as this may increase toxin production