American Board of Internal Medicine (ABIM) Certification Practice Exam

Which therapy is included in the treatment for fulminant C. diff?

1. Vancomycin orally

2. Fidaxomicin

3. Enteric vancomycin plus parenteral metronidazole

4. Metronidazole alone

The correct answer is: Enteric vancomycin plus parenteral metronidazole

The treatment for fulminant Clostridioides difficile infection (CDI) must be aggressive and comprehensive due to the severe nature of the condition. The correct approach for fulminant CDI includes the use of enteric vancomycin combined with parenteral metronidazole. Enteric vancomycin is given orally because it is effective in targeting the bacteria within the gastrointestinal tract, where CDI causes significant harm. This oral route allows the medication to locally act against the C. diff organisms effectively. Meanwhile, parenteral metronidazole is utilized because it provides systemic coverage that is important in cases of severe infection, particularly when patients may have accompanying systemic symptoms or complications such as toxic megacolon or sepsis. This combination addresses both local and systemic aspects of the infection, ensuring that the treatment is robust against the bacteria, which can sometimes be resistant to monotherapy approaches. The combination therapy aligns with current guidelines for fulminant CDI, recognizing the need for enhanced efficacy in this critical condition. For context, while vancomycin orally is effective for non-fulminant CDI cases or recurrent infections, and fidaxomicin offers a targeted approach with less risk of recurrence, they do not provide the aggressive