American Board of Internal Medicine (ABIM) Certification Practice Exam

If Vancomycin was used for the first episode of non-fulminant C. diff and a recurrence occurs, what is the next step?

1. Start Metronidazole

2. Use a pulsed-tapered regimen of Vancomycin

3. Switch to Fidaxomicin

4. Increase the Vancomycin dosage

The correct answer is: Use a pulsed-tapered regimen of Vancomycin

The correct next step after the recurrence of non-fulminant Clostridium difficile infection (CDI) following an initial treatment with Vancomycin is to implement a pulsed-tapered regimen of Vancomycin. This approach is based on the understanding that recurrent CDI has a high risk of relapse, and using a pulsed-tapered strategy can help to reduce this risk by allowing for gradual withdrawal of the antibiotic while still maintaining a therapeutic level to suppress the infection. In a pulsed-tapered regimen, the frequency of dosing is gradually reduced over time, which permits the natural flora of the gut to recover and potentially helps to prevent further recurrence of CDI. This strategy leverages the premise that elimination of the antibiotic pressure helps to restore a healthy microbiome balance, which is crucial for preventing further infections. While other alternatives like switching to Fidaxomicin or increasing the dosage of Vancomycin might be considered, the pulsed-tapered regimen specifically addresses the recurring aspect of the infection in a way that is supported by clinical evidence and guidelines. Starting Metronidazole is generally not recommended as first-line for recurrent CDI in cases where Vancomycin was the initial treatment.