Which antibiotic has lower recurrence of Clostridioides difficile infection compared with vancomycin?

Which antibiotic has lower recurrence of Clostridioides difficile infection compared with vancomycin?

• A. Fidaxomicin
• B. Metronidazole
• C. Vancomycin
• D. Ciprofloxacin

Answer: (A)

Fidaxomicin lowers recurrence of Clostridioides difficile infection compared with vancomycin because it has a narrow, targeted action in the gut and minimal disruption of the normal intestinal microbiota. It stays largely in the gastrointestinal tract (poor systemic absorption) and concentrates where C. difficile resides, inhibiting the bacterial RNA polymerase and toxin production with less collateral damage to the other gut bacteria. This preservation of the commensal flora helps the microbiome recover after therapy, reducing the chance that C. difficile will come back once treatment ends. In contrast, while vancomycin is effective for clearing the initial infection, it can cause broader disturbance of the gut microbiota, creating an environment more prone to relapse. Therefore fidaxomicin tends to achieve similar initial cure rates but lower recurrence, particularly in non-NAP1 strains. Metronidazole is generally less effective for CDI and not preferred for recurrence reduction, vancomycin is the comparator, and ciprofloxacin is not used to treat CDI.

Fidaxomicin lowers recurrence of Clostridioides difficile infection compared with vancomycin because it has a narrow, targeted action in the gut and minimal disruption of the normal intestinal microbiota. It stays largely in the gastrointestinal tract (poor systemic absorption) and concentrates where C. difficile resides, inhibiting the bacterial RNA polymerase and toxin production with less collateral damage to the other gut bacteria. This preservation of the commensal flora helps the microbiome recover after therapy, reducing the chance that C. difficile will come back once treatment ends.

In contrast, while vancomycin is effective for clearing the initial infection, it can cause broader disturbance of the gut microbiota, creating an environment more prone to relapse. Therefore fidaxomicin tends to achieve similar initial cure rates but lower recurrence, particularly in non-NAP1 strains. Metronidazole is generally less effective for CDI and not preferred for recurrence reduction, vancomycin is the comparator, and ciprofloxacin is not used to treat CDI.