A patient with diarrhea tests positive for C. difficile and is taking clindamycin. How should management proceed?

• A. Stop the clindamycin, treat the diarrhea
• B. Treat the diarrhea, give metronidazole
• C. Stop the clindamycin if possible, give metronidazole
• D. Give metronidazole

Answer: (C)

C. Clostridioides difficile infection arises when antibiotics like clindamycin disrupt the normal gut flora, allowing toxin-producing organisms to proliferate. Removing the triggering antibiotic helps stop ongoing disruption and toxin production, while starting treatment targets the infection itself. In mild to moderate cases, metronidazole is an appropriate anti-C. difficile agent, so stopping clindamycin if possible and initiating metronidazole offers the best approach. Continuing the antibiotic without addressing the CDI would allow continued overgrowth, and giving metronidazole alone without stopping the inciting antibiotic is less effective.