American Association of Critical-Care Nurses (AACN) Certification Practice Test

What is the recommended first-line treatment for C. difficile infection?

1. Intravenous metronidazole

2. Oral vancomycin

3. Probiotics

4. Oral fidaxomicin

The correct answer is: Oral vancomycin

The recommended first-line treatment for Clostridioides difficile infection is oral vancomycin due to its efficacy in targeting the bacteria directly in the gut where the infection occurs. Vancomycin is a potent antibiotic that is administered orally to ensure high concentrations reach the intestinal lumen, effectively eradicating the C. difficile bacteria while minimizing systemic absorption. This targeted approach is essential for improving clinical outcomes, particularly in cases of moderate to severe C. difficile infection. The use of oral vancomycin is supported by clinical guidelines and studies that demonstrate its effectiveness in reducing recurrence rates compared to other treatments. It is generally preferred over intravenous administration because systemic levels do not adequately penetrate the gastrointestinal tract where the infection is localized. Other options, such as probiotics, while potentially beneficial in preventing recurrence or aiding in gut flora restoration, do not have the same immediate and direct impact on treating the active infection.