From the Guidelines
This patient likely has a C. difficile infection despite the negative toxin antigen test, and I recommend treating with oral vancomycin 125 mg four times daily for 10 days, as the positive DNA test indicates the presence of toxigenic C. difficile, and treatment is still warranted to prevent recurrence or complications, as suggested by the most recent guidelines 1. The discrepancy between positive DNA and negative toxin antigen can occur because the DNA test is more sensitive but less specific.
- Alternatively, oral fidaxomicin 200 mg twice daily for 10 days could be used, which may reduce recurrence rates, as shown in previous studies 1.
- During treatment, it is essential to avoid antimotility agents, continue probiotics if already taking them, and emphasize good hand hygiene with soap and water, as alcohol-based sanitizers are less effective against C. difficile spores.
- Monitoring for recurrence of symptoms is crucial, as it occurs in about 20-30% of cases, and considering infectious disease consultation if symptoms recur after treatment is recommended, according to the guidelines 1. The recent guidelines from 2024 1 provide the most up-to-date recommendations for the management of C. difficile infection, and their suggestions should be prioritized in the treatment of this patient.
From the FDA Drug Label
Since clinical success at the end of treatment and mortality rates were similar across treatment arms The FDA drug label does not answer the question.
From the Research
Patient Profile
- The patient had watery diarrhea 2 days ago but has had no symptoms since
- Lab work shows C difficile toxin DNA positive and C difficile toxin antigen negative
Diagnosis and Treatment
- According to 2, C difficile infection should be considered in patients with three or more episodes of unexplained, unformed stools in 24 hours
- The patient's lab work indicates the presence of C difficile toxin DNA, but the toxin antigen is negative
- 3 suggests that oral vancomycin or oral fidaxomicin is recommended for an initial episode of non-severe C difficile infection
- 4 found that vancomycin had superior therapeutic effects compared to metronidazole in severe cases of C difficile infection
- 5 and 6 compared the effectiveness of fidaxomicin, vancomycin, and metronidazole in treating C difficile infection, with mixed results
Treatment Options
- Oral vancomycin is a recommended treatment option for C difficile infection, especially in severe cases 3, 4
- Fidaxomicin is also a recommended treatment option, but its effectiveness compared to vancomycin and metronidazole is still being studied 5, 6
- Metronidazole is no longer recommended as first-line therapy for adults with C difficile infection 2