Clostridium difficile treatment in neutropenic patients: Clinical outcomes of metronidazole, vancomycin, combinations, and switch therapy.

BACKGROUND: Clostridium difficile infection treatment guidelines exist for immunocompetent patients; however, there is a paucity of data evaluating clinical outcomes and time to C. difficile-associated diarrhea resolution in neutropenic patients.

OBJECTIVE: To assess clinical outcomes in neutropenic patients treated with metronidazole, oral vancomycin, the combination of metronidazole plus oral vancomycin, and switch of metronidazole to oral vancomycin.

METHODS: This retrospective, observational cohort study assessed adult neutropenic inpatients with C. difficile-associated diarrhea treated with metronidazole, oral vancomycin, combination (metronidazole and oral vancomycin), or switch therapy (metronidazole to oral vancomycin). The primary outcome was time to diarrhea resolution based on treatment regimen. Secondary outcomes included C. difficile-associated diarrhea resolution of diarrhea by day 14, recurrence, and occurrence of major complications.

RESULTS: Overall, 44 patients met full inclusion criteria (52.2% metronidazole monotherapy, 22.7% combination, and 25.0% switch therapy). Two patients on oral vancomycin monotherapy were excluded due to insufficient sample size. Overall time to C. difficile-associated diarrhea resolution was 9.1 ± 10.7 days. The Cox regression results suggested both switch and combination therapy were associated with 65.5% (p = 0.002) and 65.9% (p = 0.046) longer time to C. difficile-associated diarrhea resolution compared to metronidazole monotherapy, respectively. An increasing absolute neutrophil count was associated with an increase in C. difficile-associated diarrhea resolution (p = 0.007).

CONCLUSION: Switch or combination therapy was associated with a prolonged time to C. difficile-associated diarrhea resolution. The decision to use switch or combination therapy may represent a surrogate marker for more severe disease and need for therapy escalation. It is unknown if initial therapy with oral vancomycin would provide better outcomes as this could not be assessed.