Impact of Delayed Oral Vancomycin for Severe Clostridium difficile Infection

Background: Treatment of severe Clostridium difficile infection (CDI) with oral vancomycin (VAN) is known to be superior to treatment with metronidazole (MDZ). However, previous studies have not evaluated the impact on patients when oral VAN therapy is delayed after diagnosis of severe CDI. Materials and Methods: This was a single-center, retrospective study of adult patients who were diagnosed with severe CDI. The objective was to compare clinical outcomes for patients treated initially with oral VAN versus patients receiving delayed oral VAN after at least 48 hours of initial treatment with MDZ. The primary outcome was all-cause in-hospital mortality. Results: There were 101 patients who comprised the initial oral VAN group, while 20 patients comprised the delayed oral VAN group. There was no significant difference in all-cause in-hospital mortality for patients in the initial oral VAN treatment group compared to those who had delayed oral VAN therapy (4.95% vs 15.00%, P = 0.13). Patients who were initially treated with oral VAN experienced a significantly higher rate of clinical cure (49.50% vs 20.00%, P = 0.02), shorter median postinfection length of hospitalization (7.0 days vs 13.0 days, P < 0.001), shorter median time to resolution of leukocytosis (3.9 days vs 10.4 days, P = 0.01), and were less likely to have an end of treatment serum creatinine greater than 1.5 times their baseline (8.7% vs 29.4%, P = 0.03). Conclusion: Patients who receive oral VAN as their initial treatment for severe CDI experience improved clinical outcomes compared to patients receiving delayed oral VAN after being initially treated with MDZ.