Initial Oral Vancomycin vs. Oral Vancomycin After Metronidazole for Severe Clostridium difficile Infection

BACKGROUND: Treatment of severe Clostridium difficile infection (CDI) with oral vancomycin (oVAN) is known to be superior to treatment with metronidazole. However, previous studies have not evaluated the impact on patients when oVAN therapy is delayed after diagnosis or suspicion of severe CDI. METHODS: This was a single-center, retrospective study of adult patients who were diagnosed with severe CDI as defined by a white blood cell (WBC) count greater than 15,000 cells/mm(3). The primary outcome was in-hospital mortality between patients treated initially with oVAN vs. delayed oVAN after metronidazole. Secondary outcomes included clinical cure by day 10, post-infection length of hospitalization, the time to resolution of leukocytosis and renal function at the end of treatment. Leukocytosis was defined as a WBC greater than 12,000 cells/mm(3). Patients were excluded if they received oVAN for a previous episode of CDI, were receiving treatment for a concurrent infection, were receiving high-dose steroids, or received metronidazole or oVAN within 5 days preceding CDI diagnosis. RESULTS: A total of 121 patients were included. Overall, 49% of patients were female and the median age was 67 years old. 101 patients comprised the initial oVAN group, while 20 patients comprised the delayed oVAN group. Baseline demographics did not differ significantly between groups other than the time to initiation of oVAN (0.33 vs. 3.18 days, P < 0.001). There was no significant difference in in-hospital mortality for patients in the initial oVAN treatment group compared with those who had delayed oVAN therapy (5% vs. 15%, P = 0.13). Patients who received oVAN initially experienced a higher rate of clinical cure by day 10 (49.5% vs. 20%, P = 0.02), a shorter median post-infection length of hospitalization (7 days vs. 13 days, P < 0.001), a 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 oVAN as their initial treatment for severe CDI have improved clinical outcomes compared with those initially treated with metronidazole. DISCLOSURES: All authors: No reported disclosures.