Vancomycin vs metronidazole use for the treatment of Clostridioides difficile infection in a tertiary care hospital in Saudi Arabia

BACKGROUND: The 2017 Infectious Diseases Society of America (IDSA) Clostridioides difficile infection (CDI) guidelines recommendation for oral vancomycin as preferred treatment was based on studies conducted in North America, Australia, and Europe. According to recent published data, metronidazole remains a reasonable option. No studies have been conducted in Saudi Arabia to compare prescribing patterns before and after the release of the guidelines. Due to low CDI burden in Saudi Arabia, the aim is to assess the effectiveness and outcomes of vancomycin vs metronidazole treatment options. METHODS: This was a retrospective cohort study conducted in a tertiary care hospital in Jeddah which was approved by the Institutional Review Board (IRB 2020–53). Data was collected from January 2017 to April 2020. Eligible patients were adults (>18 years old) diagnosed with CDI who either received oral metronidazole (500 mg 3 times daily) or oral vancomycin (125–500 mg 4 times daily). Patients who received a combination of treatment or who were diagnosed with fulminant CDI were excluded. Demographic data were collected. The primary outcome was to assess treatment response to initial therapy with oral metronidazole versus oral vancomycin. Secondary outcomes included assessing early treatment response, time to discharge after diagnosis, proportion of patients with a positive VRE surveillance culture within 6 months of diagnosis, 30-day recurrence and 30-day all-cause mortality. Chi-square or Fisher's exact test were used to examine differences in categorical variables while student t-test or Mann–Whitney test, were used to examine differences in continuous variables. P value < 0.05 was considered as significant. RESULTS: A total of 166 patients were included in the analysis. Demographic characteristics were not significantly different between the two groups. There was no difference in treatment response between vancomycin and metronidazole (96.4 % versus 94.3 %, p = 0.682). However, compared with metronidazole, vancomycin treatment was significantly associated with better early response (94.0 % versus 77.8 %, p = 0.008). Other outcomes were not significantly different between the two drug groups for time to discharge after diagnosis (P = 0.522), 30-day recurrence (P > 0.99) and 30-day all-cause mortality (P = 0.782). Of note, the vancomycin versus metronidazole use before the 2017 IDSA guidelines (26 % versus 74 %) was completely reversed after the release of the guidelines (83.3 % versus 16.7 %), p < 0.001). CONCLUSION: The results of this study demonstrate that vancomycin and metronidazole have comparable outcomes in regards to treatment response for non-fulminant CDI. The study also reveals the high and quick impact of international guidelines on local prescription patterns. Further studies are needed in Saudi Arabia to guide the treatment of CDI.