S1914 Comparing Outcomes of Clostridioides difficile Infection Treated with Low vs High Dose Oral Vancomycin for an Initial Episode in Patients With Ulcerative Colitis

Introduction: Patients with ulcerative colitis (UC) are estimated to have a nearly 5-fold increased risk of Clostridioides difficile infection (CDI) and frequently experience complications, including recurrent CDI (rCDI). Oral vancomycin (OV) is commonly used for an initial episode of CDI in UC patients; however, there are no guidelines regarding specific OV dosing regimens in this population. In this study, we sought to compare rates of rCDI and UC complications in UC patients treated with different doses of OV, either 125 mg or 250 mg, for their first infection. Methods: We utilized the TriNetX dataset to identify patients with UC, defined by the presence of at least one International Classification of Diseases-10 code for UC (K51). Patients were also required to have a recorded diagnosis of CDI, defined by the presence of International Classification of Diseases-10 code A04.72 or International Classification of Diseases-9 code 008.45, occurring any time following initial diagnosis of UC. Patients were also required to have an RxNorm code for oral vancomycin (11124), either 125 mg or 250 mg, within 5 days of initial CDI diagnosis. The cohorts were matched for age, sex, race, and use of immunosuppressants. rCDI was defined as the presence of either a positive stool NAAT or a coding specifically for rCDI (A04.71) occurring between 2 and 8 weeks after initial CDI. Secondary outcomes included colectomy rates and rates of either oral or intravenous (IV) corticosteroids at 3-12 months after initial CDI episode. Binary variables were analyzed using the Chi-Square test. Results: A total of 499 UC patients (mean age 50.6 ± 21.6 years, 55% women, 68% White race) were included in each group after matching. There was no significant difference in rates of rCDI between UC patients treated with OV 125 mg (n = 69) as compared to 250 mg (n = 77); (HR: 0.88; 95% CI, 0.636 – 1.219; P = 0.443). A secondary analysis demonstrated no difference between groups in the need for IV or oral corticosteroids between 3-12 months after the initial CDI. There were no colectomies performed in either group between 3-12 months after initial CDI. Conclusion: There was no difference in rates of rCDI, need for IV or oral corticosteroids, or colectomy in UC patients treated with either 125 mg or 250 mg OV for their initial CDI. OV remains a reasonable treatment option in UC patients with CDI. Future prospective studies that effectively account for escalations in antibiotic dosage and cases of non-response to initial treatments are essential to validate these findings.