Effect of oral vancomycin dose on outcomes in patients with Clostridioides difficile infection.

Abstract Background Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality. Oral vancomycin is a cornerstone of CDI treatment, but dosing strategies in clinical practice may differ from guideline recommendations. The purpose of this study is to determine differences in outcomes between patients treated with standard (125 mg QID) and high dose (≥ 250 mg QID) oral vancomycin. Methods This dual-center study evaluated adult patients admitted between 01/2013 and 07/2017. Patients were included if they had a positive C. difficile toxin PCR, symptomatic infection, and received ≥48 hours of oral vancomycin. Disease severity was characterized using a variety of classifiers including guideline definitions. The primary outcome was 90-day CDI recurrence; secondary outcomes included clinical failure, in hospital mortality and 90-day readmission. Inverse probability of treatment weighting (IPTW) was conducted to balance differences between groups. Results A total of 535 patients were included; 261 received standard and 274 received high dose. Baseline demographics were similar between groups, except that patients receiving high dose were more likely to have more severe disease and be admitted to the intensive care unit. Few patients had fulminant disease (14.4%). No differences in recurrence (OR, 1.52; 95%CI, 0.82-2.84; p=0.186), clinical failure (OR, 0.64; 95%CI, 0.328-1.26; p=0.197), mortality (OR, 1.44; 95%CI, 0.78-2.66), or readmission (OR, 1.03, 95%CI, 0.70-1.51) were identified between standard and high dose patients in the IPTW analyses. Conclusion No differences in recurrence, mortality, or readmission were identified between standard and high dose vancomycin for the treatment of CDI not requiring surgery.