Background: Oral
vancomycin is a first line treatment for an initial episode of
Clostridioides difficile infection. However, the comparative efficacy of different dosing regimens is lacking evidence in the current literature. Methods: We searched PubMed, Embase, Cochrane Library, and ClinicalTrials.gov. from inception to May 2019. Only articles published in English are reviewed. This meta-analysis compares the effects of low dose oral
vancomycin (<2 g per day) versus high dose
vancomycin (2 g per day) for treatment of initial
Clostridioides difficile infection. Results: One randomized controlled trial and two retrospective cohort studies are included. A total of 137 patients are identified, 53 of which were treated with low dose oral
vancomycin (39%) and 84 with high dose oral
vancomycin (61%). There is no significant reduction in recurrence rates with high dose
vancomycin compared to low dose
vancomycin for treating initial episodes of non-fulminant
Clostridioides difficile infection ((odds ratio (OR) 2.058, 95%, confidence interval (CI): 0.653 to 6.489). Conclusions: Based on limited data in the literature, low dose
vancomycin is no different than high dose
vancomycin for treatment of an initial episode of
Clostridioides difficile infection in terms of recurrence rate. Additional large clinical trials comparing the different dosages of
vancomycin in initial
Clostridioides difficile infection are warranted.