Clinical Efficacy of Therapeutic Agents for Clostridioides difficile Infection Based on Four Severity Classifications.

Japanese guidelines recommend metronidazole (MNZ) and vancomycin (VCM) for non-severe and severe cases of Clostridioides difficile infection (CDI), respectively. In the present study, we investigated the use of CDI antimicrobials and evaluated their clinical efficacy and validity using four severity classifications. A retrospective chart review was conducted using the data of 137 inpatients with initially positive C. difficile toxin test results and the initiation of CDI antimicrobials between April 2015 and March 2019. Patients treated with VCM or oral MNZ were included for clinical efficacy analysis of CDI antimicrobials and validation of severity classifications. The endpoints were CDI recurrence, 30-day mortality, and diarrhea cure rates. No significant differences were found between the VCM and oral MNZ groups in the CDI recurrence rate (10.4% vs. 12.7%, P = 0.707), 30-day mortality rate (12.5% vs. 5.6%, P = 0.162), and diarrhea cure rate (61.9% vs. 72.7%, P = 0.238), regardless of severity. Treatment with oral MNZ for non-severe cases was promising, confirming its usefulness according to Japanese guidelines. Further investigation of the clinical efficacy of oral MNZ in patients with first-episode CDI and evaluation of the preferred severity classification are warranted.