The Japanese guidelines for the management of Clostridioides difficile infection (CDI) recommend metronidazole (MNZ) for non-severe cases and vancomycin (VCM) for severe cases. Here, we investigated the use of CDI antimicrobials and evaluated their clinical efficacy in four severity classifications and the validity of these classifications. A retrospective chart review was conducted on 137 inpatients with an initial positive C. difficile toxin test and initiation of CDI antimicrobials between April 2015 and March 2019. For the clinical efficacy analysis of the CDI antimicrobials and validation of the severity classifications, patients treated with VCM or oral MNZ were included. The endpoints were CDI recurrence rate, 30-day mortality rate, and diarrhea cure rate. No significant differences were found between the VCM and oral MNZ groups regarding 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 the severity. Treatment with oral MNZ for non-severe cases was promising, confirming the usefulness of treatment according to Japanese guidelines. Further investigation of the clinical efficacy of oral MNZ in patients with first-episode CDI and evaluation of the preferable severity classification are warranted.

日本艰难梭菌感染 (CDI)治疗指南建议对非重症病例使用甲硝唑 (MNZ)，对重症病例使用万古霉素 (VCM)。在这里，我们研究了 CDI 抗菌药物的使用，并评估了它们在四种严重程度分类中的临床疗效以及这些分类的有效性。对 2015 年 4 月至 2019 年 3 月期间 137 名初始艰难梭菌毒素检测呈阳性并开始使用 CDI 抗菌药物的住院患者进行了回顾性图表审查。为了 CDI 抗菌药物的临床疗效分析和严重程度分类的验证，接受 VCM 治疗的患者或口服 MNZ 也包括在内。终点为 CDI 复发率、30 天死亡率和腹泻治愈率。 VCM 组和口服 MNZ 组之间在 CDI 复发率（10.4% vs. 12.7%， p = 0.707）、30 天死亡率（12.5% vs. 5.6%，p = 0.162）和腹泻方面没有发现显着差异。治愈率（61.9% vs. 72.7%，p = 0.238），无论严重程度如何。对于非严重病例，口服 MNZ 治疗是有希望的，根据日本指南证实了治疗的有效性。有必要进一步研究口服 MNZ 对首发 CDI 患者的临床疗效并评估优选的严重程度分类。