Cefmetazole-Induced Vitamin K-Dependent Coagulopathy Associated with Life-Threatening Gastrointestinal Bleeding in a Critically Ill Older Patient: A Case Report.

introductionCefmetazole (CMZ) is frequently used in abdominal surgery and critical care settings. Although cephalosporins containing an N-methyl-tetrazole-thiol (NMTT) side chain interfere with vitamin K metabolism, life-threatening clinically significant bleeding associated with CMZ-induced coagulopathy has rarely been reported. CASE PRESENTATION: A 78-year-old woman with severe infections developed severe vitamin K-dependent coagulopathy during CMZ therapy. She subsequently experienced worsening upper gastrointestinal bleeding complicated by hemorrhagic shock in the setting of severe vitamin K-dependent coagulopathy despite preserved platelet counts and fibrinogen levels. Coagulation abnormalities rapidly improved following vitamin K administration, and no recurrence was observed after CMZ discontinuation.

conclusionsThis case report highlights CMZ-induced vitamin K-dependent coagulopathy as a rare but life-threatening adverse event in critically ill older patients. Coagulation parameters should be carefully monitored during CMZ therapy, particularly in high-risk patients.