Cefmetazole-Induced Coagulopathy in a Patient With Vitamin K Deficiency: A Case Report With Literature Review

Cefmetazole (CMZ), a cephamycin antibiotic containing an N-methyltetrazolethiol (NMTT) group, is known to interfere with vitamin K metabolism, potentially causing coagulation disorders. We present the case of a 78-year-old man with chronic kidney disease who developed a coagulation disorder during CMZ administration, exacerbated by chronic vitamin K deficiency from prolonged enteral nutrition. In the context of chronic vitamin K deficiency precipitated by prolonged enteral nutrition for renal disease, the administration of CMZ-a medication that disrupts vitamin K metabolism and reduces coagulation factor activity through a mechanism similar to that of warfarin-led to abnormal blood coagulation test results. Clinical improvement followed the discontinuation of CMZ and vitamin K supplementation. This report highlights the importance of monitoring vitamin K status in patients receiving CMZ, particularly those with risk factors for deficiency, and reviews the relevant literature to highlight the mechanisms and management strategies for such complications.