Vitamin K-dependent coagulopathy following cephazolin therapy: diagnostic and causal insights from a post-operative MSSA endocarditis case

Background: Cephalosporin-associated coagulopathy is a rare adverse effect, particularly with agents containing methyl-tetrazole or methyl-thiadiazole side chains (e.g., cephazolin). Mechanisms include reduced intestinal vitamin K production, and inhibition of vitamin K epoxide reductase, impairing γ-carboxylation of vitamin K-dependent factors.