Severe Hypoprothrombinemia Associated With Vitamin K Deficiency During Prolonged Cefazolin Therapy in a Hemodialysis Patient

This report presents a case of a dialysis patient who developed severe hypoprothrombinemia associated with vitamin K deficiency during prolonged cefazolin (CEZ) therapy. A 73-year-old man undergoing maintenance hemodialysis for end-stage kidney disease due to diabetic nephropathy was hospitalized for purulent tenosynovitis of the right ankle and treated with CEZ. During hospitalization, he had persistent anorexia and experienced recurrent gastrointestinal bleeding. On a non-dialysis day, he developed a subcutaneous hematoma around the arteriovenous fistula. Despite the absence of anticoagulant use, marked prolongation of prothrombin time and activated partial thromboplastin time was observed. Laboratory findings showed reduced activity of vitamin K-dependent coagulation factors and a markedly elevated protein induced by vitamin K absence or antagonist-II level, indicating vitamin K deficiency. Intravenous vitamin K administration and switching the antibiotic from CEZ to ampicillin resulted in rapid improvement of hypoprothrombinemia. This case suggests that in hemodialysis patients, hypoprothrombinemia may develop through cumulative effects of inadequate nutritional intake, prolonged antibiotic exposure, and bleeding-related coagulation factor depletion. Even in the absence of anticoagulant therapy, careful coagulation monitoring is warranted in hospitalized hemodialysis patients receiving prolonged antibiotic treatment.