title: Abnormal vitamin K metabolism in the presence of normal clotting factor activity in factory workers exposed to 4-hydroxycoumarins.
abstract: The case histories of two patients exposed to the novel anticoagulants brodifacoum and difenacoum are reported. Abnormal vitamin K1 metabolism, as indicated by elevated vitamin K1 2,3-epoxide plasma concentrations after i.v. administration of vitamin K1, could be detected for more than 18 months after exposure to the anticoagulants. There was a marked prolongation of prothrombin time (greater than 50 s) in both cases, at the time of exposure. However, subsequent haematological investigations (prothrombin time and vitamin K-dependent clotting factor activity) have been shown to be normal in both cases for at least 18 months. These cases confirm the long-acting nature of brodifacoum and difenacoum and present an apparent dissociation between the effect of coumarin anticoagulants on vitamin K1 metabolism and clotting factor activity.
mesh_terms: D015110:4-Hydroxycoumarins / Q000009:adverse effects* / Q000097:blood; D000328:Adult; D001778:Blood Coagulation Disorders / Q000139:chemically induced*; D001780:Blood Coagulation Tests; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000097:blood / Q000139:chemically induced*; D011517:Prothrombin Time; D010837:Vitamin K 1 / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*
chemical_list: D015110:4-Hydroxycoumarins; C016186:vitamin K1 oxide; D010837:Vitamin K 1; C013418:bromfenacoum; C012903:difenacoum