title: Warfarin anticoagulation: difficulties in interpretation of the prothrombin time.
abstract: Studies of the prothrombin time in normals and patients receiving warfarin therapy revealed a marked shortening of the prothrombin time when the blood was collected in any type of collection tube other than a polypropylene tube. This shortening of the prothrombin time in patients receiving coumadin therapy was time and temperature dependent. This in-vitro shortening of the prothrombin time could lead to serious clinical errors involving dosage of warfarin derivatives to be administered to patients.
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001800:Blood Specimen Collection / Q000379:methods*; D005898:Glass; D006801:Humans; D011126:Polypropylenes; D011517:Prothrombin Time; D013696:Temperature; D013997:Time Factors; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D011126:Polypropylenes; D014859:Warfarin