The progress of prothrombin time measurement

Abstract

Warfarin is the most widely used medicine for oral anticoagulant therapy (OAT). It inhibits the synthesis of coagulation factors II, VII, IX, and X in the liver and results in the pro-duction of inactive or partially active versions of these factors. Inactive coagulation factors interfere with prothrombin time measurement (Quick and Owren PT) measuring the sum of coagulation activity and inhibition. The nar-row therapeutic range here involves a danger of serious complications and the risk of bleed-ing or thrombosis. The new-generation PT method can measure coagulation activity and inhibition separately. This new technique pro-motes patient care and anticoagulant medica-tion (warfarin, dicoumarol) based on coagula-tion activity in vivo. Both therapy and laborato-ry controls should be unquestionably accurate and based solely on in vivo coagulation activi-ty. Inactive coagulation factors (inhibition) render measurement, calibration, and harmo-nization. The use of the new-generation PT method based on measurement of coagulation activity in vivo could develop vitamin K antag-onist (VKA) therapy for the marked benefit of patients.