[Standardization of the thromboplastin time determination]

The results of our studies prove that today it is possible for manufacturers of thromboplastin preparations to follow the international recommendations for standardization of methods for prothrombin time determination. This is valid not only for the PT reagents for coagulometric techniques but also for those for photometric techniques. New manufacturing processes allow to produce sensitive thromboplastins which can be calibrated according to the recommendations of international standardization committees. Calibrated thromboplastins enable introduction of a common scale (INR) for the control of the intensity of the oral anticoagulation. The INR system improves the comparability of the therapeutical ranges recommended from different organizations and from manufacturers of thromboplastin, so that the continuity of the oral anticoagulant therapy of patients even in different countries will be decisively improved.