Standardization of the Therapeutic Range for Oral Anticoagulants Based on Standard Reference Plasmas

Standardization of therapy with oral anticoagulants can be achieved by measuring the performance of various thromboplastins against standard reference plasmas. The reference plasmas are assayed with regard to those coagulation factors (II, VII, and X) affected by oral anticoagulants and measured by the one-stage prothrombin time. Given these common points of reference, and in the absence of an acceptable mathematic comparison among various thromboplastins, a suggestion is made for the therapeutic range to be achieved for each of the thromboplastins studied. The suggested ranges are equivalent to each other and to a range of 10 to 20% reduction in the coagulation factors affected by oral anticoagulants.