Biomaterial Database

Standardization of the prothrombin time in oral anticoagulant control. 1985

A M van den Besselaar

The establishment of International Reference Preparations for thromboplastin together with a recommended methodology for use has permitted the definition of a universal scale for intensity of oral anticoagulation. This scale is called International Normalized Ratio (INR). INRs can be calculated by using calibrated thromboplastin/instrument systems. A calibration model has been developed together with statistical methods to test this model. The imprecision of calculated INRs has been estimated using information from international collaborative studies and proficiency testing programs. Normalized prothrombin times obtained with calibrated thromboplastin/instrument systems have been shown to provide safe patient care in clinical practice. The development of control plasmas with assigned INR equivalents will complete the standardization system. The INR scale will facilitate the process of consensus-making with respect to optimal therapeutic ranges for anticoagulant intensity. Finally, it will improve the continuity of anticoagulant control of travelling patients.

UI	MeSH Term	Description	Entries
D011517	Prothrombin Time	Clotting time of PLASMA recalcified in the presence of excess TISSUE THROMBOPLASTIN. Factors measured are FIBRINOGEN; PROTHROMBIN; FACTOR V; FACTOR VII; and FACTOR X. It is used for monitoring anticoagulant therapy with COUMARINS.	Quick Test,Russell's Viper Venom Time,Thrombotest,Russell Viper Venom Time,Russells Viper Venom Time,Prothrombin Times,Test, Quick,Time, Prothrombin,Times, Prothrombin
D012015	Reference Standards	A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.	Standard Preparations,Standards, Reference,Preparations, Standard,Standardization,Standards,Preparation, Standard,Reference Standard,Standard Preparation,Standard, Reference
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000284	Administration, Oral	The giving of drugs, chemicals, or other substances by mouth.	Drug Administration, Oral,Administration, Oral Drug,Oral Administration,Oral Drug Administration,Administrations, Oral,Administrations, Oral Drug,Drug Administrations, Oral,Oral Administrations,Oral Drug Administrations
D000925	Anticoagulants	Agents that prevent BLOOD CLOTTING.	Anticoagulant Agent,Anticoagulant Drug,Anticoagulant,Anticoagulant Agents,Anticoagulant Drugs,Anticoagulation Agents,Indirect Thrombin Inhibitors,Agent, Anticoagulant,Agents, Anticoagulant,Agents, Anticoagulation,Drug, Anticoagulant,Drugs, Anticoagulant,Inhibitors, Indirect Thrombin,Thrombin Inhibitors, Indirect
D013925	Thromboplastin	Constituent composed of protein and phospholipid that is widely distributed in many tissues. It serves as a cofactor with factor VIIa to activate factor X in the extrinsic pathway of blood coagulation.	Antigens, CD142,CD142 Antigens,Coagulation Factor III,Factor III,Tissue Factor,Tissue Thromboplastin,Blood Coagulation Factor III,Coagulin,Glomerular Procoagulant Activity,Prothrombinase,Tissue Factor Procoagulant,Urothromboplastin,Activity, Glomerular Procoagulant,Factor III, Coagulation,Procoagulant Activity, Glomerular,Procoagulant, Tissue Factor,Thromboplastin, Tissue