RT Journal
A1 QUICK AJ
T1 Control of anticoagulant therapy: Progress and problems blems
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 1963
FD February 1
VO 111
IS 2
SP 234
OP 239
DO 10.1001/archinte.1963.03620260094017
UL http://dx.doi.org/10.1001/archinte.1963.03620260094017
AB The one-stage prothrombin time was intimately associated with the development of oral anticoagulant therapy. As Link has stated: "Through it the hemorrhagic agent of spoiled sweet clover hay was laid out on the table in pure crystalline form." Furthermore, without this simple test, the introduction of bishydroxycoumarin (Dicumarol) into therapy would have been exceedingly hazardous. In the early studies,1 the increased prothrombin time was regarded as a depression solely of prothrombin, and this assumption was supported by the finding that the 2-stage method of Warner, Brinkhous, and Smith2 likewise showed a marked decrease of prothrombin when bishydroxycoumarin was given. The discoveries of Factor V (labile factor) in 1943,3 and of a serum agent (Factor VII) a few years later,4,5 made it evident that neither method measured prothrombin specifically. It was the one-stage test, however, which has received most of the criticism and been subjected to numerous