Oral anticoagulation therapy (OAT)is one of the
most common medication regimens. The narrow
therapeutic window means risk of bleeding or
thrombosis. The prothrombin time test (PT) was
introduced by professor Armand Quick in 1935 more
than 70 years ago to monitor this therapy. Over
twenty years later professor Paul Owren developed a
new PT method (combined thromboplastin reagent) to
overcome the drawbacks of the Quick PT method. Both
methods are today accepted for anticoagulant therapy
control.The WHO recommendation in 1985 for the use
of INR aims to harmonize PT results for OAT
regardless of the reagent, instrument or method
used.Warfarin (or Coumarin) inhibits the synthesis
of K-vitamin dependent coagulation factors in the
liver,but at the same time blocked inactive
coagulation factors are formed.Quick and Owren PT
methods measure the sum of inhibition and active
coagulation factors in the patient plasma.
The new generation PT method measures active
coagulation factors and inhibition separately. The
new PT method develops anticoagulation therapy based
on active coagulation factors in vivo and improves
INR harmonization.
The Progress of Prothrombin Time to a New Generation Method for INR; .: The Progress of Prothrombin Time Method