A Simple Rule for Control of Anticoagulant Therapy

Since anticoagulants of the coumarin type have been reported to decrease at least four coagulation factors, there is doubt as to which test to use in the control of anticoagulant therapy. Early extensive experience showed the Quick prothrombin time alone to suffice for laboratory control of therapy with coumarin-type anticoagulants. Subsequent failures with this test are explained by the use of unsatisfactory thromboplastin.