Blood Clotting Test for Anticoagulants

Prothrombin time is most commonly measured using the blood plasma. Chemicals like calcium and tissue factor are added to the plasma sample and then the time is noted when the plasma clots. To analyze if a blood thinner agent or an anticoagulant drug like Coumadin is working, the drug is mixed in blood plasma or the patient is instructed to take the medicine before the test. The anticoagulant drug, when properly acting, causes a delay in clotting of blood. Choose a location to see hospital-reported price summaries. This page does not show national, sample, or aggregate pricing.