Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Therapeutic Index01:13

Therapeutic Index

The therapeutic index of a drug is a key parameter in pharmacology that quantifies the relative safety of a drug by calculating the ratio between the dose that causes toxicity in half the population (50%) to the dose that proves to be effective for half the population (50%). It provides a spectrum of doses for a particular drug ranging from effective to potentially toxic. To illustrate, consider an anticoagulant agent like warfarin. It possesses a narrow window within its therapeutic index to...
Anticoagulant Drugs: Low-Molecular-Weight Heparins01:30

Anticoagulant Drugs: Low-Molecular-Weight Heparins

Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants01:18

Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants

Oral anticoagulants are vital tools in preventing and treating blood clotting disorders. This diverse class of medications can be categorized as vitamin K antagonists, exemplified by warfarin, and direct thrombin inhibitors (DTIs), such as dabigatran, as well as factor Xa inhibitors, including rivaroxaban.
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors01:20

Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors

Antiplatelet drugs emerge as frontline defenders against the insidious threat of thromboembolic diseases, where abnormal clots obstruct vital blood vessels. These drugs stand as bulwarks, inhibiting platelet aggregation and clot formation, thereby mitigating the risk of life-threatening conditions like myocardial infarction, coronary artery disease, and thrombotic strokes.
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Venous Thrombosis III: Interprofessional Care01:29

Venous Thrombosis III: Interprofessional Care

Venous thrombosis requires effective prevention and treatment strategies to improve patient outcomes and reduce potential complications.Prevention StrategiesHealthcare providers must prioritize preventing venous thromboembolism (VTE) for all adult patients upon admission. Interventions depend on bleeding and thrombosis risk, medical history, current medications, diagnoses, planned procedures, and patient preferences. Patients on bed rest should change positions every two hours and, if not...
Venous Thrombosis IV: Nursing Management01:30

Venous Thrombosis IV: Nursing Management

Nursing management begins with a thorough assessment of the patient's health history. Key factors include trauma to veins, peripherally inserted central catheters, varicose veins, recent pregnancy or childbirth, surgery, bacteremia, prolonged bed rest, atrial fibrillation, COPD, heart failure, cancer, coagulation disorders, myocardial infarction, spinal cord injury, stroke, prolonged travel, recent bone fractures, and dehydration. Review medication intake, particularly oral contraceptives,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Thrombin generation and cell-dependent hypercoagulability in sickle cell disease.

Journal of thrombosis and haemostasis : JTH·2016
Same author

Effects of an acidic environment on coagulation dynamics.

Journal of thrombosis and haemostasis : JTH·2016
Same author

Activation, activity and inactivation of factor VIII in factor VIII products.

Haemophilia : the official journal of the World Federation of Hemophilia·2016
Same author

TACTIC: Trans-Agency Consortium for Trauma-Induced Coagulopathy.

Journal of thrombosis and haemostasis : JTH·2015
Same author

The effect of corn trypsin inhibitor and inhibiting antibodies for FXIa and FXIIa on coagulation of plasma and whole blood: comment.

Journal of thrombosis and haemostasis : JTH·2014
Same author

Why does aspirin decrease the risk of venous thromboembolism? On old and novel antithrombotic effects of acetyl salicylic acid.

Journal of thrombosis and haemostasis : JTH·2014

Related Experiment Video

Updated: Jun 28, 2026

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
23:33

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Published on: February 28, 2012

Oral anticoagulation thresholds.

K E Brummel1, S G Paradis, R F Branda

  • 1Department of Biochemistry, Given Building, Health Science Complex University of Vermont, College of Medicine, Burlington, USA.

Circulation
|November 7, 2001
PubMed
Summary
This summary is machine-generated.

Warfarin therapy shows significant variability in blood clotting times and thrombin-antithrombin III (TAT) profiles, even with similar International Normalized Ratios (INRs). This suggests anticoagulation control may be less secure than anticipated, with individual responses impacting bleeding and clotting risks.

More Related Videos

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
28:13

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Published on: February 26, 2013

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
11:17

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood

Published on: October 12, 2012

Related Experiment Videos

Last Updated: Jun 28, 2026

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
23:33

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Published on: February 28, 2012

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
28:13

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Published on: February 26, 2013

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
11:17

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood

Published on: October 12, 2012

Area of Science:

  • Hematology
  • Pharmacology
  • Clinical Medicine

Background:

  • Monitoring oral anticoagulation is crucial for preventing bleeding and thrombosis.
  • Warfarin therapy requires careful management to maintain therapeutic efficacy.
  • Individual patient responses to anticoagulation can vary significantly.

Purpose of the Study:

  • To investigate whole-blood coagulation in patients on warfarin therapy with similar International Normalized Ratios (INRs).
  • To assess the variability in coagulation profiles and thrombin-antithrombin III (TAT) generation.
  • To explore the relationship between INR, coagulation parameters, and factor VIII levels.

Main Methods:

  • Studied tissue factor-induced whole-blood coagulation in 8 male subjects on warfarin (group W) and one individual multiple times (subject A).
  • Measured clot times, thrombin-antithrombin III (TAT) formation rates and levels, platelet activation, and fibrinopeptide A generation.
  • Assessed factor VIII levels and correlated them with years of warfarin therapy.

Main Results:

  • Subjects with similar INRs exhibited wide variations in clot times (6.2-23 min) and TAT profiles.
  • Normal controls had shorter clot times (5.7±0.3 min) and higher TAT levels (742±91 nmol/L).
  • Factor VIII levels were significantly increased in group W (204±34.4%) compared to controls (149.4±37.4%), correlating with duration of warfarin therapy (r=0.78, P=0.01).

Conclusions:

  • Anticoagulation control to a set INR therapeutic range may be less secure than assumed.
  • Significant individual variability in tissue factor coagulation response exists among patients with similar INRs.
  • This variability suggests differing risks of hemorrhage and thrombosis, potentially linked to underlying vascular anomalies and compensatory mechanisms like increased Factor VIII.