Update on Anticoagulants Monitoring Practice


The direct oral anticoagulants (DOACs) currently include one direct thrombin inhibitor (dabigatran) and three direct factor Xa inhibitors (rivaroxaban, apixaban, edoxaban) which have various approvals for treatment and prevention of thromboembolic events, As opposed to more traditional anticoagulants, DOACs do not require routine laboratory monitoring due to predictable pharmacodynamics, pharmacokinetics, and wide therapeutic windows. DOACs have variable effects on routine coagulation tests, such as PT/INR and aPTT, depending on the specific drug, drug concentration in the specimen, patient and specific indication and dose, and assay, including the specific reagent used. Understanding DOAC effects on locally available routine coagulation tests may allow qualitative use of routine tests in emergent clinical situations but these tests do not reliably determine drug concentration. Although quantitative tests for the new drugs exist, they are not widely available, usually do not have turnaround times that would allow use in urgent clinical situations, and none are FDA approved. Aside from the issues with monitoring DOACs, it is also important for physicians and laboratory professionals to know that DOACs can interfere with specialized coagulation testing, such as thrombophilia testing, and that this testing should generally be avoided when DOACs are present.

Originally presented on February 6, 2017 in Park City, Utah.

Lecture Presenter

Kristi J. Smock, MD

Kristi J. Smock, MD

Associate Professor of Pathology
University of Utah School of Medicine
Medical Director, Hemostasis/Thrombosis Laboratory
ARUP Laboratories

Dr. Smock is an associate professor of pathology at the University of Utah School of Medicine. She received her MD from the University of Utah and completed residency training in anatomic and clinical pathology and fellowship training in hematopathology at the University of Utah. She is actively involved in resident and fellow education and serves as associate residency program director. Dr. Smock is board certified in anatomic and clinical pathology, with subspecialty certification in hematology. She is an active member of several professional organizations and national committees related to hemostasis and thrombosis, and serves on the College of American Pathologists Coagulation Resource Committee. Dr. Smock’s research interests include heparin-induced thrombocytopenia and lupus anticoagulants.


After this presentation, participants will be able to:

  • Review new direct oral anticoagulants (DOACs), mechanisms of action, and clinical uses
  • Understand the effects of DOACs on routine coagulation testing
  • Describe approaches to laboratory monitoring of DOACs
  • Discuss DOACs potential to interfere with specialized coagulation testing

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories