When you start a patient on Warfarin (i.e after a PE); there will be an overlap of administration of Warfarin and LMWH/ UFH for typically 5 days with a goal INR of 2-3. This is referred to as “Bridging“.

WHY? Warfarin introduces a temporary hypercoagulable stage during the first 36 hours. Protein C and Protein S (anti-coagulation factors) are vitamin K-dependent plasma proteins. Levels of these anti-coagulation factors drop faster than the pro-coagulation factors (10,9,7,2) we attempt to block with Warfarin. Therefore, bridging is used to counteract this transient pro-clotting state.


  1. Esmon CT, Vigano-D’Angelo S, D’Angelo A, Comp PC. Anticoagulation proteins C and S. Adv Exp Med Biol. 1987;214:47-54.
  2. Protein C / Protein S anticoagulant pathway. Anticoagulant pathway. Jeremy Parsons, M.D. (c) 2002-2016, PathologyOutlines.com, Inc.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

This site uses Akismet to reduce spam. Learn how your comment data is processed.