Abstract
Oral anticoagulation with warfarin is a widely used form of treatment for an increasing number of medical conditions. Nevertheless, appropriate therapeutic monitoring and dosage readjustments should be carried out in order to ensure its safety and efficacy. Although prothrombin time (usually expressed as International normalized ratio [INR]) is the most common warfarin response marker, clotting factors (namely factors II and X) are also indicated as alternative anticoagulant effect markers. In this paper, we examine the relationship between these warfarin response markers using information obtained from eighty 80 patients undergoing long-term warfarin therapy. Within the usual INR therapeutic range (2.0–3.5), a moderate inverse correlation between INR and both clotting factors II and X was observed. However, for INR values above 3.5, a non-proportional relationship were found between INR and both response markers. Therefore, it can be concluded that below critical clotting factor concentrations (20.6% and 15.6% of factors II and X activity, respectively), time required for clot formation becomes non-proportional and haemostasis will be jeopardised.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
