Therapeutic Range: Using the INR: Standardization of the Prothrombin Time (PT) with the International Normalized Ratio (INR) allows for uniform measurement of the anticoagulation status of patients on oral anticoagulants (Warfarin/Coumadin/Coumarin). The use of the INR has permitted development of effective recommendations for use of oral anticoagulants in a variety of clinical settings. Most published studies indicate that, in most cases, an INR of at least 2.0 is required for effective anticoagulation. The risk of bleeding increases with an increasing INR, and may increase dramatically above an INR of 4.5 - 5.0. Refer to Monitoring Oral Anticoagulant Therapy or contact laboratory [409-772-3314] for further recommendations.
Critical Values: INR > 4.5
Interfering Substances: Heparin above therapeutic ranges, afibrinogenemia or hypofibrinogenemia