Chest
Volume 133, Issue 6, Supplement, June 2008, Pages 160S-198S
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Antithrombotic and Thrombolytic Therapy, 8th ED: ACCP Guidelines
Pharmacology and Management of the Vitamin K Antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

https://doi.org/10.1378/chest.08-0670Get rights and content

This article concerning the pharmacokinetics and pharmacodynamics of vitamin K antagonists (VKAs) is part of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). It describes the antithrombotic effect of the VKAs, the monitoring of anticoagulation intensity, and the clinical applications of VKA therapy and provides specific management recommendations. Grade 1 recommendations are strong and indicate that the benefits do or do not outweigh the risks, burdens, and costs. Grade 2 recommendations suggest that the individual patient's values may lead to different choices. (For a full understanding of the grading, see the “Grades of Recommendation” chapter by Guyatt et al, CHEST 2008; 133:123S–131S.)

Among the key recommendations in this article are the following: for dosing of VKAs, we recommend the initiation of oral anticoagulation therapy, with doses between 5 mg and 10 mg for the first 1 or 2 days for most individuals, with subsequent dosing based on the international normalized ratio (INR) response (Grade 1B); we suggest against pharmacogenetic-based dosing until randomized data indicate that it is beneficial (Grade 2C); and in elderly and other patient subgroups who are debilitated or malnourished, we recommend a starting dose of ≤ 5 mg (Grade 1C). The article also includes several specific recommendations for the management of patients with nontherapeutic INRs, with INRs above the therapeutic range, and with bleeding whether the INR is therapeutic or elevated. For the use of vitamin K to reverse a mildly elevated INR, we recommend oral rather than subcutaneous administration (Grade 1A). For patients with life-threatening bleeding or intracranial hemorrhage, we recommend the use of prothrombin complex concentrates or recombinant factor VIIa to immediately reverse the INR (Grade 1C). For most patients who have a lupus inhibitor, we recommend a therapeutic target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. We recommend that physicians who manage oral anticoagulation therapy do so in a systematic and coordinated fashion, incorporating patient education, systematic INR testing, tracking, follow-up, and good patient communication of results and dose adjustments [Grade 1B]. In patients who are suitably selected and trained, patient self-testing or patient self-management of dosing are effective alternative treatment models that result in improved quality of anticoagulation management, with greater time in the therapeutic range and fewer adverse events. Patient self-monitoring or self-management, however, is a choice made by patients and physicians that depends on many factors. We suggest that such therapeutic management be implemented where suitable (Grade 2B).

Section snippets

Initiation and Maintenance Dosing

2.1.1. In patients beginning vitamin K antagonist (VKA) therapy, we recommend the initiation of oral anticoagulation with doses between 5 mg and 10 mg for the first 1 or 2 days for most individuals, with subsequent dosing based on the international normalized ratio (INR) response (Grade 1B). At the present time, for patients beginning VKA therapy without evidence from randomized trials, we suggest against the use of pharmacogenetic-based initial dosing to individualize warfarin dosing (Grade

CONFLICT OF INTEREST DISCLOSURES

Dr. Anselldiscloses that he has received consultant fees from Bristol-Myers Squibb, Roche Diagnostics, and International Technidyne Corporation. He is also on the speakers bureau for Roche Diagnostic Corporation and Sanofi-Aventis, and is the past president of the Anticoagulation Forum.

Dr. Hirshdiscloses that he has received partial support for writing two books, one on fondaparinux and one on low-molecular-weight heparin.

Dr. Jacobsondiscloses that he has received grant monies from the National

ACKNOWLEDGMENT

We wish to acknowledge the important assistance of Ann Wittkowsky, Pharm D, in developing these guidelines.

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