Abstract
Patients with asymptomatic elevated International Normalized Ratios (INRs) are commonly seen in practice, but there is no consensus on how best to manage this condition. Evidence suggests that low-dose (1 mg to 2.5 mg) oral vitamin K restores patients to INR values associated with a lower risk of hemorrhage more rapidly than discontinuing warfarin alone. Vitamin K therapy remains under-utilized despite evidence for its effectiveness. The studies discussed in this review suggest that vitamin K1 should be considered if rapid reductions in the INR are desired. For most rapid corrections in the INR, vitamin K should be administered by the intravenous route since it begins to reduce the INR within 8 hours. Subcutaneous vitamin K is relatively ineffective, and its use may be associated with over-correction of the INR.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
McMahon DA, Smith DM, Carey MA, Zhou XH. Risk of major hemorrhage for outpatients treatment with warfarin. Journal Gen Intern Med 1998;13:311-316.
Samsa GP, Matchar DB, Goldstein LB, et al. Quality of anticoagulation management among patients with atrial fibrillation: Results of a review of medical records from 2 communities. Arch Intern Med 2000;160:967-973.
Oden A, Fahlen M. Oral anticoagulation and risk of death: A medical record linkage study. BMJ 2002;325(7372): 1073-1075.
Kearon C, Ginsberg JS, Kovacs MJ, et al. Low-intensity (INR 1.5-1.9) versus conventional-intensity (INR 2.0-3.0) anticoagulation for extended treatment of unprovoked VTE: A randomized double blind trial. Blood 2002;100:150a (Abs. 562).
Palareti G, Leali N, Coccheri S, et al. Bleeding complications of oral anticoagulant treatment: An inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy. Lancet 1996;348(9025):423-428.
Wilson SE, Douketis JD, Crowther MA. Treatment of warfarin-associated coagulopathy: A physician survey. Chest 2001;120:1972-1976.
Libby EN, Garcia DA. A survey of oral vitamin K use by anticoagulation clinics. Arch Intern Med 2002;162:1893- 1896.
Crowther MA, Douketis JD, Schnurr T, et al. Oral vitamin K lowers the international normalized ratio more rapidly than subcutaneous vitaminKin the treatment ofwarfarinassociated coagulopathy. A randomized, controlled trial.Ann Intern Med 2002;137:251-254.
Nee R, Doppenschmidt D, Donovan DJ, Andrews TC. Intravenous versus subcutaneous vitamin K1 in reversing excessive oral anticoagulation. American Journal of Cardiology 1999;83:286-288.
Raj G, Kumar R, McKinney WP. Time course of reversal of anticoagulant effect of warfarin by intravenous and subcutaneous phytonadione. Arch Intern Med 1999;159:2721-2724.
Watson HG, Baglin T, Laidlaw SL, Makris M, Preston FE. Acomparison of the efficacy and rate of response to oral and intravenous vitamin K in reversal of over-anticoagulation with warfarin. Br J Haematol 2001;115:145-149.
Crowther MA, Donovan D, Harrison L, McGinnis J, Ginsberg J. Low-dose oral vitamin K reliably reverses over-anticoagulation due to warfarin. Thrombosis and Haemostasis 1998;79:1116-1118.
Crowther MA, Julian J, Douketis JD, et al. Treatment of warfarin-associated coagulopathy with oral vitamin K: A randomized clinical trial. Lancet 2000;356:1551-1553.
Duong TM, Plowman BK, Morreale AP, Janetzky K. Retrospective and prospective analyses of the treatment of overanticoagulated patients. Pharmacotherapy 1998;18:1264-1270.
Patel RJ, Witt DM, Saseen JJ, Tillman DJ, Wilkinson DS. Randomized, placebo-controlled trial of oral phytonadione for excessive anticoagulation. Pharmacotherapy 2000;20:1159-1166.
Pendry K, Bhavnani M, Shwe K. The use of oral vitamin K for reversal of over-warfarinization. Br J Haematol 2001; 113:839-840.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Crowther, M.A., Wilson, S. Vitamin K for the Treatment of Asymptomatic Coagulopathy Associated with Oral Anticoagulant Therapy. J Thromb Thrombolysis 16, 69–72 (2003). https://doi.org/10.1023/B:THRO.0000014597.87575.e9
Issue Date:
DOI: https://doi.org/10.1023/B:THRO.0000014597.87575.e9