Matthew Rondina, MD
In patients with warfarin-associated coagulopathy, does low-dose oral vitamin K reduce risk for bleeding?
Randomized placebo-controlled trial. ClinicalTrials.gov NCT00143715.
Blinded (patients, clinicians, research coordinators, and outcome adjudicators).*
14 anticoagulant centers in the USA, Canada, and Italy.
724 outpatients ≥ 18 years of age (mean age 69 y, 53% men) who attended clinic for routine international normalized ratio (INR) assessment, were receiving warfarin with a target INR of 2.0 to 3.5, were not bleeding, and had an INR between 4.5 and 10.0 in the past 24 hours. Exclusion criteria included life expectancy < 10 days, indication for acute normalization of INR, scheduled discontinuation of warfarin, known bleeding disorder, recent major bleeding, inability to take oral medication or undergo follow-up, contraindication to vitamin K, severe liver disease, thrombolytic therapy within 48 hours, and platelet count < 50 x 109 cells/L.
Single-dose oral vitamin K, 1.25 mg (n = 355), or placebo (n = 369).
Any bleeding events at 90 days. Secondary outcomes included major bleeding (fatal bleeding, bleeding requiring transfusion of ≥ 2 units of packed red blood cells or therapeutic intervention, or objectively confirmed bleeding into an enclosed space), objectively confirmed venous or arterial thromboembolism, and death.
98% (100% in intention-to-treat analysis).
At 90 days, oral vitamin K did not reduce bleeding events or major bleeding events and did not cause venous or arterial thromboembolism or death (Table).
In patients with warfarin-associated coagulopathy, oral vitamin K did not reduce bleeding or cause thromboembolism or death.
Vitamin K vs placebo in patients with warfarin-associated coagulopathy†
†Abbreviations defined in Glossary. RRI, RRR, NNH, NNT, and CI calculated from data in article.
Rondina M. Oral vitamin K did not reduce bleeding in patients with excessive anticoagulation after receiving warfarin. Ann Intern Med. ;150:JC6–9. doi: 10.7326/0003-4819-150-12-200906160-02009
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Published: Ann Intern Med. 2009;150(12):JC6-9.
Coagulopathies, Gastroenterology/Hepatology, Hematology/Oncology, Liver Disease.
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