Keywords: Warfarin,vitamin K,coagulation,INR,supratherapeutic (PubMed Search)
It may not be necessary to give oral vitamin K to patients that are not bleeding that have INRs between 4.5 and 10.
Patients who were supratherapeutic on warfarin were randomized to vitamin K 1.25 mg (n=355) versus placebo (n=369).
In the 90 days after enrollment, 15.8% of patients allocated to vitamin K and 16.3% allocated to placebo had a bleeding event. Major bleeding events occurred in 9 patients in the vitamin K group and 4 in the placebo.
Thromboembolic events occurred in 1.1% of patients in the vitamin K group, compared to 0.8% of patients in the placebo group. An equal number of patients died in each group (n=7).
Crowther MA, Ageno W, Garcia D, et. al. Oral Vitamin K Versus Placebo to Correct Excessive Anticoagulation in Patients Receiving Warfarin. Ann Intern Med 2009, 150:293-300.