Low-dose oral vitamin K therapy for the management of asymptomatic patients with elevated international normalized ratios: a brief review

Abstract

ASYMPTOMATIC ELEVATION OF THE INTERNATIONAL normalized ratio (INR) is a common problem associated with hemorrhage. Evidence from randomized controlled trials supports the use of low-dose oral vitamin K therapy as a treatment that promptly reduces the INR. Vitamin K given orally is more effective than subcutaneous vitamin K injection, and as effective as intravenous administration when INR values are compared 24 hours after administration. A 1.0-mg vitamin K dose is likely most appropriate for patients with INR values between 4.5 and 10. The fear of over-correction of the INR has limited the widespread use of vitamin K; however, our review suggests that this occurs infrequently when small doses are administered orally

Effectiveness and safety of a management protocol to correct over-anticoagulation with oral vitamin K: a retrospective study of 1,043 cases

“…The review concludes that doses of 1 mg of oral vitamin K are more appropriate for correcting INRs 4.0-10.0 [12]. Crowther et al [28] showed that 1 mg of vitamin K was effective in correcting low-baseline INRs and Baker et al [33] showed that the extent of response to 2 mg of vitamin K is related to the initial INR level.…”

“…In cases associated with major bleeding, intravenous vitamin K, fresh frozen plasma and prothrombin complex concentrate are used [2]. Minor changes in INR do not activate changes in dosage or other interventions [4] and the lower limit for intervention is usually between 4.5 and 6.0 [12,13]. Excessive elevation in INR values can be provoked by a number of factors such as fluctuations in dietary uptake of vitamin K, hepatic dysfunctions, alcohol uptake, inappropriate dosing, drug interactions and laboratory errors [14][15][16].…”

Efficacy of high dose phylloquinone in correcting vitamin K deficiency in cystic fibrosis

“…Since no tablet form of vitamin K 1 is currently commercially available in Canada, the injectable formulation of vitamin K 1 -phytonadione (Sandoz Canada, Boucherville, Qc) -was diluted to 1 mg/ml and given orally. Injectable vitamin K 1 , given orally, has recently been shown to be more effective than subcutaneous injections and as effective as intravenous administration [12].…”

Management of Excessive Anticoagulant Effect Due to Vitamin K Antagonists

“…32 No studies have directly compared the efficacy of differing doses of oral vitamin K. A recent cumulative analysis of the available literature does suggest, however, that the optimal dose of oral vitamin K is 1 to 1.25 mg for patients with INR values between 4.5 and 10.0, and 2.5 mg for patients with INR values of more than 10.0. 33 When oral vitamin K is not available, the intravenous form of vitamin K can be mixed with orange juice, to mask its unpleasant flavor, and administered by mouth. 22,23,25 In many jurisdictions the smallest available dose of vitamin K is a 5 mg tablet; this tablet is usually scored, allowing a 2.5 mg dose to be used.…”