Vitamin K for the Treatment of Asymptomatic Coagulopathy Associated with Oral Anticoagulant Therapy

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.