Anticoagulation instability with life-threatening complication after dietary modification

Abstract

Summary: Anticoagulation instability due to a change in intake of vitamin K after dietary modification was observed in 2 patients on long-term oral anticoagulants. One patient developed diffuse bruises treated conservatively with fresh frozen plasma transfusion and the other had a thrombosed aortic prosthesis which required emergency operation. To prevent such complications, dietary modification especially with food rich in vitamin K should be undertaken with care in patients on long-term oral anticoagulants.

Vitamin K deficiency amplifies anticoagulation response to ximelagatran: possible implications for direct thrombin inhibitors and their clinical safety

“…However, since the activation of thrombin is inextricably linked with the vitamin K cycle in the coagulation cascade, there is the possibility that the pharmacological activity of direct thrombin inhibitors could be influenced by alterations in vitamin K availability. The enhanced pharmacological activity of warfarin in vitamin K deficient rats observed in this study confirms the well-established impact of vitamin K deficiency on anticoagulation response to warfarin in man [4][5][6][8][9][10]. This study also demonstrates that overt vitamin K deficiency enhances the anticoagulant activity of the direct thrombin inhibitor, ximelagatran, in rats.…”

“…Warfarin causes anticoagulation by inhibiting the reductase enzymes, which generate vitamin K hydroquinone from vitamin K epoxide in the liver, thus preventing activation of the clotting proteins [7]. The availability of vitamin K thus plays a role in determining the effectiveness of warfarin, and dietary modification by either lowering or increasing vitamin K intake can increase or decrease patients' sensitivities to the drug [5,[8][9][10].…”

Vitamin K supplementation can improve stability of anticoagulation for patients with unexplained variability in response to warfarin

“…Alterations in dietary intake of vitamin K can have a significant effect on anticoagulation response to oral anticoagulants; increases in the dietary intake of vitamin K are associated with significant reductions in anticoagulation response, 6,9,[12][13][14][15] whereas the opposite causes warfarin sensitivity. 6,12 Earlier we showed that in patients with stable control of anticoagulation, for every 100-g increase in vitamin K intake in the previous 4 days, INR falls by 0.2, 16 further exemplifying the relationships between dietary vitamin K and anticoagulation response.…”

“…6,12 Earlier we showed that in patients with stable control of anticoagulation, for every 100-g increase in vitamin K intake in the previous 4 days, INR falls by 0.2, 16 further exemplifying the relationships between dietary vitamin K and anticoagulation response.…”

Efficacy of Therapy With Indirect Anticoagulants: Role of the Foodstuff Vitamin K Contents

“…С другой стороны, по-требление препаратов витамина К или пищевых про-дуктов, богатых этим витамином, блокирует дей-ствие данной группы лекарственных средств. В связи с этим изменения количества поступающего с пище-выми продуктами витамина К 1 могут приводить к не-желательным последствиям для пациентов, получаю-щих варфаринотерапию, и даже быть причиной опасных для жизни осложнений -кровотечений или тромбозов [13,22].…”