Warfarin drug interaction with vitamin K and other foodstuffs / Interacción de la droga warfarina con la vitamina K y otros productos alimenticios

Vitamin K is found in higher concentrations in dark green plant and in vegetable oils. The adequate intake of vitamin K is 90 and 120ug/day for adult elderly men and women, respectively. The main function of vitamin K is to act as an enzymatic cofactor for hepatic prothrombin synthesis, blood coagulation factors, and anticoagulant proteins. Prominent among the many available anticoagulants is warfarin, an antagonist of vitamin K, which exerts its anticoagulant effects by inhibiting the synthesis of vitamin K1 and vitamin KH2. From the beginning of the therapy it is necessary that the patients carry out the monitoring through the prothrombin time and the international normalized ratio. However, it is known that very low intake and/or fluctuations in vitamin K intake are as harmful as high consumption. In addition, other foods can interact with warfarin, despite their content of vitamin K. The aim of this study was to gather information on the drug interaction of warfarin with vitamin K and with dietary supplements and other foods.

La vitamina K se encuentra en concentraciones más altas en plantas de color verde oscuro y en aceites vegetales. La ingesta adecuada de vitamina K es de 90 y 120 ug/día para hombres y mujeres adultos mayores, respectivamente. La función principal de la vitamina K es actuar como un cofactor enzimático para la síntesis de protrombina hepática, factores de coagulación de la sangre y proteínas anticoagulantes. Entre los muchos anticoagulantes disponibles destaca la warfarina, un antagonista de la vitamina K, que ejerce sus efectos anticoagulantes al inhibir la síntesis de la vitamina K1 y la vitamina KH2. Desde el inicio de la terapia, es necesario que los pacientes realicen el monitoreo a través del tiempo de protrombina y la proporción normalizada internacional. Sin embargo, se sabe que una ingesta muy baja y/o fluctuaciones en la ingesta de vitamina K son tan dañinas como un consumo alto. Además, otros alimentos pueden interactuar con la warfarina, a pesar de su contenido de vitamina K. El objetivo de este estudio fue recopilar información sobre la interacción de los medicamentos de la warfarina con la vitamina K y con los suplementos dietéticos y otros alimentos.

role of CYP2C9 gene polymorphisms on anticoagulant therapy after heart valve replacement

The aim of the present study was to investigate the role of CYP2C9 gene polymorphisms after heart valve replacement in a group of patients on warfarin therapy. The study population consisted of 74 patients with heart valve replacement. Peripheral blood was collected into evacuated tubes containing EDTA, and DNA was extracted from circulating leukocytes by using a high pure PCR template preparation kit. CYP2C9*2, CYP2C9*3 alleles were detected by using real-time PCR. The patients with CYP2C9*1/*3 and CYP2C9*2/*3 genotypes were taking 28.21 and 24.47 mg, respectively, as mean weekly warfarin dose, whereas patients with CYP2C9*1/*1 genotype were taking 33.90 mg. The data show that patients with CYP2C9*1/*3 and CYP2C9*2/*3 genotypes needed a lower maintenance dose of warfarin than patients with CYP2C9*1/*1 wild-type genotype