Plasmatic concentrations of vitamin K1 and acenocoumarol related to the INR values

Reduced vitamins K are acting as cofactors of glutamic carboxylation of pro coagulant factors (II, VII, IX and X). The reduction of these vitamins is i nhibited by oral anticoagulants. The response to antivitamins K is individual and may change during the trea tment of a patient. The determinations of plasmatic vitamin K and acenocoum arol may help to explain the mechanism of a resistance to the anticoagulant therapy. Quantifications of vitamin K1 are realized after liquid-liquid extraction w ith liquid chromatography and fluorescence detection after post-column redu ction. For acenocoumarol, plasma concentration is measured, after liquid-li quid extraction, by liquid chromatograph, with ion trap mass spectrometer d etector.