CYTOCHROME P450 (CYP2C9) ACTIVENESS, EVALUATED VIA LOSARTAN TEST, AS PREDICTION MARKER FOR THE WARFARIN TREATMENT DOSAGE CHOICE IN PATIENTS WITH DELAYED OUTCOMES AFTER HEART VALVES REPLACEMENT

Aim. To evaluate the influence of gene СYP2C9 activeness via losartan test on the warfarin dosage management in earlier and long-term post-operational periods.Material and methods. Totally 33 patients included with artificial heart valves. All patients underwent assessment of genes carriage by polymorphic marker СYP2C9 by PCR after preparing of DNA from whole blood. The activeness of СYP2C9 was assessed with losartan concentration and its metabolite (E-3174) in urine after single intake of losartan 50 mg.Results. The level of losartan and its active metabolite (E-3174) in urine was a prognostic marker determining therapeutic dose of warfarin in cardiac surgery patients in long-term post-operation period.Conclusion. The СYP2C9 assessment by losartan concentration and E-3174 in“losartan test” might help to determine warfarin treatment dosage in delayed postoperational period that might improve the efficiency and safety of pharmacotherapy in valve prosthesis patients.