warfarin and citroxanthin

There are significant differences among patients treated with warfarin in the dosage volumes necessary to reach an optimum therapeutic effect. Apart from the external influences (interactions with drugs and food), genetic predispositions play an important role. Polymorphysms of the P 450 2C9 cytochrome bear upon the speed ofbreaking down S-warfarin, polymorfysms VKORC1 bear on the volume and quality of epoxide reductase--an enzyme whose blockade is the crux of the mechanism how cumarin anticoagulants act. These two genes are responsible for at least 50% of the warfarin effect variability. Warfarin's effect is further determined by the genetic variants of gamma-carboxylase, prothrombin, factors VII and IX. In near future, further results of pharmacogenetic research and clinical studies can be expected. They study the impact of the findings in clinical practice.

Topics: Anticoagulants; Aryl Hydrocarbon Hydroxylases; beta Carotene; Biotransformation; Cytochrome P-450 CYP2C9; Humans; Mixed Function Oxygenases; Pharmacogenetics; Polymorphism, Genetic; Vitamin K Epoxide Reductases; Warfarin