Concomitant use of warfarin and omeprazole is associated with increased INR and prothrombin time(PT).

Omeprazole is CYP2C19 inhibitor which can prolong the elimination of warfarin, particularly R-warfarin. R- warfarin is partially metabolized by CYP2C19. The combined use of omeprazole and warfarin has been associated with reports of increased INR and prothrombin time (PT).