Prediction of warfarin dose reductions in Puerto Rican patients, based on combinatorial CYP2C9 and VKORC1 genotypes.

Background: The influence of CYP2C9 and VKORC1 polymorphisms on warfarin dose has been investigated in white, Asian, and African American populations but not in Puerto Rican Hispanic patients.

Objective: To test the associations between genotypes, international normalized ratio (INR) measurements, and warfarin dosing and gauge the impact of these polymorphisms on warfarin dose, using a published algorithm.

Methods: A retrospective warfarin pharmacogenetic association study in 106 Puerto Rican patients was performed.