Failure of Pharmacogenetic-based Dosing Algorithms to Identify Older Patients Requiring Low Daily Doses of Warfarin

Pharmacogenetic data add to our understanding of variability in warfarin dosing requirements but do not accurately identify older patients requiring the lowest warfarin doses. Therefore, the most prudent approach to warfarin therapy in older patients should include low initial doses in the absence of genotype variants associated with very low warfarin sensitivity and careful monitoring of INR responses.