Warfarin (also known as Coumadin) is a blood thinner frequently prescribed to individuals vulnerable to stroke, and to patients having joint replacement surgery. However, determining the correct dose for different patients has been a challenge, as some patients are more sensitive to Warfarin than others. This can lead to side effects such as internal bleeding. Warfarin use accounts for more medication-related emergency visits among older patients than any other drug.
Sensitivity to Warfarin is largely determined through genetic variations in 3 genes. Researchers at Washington University led a clinical trial to determine if prior genotype testing could help make warfarin safer for patients. This trial, called “Genetic Informatics Trial (GIFT)”, studied 1,650 patients aged over 65 years undergoing elective hip or knee replacement surgery. The patients were randomly assigned to one of two groups: one group received clinically-guided warfarin doses, while the other group received warfarin doses that were customized to their genotype. In this trial, genetic testing cost less than $200 per person.
Their study found that customising the dose to the patient’s genetic profile helps significantly reduce the risk of major bleeding.
Link to the study: http://jamanetwork.com/journals/jama/fullarticle/2654820
