Genotype-guided warfarin dosing could improve safety

Patients receiving genotype-guided dosing of warfarin were less likely to have a major bleed or die than patients whose dosing was clinically guided.

Person takes INR pin-prick blood test

Warfarin is a leading cause of medication-related accident and emergency visits. Experts have debated whether genotype-based warfarin dosing can prevent these adverse events.

In a recent trial published in JAMA (online, 26 September 2017), researchers randomly assigned 1,650 patients with a mean age of 72.1 years beginning warfarin at the time of elective hip or knee arthroplasty to genotype- or clinically-guided warfarin dosing[1]

They found that, during 90 days’ follow-up, patients in the genotype-guided dosing group were significantly less likely to reach the composite primary endpoint of major bleeding, an international normalised ratio of four or more, venous thromboembolism or death than those in the clinically guided group (10.8 vs 14.7%; relative rate: 0.73).

The results indicate that genotype-based dosing improved the safety of warfarin among patients undergoing elective hip or knee arthroplasty, but further research is needed to assess the cost-effectiveness of the approach, the researchers concluded.


[1] Gage B, Bass A, Lin H et al. Effect of genotype-guided warfarin dosing on clinical events and anticoagulation control among patients undergoing hip or knee arthroplasty: The GIFT randomized clinical trial. JAMA 2017;318(12):1115–1124. doi:10. 1001/jama.2017.11469

Last updated
Clinical Pharmacist, CP, November 2017, Vol 9, No 11;9(11)::DOI:10.1211/PJ.2017.20203820

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