Warfarin has continued to be the leading vitamin K-dependent oral anticoagulant around the globe since its introduction in 1954. Its dosing is notoriously difficult because the medication has a very small therapeutic range and shows broad variability in dose needs across individuals, which has made it one of the most extensively investigated drugs in genotype–phenotype research. Yet, the majority of this work has focused on Asian and White cohorts, resulting in a pharmacogenomic evidence base that does not adequately represent global ancestral diversity. Since the frequencies of crucial genetic variants vary markedly between populations, findings derived from Asian/White groups may not translate reliably to groups that have historically been understudied—such as Black, Hispanic/Latino, American Indian/Alaska Native, and Native Hawaiian/Pacific Islander communities. As a result, inequities may worsen when validated dosing algorithms improve anticoagulation outcomes primarily in Asian/White patients but underperform in others. To assess how well different racial and ethnic groups are represented in current pharmacogenomic knowledge, we summarize data on published warfarin pharmacogenomic dosing algorithms and related literature, including studies on clinical benefit, cost-effectiveness, and implementation guidance.
