Pharmacogenetics of dabigatran and apixaban in association with gastrointestinal bleeding.

OBJECTIVES: To determine whether selected single nucleotide polymorphisms (SNPs) of genes encoding proteins responsible for the activation, transport, or metabolism of dabigatran and apixaban might be associated with a risk of gastrointestinal bleeding in a cohort of adult patients treated with these drugs. No previous study has focused specifically on the association with gastrointestinal bleeding. MATERIALS AND METHODS: Ninety-one patients treated with dabigatran or apixaban were genotyped for selected polymorphisms. The following polymorphisms were studied: ABCB1 gene rs1045642, rs4148738, rs1128503 and rs2032582; CES1 gene rs2244613, rs8192935 and rs2244614; and SULT1A1 gene rs9282861 and SULT1A2 gene rs1136703. Two groups divided by particular drugs and genotypes were compared in terms of the presence (bleeding group) or absence (nonbleeding group) of gastrointestinal bleeding. The genotype distribution was expressed via dominant and recessive models. RESULTS: In patients treated either with dabigatran or with apixaban, no evidence was found to support the association of gastrointestinal bleeding with any genotype for any of the studied SNPs. CONCLUSION: In both dabigatran- and apixaban-treated patients, no associations between the selected polymorphisms and gastrointestinal bleeding risk were found, however the results should be interpreted with caution because of the small cohort size.