Risk of major adverse cardiovascular events for concomitant use of clopidogrel and proton pump inhibitors in patients inheriting CYP2C19 loss-of-function alleles: meta-analysis

Background Efficacy of clopidogrel may be diminished due to either co-administration of proton pump inhibitors or carrying CYP2C19 loss-of-function alleles. However, patients may be at greater risk of major adverse cardiovascular events if taking clopidogrel together with proton pump inhibitors and also inherited the CYP2C19 loss-of-function alleles which may cause further reduction of clopidogrel efficacy. This is due to the cumulative effects of drug-drug interactions and drug-gene interactions collectively referred to as multifactorial drug-gene interactions. Aim of the review The aim of this analysis was to estimate aggregated risk of major adverse cardiovascular events for either coronary heart disease or stroke patients with multifactorial drug-gene interactions versus clopidogrel alone with or without drug-gene interactions. Methods Literatures were searched using different resources based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Meta-analysis was performed using RevMan software following either fixed/random effects model based on the levels of heterogeneity. A p value < 0.05 (2-sided) was considered statistically significant. Results In total, five studies consisting 8,802 patients of coronary artery diseases or stroke were included in this meta-analysis in which 3,767 were prescribed clopidogrel alone, 1,931 were concomitantly taking clopidogrel and PPIs, 2,146 were carrying CYP2C19 loss-of-function alleles and 958 were taking both clopidogrel and proton pump inhibitors while also carrying CYP2C19 loss-of-function alleles. It was found that patients with multifactorial drug-gene interactions were associated with significantly increased risk of major adverse cardiovascular events compared to those taking clopidogrel alone without CYP2C19 loss-of-function alleles (12% vs. 5.8%; RR 1.73; 95% CI 1.12–2.67; p = 0.01). Patients with multifactorial drug-gene interactions were also associated with significantly increased risk of major adverse cardiovascular events compared to drug-gene interactions (RR 1.63; 95% CI 1.31–2.03; p < 0.0001). Patients taking clopidogrel with proton pump inhibitors were also associated with 35% significantly increased risk of major adverse cardiovascular events compared to those taking only clopidogrel (RR 1.35; 95% CI 1.11–1.65; p = 0.003). Conclusion Patients inheriting CYP2C19 loss-of-function alleles have significantly increased risk of major adverse cardiovascular events when taking clopidogrel and proton pump inhibitors concurrently.