Investigation Of Drug Interaction Between Clopidogrel And Proton Pump Inhibitors

Objective: To characterize the effect of clopidogrel and its carboxylic acid metabolite, omeprazoleon the spectrum of gene expression in the cultrured human umbilical vein endothelial cell(HUVEC) line (EA.hy926), and preliminarily explore the potential molecular mechanism of thecompounds on HUVEC; To evaluate impact of20mg omeprazole and10mg rabeprazole onplasma concentration and pharmacodynamics of75mg clopidogrel in Chinese healthy volunteers;To investigate outcomes of clopidogrel therapy combined with proton pump inhibitor(PPI)inelderly patients with coronary artery disease(CAD).Methods: Part Ⅰ Affymetrix HU133A plus2.0oligonucleotide microarray was used to detectthe alteration in the gene expression profiles induced48h by1×10-5mol/L clopidogrel and itscarboxylic acid metabolite, meprazole in HUVEC. Clustering analysis of differentially expressedgenes was performed with MAS (Molecule Annotation System) version3.0. Real-time PCR wasemployed to verify the results of selected differentially expressed genes, and Western blotting wasperformed to test the expression levels of the related proteins. Part Ⅱ Eighteen Chinese healthyvolunteers were enrolled in the three-period crossover study, following below drug regimen: oralclopidogrel75mg alone; clopidogrel75mg combined with omeprazole20mg; or clopidogrel75mgplus rabeprazole10mg once a day for1week, the washout period is2weeks. Blood samples weretaken4hrs after dose every7thday of the treatment, Plasma concentration of active metabolite andcarboxylic acid metabolite of clopidogrel was test, Maximal platelet aggregation (MPA) andplatelet reactivity index (PRI) was assessed using light transmittance aggregometry (LTA) andvasodilator-stimulated phosphoprotein (VASP) respectively. Part Ⅲ We conducted aretrospective cohort study of hospitalized coronary artery disease (CAD) patients aged60years orolder who commenced clopidogrel between January.1,2001, and February.28,2011, toevaluate adverse clinical outcomes possibly related to using clopidogrel plus a PPI compared withclopidogrel alone. The primary endpoint was all cause death, the secondary endpoint were nonfatal myocardial infarction (MI), and hospitalization for unstable angina, stroke, transientischemic attack(TIA), repeat revascularization (Percutaneous coronary intervention, PCI orcoronary artery bypass graft, CABG), or bleeding complications.Results: PartⅠ Total508including139up-regulated and369down-regulated genes wereobtained with fold change more than1.5after clopidogrel (10-5M) acted on HUVEC for48hours.Affected genes involved in protein binding, transcription factor activity, zinc ion binding,regulation of transcription, transcription, RNA splicing in HUVEC; After SR26334(10-5M)treated,235including176up-regulated and59down-regulated genes were obtained with foldchange more than1.5SR26334affected the expression levels of genes involving in regulation oftranscription, transcription, positive regulation of transcription from RNA polymerase II promoter,cell cycle, cell division, protein amino acid dephosphorylation; After omeprazole (10-5M) treated,total282including236up-regulated and46down-regulated genes were obtained with fold changemore than1.5fold. Affected genes involved in bioprocess of regulation of transcription,inflammatory response, immune response, cell adherence, anti-apoptosis, signal transduction inHUVEC. RT-PCR and Western blotting verified the results of selected gene expression. Part ⅡCLopidogrel75mg inhibited platelet aggregation of the volunteers significantly compared withtheir baseline level. Omeprazole20mg and rabeprazole10mg weakened antiplatelet effect ofclopidogrel. There was a significant linear correlation between antiplatelet effect and activemetabolite plasma concentration of clopidogel, but no such linear correlation between antiplateleteffect and level of its carboxylic acid metabolite. PartⅢ1033old CAD patients undercontinuous clopidogrel therapy were enrolled,739were prescribed clopidogrel solely and249were administrated clopidogrel combined with PPI(omeprazole170, rabeprazole112andesomeprazole12). The incidence density of all cause death of clopidogrel group and clopidogrelplus PPI group was3.54/1000person-months和4.23/1000person-month respectively, OR1.196(95%CI:0.777-1.842, P=0.415); The incidence density of composite thromboembolic eventswasn't statistical significance (P=0.492). After propensity scored all listed confounders and weightthe incidence data with the score, further analysis still did not show any difference in mortalityand end point events between the two group(sP>0.05). Kaplan-Meier survival analysis showed nodifference of mortality and end point events among the three different PPI(P>0.05).Conclusion: Clopidogrel and its carboxylic acid metabolite, omeprazole influence gene expression of cultured HUVEC, which include that clopidogrel and omeprazole both affect thefunction of endothelial cell through different pathway apart from their interaction on the aspect ofantiplatelet; Omeprazole and rabeprazole weaken antiplatelet effect of clopidogrel by decreaseformation of its active metabolite; Clopidogrel with omeprazole, rabeprazole, or esomeprazoledoes not increase all cause mortality and incidence of cardiovascular events in elderly CADpatients compared with those under clopidogrel therapy without any PPI, The results persists afterweighted data with confounders propensity score.