OBJECTIVES: Because of the known CYP3A4 inhibition by calcium-channel blockers (CCBs), we hypothesized that there might be a drug-drug interaction between clopidogrel and dihydropyridines in patients with coronary artery disease. BACKGROUND: Clopidogrel is activated by CYP3A4, which also metabolizes CCBs of the dihydropyridine class. METHODS: Responsiveness to clopidogrel was assessed by the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and aggregometry in 200 patients with coronary artery disease undergoing percutaneous coronary intervention. RESULTS: The platelet reactivity index (PRI) (in the VASP assay, normal range 69% to 100%) was higher in patients receiving both clopidogrel and CCBs (61%) as compared with patients receiving clopidogrel without CCBs (48%). The absolute difference was 13% (95% confidence interval: 6% to 20%; p = 0.001), and the relative difference approached 21%. A decreased platelet inhibition by clopidogrel (PRI >69%) was seen in 40% of patients with concomitant CCB treatment and in 20% of patients without concomitant treatment (chi-square test, p = 0.008). Intake of CCB remained an independent predictor of reduced platelet inhibition by clopidogrel after adjustment for cardiovascular risk factors. Adenosine diphosphate-induced platelet aggregation was 30% higher in patients on concomitant CCB treatment compared with patients without CCBs (p = 0.046). Moreover, intake of CCBs was associated with adverse clinical outcome. In vitro incubation with CCBs (nimodipine, verapamil, amlodipine, and diltiazem) did not alter the PRI or the adenosine diphosphate-induced platelet aggregation of patients taking clopidogrel. This finding indicates that the negative effect occurs in vivo, conceivably at the level of the CYP3A4 cytochrome. CONCLUSIONS: Coadministration of CCBs is associated with decreased platelet inhibition by clopidogrel.
OBJECTIVES: Because of the known CYP3A4 inhibition by calcium-channel blockers (CCBs), we hypothesized that there might be a drug-drug interaction between clopidogrel and dihydropyridines in patients with coronary artery disease. BACKGROUND:Clopidogrel is activated by CYP3A4, which also metabolizes CCBs of the dihydropyridine class. METHODS: Responsiveness to clopidogrel was assessed by the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and aggregometry in 200 patients with coronary artery disease undergoing percutaneous coronary intervention. RESULTS: The platelet reactivity index (PRI) (in the VASP assay, normal range 69% to 100%) was higher in patients receiving both clopidogrel and CCBs (61%) as compared with patients receiving clopidogrel without CCBs (48%). The absolute difference was 13% (95% confidence interval: 6% to 20%; p = 0.001), and the relative difference approached 21%. A decreased platelet inhibition by clopidogrel (PRI >69%) was seen in 40% of patients with concomitant CCB treatment and in 20% of patients without concomitant treatment (chi-square test, p = 0.008). Intake of CCB remained an independent predictor of reduced platelet inhibition by clopidogrel after adjustment for cardiovascular risk factors. Adenosine diphosphate-induced platelet aggregation was 30% higher in patients on concomitant CCB treatment compared with patients without CCBs (p = 0.046). Moreover, intake of CCBs was associated with adverse clinical outcome. In vitro incubation with CCBs (nimodipine, verapamil, amlodipine, and diltiazem) did not alter the PRI or the adenosine diphosphate-induced platelet aggregation of patients taking clopidogrel. This finding indicates that the negative effect occurs in vivo, conceivably at the level of the CYP3A4 cytochrome. CONCLUSIONS: Coadministration of CCBs is associated with decreased platelet inhibition by clopidogrel.
Authors: Kiran Kalra; Christopher J Franzese; Martin G Gesheff; Eli I Lev; Shachi Pandya; Kevin P Bliden; Udaya S Tantry; Paul A Gurbel Journal: Curr Atheroscler Rep Date: 2013-12 Impact factor: 5.113
Authors: Thomas O Bergmeijer; Jean-Luc Reny; Ruth E Pakyz; Li Gong; Joshua P Lewis; Eun-Young Kim; Daniel Aradi; Israel Fernandez-Cadenas; Richard B Horenstein; Ming Ta Michael Lee; Ryan M Whaley; Joan Montaner; Gian Franco Gensini; John H Cleator; Kiyuk Chang; Lene Holmvang; Willibald Hochholzer; Dan M Roden; Stefan Winter; Russ B Altman; Dimitrios Alexopoulos; Ho-Sook Kim; Jean-Pierre Déry; Meinrad Gawaz; Kevin Bliden; Marco Valgimigli; Rossella Marcucci; Gianluca Campo; Elke Schaeffeler; Nadia P Dridi; Ming-Shien Wen; Jae Gook Shin; Tabassome Simon; Pierre Fontana; Betti Giusti; Tobias Geisler; Michiaki Kubo; Dietmar Trenk; Jolanta M Siller-Matula; Jurriën M Ten Berg; Paul A Gurbel; Jean-Sebastien Hulot; Braxton D Mitchell; Matthias Schwab; Marylyn DeRiggi Ritchie; Teri E Klein; Alan R Shuldiner Journal: Am Heart J Date: 2017-12-17 Impact factor: 4.749