Inhibitory interaction between calcium channel blocker and clopidogrel: Efficacy of cilostazol to overcome it

Seung Pyo Lee, Jang Whan Bae, Kyung Woo Park, Seung Woon Rha, Jang Ho Bae, Jung Won Suh, In Ho Chae, Myeong Chan Cho, Hyo Soo Kim

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Background: The clinical effect of, and additive measures to overcome the possible inhibitory calcium channel blocker (CCB)-clopidogrel interaction in Asian patients undergoing percutaneous coronary intervention is unknown. Methods and Results: A total of 900 Korean patients enrolled for the multicenter, prospective, randomized Influence of CILostazol-based triple antiplatelet therapy ON ischemic complication after drug-eluting stenT implantation (CILON-T) trial were divided into 4 groups depending on CCB prescription and type of anti-platelet therapy (dual [DAT] vs. triple [TAT; addition of cilostazol to DAT]) in a 2×2 factorial manner. The primary endpoint was a composite of cardiac death, non-fatal myocardial infarction and ischemic stroke at 6 months after PCI. On-treatment platelet reactivity (OPR) was assessed on VerifyNow P2Y12 assay. Concomitant CCB use increased OPR in the DAT group (mean ± SEM: 251.2±7.6 vs. 225.6±5.1; P=0.008), but not in the TAT group (214.5±9.1 vs. 203.4±5.6; P=0.294). Primary endpoint increased by use of CCB in patients with DAT (4.9% vs. 0.9%, P=0.016), but not in those with TAT (0% vs. 1.8%, P=0.346). Addition of cilostazol to DAT reduced OPR and clinical events in patients taking CCB (P=0.007 for P2Y12 reaction units; P=0.027 for thrombotic events). CCB without concomitant cilostazol use was a significant predictor of total thrombotic events. Conclusions: Concomitant use of CCB may weaken the anti-platelet effect of clopidogrel and increase subsequent thrombotic events in Asian subjects. This hazardous CCB-clopidogrel interaction may be overcome by addition of cilostazol.

Original languageEnglish
Pages (from-to)2581-2589
Number of pages9
JournalCirculation Journal
Issue number11
Publication statusPublished - 2011


  • Calcium channel blocker
  • Cilostazol
  • Clopidogrel
  • Platelet function test
  • Thrombosis

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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