Abstract

OBJECTIVE
To test the effect of a loss-of-function variation of the cytochrome P450 (CYP) 3A5 on drug-drug interaction between amlodipine and clopidogrel. Amlodipine is a well-known inhibitor of CYP 3A4, an isoenzyme of CYP3A that activates clopidogrel. However, controversy exists regarding whether amlodipine adversely affects clopidogrel response and clinical outcome after percutaneous coronary intervention (PCI). In the presence of CYP3A4 inhibitors such as amlodipine, the genetic variation of CYP3A5, the isoenzyme responsible for the backup CYP3A activity, may play an important role in clopidogrel activation.
DESIGN
Post hoc analysis of a prospectively enrolled cohort.
PATIENTS
Patients enrolled in the CROSS-VERIFY cohort from June 2006 to June 2010, with successful genotyping of CYP3A5.
MAIN OUTCOME MEASURES
The pharmacodynamic analysis end point was clopidogrel on-treatment platelet reactivity (OPR) and the clinical analysis end point was the composite of cardiac death, non-fatal myocardial infarction, ischaemic stroke and stent thrombosis at 12 months post-PCI.
RESULTS
1258 patients had successful genotyping and were categorised as CYP3A5 non-expressers (749 patients) and expressers (509 patients) according to the CYP3A5 genotype. Amlodipine users showed higher OPR versus non-users only in CYP3A5 non-expressers (249 ± 83 vs 228 ± 84 P2Y12 reaction units, p=0.013). These findings was corroborated by clinical outcomes, in which amlodipine users had a higher incidence of events compared with non-users only in CYP3A5 non-expressers (4.6% vs 0.6%, HR 7.731, CI 2.042 to 29.264, p=0.004).
CONCLUSIONS
Treatment with amlodipine is associated with increased clopidogrel OPR and increased risk of thrombotic events after PCI, which is dependent on the CYP3A5 genetic status.

Links

Publisher Full Text

Authors

Park KW, Kang J, Park JJ, Yang HM, Lee HY, Kang HJ, Koo BK, Oh BH, Park YB, Kim HS

Institution

Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Korea.

Source

Heart (British Cardiac Society) 98:18 2012 Sep pg 1366-72

MeSH

Aged
Amlodipine
Angioplasty, Balloon, Coronary
Cytochrome P-450 CYP3A
Drug Interactions
Female
Graft Occlusion, Vascular
Humans
Male
Middle Aged
Myocardial Infarction
Platelet Aggregation
Platelet Aggregation Inhibitors
Polymorphism, Single Nucleotide
Prospective Studies
Stroke
Ticlopidine

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22735685