Clopidogrel

Pharmacogenomic Information in the Context of the FDA-Approved Drug Label*

The clopidogrel label highlights the pharmacogenetics of this drug.

Excerpt from the clopidogrel drug label:

"The effectiveness of Plavix is dependent on its activation to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19 [see Warnings and Precautions (5.1)]. Plavix at recommended doses forms less of that metabolite and has a smaller effect on platelet function in patients who are CYP2C19 poor metabolizers. Poor metabolizers with acute coronary syndrome or undergoing percutaneous coronary intervention treated with Plavix at recommended doses exhibit higher cardiovascular event rates than do patients with normal CYP2C19 function. Tests are available to identify a patient's CYP2C19 genotype; these tests can be used as an aid in determining therapeutic strategy [see Clinical Pharmacology (12.5)]. Consider alternate treatment or treatment strategies in patients identified as CYP2C19 poor metabolizers [see Dosage and Administration (2.3)]."

Twenty-one studies involving 4,520 subjects have shown that CYP2C19*2, CYP2C19*3, and other CYP2C19 loss-of-function alleles are associated with diminished antiplatelet responses to treatment with clopidogrel. CYP2C19 participates in the formation of both the active metabolite of clopidogrel and the 2-oxo-clopidogrel intermediate metabolite. Individuals with CYP2C19 loss-of-function alleles have reduced exposure to the active metabolite of clopidogrel, leading to less platelet inhibition or higher residual platelet reactivity. Key publications on pharmacogenetic studies of response to clopidogrel include: [PMID:19106083, PMID:19106084, PMID:19108880, PMID:19193675].

The clopidogrel drug label was updated on 3/2010 to include a boxed warning with pharmacogenetic information. For the complete updated drug label text, see the Clopidogrel drug label PDF.

Pharmacogenomic Testing

The information below is provided for educational purposes only and does not constitute an endorsement of any listed test or manufacturer.

¹ Entries in this column link to test manufacturer's website.
² Information in this column was found using searches of the entire FDA website (http://www.fda.gov/search.html), searches of the FDA CDRH CLIA database (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfClia/Search.cfm), or searches of the FDA CDRH Premarket Approval Database (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pma.cfm).

Table updated 10/19/2009.

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