Diagnosis: Clopidogrel pharmacogenomics
• Clopidogrel is an antiplatelet agent that is used for secondary prophylaxis of acute neurologic and cardiovascular events (i.e., stroke and myocardial infarction, respectively).
• Clopidogrel is a pro-drug and is converted by CYP2C19 to its active metabolite, which then inhibits the platelet P2Y12 (i.e., ADP) receptor.
• CYP2C19 loss-of-function alleles (e.g., CYP2C19*2) appear to be associated with higher rates of recurrent cardiovascular events in patients receiving clopidogrel. If the patient is a poor metabolizer, an alternate P2Y12 inhibitor may be indicated.
• Pharmacogenomic testing is not recommended for all patients receiving clopidogrel.
• Testing is recommended when there is recurrent stent thrombosis despite compliance with taking medications and when dual-antiplatelet therapy is otherwise indicated.
