CYP2C19 and transient ischemic attack: The response to clopidogrel may depend on the number of altered alleles of CYP2C19 (gene-dose effect).14,15 Thus, the US Food and Drug Administration–approved drug label (from 2017) gives guidance for CYP2C19 poor metabolizers to use a different platelet P2Y12 inhibitor; however, it does not give dosing guidance for CYP2C19 intermediate metabolizers.16 It is important to understand whether therapy recommendations should differ between intermediate and poor metabolizers with minor stroke and TIA.