Clopidogrel is a second-generation thienopyridine that was approved for marketing in the United States (US) in 1998. Clopidogrel covalently binds to the P2Y12 receptor, which is the main platelet receptor responsible for ADP-induced platelet aggregation, leading to irreversible platelet inhibition. 1 Clopidogrel is absorbed in the gastrointestinal tract by the drug efflux transporter P-glycoprotein,