Clopidogrel (brand name Klopidex) is an oral antiplatelet agent (thienopyridine class) which inhibits blood cloting and is indicated for prevention of vascular ishaemic events in patients with symptomatic atherosclerosis, acute coronary syndrome without ST-segment elevation (NSTEMI), and ST elevation MI (STEMI). It is also used, along with acetylsalicylic acid, for the prevention of thrombosis after placement of intracoronary stent or as an alternative antiplatelet drug for patients who are intolerant to acetylsalycilic acid.