Indications

Clopidogrel is indicated for:^[2]

• Prevention of vascular ischemic events in patients with symptomatic atherosclerosis
• Acute coronary syndrome without ST-segment elevation (NSTEMI),
• ST elevation MI (STEMI)

It is also used, along with aspirin, for the prevention of thrombosis after placement of intracoronary stent^[2] or as an alternative antiplatelet drug for patients who are intolerant to aspirin.^[3]

International guidelines granted the highest grade of recommendation for NSTE-ACS, PCI and stent,^{[clarification needed]} for clopidogrel in addition to aspirin. Consensus-based therapeutic guidelines recommend also the use of clopidogrel, instead of aspirin, in patients requiring antiplatelet therapy but with a history of gastric ulceration, as inhibition of the synthesis of prostaglandins by aspirin (acetylsalicylic acid) can exacerbate this condition. A study has shown that in patients with healed aspirin-induced ulcers, however, patients receiving aspirin plus the proton pump inhibitor esomeprazole had a lower incidence of recurrent ulcer bleeding than patients receiving clopidogrel.^[4] However, a more recent study suggested that prophylaxis with proton pump inhibitors along with clopidogrel following acute coronary syndrome may increase adverse cardiac outcomes, possibly due to inhibition of CYP2C19, which is required for the conversion of clopidogrel to its active form.^[5][6][7] The European Medicines Agency has issued a public statement on a possible interaction between clopidogrel and proton pump inhibitors.^[8] However, several cardiologists have voiced concern that the studies on which these warnings are based have many limitations and that it is not certain whether there really is an interaction between clopidogrel and proton pump inhibitors.^[9]