Clopidogrel - an Overview

INTRODUCTION Clopidogrel bisulfate, chemically S (+)-2-(2chlorophenyl)-6, 7-dihydrothiene [3,2-C]pyridine-5(4H)acetic acid methyl ester sulphate is a potent antiplatelets and antithrombotic drug (at C-7 clopidogrel has an absolute S configuration). Clopidogrel has been approved and marketed globally with the primary indication being to reduce atherosclerotic events in patients with several comorbid conditions due to stroke, myocardial infarction and cardiovascular disease. Clopidogrel displays a selective binding on the platelet surface to adenylate cyclase-coupled ADP receptors, which is unique as compared with aspirin and other related drugs. The mechanism of action of aspirin or other related agents involves inhibition of arachidonic acid metabolism, inhibition of cyclo oxygenase enzyme system or the inhibition of prostaglandin synthesis. Reports have suggested that clopidogrel does not have a direct effect on the enzyme systems cAMP phosphodiesterase, thromboxane A2, adenylate cyclase, as well no effects on the synthesis of prostacyclin [1].