THE ANTIPLATELET EFFECTS OF TICLOPIDINE AND CLOPIDOGREL

Ticlopidine and clopidogrel achieve antiplatelet effects by inhibiting the binding of adenosine 5'-disphosphate to its platelet receptor. Ti clopidine was first shown to decrease major events compared with place bo or aspirin in patients with stroke or recent transient ischemic att ack. Randomized studies in patients undergoing coronary artery stentin g have shown that ticlopidine reduces the risk for subacute stent thro mbosis compared with warfarin-based regimens. Smaller studies have als o shown this drug to have benefit during follow-up in patients with un stable angina, peripheral arterial disease, saphenous vein coronary by pass grafts, and diabetic retinopathy. Clopidogrel was recently approv ed by the U.S. Food and Drug Administration for the reduction of ische mic events in patients with recent myocardial infarction, stroke, or p eripheral arterial disease (incidence, 5.32% per year compared with 5. 83% per year for aspirin; P = 0.043) with no added risk for neutropeni a. The combination of clopidogrel and aspirin, as well as the utility of clopidogrel in other patient populations and in stenting, requires further study. Ticlopidine and clopidogrel seem to have beneficial eff ects compared with aspirin (the current standard) in a broad range of patients. These observations highlight the importance of antiplatelet therapy in cardiovascular disease.