antithrombotic therapies have markedly improved the outcome of patients undergoing coronary revascularization or with acute coronary syndromes. Glycoprotein IIblIlIa receptor antagonists were introduced into clinical practice to overcome the limitations of approaches that inhibit only individual pathways of platelet activation. Multiple mechanisms of platelet activation in response to different agonists converge on the platelet membrane glycoprotein IIblIlIa complex, the "final common pathway" of platelet aggregation. The clinical hemorrhagic syndrome caused by a rare inherited defect in this receptor (Glanzmann' s thrombasthenia), characterized by muco­ cutaneous and postsurgical bleeding, but infrequent spontaneous organ (particularly central nervous system) bleeding, suggested that therapeutic inhibition of this receptor might be a potent, yet well-tolerated means of treating thrombotic disorders.