Novel antiplatelet therapies for treatment of patients with ischemic heart disease: inhibitors of the platelet glycoprotein IIb/IIIa integrin receptor.

Blood platelets play essential roles in normal coagulation and in coronary atherosclerotic disease and its complications. Various antiplatelet therapies, including aspirin, ticlopidine, and dipyridamole, have been developed for use in patients with known coronary artery artery disease to prevent ischemic complications. More recently a more complete anti-aggregation effect has been accomplished by the use of monoclonal antibodies and specific peptide and nonpeptide compounds that bind to the platelet GP IIb/IIIa surface receptor. This receptor becomes activated by platelet stimulation and binds fibrinogen molecules between platelets in the aggregation process. These new antiplatelet drugs are now being evaluated in clinical trials in patients undergoing balloon coronary angioplasty, in whom fewer ischemic events occur when the receptor blocker is used intravenously than with standard therapy, and in patients with stable and unstable angina. Excessive bleeding is an important problem with these agents, and efforts must be made to eliminate this side effect.