Bleeding complications with glycoprotein IIb/IIIa inhibitors

The new class of antiplatelet drugs, the GPIIb/IIIa inhibitors, has proven to be effective in acute coronary syndromes including unstable angina and myocardial infarction as well as adjunct therapy for coronary interventions for preventing morbidity and mortality. As these drugs inhibit the final common pathway of platelet activation, effectively blocking the platelet aggregation response, potential bleeding is a concern with their use. The risk of bleeding has been demonstrated to be higher in patients treated with combination drug therapy (heparin, aspirin, thienopyridines, thrombolytics, oral anticoagulants), when antithrombotic drugs are not given on an individual weight basis and with late removal of vascular access sheaths. The early clinical trials have defined modifications in patient management that have effectively reduced bleeding. Pooled data from the more recent clinical trials, mostly in coronary intervention enrolling over 27,000 patients, show a bleeding rate of 3.6% in the drug group and 2.3% in the placebo group. Although this is acceptable, several unresolved issues remain to be addressed regarding the GPIIb/IIIa inhibitors. Thrombocytopenia occurs infrequently with all GPIIb/IIIa inhibitors but can be severe. The use of these drugs by oral administration presents new challenges with determining optimal dosing, drug-drug interactions and long-term effects. Incorporating point-of-care monitoring may enable better titration of these drugs to avoid bleeding complications. GPIIb/IIIa inhibitors are destined to become a mainstay therapy for cardiovascular treatment and over time these issues should be resolved.