A practical approach to the diagnosis and management of thrombocytopenia associated with glycoprotein IIb/IIIa receptor inhibitors

The introduction of drugs that inhibit the GP IIb/IIIa receptor represents one of the most important new developments in the field of cardiovascular p harmacotherapeutics of the past decade. Thrombocytopenia associated with a GP IIb/IIIa inhibitor can occur in up to 5% of patients and is associated w ith poor clinical outcomes. Monitoring of the platelet count early after ad ministration of these drugs is recommended and further assessment of the pl atelet count should be performed with long-term oral administration. Confir mation of true thrombocytopenia and an investigation of other potential eti ologies are crucial initial diagnostic steps that should be taken when a pl atelet count of < 100,000/cm(3) is encountered. In patients receiving conco mitant heparin, identification of heparin-induced thrombocytopenia using an enzyme-linked immunosorbent assay to detect anti-heparin-PF4 antibodies is preferred. Treatment recommendations depend upon the severity of thrombocy topenia and presence of bleeding. In general, GP IIb/IIIa inhibitor therapy should be stopped; conventional critical care instituted; and platelet tra nsfusions considered if the platelet count is < 10,000/cm(3), if there is s evere bleeding, or if an emergency invasive procedure is required. Readmini stration of GP IIb/IIIa inhibitors may be associated with an increased risk of thrombocytopenia in selected circumstances, and caution is advised if t he patient had previously experienced a significant decline in the platelet count or developed drug-induced antibodies following prior use. Future are as of research should target the mechanism(s) of thrombocytopenia, more acc urate diagnostic methods, and the risk of thrombocytopenia when these drugs are combined with other antiplatelet and anticoagulant agents.