Acute profound thrombocytopenia following abciximab therapy

OBJECTIVE: To report a case of acute, profound thrombocytopenia (APT) defin ed as an abrupt drop in platelet count to 20 000/mm(3) that occurred within 24 hours of administration of an abciximab bolus, to summarize other abcix imab-associated APT cases reported in the literature, to review the postula ted mechanisms behind this reaction, and to emphasize the importance of per iodically monitoring platelet counts after initiating abciximab therapy. DATA SOURCES: MEDLINE and Index Medicus searches restricted to English-lang uage literature from 1993 through June 1999 were conducted. MeSH headings i ncluded abciximab, ReoPro, thrombocytopenia, and glycoprotein IIb-IIIa (GP IIb-IIIa) inhibitors. References of the articles obtained were also reviewe d. DATA EXTRACTION: Search and evaluation were focused on published case repor ts and reviews of abciximab-induced APT, as well as the incidence of thromb ocytopenia from the drug compared with that from other GP IIb-IIIa inhibito rs. DATA SYNTHESIS: Platelet aggregation has been identified as the structural basis for coronary thrombosis. This may lead to ischemic complications duri ng acute coronary syndromes or following coronary intervention procedures. The use of GP IIb-IIIa inhibitors such as abciximab as antiplatelet agents has bee effective in reducing these ischemic complications. We summarize 15 published cases of abciximab-associated APT gathered from data on 2482 pat ients treated wit the drug. Prior to suspecting abciximab, other potential causes of thrombocytopenia should be evaluated. It is important to monitor the platelet count at baseline, two hours after initiating abciximab, and 2 4 hours after initiation of therapy or prior to discharge, whichever comes first, to identify patients at risk for developing APT. If APT occurs and i s left untreated, it can produce excessive hemorrhage and ischemia, potenti ally leading to death. Platelet transfusion shave been more effective than immunoglobulin in the management of APT. CONCLUSIONS: Abciximab-induced APT has a low incidence of occurrence. It it does develop and is not recognized or treated promptly, it can lead to ser ious hemorrhagic complications. Consequently, monitoring the platelet count two hours after initiation of the infusion is essential. If APT develops, abciximab should be discontinued and a platelet transfusion should be consi dered.