Abciximab binds to the intact platelet GPIIb/IIIa receptor, which is a member of the integrin family of adhesion receptors and the major platelet surface receptor involved in platelet aggregation. This binding is thought to involve steric hindrance and/or conformational alterations which block access of large molecules to the receptor rather than direct interaction with the RGD (arginine-glycine-aspartic acid) binding site of GPIIb/IIIa.
Abciximab inhibits platelet aggregation by preventing the binding of fibrinogen, von Willebrand factor, and other adhesive molecules to GPIIb/IIIa receptor sites on activated platelets. GPIIb/IIIa is the major surface receptor involved in the final pathway of platelet aggregation. Abciximab is thought to proclude GPIIb/IIIa substrate binding via steric hindrance and/or conformational effects rather than by direct interaction with the arginine-glycine-aspartic acid binding site of the receptor.
Most likely removed by opsonization via the reticuloendothelial system when bound to platelets, or by human antimurine antibody production. Excreted renally.