Abciximab or Abcixifiban is a platelet aggregation inhibitor drug sold under the name ReoPro (also called c7E3 Fab as it is a Fab fragment of the chimeric human-murine monoclonal antibody 7E3). It can decrease platelet aggregation for up to two days after administration, which is intravenous. Abciximab is an antigen binding fragment that targets glycoprotein IIb/IIIa receptors on the outer membrane of human platelets. It acts as an integrin (integrin alpha-IIb and integrin beta-3) receptor antagonist - thus, binding of abciximab to integrin receptor will block any large molecule to attach on the receptor, which will lead to block any associated signal transduction pathways: in this case, those involved in platelet aggregation are inhibited as fibrinogen and other adhesive molecules are blocked by abciximab. In the vein, abciximab causes a conformational change in the integrins on the surface of activated platelets. This prevents the binding of fibrinogen to these integrins, which in turn prevents the platelets from being held together by these fibrinogen fibres. The conformational change also prevents the binding of von Willebrand factor to the platelets, which also prevents aggregation and adhesion. It also binds to vitronectin (αvβ3) receptor found on platelets and vessel wall endothelial and smooth muscle cells. It also blocks the Mac-1 receptor on monocytes and neutrophils thus inhibiting monocyte adhesion. Altogether, abciximab increases bleeding time when administered. It has an initial plasma half-life of less than ten minutes and a second phase half-life of about half an hour, likely related to GPIIb/IIIa binding kinetics; however, it may occupy receptors for weeks due to its strong affinity. Abciximab is commonly used in the clinic during coronary artery procedures to prevent clotting during surgery.

Abciximab Drug Action References