Glycoprotein IIb/IIIa Inhibitors
Glycoprotein IIb/IIIa inhibitors have revolutionized interventional cardiology. All act upon the same target receptor, the glycoprotein IIb/IIIa receptor, the final site for platelet aggregation. However, structural differences between the various agents allow them to react with other receptors as well. The clinical significance is not known but is currently a hotbed of study.
Platelet aggregation
There are three agents currently available: abciximab (ReoProÔ , a chimeric monoclonal antibody), tirofiban (AggrastatÔ, an RGD peptidomimetic), and eptifibatide (IntegrelinÔ, a small peptide). A recent study, TARGET, compared tirofiban and abciximab in patients who plan to undergo stenting and found that abciximab was superior to tirofiban at the primary endpoint at 30 days.
A brief review [Topol EJ et al (1999). Platelet GPIIb-IIIa blockers. Lancet 353 (9148):227-31] was recently published. Our guidelines on the use of GP IIb/IIIa inhibitors are available here.
Recent work has focused upon the early ("upstream") use of these agents in acute coronary syndromes.
Finally, the recent development and FDA approval of a point-of-care assay for measuring platelet inhibition may help guide future usage of these important drugs.
David P. Lee, M.D.