The three glycoprotein-IIb/IIIa inhibitors currently in clinical use, abciximab, eptifibatide and tirofiban, all share the same therapeutic target, namely blockade of the final common pathway of platelet aggregation. However, they differ significantly in chemical structure, in the way in which they block platelet integrin 伪2b尾3, and in specificity for the receptor. Consequently, each drug inhibits platelet function in a different way and it is unclear whether they offer equivalent clinical benefits for the same indication. To date, there have been no clinical trials on the equivalence of these drugs that would enable us to conclude that glycoprotein-IIb/IIIa inhibitors either do or do not exhibit a class effect for any particular clinical indication. Moreover, the findings of meta-analyses carried out for various indications have been inconclusive because the magnitude and direction of the clinical benefits associated with different glycoprotein-IIb/IIIa inhibitors have often diverged. Therefore, the exchange or substitution of one glycoprotein-IIb/IIIa inhibitor for another cannot be recommended beyond the specific indication for which the drug has been investigated and approved.