Are Two “Antiplatelet” Drugs Better Than One?
Many different processes are involved in platelet activation. Most drugs affect one of these chemical reactions. Theoretically, platelet functions (secretion, aggregation, and adhesion) can be reduced most effectively by using >1 agent or by inhibiting the final step in the attachment of the platelet to fibrin at the level of the glycoprotein IIb/IIIa (GpIIb/IIIa) receptor. Preliminary experience with oral and intravenous GpIIb/IIIa inhibitors has shown that bleeding is an important problem. In MATCH, 2 platelet function inhibitors, clopidogrel and aspirin, did prevent slightly more strokes (but not with statistical significance) but at the price of significantly more excess bleeding. Killing platelets causes bleeding. What About the Endothelium Platelet Attachment to the Endothelium? Platelets seem to swim happily in the blood until they reach an area of irregular or damaged endothelium, for example, on the surface of an ulcerated atherosclerotic plaque in a large artery. They then st