Lopirel Plus is a fixed-dose combination drug containing Clopidogrel and Aspirin. Clopidogrel is an inhibitor of platelet aggregation. Clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet receptor and the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation. Clopidogrel also inhibits platelet aggregation induced by agonists other than ADP by blocking the amplification of platelet activation released by ADP.
Aspirin is also an antiplatelet agent. Aspirin acts by causing irreversible inhibition of the cyclooxygenase enzyme, which leads to decreased formation of thromboxane A2 and ultimate inhibition of platelet aggregation.