"Pharmacodynamic Comparison of Omeprazole Versus Pantoprazole on Platelet Reactivity in Patients With Acute Coronary Syndromes on Dual Antiplatelet Therapy With New P2Y12 Inhibitors" -Trial dOPPLER-

Clopidogrel and Prasugrel are pro-drug necessitating conversion in active metabolites through CYP 450 system (CYP), particularly CYP3A and CYP2C19 isoforms.

These drugs are platelet purinergic receptor antagonists, known as P2Y12. The link between active metabolite of Clopidogrel and Prasugrel to P2Y12 receptor prevents ADP receptor activation and inhibits several events leading to conformational change of platelets, therefore facilitating their activation and aggregation, that is the basis of acute coronary syndromes. Proton pump inhibitors (PPI) are actually considered principal agents reducing gastroenteric bleeding risk associated to antiplatelet therapy. Nevertheless the interaction between PPI and antiplatelet therapy has been object of interest. Several studies demonstrated PPI reduce efficacy of clopidogrel on platelet reactivity. Only few data about Prasugrel are available showing a minor effect of PPI on its antiplatelet activity than clopidogrel. Differing from prasugrel and clopidogrel, ticagrelor is a direct inhibitor of P2Y12, not necessitating biotransformation in the liver; therefore its interaction with PPI remains unclear. Interaction between omeprazole and clopidogrel seems related to high inhibitory activity of PPI on CYP2C19, interfering with the conversion of clopidogrel in its active metabolite.