aspirin + clopidogrel + prasugrel + ticagrelor

This is a combination of four oral antiplatelet drugs—aspirin, clopidogrel, prasugrel, and ticagrelor. All are used to prevent platelet aggregation and reduce the risk of thrombotic cardiovascular events such as heart attack and stroke. Aspirin acts as a cyclooxygenase (COX) inhibitor, blocking thromboxane A2 production to inhibit platelet activation[1][2]. Clopidogrel and prasugrel are thienopyridines that irreversibly inhibit the P2Y12 ADP receptor on platelets, preventing ADP-mediated platelet activation for the lifespan of affected platelets[4][6]. Ticagrelor is a cyclopentyltriazolopyrimidine that reversibly inhibits the same P2Y12 receptor but does not require metabolic activation; it has a faster onset and offset than thienopyridines[4][6]. These agents are typically used in dual or triple combinations for acute coronary syndrome (ACS), percutaneous coronary intervention (PCI), or secondary prevention in high-risk patients. The simultaneous use of all four agents together is not standard clinical practice due to an extremely high risk of bleeding; instead, various two-drug combinations (most commonly aspirin plus one P2Y12 inhibitor) are recommended depending on patient characteristics and indication[4][5][6].