Which drugs are classic antiplatelet agents?

• A. Heparin, Warfarin
• B. Aspirin, Clopidogrel
• C. Alteplase, Streptokinase
• D. Montelukast, Cromolyn

Answer: (B)

Antiplatelet therapy aims to prevent platelet aggregation and arterial thrombosis. Aspirin and clopidogrel are classic examples because they act directly on platelets to reduce their ability to clump together.

Aspirin works by irreversibly inhibiting the enzyme COX-1 in platelets, which lowers production of thromboxane A2, a chemical that promotes platelet activation and aggregation. Since platelets don’t have the machinery to make new COX-1, this effect lasts for the platelet’s whole life span, helping to prevent clot formation in arteries.

Clopidogrel blocks the P2Y12 ADP receptor on platelets, preventing ADP-mediated platelet activation and aggregation. This is a separate pathway from aspirin, and together they provide complementary antiplatelet effects in many settings, such as after certain heart procedures.

The other drugs listed aren’t antiplatelets: heparin and warfarin are anticoagulants that target the coagulation cascade in plasma; thrombolytics like alteplase and streptokinase dissolve clots; and montelukast and cromolyn are used for asthma/allergic conditions, not to inhibit platelets.

So aspirin and clopidogrel are the classic antiplatelet agents.