Name two commonly used anticoagulants.

Warfarin and Heparin are two commonly used anticoagulants that serve critical roles in the management and prevention of thromboembolic events.

Warfarin is a vitamin K antagonist that works by inhibiting the synthesis of vitamin K-dependent clotting factors in the liver, such as factors II, VII, IX, and X. This decreases the blood's ability to clot, making it effective for conditions like atrial fibrillation and venous thromboembolism.

Heparin, on the other hand, is an antithrombotic that works by activating antithrombin III, which in turn inactivates thrombin and factor Xa, leading to an immediate anticoagulant effect. Heparin is often used in hospital settings for patients undergoing surgery or those with acute coronary syndrome, due to its rapid action.

The other options listed do not consist of anticoagulants. Aspirin and Ibuprofen are non-steroidal anti-inflammatory drugs (NSAIDs), Acetaminophen is an analgesic and antipyretic, and Clopidogrel is an antiplatelet drug, which prevents platelet aggregation but does not function as an anticoagulant. Dabigatran is indeed an anticoagulant,