What is the method of action for both Heparin and Coumadin?

The mechanism of action for both Heparin and Coumadin involves the prevention of the formation of new clots. Heparin, an anticoagulant, works by increasing the activity of antithrombin III, which helps inhibit thrombin and factor Xa, thereby preventing the conversion of fibrinogen to fibrin, a critical step in the clotting process. Coumadin (warfarin) functions by inhibiting vitamin K-dependent clotting factors, which are essential in the synthesis of several key proteins in the coagulation cascade. By interfering with these pathways, both medications reduce the likelihood of clot formation, making them effective in managing and preventing thromboembolic events.

The other options do not accurately describe the primary purpose of these anticoagulants. Neither Heparin nor Coumadin is designed to dissolve existing clots; this is typically a function of thrombolytic agents. Although they may indirectly increase bleeding time as a consequence of their anticoagulant action, this is not their primary method of action. Similarly, while Heparin does activate endogenous anti-clotting factors, its primary role is to inhibit clot formation, aligning with the correct answer.