Final answer:
Warfarin (Coumadin) is a vitamin K antagonist affecting the synthesis of vitamin K-dependent clotting factors such as factor II (prothrombin), VII (proconvertin), IX (Christmas factor), and X (Stuart-Prower factor), thus prolonging clotting time.
Step-by-step explanation:
Warfarin, also known by its brand name Coumadin, is classified as a vitamin K antagonist. The clotting factors that are impacted by warfarin therapy include several produced by the liver that are essential for blood coagulation. These factors are part of the intrinsic pathway (factor II, VII, IX, and X) and common pathway (prothrombin and fibrinogen) of the coagulation cascade, all of which are vitamin K-dependent.
Warfarin therapy works by inhibiting the synthesis of vitamin K-dependent clotting factors, which are necessary for blood clot formation. The liver requires vitamin K to produce these clotting factors, which include factor II (prothrombin), VII (proconvertin), IX (Christmas factor), and X (Stuart-Prower factor). By limiting the activity of vitamin K, Warfarin prolongs the time it takes for blood to clot, thus acting as an anticoagulant and reducing the risk of blood clots.