Warfarin works by inhibiting which enzyme to reduce Vitamin K-dependent coagulation factors?

Warfarin works by inhibiting which enzyme to reduce Vitamin K-dependent coagulation factors?

• A. Gamma-carboxylase
• B. Vitamin K reductase
• C. Epoxide reductase
• D. Factor Xa

Answer: (C)

Warfarin functions by inhibiting the vitamin K epoxide reductase enzyme, which is crucial in the vitamin K recycling process. This inhibition prevents the conversion of vitamin K epoxide back into its active form, thus reducing the availability of active vitamin K needed for the synthesis of vitamin K-dependent coagulation factors, including factors II, VII, IX, and X, as well as proteins C and S. By impairing the regeneration of active vitamin K, warfarin effectively decreases the concentration of these coagulation factors, leading to an anticoagulant effect. This pharmacological action is essential in the prevention and treatment of thromboembolic disorders. The other options mentioned do not directly explain the mechanism of action for warfarin. Gamma-carboxylase is involved in the carboxylation of glutamic acid residues on clotting factors, which requires active vitamin K. Vitamin K reductase refers more generally to the metabolic pathways involving vitamin K but does not specify the mechanism targeted by warfarin. Factor Xa is a coagulation factor involved in the common pathway of the coagulation cascade, but it is not the enzyme that warfarin directly inhibits. Thus, the inhibition of vitamin K epoxide reductase is the key mechanism through which

Warfarin functions by inhibiting the vitamin K epoxide reductase enzyme, which is crucial in the vitamin K recycling process. This inhibition prevents the conversion of vitamin K epoxide back into its active form, thus reducing the availability of active vitamin K needed for the synthesis of vitamin K-dependent coagulation factors, including factors II, VII, IX, and X, as well as proteins C and S.

By impairing the regeneration of active vitamin K, warfarin effectively decreases the concentration of these coagulation factors, leading to an anticoagulant effect. This pharmacological action is essential in the prevention and treatment of thromboembolic disorders.

The other options mentioned do not directly explain the mechanism of action for warfarin. Gamma-carboxylase is involved in the carboxylation of glutamic acid residues on clotting factors, which requires active vitamin K. Vitamin K reductase refers more generally to the metabolic pathways involving vitamin K but does not specify the mechanism targeted by warfarin. Factor Xa is a coagulation factor involved in the common pathway of the coagulation cascade, but it is not the enzyme that warfarin directly inhibits. Thus, the inhibition of vitamin K epoxide reductase is the key mechanism through which