A patient with a history of deep vein thrombosis is prescribed warfarin. What happens to Vitamin K-dependent clotting factors when warfarin inhibits Vitamin K epoxide reductase?

💡 Explanation

Warfarin inhibits Vitamin K epoxide reductase, which is crucial for recycling Vitamin K. Because Vitamin K is required for the synthesis of clotting factors II, VII, IX, and X, its inhibition leads to reduced production of these factors; therefore, the synthesis of clotting factors is reduced, rather than enhancing platelet aggregation or fibrinolysis, which would promote clot breakdown.

• Why does prolonged isometric contraction of a muscle, like holding a plank, eventually lead to fatigue despite consistent neural input?
• A researcher observes that neutrophils exposed to interferon-gamma (IFN-γ) exhibit enhanced phagocytosis of Staphylococcus aureus. Why does this occur in the immune response?
• Why does fever increase heart rate, even though cardiac output could initially meet metabolic demands?
• If the diameter of a blood vessel decreases due to atherosclerosis, which consequence follows regarding blood flow and pressure?
• If a muscle biopsy of a marathon runner reveals elevated intracellular lactate levels immediately after finishing a race, which consequence follows regarding muscle fiber function?
• A patient undergoing allergen immunotherapy experiences a localized skin reaction, despite gradually increasing allergen doses. Why does this localized reaction persist during desensitization?