The Blood Clotting System Is Blocked Both in Patients with Classical

Multiple Choice

The blood clotting system is blocked both in patients with classical hemophilia and as a result of high doses of coumarin-type anticoagulants.However, coumarin and related drugs can be deadly, whereas hemophiliac patients can live with their clotting disorder.The reason for this difference is:

A) Coumarin and related drugs activate the fibrinolytic system, in addition to blocking the clotting cascade.
B) Only the intrinsic pathway of blood clotting is blocked in hemophilia, but intrinsic, extrinsic, and final common pathways are all blocked in coumarin poisoning.
C) Von Willebrand factor is abnormal in coumarin poisoning but not in classical hemophilia.
D) Coumarin and related drugs inhibit contact phase activation in the intrinsic pathway; this process is intact in classical hemophilia.
E) Fibrinogen is normal in classical hemophilia, but coumarin and related drugs cause the formation of structurally abnormal fibrinogen.