05-03-2008, 09:32 AM
A 72-year-old man with chronic atrial fibrillation
presents with bruising. He is otherwise well, although he
admits to being concerned about a failing memory and is
taking a host of over-the-counter remedies in an effort to
deal with this problem. His only medicines are furosemide,
digoxin, and warfarin. His physical examination, with
the exception of ecchymoses and irregular heartbeat, is
normal; there is no evidence of cognitive impairment. His
serum chemistry profile and complete blood count are normal.
However, coagulation tests reveal an INRof 7. What
is the most likely cause of this patient™s coagulopathy?
(A) Warfarin overdose
(B) Interaction between digoxin and warfarin
© Dietary change
(D) Interaction between furosemide and warfarin
(E) Use of dietary herbal supplements
presents with bruising. He is otherwise well, although he
admits to being concerned about a failing memory and is
taking a host of over-the-counter remedies in an effort to
deal with this problem. His only medicines are furosemide,
digoxin, and warfarin. His physical examination, with
the exception of ecchymoses and irregular heartbeat, is
normal; there is no evidence of cognitive impairment. His
serum chemistry profile and complete blood count are normal.
However, coagulation tests reveal an INRof 7. What
is the most likely cause of this patient™s coagulopathy?
(A) Warfarin overdose
(B) Interaction between digoxin and warfarin
© Dietary change
(D) Interaction between furosemide and warfarin
(E) Use of dietary herbal supplements