An Asian American Man and His Caucasian Wife Are Both

An Asian American man and his Caucasian wife are both taking warfarin (Coumadin) daily because of atrial fibrillation.The husband asks why he is prescribed a much smaller than average dose of the drug to keep his international normalized ratio (INR) at 2.0 and his wife takes the average dose even though he is taller and heavier than she is.What is the nurse's best response?

A) "Body size is not important for warfarin but gender differences are because testosterone improves its action."
B) "You are probably anemic,which would reduce your ability to form blood clots,so your doses can be lower."
C) "Many Asian Americans do not break down warfarin as fast as Caucasians,so the drug is more effective at lower dosages."
D) "Caucasians have higher levels of the enzyme that breaks down warfarin,requiring higher dosages for the same effect on INR."