Warfarin is a drug used as an anticoagulant. After administration of the drug is
ID: 2855450 • Letter: W
Question
Warfarin is a drug used as an anticoagulant. After administration of the drug is stopped, the quantity remaining in a patient's body decreases at a rate proportional to the quantity remaining. Suppose that the half-life of warfarin in the body is 39 hours.
Sketch the quantity, Q, of warfarin in a patient's body as a function of the time, t (in hours), since stopping administration of the drug. Mark 39 hours on your graph.
(A) Write a differential equation satisfied by Q:
(B) How many days does it take for the drug level in the body to be reduced to 20 percent of its original level?
time =____________________ (Include Units)
Explanation / Answer
(A) -kQ
(B) 39 *(log 5/ log 2) = 90.56 hours