QuestionSBA
QuestionChoice
At 108 hours, three half-lives have passed, meaning that the drug concentration will be at 12.5% of the maximum.
10006925
e
108 hours
QuestionChoice
36 hours is the half-life for digoxin, meaning that the plasma concentration would in theory be exactly 50% of it's peak at this point.
10006922
b
36 hours
QuestionChoice
At 144 hours, four half-lives have passed, meaning that the drug concentration will have reached 6.125% of the maximum concentration. This is higher than 5%, and is therefore incorrect.
10006924
d
144 hours
QuestionChoice
At 72 hours, two half-lives have passed, meaning that the drug concentration will be at 25% of it's maximum.
10006923
c
72 hours
QuestionChoice
The half-life of a drug represents the time taken for it's plasma concentration to fall to half of it's peak plasma concentration. A drug's concentration will fall to 1/32 or 3.125% of it's peak concentration in five half-lives. Given that the half-life for digoxin is 36 hours, it would fall to 25% of peak concentration at 72 hours, 12.5% at 108 hours, 6.25% at 144 hours, and 3.125% at 180 hours. This can be more easily calculated as 36 X 5.
10006921
a
180 hours
Concept
Chapter
2693
4552
Digoxin
Topic
169
Cardiovascular pharmacology
13931
A 64-year-old man is prescribed digoxin for his chronic atrial fibrillation. Digoxin has a half-life of 36 hours.

How long would it take for digoxin to be effectively eliminated from the body (reach a level less than 5% of peak concentration)?
a