The nurse gives 800 mg of a drug that has a half-life of 8 hours. How much drug will be left in the body in 24 hours if no additional drug is given?

Question

Quizplus · Accepted Answer

The drug has a half-life of 8 hours, which means that half of the drug will be eliminated from the body after 8 hours. 
After another 8 hours (total of 16 hours), half of the remaining drug will be eliminated. 
After 24 hours (3 half-lives), the remaining amount of drug can be calculated as follows:

800 mg / 2 = 400 mg after 8 hours 
400 mg / 2 = 200 mg after 16 hours 
200 mg / 2 = 100 mg after 24 hours

Therefore, 100 mg of the drug will be left in the body in 24 hours if no additional drug is given.

The Nurse Gives 800 Mg of a Drug That Has