Thread: decay rate of drug

This problem is long, no idea how to start this..plz help
Suppose that sodium pentobarbital is used to anesthetize a dog. The dog is anestheized when its bloodstream contains at least 45 milligrams (mg) of sodium pentobarbitol per kilogram of the dog's body weight. Suppose also that sodium pentobarbital is eliminated exponentially from the dog's bloodstream, with a half-life of 5 h. what single dose should be adminstered in order to anesthetize a 50-kg dog for 1 h?

Originally Posted by DMDil

This problem is long, no idea how to start this..plz help
Suppose that sodium pentobarbital is used to anesthetize a dog. The dog is anestheized when its bloodstream contains at least 45 milligrams (mg) of sodium pentobarbitol per kilogram of the dog's body weight. Suppose also that sodium pentobarbital is eliminated exponentially from the dog's bloodstream, with a half-life of 5 h. what single dose should be adminstered in order to anesthetize a 50-kg dog for 1 h?

Substitute and t = 5 into and solve for k. So:

.

Substitute and and solve for .