Drug Elimination

Question 1

what is the principal organ for drug elimination?

Answer 1

kidneys

Question 2

what happens to drug plasma concentration when rate of absorption > rate of elimination?

Answer 2

increases

Question 3

what happens to drug plasma concentration when rate of absorption = rate of elimination?

Answer 3

peaks

Question 4

what happens to drug plasma concentration when rate of absorption < rate of elimination?

Answer 4

decreases

Question 5

what is clearance?

Answer 5

the volume of blood cleared of drug per unit time

Question 6

what is CLr?

Answer 6

renal clearance

Question 7

what is CLh?

Answer 7

hepatic clearance

Question 8

what is CLo?

Answer 8

clearance by other elimination routes

Question 9

what is CLt?

Answer 9

total clearance

Question 10

why is clearance important?

Answer 10

helps determine the dosage rate needed to maintain a desired plasma drug concentration

Question 11

how do you calculate CL?

Answer 11

rate of drug elimination/plasma drug concentration

Question 12

what does first order kinetics refer to?

Answer 12

the rate of drug elimination increases as plasma drug concentration increases

Question 13

what does zero order kinetics refer to?

Answer 13

when elimination mechanisms become saturated and reach Vmax

Question 14

when does drug plasma concentration reach a steady state?

Answer 14

when rate of drug administration = rate of elimination

Question 15

what is t1/2?

Answer 15

elimination half life

Question 16

what does elimination half life determine?

Answer 16

the time required for plasma drug concentration to achieve steady state

Question 17

what effect does ageing have on t1/2?

Answer 17

decreases

Question 18

what effect does obesity have on t1/2?

Answer 18

increases

Question 19

what effect does pathological fluid have on t1/2?

Answer 19

increases

Question 20

what effect does cytochrome P450 have on t1/2?

Answer 20

induction = decreases 
inhibition = increases

Question 21

what effect does cardiac failure have on t1/2?

Answer 21

increases

Question 22

what effect does hepatic failure have on t1/2?

Answer 22

increases

Question 23

what effect does renal failure have on t1/2?

Answer 23

increases