Drug elimination

Question 1

principle organ for drug elimination

Answer 1

kidneys

Question 2

what is drug elimination mostly accomplished by

Answer 2

renal filtration of blood plasma

Question 3

what are water and most electrolytes reabsorbed into

Answer 3

blood circulation in the renal tubules

Question 4

what are not reabsorbed and instead excreted in urine

Answer 4

drug metabolites rendered polar by phase 2

Question 5

clearance

Answer 5

elimination of a drug form the body
volume of blood removed of drug per unit of time

Question 6

what can clearance be broken down into

Answer 6

renal, hepatic, other or total clearanceqh

Question 7

why is clearance important

Answer 7

helps determine dosage rate needed to maintain a desired plasma

Question 8

what is cl indeendant of

Answer 8

dv but both determine elimination half life of a drug

Question 9

clearance calc

Answer 9

rate of drug elimination/ drug plasma

Question 10

vmax

Answer 10

maximal elimination rate

Question 11

first order kinetics

Answer 11

rate of drug elimination increasees as plasma drug conc increases

Question 12

zero order kinetics

Answer 12

elimination reaches max

Question 13

Michaelis menten kinetics

Answer 13

re = vmax x drug plasma/ km + drug plasma

Question 14

km

Answer 14

drug concentration at which rate of elimination is 1/2 vmax

Question 15

drug plasma

Answer 15

drug concentration in plasma

Question 16

steady state

Answer 16

rate of drug administration = drug elimination

Question 17

dosage rate calc

Answer 17

drug plasma x cl

Question 18

elimination half life - t1/2

Answer 18

determines the time required for drug plasma to achieve drug plasma ss and how much time is required for drug to be eliminated from body

Question 19

elimination half life calc

Answer 19

0.693 x vd/ cl

Question 20

how many half lives are required to reach steady state

Answer 20

5

Question 21

determinants of t1/2

Answer 21

cl increases, t1/2 decreases
cl decreases t/12 increases
vd increases, t1/2 increases
vd decreases t/12 decreases

Question 22

effects on volume of distribtuon

Answer 22

aging, decreases t1/2 due to decrease in muscle mass
obesity; t/12 increases
pathologic fluid increases t1/2