Multiple Dosing

Question 1

When V is < 42 L it means that

Answer 1

the drug is distributed in vasculature and to some extent in
interstitial or extracellular fluid space (ECF). It is not extensively distributed into the peripheral tissues.

Question 2

how much

Answer 2

FD

Question 3

how often

Answer 3

tau (dosing interval)

Question 4

we give second and subsequent doses at

Answer 4

constant time intervals

Question 5

as successive doses are given, if next dose(s) is given before drug is completely eliminated, drug will begin to

Answer 5

accumulate in the body

Question 6

Css

Answer 6

plasma concentration at steady-state

Question 7

loading C

Answer 7

FD/V

Question 8

accumulation ratio formula

Answer 8

1/1-e^-k tau

Question 9

Css,max formula

Answer 9

Question 10

Css,min formula

Answer 10

Question 11

AR definition

Answer 11

relates the initial concentration to Css; indicates extent to which drug accumulates under the dosing regimen

Question 12

Decay

Answer 12

e^-kt’

Question 13

Formula at any time (t’) during the steady-state

Answer 13

Question 14

Rate in formula

Answer 14

FD/tau

Question 15

Rate out

Answer 15

Cl * Css,avg

Question 16

At plateau

Answer 16

Cl * Css,avg = FD/tau

Question 17

Css, avg formula

Answer 17

Question 18

Ass, avg

Answer 18

average amount of drug in the body over the dosing interval

Question 19

accumulation ratio

Answer 19

amount after a single dose to amount after “n” doses

Question 20

AR formula

Answer 20

Question 21

C1, max * AR

Answer 21

Css, max

Question 22

C1, min * AR

Answer 22

Css, min

Question 23

AR is only determined by

Answer 23

tau

Question 24

t1/2 is only determined by

Answer 24

Cl & V

Question 25

Tau is irreversibly proportional to

Answer 25

AR

Question 26

DL formula

Answer 26

Question 27

Which parameters are altered when tau is increased?

dose is given less frequently

Answer 27

decreases AR, Css avg, Css max, Css min

Question 28

Does changing tau affect the time to reach steady state?

Answer 28

Changing tau does not affect the tss, since tss is based on
half-life. It does however affect the steady state concentrations.