Issar- Drug Distribution

Question 1

what are the patterns of drug distribution?

Answer 1

drug confined to blood, low m.w/ water soluble, concentrate in specific tissues, non-uniform distribution

Question 2

if volume distribution of a drug is larger, than what would concentration of drug in the plasma be?

Answer 2

smaller. (inversely proportional)

Question 3

how would you find the amount of drug outside the plasma if you are only given volume distribution (Vd) and volume in plasma (Vp)?

Answer 3

(Vd-Vp)/Vd

Question 4

if you are given a drug with a large volume distribution (Vd) what can you imply about the volume in the the plasma?

Answer 4

it will be smaller.

Vp/Vd

Question 5

what equation would be needed to calculate the volume distribution to a particular tissue?

Answer 5

Vd=Vp+(Vt*Kp)

Question 6

describe permeability-limited distribution.

Answer 6

an example would be that polar substances have a hard time entering the brain because of the blood brain barrier, which is extremely selective at letting in polar substances

Question 7

describe perfusion rate-limited distribution.

Answer 7

when cell membranes dont act as anatomical barriers to drug distribution

Question 8

what are the typical characteristics of a protein-bound drug?

Answer 8

pharmacologically inactive, has restricted distribution, cannot be metabolized, cannot be excreted

Question 9

how many moles of protein will one mole of a drug bind too?

Answer 9

one mole

Question 10

what represents almost 60% of total circulating plasma proteins and represents the principal binding protein for a majority of drugs?

Answer 10

albumin

Question 11

what type of binding occurs when you have a low fraction of free unbound fraction? and what would be the volume distribution?

Answer 11

high drug to protein binding. and low volume distribution