drug distribution

Question 1

drug distribution varies between different body compartments, which are…

Answer 1

bone and teeth, adipose tissue, blood plasma, total body water, extracellular water

Question 2

describe what the apparent volume of distribution is

Answer 2

volume of distribution(Vd) = describes the extent to which the drug partitions between the plasma and tissue compartments

Question 3

give the equation for volume of distribution(Vd)

Answer 3

Vd = dose/[drug] in plasma

Question 4

describe why the word ‘apparent’ is used when talking about volume of distribution

Answer 4

because it is NOT a physical volume, many drugs will have an apparent Vd greater then the volume of water in the body(therefore it is an apparent volume)

Question 5

physiochemical properties largely determine the Vd of a drug, describe how they effect it

Answer 5

hydrophilic/ionised drugs cant cross membrane that easily, so Vd is closer to total body volume water(41L)
lipophilic/hydrophobic drugs can cross membrane more easily and so Vd is greater than the total volume body water