Pharmacokinetics 1

Question 1

the diffusion coefficient ?

Answer 1

1 / square root of the molecular weight

Question 2

uptake of molecule into blood

Answer 2

discussion if lipid soluble and uncharged, carrier or channel or pinocytosis if large

Question 3

ways of administering drug

Answer 3

intravenous - quickest avoids metablism
oral - into gut, metabolism enzymes
rectal - avoid gut
intramuscular - avoid git, e.g. insulin
intrathecal - into CSF e.g. lumbar puncture
inhalation - out and in same way may breath it out

Question 4

What may affect absorption of drug

Answer 4

site administere, molecular weight, lipid solubility, pH, ionisation

Question 5

pka?

Answer 5

used to calculate how much drug charged and how much non charged - only uncharged can cross lipid membranes to other compartments

Question 6

Weak acid drug (aspirin 3.5 pH) in alkaline solution

Answer 6

will dissociate and be trapped in compartment

Question 7

weak base in an acidic solution

Answer 7

will dissociate and trapped

Question 8

how do you trap a weak acid in a compartment ?

Answer 8

give sodium carbonate

Question 9

metformin where is it and what is the transporter

Answer 9

in hepatocytes, transported by OCT1

Question 10

Ways receptor can be desensitised -

Answer 10

decrease coupling with ligand, no longer produces signal, receptor loss