pharmacology

Question 1

what factors affect distribution

Answer 1

cardiac output and blood flow
plasma protein binding
lipid solubility 
ph of compartments
drug ionisation
capillary permeability

Question 2

what types of drugs bind to albumin

Answer 2

lipid soluble- non specific
weak acids- specific, saturable site

hyperalbuminemia causes a decrease in free drug levels and vice versa

Question 3

What is the rate of distribution of hydrophilic drugs dependant on

Answer 3

diffusion characteristics (rate limiting step)

Question 4

what is the rate of distribution of lipophilic drugs dependant on

Answer 4

rate of delivery to tissues ( rate limiting step) i.e. blood flow

Question 5

what could cause hypoalbuminaemia

Answer 5

hepatic disease
malnutrition
renal disease
burns

Question 6

will ionised drugs diffuse across cell membranes?

Answer 6

no

Question 7

what affects capillary diffusion

Answer 7

surface area
time
type of capillary: fenestrated, discontinuous, continuous

Question 8

where might specialised barriers be found

Answer 8

placenta
chronic abscesses (avascular)
lung infection (vasoconstriction)
BBB

usually lipid drugs can cross

Question 9

what is the apparent volume of distribution

Answer 9

total amount of drug in the body / blood plasma concentration of drug

it is the theoretical volume required to account for the amount of drug in the body

units are litres

think of v = n / c

can be used to determine a loading dose to achieve a desired plasma concentration

Question 10

what does Vd vary with

Answer 10

height
weight
age 
fluid accumulation
fatness