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Flashcards in pharmacology Deck (10)
1

what factors affect distribution

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

2

what types of drugs bind to albumin

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

hyperalbuminemia causes a decrease in free drug levels and vice versa

3

What is the rate of distribution of hydrophilic drugs dependant on

diffusion characteristics (rate limiting step)

4

what is the rate of distribution of lipophilic drugs dependant on

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

5

what could cause hypoalbuminaemia

hepatic disease
malnutrition
renal disease
burns

6

will ionised drugs diffuse across cell membranes?

no

7

what affects capillary diffusion

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

8

where might specialised barriers be found

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

usually lipid drugs can cross

9

what is the apparent volume of distribution

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

10

what does Vd vary with

height
weight
age
fluid accumulation
fatness