intro to pharmacokinetics (drug distribution)

Question 1

what determines ADME

Answer 1

structure of a drug molecule

Question 2

what may be needed for a drug to provide a response

Answer 2

prolonged exposure of the target with the drug

by repeated dosing

Question 3

best way for drugs to get to targets

Answer 3

through blood

Question 4

how much of every person is water

Answer 4

70%

Question 5

what do some drugs bind to in the blood

Answer 5

plasma proteins

Question 6

do drugs bound to plasma proteins have clinical effect

Answer 6

no, only free drugs do

Question 7

is there equilibrium in the drug between those bound to plasma protein and those that are free

Answer 7

yes

Question 8

what happens with drugs not bound to plasma protein

Answer 8

more of the drug can leave to
- go to the target
- be metabolised
- be excreted

drugs bound have much less concentration leaving to do those things

Question 9

do free drugs or drugs bound to plasma proteins stay around for longer

Answer 9

drugs bound to plasma proteins stay around for longer

Question 10

how do drugs leave the circulatory system

Answer 10

through pores

Question 11

is there many pores in CNS

Answer 11

no, makes it harder for drugs to leave

Question 12

once the drug enters the cell can they still bind to other things

Answer 12

yes, can bind to mitochondria etc

Question 13

what is in the central compartment (two compartment model)

Answer 13

water and proteins

Question 14

what does the drug do in the central compartment

Answer 14

equilibrates between free and bound drug

only free drug in the water can get to targets

Question 15

what is the second compartment made up of (two compartment model)

Answer 15

proteins and lipids
water

Question 16

what happens to the drug in the second compartment

Answer 16

equilibrate between free and bound drugs

Question 17

what happens to drugs with high plasma protein affinity

Answer 17

they stay in the blood

Question 18

what happens to drug with high tissue protein affinity

Answer 18

it all goes to the tissues

Question 19

what volume is the water compartment

Answer 19

0.07L/kg

Question 20

how is drug distribution measured

Answer 20

measure of how distributed drug is between blood and tissue

Question 21

Vd of blood

Answer 21

0.06L/kg

Question 22

what does it mean is Vd of drug is 0.06L/Kg

Answer 22

drug stays in the blood

Question 23

what does it mean if drug has a Vd of 0.25L/kg

Answer 23

the drug stays in water, blood and extra vascular fluid

can’t get into cell

Question 24

what does it mean is Vd of drug is 0.07L/Kg

Answer 24

the drug stays in the cells, blood and water

Question 25

what does it mean if Vd is less than 0.7L/Kg

Answer 25

the drug must leave the water and go into the tissues

means very little free drug in water as its all in tissues and you must give more drug to get to target

Question 26

what does Vd of less than 0.7l/kg mean in terms of half life

Answer 26

it is greater and it can’t be excreted as its all in tissues

Question 27

do drugs that are lipophilic have low of high Vd

Answer 27

high

Question 28

do drugs that are hydrophilic have low of high Vd

Answer 28

low as can’t get into cells easily

Question 29

are acidic drugs highly plasma bound or free drugs

Answer 29

highly plasma bound as they are attracted to albumin (plasma protein)

Question 30

what are basic drugs attracted to

Answer 30

tissues

Question 31

do acidic or basic drugs have a higher Vd

Answer 31

basic have higher Vd compared to acids

Question 32

can drugs with high Vd be removed via haemodialysis

Answer 32

no

Question 33

why does high Vd vary from person to person

Answer 33

high fat content etc

high fat means drug enters adipose tissues
low fat means all drugs go to tissues