Chapter 5 - Distribution

Question 1

true or false

if a drug is highly protein bound, the half life will be short

Answer 1

false - prolonged

Question 2

if a drug is highly protein bound, is this linear or nonlinear pharmacokinetics

Answer 2

nonlinear

Question 3

as free drug is excreted and leaves circulation, what happens to protein bound drug?

Answer 3

the bound drug will release from its protein and go into circulation to maintain equilibrium

Question 4

true or false

a drug can bind to proteins not only in the plasma, but in the tissue as well

Answer 4

true

but more focused on plasma proteins

Question 5

true or false

both free and bound drug can be distributed and eliminated

Answer 5

false - only free drug

Question 6

are we able to measure the amount of FREE DRUG in a patient

Answer 6

no – just the total amount

measuring just free drug is too much $$

Question 7

how much plasma is in an average 70kg male

Answer 7

3L

Question 8

3 areas that drug can be distributed

Answer 8

plasma
other body areas (adipose tissue, protein, bone, etc)
plasma proteins

Question 9

name 3 plasma proteins

Answer 9

albumin, alpha glycoprotein, lipoprotein

Question 10

ACIDIC DRUGS principally bind to what plasma protein

Answer 10

albumin

Question 11

BASIC DRUGS primarily bind to what plasma protein

Answer 11

all 3 - albumin, lipoprotein, and alpha glycoprotein

Question 12

minimum VD in an average person

Answer 12

3L

Question 13

true or false

in a normal person, the concentration of plasma proteins usually fluctuates

Answer 13

FALSE - usually constant

if a patient has a certain disease state - changes

Question 14

what will happen if a patient has NO plasma proteins

Answer 14

the entire dose will be free

Question 15

true or false

high plasma protein binding = linear kinetics

Answer 15

FALSE - nonlinear

Question 16

*just an important note

Answer 16

ONLY FREE DRUG CAN HAVE THERAPEUTIC EFFECT!!!!!

Question 17

What is a disadvantage of drug being distributed to other tissues (aside from the target tissue)

Answer 17

side effects

Question 18

formula to determine the fraction of free drug (a)

Answer 18

a = Cfree/C bound + Cfree

Question 19

as alpha decreases, what happens

Answer 19

the amount of free drug increases significantly - need to reduce dose

Question 20

true or false

if the alpha value decreases, we need to increase the dose of the drug

Answer 20

FALSE

there will be more free drug, so need to decrease the dose

Question 21

after the drug molecules have entered the bloodstream, the pattern of DISTRIBUTION is determined by what

Answer 21

PERFUSION to each tissue

Question 22

4 factors that affect drug distribution

Answer 22

-rate of flow of blood

-partition characteristics of the drug between plasma and tissue

-partition coefficient of drug into various tissues

-volume or mass of the tissue

Question 23

if Vd is low, where will the drug remain

Answer 23

drug remains in the plasma and keeps circulating

Question 24

rate of renal plasma flow

this is also known as the rate of…

Answer 24

590-695mL/min

rate of filtration

Question 25

how many perfusion groups are there

Answer 25

4

Question 26

true or false most drugs are water soluble and dissolve in the plasma

Answer 26

true

Question 27

total body water is ____ +____

Answer 27

extracellular fluid + intracellular fluid

Question 28

**true or false our body water content is lowest in infancy

Answer 28

false - highest in infancy. continues to decrease with age. gets to be 58% (~60%) when we get from 16 yrs - adulthood

Question 29

true or false water content does not change with age

Answer 29

false - it does

Question 30

*around ___% of our body weight is water

Answer 30

60%

Question 31

70kg adult. what vol of total water to use for calculation

Answer 31

41L

Question 32

3L of the 41L of total body water is ___

Answer 32

plasma

Question 33

true or false it is not possible for the Vd of a drug to be below 3L

Answer 33

true

Question 34

"the fluid portion of blood"

Answer 34

plasma

Question 35

"the fluid portion of blood in combo with the formed elements - RBC, WBC, platelets

Answer 35

WHOLE BLOOD

Question 36

what is "serum"

Answer 36

the product that's left after fibrinogen, a soluble protein, is removed from the plasma

Question 37

the drug concentration in the ______ correllates to the therapeutic effect (whole blood, plasma, or serum)

Answer 37

plasma

Question 38

are glucose levels checked using whole blood, plasma, or serum?

Answer 38

whole blood

Question 39

"whole blood with the formed elements removed"

Answer 39

plasma

Question 40

"plasma with the fibrinogen removed"

Answer 40

serum

Question 41

what is the easiest way to measure drug concentration - whole blood, plasma, or serum

Answer 41

whole blood however --- not good. not very accurate.

Question 42

are SOLUBLE PROTEINS included in the plasma?

Answer 42

yes - but not the formed elements

Question 43

true or false plasma is whole blood without solid matter and without dissolved matter

Answer 43

FALSE - without solid manner but has manner dissolved in the blood

Question 44

true or false if the Vd is high, the drug concentration in the plasma is likely low

Answer 44

true

Question 45

define volume of distribution

Answer 45

the volume of fluid in which the drug appears to be distributed

Question 46

true or false the volume of distribution is a true physical volume

Answer 46

FALSE - not a true anatomical, physiological, or physical volume it's a calculated volume of the apparent volume - no true physiologic meaning

Question 47

true or false the volume of distribution has not true physiologic meaning

Answer 47

true -- it's a hypothetical volme of body fluid in which the drug appears to be dissolved or distributed

Question 48

is it possible for the dose to be toxic for 1 patient and therapeutic to another?

Answer 48

YES ie - if the drug distributes less in the tissues of 1 patient, (due to the 4 factors mentioned earlier) -- more will be in the plasma. will need to decrease the dose for that patient

Question 49

are we able to measure the drug concentration in the tissue?

Answer 49

no - only plasma

Question 50

if you give a dose and the plasma concentration is low, what does this say about the vd

Answer 50

high vd - a lot is going to the tissues!

Question 51

formula to find volume of distribution

Answer 51

V= Ab/C Ab=total amount of drug in body C = plasma concentration of the drug

Question 52

volume of distribution is the size of a compartment to account for....

Answer 52

the TOTAL AMOUNT of drug in the body

Question 53

true or false protein binding only takes place in the plasma

Answer 53

FALSE - both in the plasma and the tissue

Question 54

is there a difference in body composition between male and female

Answer 54

yes

Question 55

3 components of our body composition

Answer 55

water fat fat-free solids