Lecture 5- Pharmokinetics

Question 1

what are the pros or oral administration of drugs

Answer 1

convenient
economic
safe (drug absorp. slow so OD less likely)

Question 2

what are the cons of oral administration of drugs?

Answer 2

patient compliance

drug absorp slow (rapid metabolism may cause failure of drug to reach optimum concentration)

Question 3

what are the most important sites of absorption of drugs taken orally?

Answer 3

stomach

small intestine

Question 4

what molecule structures will reduce solubility in lipid (diminish the partition coefficient) and imede absorption?

Answer 4

1. charge
2. polar moities

(makes water more likely to surround and less likely to go through membrane)

Question 5

the …. is the solubility of a drug in a non polar environment

Answer 5

partition coefficient (PC)

Question 6

the larger the PC of a drug, the more likely that the drug will be …

Answer 6

absorbed by passive diffusion

Question 7

… molecules are more likely to be absorbed by passive diffusion than … molecules

Answer 7

smaller

larger

Question 8

pH of stomach that is at rest/empty?

pH of stomach immediately after high protein meal?

Answer 8

4-5

1-2

Question 9

… can dramatically passive diffusion of drugs that are acids and bases

Answer 9

pH

Question 10

aspirin has a pKa of 3.4 so it is better absorbed in the …

Answer 10

stomach

Question 11

codeine has a pKa of 8.1 so it is better absorbed in the …

Answer 11

small intestine

Question 12

facilitated diffusion can happen through …. which are always open or … that let things in when activated

Answer 12

pores

channels

Question 13

facilitated diffusion through pores and channels work …. the concentration gradient

Answer 13

with

Question 14

active transport of drugs are done through … and … transporters

Answer 14

ABC

SLC

Question 15

ABC transporters can …

Answer 15

kick drugs out of cells (*if over expressed, get drug resistance)

Question 16

SLC transporters (exchange Na or K) are important for transport of certain drugs that are…

Answer 16

organic acids or bases

Question 17

5 factors that affect oral absorption of drugs

Answer 17

pH
surface area
gastric emptying
dosage form
drug inactivation

Question 18

other routes to administer drugs other than oral

Answer 18

inhalation
intravenous
intramuscular
subcutaneous
topical

Question 19

parenteral routes to administer drugs

Answer 19

intravenous
intramuscular
subcutaneous

Question 20

capillary penetration:
lipophilic drugs is ….
water soluble drugs through endothelial gaps is….
bigger proteins (>20kd) happens through…

Answer 20

fast
slower
transcytosis

Question 21

bigger proteins penetrate the capillary through transcytosis which is when

Answer 21

vesicles form and are internalized

Question 22

equation for volume of distribution (Vd)

Answer 22

Vd= Q/C
Q=known amt of drug (mg)
C=concentration of drug in blood some time after administration (mg/L)

Question 23

the average person has about … liters of plasma, … liters interstitial space and …. liters of cells

Answer 23

3
9
29

41 total liters

Question 24

if a drug has a large Vd then not much of the drug will be in the …. because it has been distributed to other places (on proteins, in tissues)

Answer 24

plasma

Question 25

the …. is the theoretical volume that would be necessary to contain the total amount of an administered drug at the same concentration that it is observed in the plasma. It is defined as the distribution of a medication btn plasma and the rest of the body

Answer 25

volume of distribution

Question 26

the … of a drug represents the degree to which a drug is distributed in body tissue rather than plasma

Answer 26

Vd

Question 27

a …. Vd indicates a greater amount of tissue distribution

Answer 27

higher

Question 28

is a Vd greater than the total volume of body water possible?

Answer 28

yes (indicates that the drug is highly distributed into tissue)

Question 29

drugs with a high lipid solubility, low rates of ionization, or low plsma binding capabilities have …. Vd values

Answer 29

higher

Question 30

drugs that are polar, more highly ionized or exhibit high plasma binding have …. Vd values

Answer 30

lower

Question 31

Vd may be …. by renal failure and/or liver failure

Answer 31

increased

Question 32

Vd may be …. during dehydration

Answer 32

decreased

Question 33

the general strategy of metabolism of drugs is for the liver to make drugs more … for excretion in the urine

Answer 33

water soluble

Question 34

metabolism of drugs:
phase 1 is to ….
phase 2 is to…

Answer 34

add functional group (make more polar)

conjugation

Question 35

the … is the most important place for drug metabolism

Answer 35

liver