Pharmacokinetics (main slideshow - page 30 and up)

Question 1

where are drugs mostly metabolized

Answer 1

in the liver

Question 2

what is the first phase of drug metabolism

Answer 2

modification that results in adding or exposing reactive groups to the drug

Question 3

what is the second phase of drug metabolism

Answer 3

conjugation of the reactive group with a highly charged, water soluble substrate

Question 4

what are some examples of reactive groups

Answer 4

-OH
-NH2

Question 5

what is the result of drug metabolism

Answer 5

highly charged, sometimes inactive, mostly water soluble compound

Question 6

many Phase 1 reactions of drug metabolism are catalyzed by members of what family

Answer 6

cytochrome P450

Question 7

most drugs are metabolized by what cytochrome

Answer 7

CYP 3A4

Question 8

where does CYP 3A4 exist?

Answer 8

liver and intestinal brush border membrane

Question 9

what kind of drugs are ACTIVATED by metabolism

Answer 9

pro-drugs

Question 10

what are 3 inducers of CYP activity

Answer 10

cigarette smoke
phenytoin
rifampin

Question 11

what are 4 inhibitors of CYP activity

Answer 11

ketoconazole
erythromycin
grapefruit juice
THC

Question 12

true or false: people can be genetically predisposed to have very high or very low CYP activity

Answer 12

True (for specific CYPs)

Question 13

CYP inducers have what effect on therapeutic levels

Answer 13

decrease them (unless its a pro-drug, then they increase the levels)

Question 14

CYP inhibitors have what effect on therapeutic levels

Answer 14

increases them due to accumulation of the drug (unless it’s a pro-drug, then the levels are decreased)

Question 15

excretion of drugs occur mainly from what organ

Answer 15

the kidneys

Question 16

although the kidneys are the main source of drug excretion, what other routes can they be excreted by

Answer 16

the GI tract
lungs
sweat glands

Question 17

true or false: protein-bound drugs are filtered at the kidney

Answer 17

false, they are NOT

Question 18

what kind of drugs are unlikely to be reabsorbed in the kidney

Answer 18

charged drugs

Question 19

true or false: free drugs are filtered at the kidney

Answer 19

true

Question 20

what is the elimination half-life

Answer 20

the time required to reduce the drug plasma concentration by 50%

Question 21

true or false: half life is independent of the dose in most cases

Answer 21

true

Question 22

after how many half lives is 100% of the drug assumed to be eliminated

Answer 22

4-5

Question 23

what is Css

Answer 23

concentration at steady-state whereby absorption=elimination

(aka the levels of the drug stay steady)

Question 24

if a drug is repeatedly administered before the previous dose is completely eliminated, what happens?

Answer 24

the drug levels accumulate with time

Question 25

what does the time to steady-state depend solely on

Answer 25

elimination half life

Question 26

when is steady state attained typically

Answer 26

after 4-5 half lives

Question 27

what two things does the concentration level at Css depend on?

Answer 27

dose/dosage interval bioavailability

Question 28

in a continuous intravenous infusion, what would the dose/dosing interval be named

Answer 28

the infusion rate

Question 29

what is the formula for the concentration level at steady-state

Answer 29

dose/ dosing interval*clearance

Question 30

Css is proportional to:

Answer 30

F/CL dose/dosage interval bioavailability/clearance

Question 31

what is a loading dose used for

Answer 31

to administer a higher initial dose to quickly reach a therapeutic concentration

Question 32

what is the formula for a loading dose

Answer 32

Loading dose=Vd*target concentration

Question 33

what are some physical processes that can cause pharmacological effects

Answer 33

changes in surface tension lubrification adsorption

Question 34

what are some chemical processes that can cause pharmacological effects

Answer 34

neutralization pH changes changes in bodily fluids

Question 35

what is affinity

Answer 35

force of attraction between receptor and drug

Question 36

what is selectivity

Answer 36

degree to which a drug acts on a given target relative to other sites

Question 37

what is agonism

Answer 37

when a drug has affinity for a receptor and binding to that receptor causes a pharmacological response

Question 38

what is antagonism

Answer 38

when a drug has affinity for a receptor and binding to that receptor DOES NOT cause a pharmacological response

Question 39

What 3 things does the dose-response curve determineq

Answer 39

min amount of drug to be used max response a drug can elicit how much to inc the dosage to produce the desired inc in response

Question 40

what is the dose response curve

Answer 40

the relationship between size of an administered dose and the intensity of the response produced

Question 41

what are the two properties of drugs that can be obtained from dose-response curves

Answer 41

efficacy potency

Question 42

what is potency

Answer 42

the amount of drug that must be given to elicit an effect

Question 43

what is efficacy

Answer 43

the largest effect that a drug can produce

Question 44

what is therapeutic drug monitoring

Answer 44

management of drug dosing regimen to keep drug levels within a normal rnage