Metabolism of Drugs - Exam 3

Question 1

definition of metabolism of drugs

Answer 1

chemical alteration of the drug molecule by the cells of the animal

Question 2

bioinactivation

Answer 2

detoxification, most common, parent drug -> inactivate

Question 3

bioactivation

Answer 3

lethal synthesis, “prodrug” -> active drug

Question 4

liver as a site of biotransformation

Answer 4

most common site, sER, hepatocyte cytoplasm, mitochondria, lysosomes, nuclear envelope, plasma membrane

Question 5

other tissue sites of biotransformation

Answer 5

nervous tissue, kidney, GI epithelium, lungs, skin, plasma

Question 6

example of active drug -> active metabolite

Answer 6

aspirin converted to salicylic acid

Question 7

example of inactive drug -> active metabolite

Answer 7

cortisone -> cortisol

prenisone -> prednisolone

Question 8

example of nontoxic drug -> toxic metabolite

Answer 8

parathion -> paroxon

ethylene glycol -> glyoxylic acid “lethal transformation”

Question 9

antifreeze toxicity is an example of ________ ; includes what 2 toxic metabolites

Answer 9

biotransformation; glycoaldehyde & glycoxylate

Question 10

microsomal enzymes

Answer 10

non-specific, large groupings of enzymes, cause oxidation, reduction, hydrolysis, & conjugation to glucuronic acid

Question 11

T/F: enzymatic reactions are saturable

Answer 11

true

Question 12

T/F: enzymes can inhibited or induced by drugs

Answer 12

true

Question 13

Phase I reactions include

Answer 13

oxidation, reduction, hydrolysis; non-synthetic

Question 14

Phase II reactions include

Answer 14

conjugation; synthetic

Question 15

definition of oxidation

Answer 15

loss of one or more electrons by a substance, gain O2, remove H+; most common biotransformation reaction

Question 16

definition of reduction

Answer 16

gain of one or more electrons by a substance, gain H+, remove O2

Question 17

definition of hydrolysis

Answer 17

splitting of a molecule into fragments by the addition of H2O

Question 18

microsomal oxidation phase I

Answer 18

sER

Question 19

nonmicrosomal oxidation phase I

Answer 19

cytoplasm, mitochondria

Question 20

microsomal reduction phase I

Answer 20

reduction of chloramphenicol

Question 21

nonmicrosomal reduction phase I

Answer 21

aldehyde reduction of chloral hydrate

Question 22

lipid soluble drugs must go to phase ____ prior to excretion

Answer 22

II

Question 23

conjugation reactions phase II

Answer 23

combination of a drug or its metabolite with an endogenous substance

Question 24

conjugation is deficient in

Answer 24

neonates & cats

Question 25

metabolite conjugates are usually

Answer 25

inactive, water soluble, and non toxic

Question 26

most common & microsomal conjugation reaction

Answer 26

glucuronic acid (glucurodination)

Question 27

cats are deficient in

Answer 27

glucuronyl transferases

Question 28

dogs are deficient in

Answer 28

acetylating enzymes

Question 29

ruminants have less

Answer 29

plasma pseudocholerestinase

Question 30

ruminants and horses have high levels of

Answer 30

oxidative enzymes

Question 31

pigs are deficient in

Answer 31

sulfate conjugating enzymes

Question 32

birds lack

Answer 32

oxidative enzymes

Question 33

first pass effect occurs with which type of drug administration

Answer 33

oral

Question 34

hepatic first pass metabolism criteria

Answer 34

liver before systemic circulation
metabolized by liver
high hepatic extraction ratio

Question 35

results of hepatic first pass metabolism

Answer 35

drug metabolized before distribution

decrease oral bioavailability

Question 36

enzyme inducers

Answer 36

drugs that stimulate the liver to produce more metabolic enzymes

Question 37

only what enzymes are inducible by drugs

Answer 37

microsomal

Question 38

T/F enzyme induction is irreversible

Answer 38

false

Question 39

examples of drug enzyme inducers

Answer 39

phenobarbital, phenylbutazone, griseofulvin, rifampin

Question 40

enzyme inhibitors

Answer 40

drugs that inhibit liver production of metabolic enzymes

Question 41

examples of drug enzyme inhibitors

Answer 41

chloramphenicol, cimetidine, ketoconazole

Question 42

decreased distribution = decreased

Answer 42

metabolism because less drug can get to the liver

Question 43

what tissue is common site for drug storage

Answer 43

adipose

Question 44

drug storage in other tissues can lead to

Answer 44

re-distribution & delayed clinical effects

Question 45

food enzyme inducer

Answer 45

charbroiled

Question 46

food enzyme inhibitor

Answer 46

grapefruit juice

Question 47

animals in the tropics may have less

Answer 47

biotransformation