Toxicokinetics

Question 1

Most common route of exposure in toxicology

Answer 1

oral

Question 2

____ route important in toxic gases and insecticides

Answer 2

inhalation

Question 3

____ route important in insecticides

Answer 3

dermal

Question 4

____ is where a metabolite is more toxic/important than the parent compound

Answer 4

Lethal synthesis

Question 5

The transfer of the toxin from site of administration to systemic circulation is the

Answer 5

absorption

Question 6

T/F: the smaller the molecular size, the faster the penetration through cell membrane pores

Answer 6

true

Question 7

T/F: increased lipid solubility decreases absorption

Answer 7

false, it increases it

Question 8

T/F: the more non-ionized, the greater the absorption

Answer 8

true

Question 9

T/f: the lower the concentration of the drug at absorptive site, the faster the absorption

Answer 9

False

Question 10

What is first pass effect?

Answer 10

drugs absorbed from GIT –> liver for metabolism
some drugs metabolized before distribution to other tissues
drugs with high first-pass metabolism have less distribution

Question 11

The transport of drugs from plasma to tissues is

Answer 11

distribution

Question 12

Factors that affect distribution

Answer 12

physicochemical properties (lipid solubility, degree of ionization)
concentration gradient
plasma protein binding
blood flow
tissue barriers
affinity to certain tissues

Question 13

what protein do acidic compounds bind to?

Answer 13

albumin

Question 14

what proteins do basic compounds bind to?

Answer 14

a1-glycoproteins and lipoproteins

Question 15

T/F: plasma protein binding shortens a compounds half life

Answer 15

false, it prolongs it

Question 16

T/F: a plasma protein bound compound is inactive

Answer 16

true

Question 17

highly perfused tissues

Answer 17

brain, liver, kidney, endocrine glands

Question 18

poorly perfused tissues

Answer 18

bone, adipose

Question 19

moderately perfused tissues

Answer 19

muscle, skin

Question 20

tissue barriers

Answer 20

BBB, eye, testicles, placenta, mammary gland

Question 21

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

Answer 21

biotransformation

Question 22

main site of biotransformation

Answer 22

liver

Question 23

phase 1 biotransformation reactions

Answer 23

oxidation, reduction, hydrolysis

Question 24

phase II biotransformation reactions

Answer 24

conjugation (synthetic)

Question 25

most common form of biotransformation reaction

Answer 25

oxidation

Question 26

most common conjugation reaction

Answer 26

to glucuronic acid

Question 27

T/F: neonates have a lot of conjugation activity

Answer 27

false it is deficient

Question 28

what species is deficient in glucuronyl transferases?

Answer 28

cats

Question 29

what species is deficient in hydroxylation and dealkylation?

Answer 29

cats

Question 30

what species lack acetylating enzymes?

Answer 30

dogs

Question 31

_____ have high levels of oxidative enzymes

Answer 31

ruminants and horses

Question 32

which species is deficient in methylates?

Answer 32

horses

Question 33

___ lack oxidative enzymes

Answer 33

birdss

Question 34

___ have low levels of drug metabolizing enzymes

Answer 34

fish

Question 35

List some enzyme inducers

Answer 35

phenobarbital, phenylbutazone, griseofulvin, rifampin, chlorinated hydrocarbon insecticides

Question 36

T/F: all enzymes are inducible by drugs

Answer 36

False - only microsomal enzymes are

Question 37

List some enzyme inhibitors

Answer 37

chloramphenicol, cimetidine, ketoconazole

Question 38

T/F: biotransformation continues to increase with age

Answer 38

False, both newborns and geriatrics may have less biotransformation than adults

Question 39

T/F: grapefruit juice is an enzyme inhibitor

Answer 39

True

Question 40

Plasma protein binding ______ biotransformation

Answer 40

decreases

Question 41

Effect of hypothermia on biotransformation

Answer 41

decreases it

Question 42

removal of drug from the body

Answer 42

excretion

Question 43

3 aspects of renal excretion

Answer 43

glomerular filtration active tubular secretion tubular reabsorption

Question 44

4 factors that affect glomerular filtration

Answer 44

GFR, molecular size, molecular charge, protein binding

Question 45

T/F: negative charged particles pass through the glomerulus easier than positive

Answer 45

false - they're inhibited by negatively charged proteins in capillary wall

Question 46

T/F only unbound drugs can be filtered by the glomerulus

Answer 46

true

Question 47

OCTs transport bases and OATs transport acids in active tubular secretion

Answer 47

true

Question 48

4 factors affecting tubular reabsorption

Answer 48

physicochemical properties of the drugs degree of ionization GFR active tubular reabsorption

Question 49

``` The second most important organ for drug excretion (kidney is first) is: A) sweat glands B) spleen C) liver D) tears ```

Answer 49

liver

Question 50

T/F: enterohepatic circulation shortens the half life of a drug

Answer 50

false, it prolongs it