Chapter 4

Question 1

bioavailability

Answer 1

percent of drug administered that enters the systemic circulation

Question 2

pinocytosis/phagocytosis

Answer 2

type of cellular movement that allows intake of large molecules

Question 3

volume of distribution

Answer 3

indicator of how well a drug is distributed throughout the body

Question 4

what type of molecule can perform passive diffusion

Answer 4

lipophilic, nonionized, small

Question 5

primary site of drug metabolism

Answer 5

liver

Question 6

drug distribution

Answer 6

physiological movement of drugs from the systemic circulation to the tissues

Question 7

induce

Answer 7

describes an increase in the rate of metabolism by an enzyme system

Question 8

ionized

Answer 8

charged

Question 9

passive diffusion movement

Answer 9

high concentration to low concentration

Question 10

active transport movement

Answer 10

low concentration to high concentration

Question 11

what types of drugs absorb well in the GI tract?

Answer 11

hydrophilic drugs

Question 12

which body compartment gets adequate drug levels the fastest?

Answer 12

fat

Question 13

what condition will allow for greater volume of distribution?

Answer 13

normal conditions
dehydrated animals will have less

Question 14

drug affinity

Answer 14

measure of a drug’s strength at which it binds to its receptor

Question 15

bioequivalency

Answer 15

when two drugs would be expected to be essentially the same

Question 16

first-pass metabolism

Answer 16

phenomenon of drug metabolism in which the concentration of active drug is greatly reduced before it reaches systemic circulation because it passes through liver first

Question 17

acidic drug in an acidic environment

Answer 17

nonionized molecules

Question 18

acidic drug in alkaline environment

Answer 18

ionized molecules

Question 19

alkaline drug in acidic environment

Answer 19

ionized molecules

Question 20

alkaline drug in alkaline environment

Answer 20

nonionized molecules

Question 21

ion trapping

Answer 21

occurs when a drug molecules changes from ionized to nonionized form as it moves from one body compartment to another

Question 22

tissue perfusion

Answer 22

relative amount of blood supply to an area or body system

Question 23

free drug

Answer 23

drug that isn’t bound to a protein and is free in blood
penetrates tissues

Question 24

increased protein binding

Answer 24

less free drug

Question 25

decreased protein binding

Answer 25

more free drug

Question 26

more free drug causes more chance for ______

Answer 26

toxicity

Question 27

biotransformation

Answer 27

(drug metabolism) chemical alteration of drug molecules into metabolites by body cells

Question 28

characteristics of metabolites

Answer 28

more hydrophilic, eliminated in urine or bile, wider distribution to tissues or excretion

Question 29

reactions that cause drugs to be altered by metabolism

Answer 29

1. oxidation reactions (lose electrons) 2. reduction reactions (gain electrons) 3. hydrolysis (adding H2O causing split) 4. conjugation (addition of substance which makes drug more water soluble)

Question 30

other sites that can absorb drugs

Answer 30

kidneys, small intestine, brain/neurologic tissue, lungs, skin

Question 31

altered absorption

Answer 31

one drug alters absorption of other drugs (antacids)

Question 32

altered metabolism

Answer 32

same enzyme needed to metabolize more than one drug, slows down metabolizing of both drugs

Question 33

altered elimination

Answer 33

some drugs act directly on kidney and decrease elimination of other drugs (diuretics)

Question 34

microsomal enzyme inducers

Answer 34

drugs that induce enzyme system alter metabolism by causing liver to become more efficient

Question 35

drug tolerance

Answer 35

increased metabolism due to enzyme induction metabolic: drug is metabolized more rapidly with chronic use cellular: decreased cellular receptors with repeated use

Question 36

pathways for elimination

Answer 36

kidneys, liver, intestine, lungs, milk

Question 37

half life

Answer 37

time required for the concentration of drug in the blood to be reduced by half

Question 38

steady-state concentration

Answer 38

drug concentration reaches a plateau where peak concentrations and lowest concentrations are the same after repeated doses of drug

Question 39

minimal effective concentration (MEC)

Answer 39

onset of action begins when drug achieves MEC

Question 40

peak plasma level

Answer 40

elimination rate of drug is equivalent to rate of absorption

Question 41

time to peak

Answer 41

time of administration to the time that the peak plasma level is reached

Question 42

minimum toxic concentration (MTC)

Answer 42

plasma level at which toxic effects are observed

Question 43

loading dose

Answer 43

given to rapidly achieve therapeutic plasma levels

Question 44

dissociation constant K

Answer 44

measure of a drug's affinity for its receptor