chapter 4: properties of drugs

Question 1

four components of pharmacokinetics

Answer 1

absorption, distribution, metabolism, elimination

Question 2

passage of a drug from the site of administration to the bloodstream; passes through membranes

Answer 2

absorption

Question 3

administration into a muscle

Answer 3

intramuscular

Question 4

administration directly into the bloodstream; the only route that doesn’t have to pass through a membrane

Answer 4

intravenous

Question 5

administration under the skin

Answer 5

subcutaneous

Question 6

administration under the tongue

Answer 6

sublingual

Question 7

administration on the skin (e.g. nicotine patch)

Answer 7

transdermal

Question 8

route of administration with a rapid absorption time

Answer 8

inhalation

Question 9

route of administration with immediate absorption time

Answer 9

intravenous

Question 10

route of administration most common for many drugs of abuse

Answer 10

inhalation

Question 11

passive movement across membranes

Answer 11

diffusion

Question 12

when administered into the body, drug molecules will either become __________ or remain neutral

Answer 12

ionized

Question 13

how many molecules of a drug stay neutral upon administration depends on the __________ of the tissue

Answer 13

pH

Question 14

ideal pH of a drug when we take it

Answer 14

neutral (7)

Question 15

are drugs ionized or neutral when we take them?

Answer 15

neutral

Question 16

calculates the ratio of ionized vs. neutral drug molecules, depending on the pH of the tissue and the pKa of the drug

Answer 16

henderson-hassleback equation

Question 17

the pH level at which half of the drug will be absorbed

Answer 17

pKa

Question 18

will drugs with a pKa close to the local pH have more neutral or ionized molecules than those with a pKa further away from the local pH?

Answer 18

neutral

Question 19

what characteristic of a tissue can overcome pKa/pH differences (e.g. the small intestine, the lungs)?

Answer 19

large surface area

Question 20

process of drug molecules separating from the pill or solution (binder) in which they were delivered

Answer 20

liberation

Question 21

the passage of a drug from the bloodstream to sites (target tissue) in the body

Answer 21

distribution

Question 22

ability of a drug to reach a site of action; percentage of the initial dose that actually reaches its target

Answer 22

bioavailability

Question 23

binding of a drug to sites that are not the intended target for a drug’s effect

Answer 23

nonspecific binding

Question 24

drug binds to proteins in the bloodstream and doesn’t leave the bloodstream

Answer 24

protein binding

Question 25

drug binds to other receptors that elicit no effect

Answer 25

depot binding

Question 26

barrier that surrounds the blood vessels in the brain and prevents substances in the blood from entering the brain

Answer 26

blood-brain barrier

Question 27

what is the biggest barrier to the distribution of psychotropic drugs?

Answer 27

blood-brain barrier

Question 28

diffusion of molecules across the BBB

Answer 28

passive transport

Question 29

very few molecules can enter the brain by passive diffusion because they have to be __________ soluble, __________ charge, and __________

Answer 29

lipid, neutral, small

Question 30

uses membrane channels or transporters that allow the passage of chemicals across the BBB

Answer 30

active transport

Question 31

converting a drug into one or more metabolites (enzymatic transformation)

Answer 31

biotransformation/metabolism

Question 32

what family of enzymes is involved in phase one of biotransformation?

Answer 32

CYP450

Question 33

drugs must be __________ soluble to enter the body and __________ soluble to leave the body

Answer 33

lipid, water

Question 34

what process occurs during phase one of biotransformation?

Answer 34

catabolism

Question 35

what process occurs during phase two of biotransformation?

Answer 35

conjugation

Question 36

during conjugation, metabolites become __________, more __________, and less __________ soluble

Answer 36

bigger, charged, lipid

Question 37

in these people, enzymes are slower or there are fewer of them; medication will last longer in the body and they will need a lower dose

Answer 37

poor metabolizers

Question 38

in these people, enzymes are faster or there are more of them; need a higher dose

Answer 38

rapid metabolizers

Question 39

metabolism that occurs before a drug enters circulation i.e. in the mouth, stomach, intestines, liver, etc.

Answer 39

first-pass metabolism

Question 40

a drug's metabolite that has its own physiological effect (e.g. dopamine as a metabolite of L-DOPA)

Answer 40

active metabolite

Question 41

a physiologically weak or inactive compound metabolized in the body to produce an active drug (e.g. codeine becomes morphine via first-pass metabolism)

Answer 41

prodrug

Question 42

process for how a drug leaves the body

Answer 42

elimination

Question 43

amount of drug eliminated from the body over time

Answer 43

elimination rate

Question 44

constant elimination rate, regardless of concentration of the drug (e.g. alcohol)

Answer 44

zero-order kinetics

Question 45

non-constant elimination rate i.e. half lives (e.g. caffeine)

Answer 45

first-order kinetics

Question 46

a sustained concentration of drug in the body over multiple doses (i.e. high enough to have an effect without reaching toxic levels)

Answer 46

steady-state concentration

Question 47

pufferfish toxin; blocks sodium channels

Answer 47

TTX

Question 48

how well a drug binds to the receptor

Answer 48

binding affinity

Question 49

the effect a drug has on the receptor

Answer 49

receptor efficacy

Question 50

binding to its receptor causes receptor activation (NTs)

Answer 50

natural ligand

Question 51

binding to a receptor causes receptor activation; mimics the function of a NT

Answer 51

agonist

Question 52

binding to a receptor causes some activation, but not the maximal effect; diluted effect of the NT

Answer 52

partial agonist

Question 53

binding to a receptor does not cause activation and prevents the natural ligand (NT) from binding

Answer 53

antagonist

Question 54

binding to a receptor produces the opposite effect of the natural ligand (NT)

Answer 54

inverse agonist

Question 55

antagonist that prevents NT binding to the receptor

Answer 55

competitive

Question 56

antagonist that does not prevent the NT from binding but prevents activation of the receptor

Answer 56

noncompetitive

Question 57

a binding site on a receptor that is different than where the NT binds (i.e. a drug and NT can act on the same channel at the same time)

Answer 57

allosteric binding site

Question 58

bind to the same site on the receptor where the NT binds

Answer 58

orthosteric ligands

Question 59

bind to a different site on the receptor than where the NT binds

Answer 59

allosteric ligands

Question 60

increases the ability of a NT to bind to and/or activate the receptor

Answer 60

positive regulator

Question 61

decreases the ability of a NT to bind to and/or activate the receptor

Answer 61

negative regulator

Question 62

an adaptation that increases a drug's effects

Answer 62

sensitization

Question 63

an adaptation that weakens a drug's effects, requiring greater doses to achieve the desired effects

Answer 63

tolerance

Question 64

type of adaptation to drug use that reduces the amount of drug reaching the target organ (i.e. increasing enzymes, faster metabolism)

Answer 64

pharmacokinetic

Question 65

type of adaptation to drug use that reduces the responsiveness of the target organ to the drug

Answer 65

pharmacodynamic

Question 66

type of adaptation to drug use that reduces the drug effect from learned behaviour and environmental cues

Answer 66

behavioural

Question 67

type of adaptation to drug use in which conditioned physiological responses counteract the drug's effects; depends on the presence of drug-associated stimuli

Answer 67

conditioned

Question 68

type of adaptation to drug use in which frequent use of one drug leads to tolerance for other drugs with similar biological actions

Answer 68

cross

Question 69

collection of responses that occur when a drug is no longer administered

Answer 69

withdrawal syndrome

Question 70

withdrawal effects that include drug cravings or mood changes; often result from the body's compensatory adaptive changes to drug actions

Answer 70

psychological effects