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Flashcards in Pharmacodynamics intro Deck (97):
1

extent of pharm response based on

affinity of active receptor for ligand

2

drug-receptor complex strength is measure of

affinity

3

characteristics that influence affinity

molecular size, shape, and electrical charge of drug

4

binding of drug to receptor often exhibits

stereospecificity--i.e. one enantiomer will form stronger attachment than other--R/L handed molecules may have varying side-effects

5

stereoisomer aka

enantiomer

6

pharmacologic response based on

change to system related to receptor

7

acetaminophen binds to receptor in brain

receptor (cyclooxygenase) won't produce prostaglandins at site --> analgesia

8

receptor that when bound drug result in no physiologic change

inert receptor--i.e. albumin although some indirect effects--

9

Drug-receptor bonds--strong-->weak

1. covalent--share e- --IRREVERSIBLE @ body temp--drug effect lasts much longer--
2. electrostatic or ionic bond--more common reversible bond
3. hydrogen bond--dipole-dipole +_-
4. hydrophobic--very weak--imp in LIPID SOLUBLE d-r interactions

10

time it takes for drug concentration in plasma to be reduced by 50%

elimination half-life--if sustained response likely covalent--aspirin covalent to COX on platelet inhibit clotting

11

All drug receptor bonds reversible except

covalent -- at body temp

12

nonpolar substances as lipid tend to

clmp together rather than distribute in water--so minimal contact w/ water--reversible bond

13

drug receptor interactions often involve

multiple bond types simultanious

14

body's response to drug concentration changes is _______

nonlinear in progression--more change at lower concentrations

15

nonlinear progression of drug response due to

receptors become saturated--plateau reached at max response

16

time before drug takes effect

lag period

17

maximum response of drug

"peak effect"--top of curve builds and tapers (symptoms return)

18

Maximum effective concentration MEC

between desired and adverse responses is THERAPEUTIC WINDOW

19

measurable PARAMETERS of drug effect

1. symptom--i.e. pain
2. sign-- i.e. BP
3. Biological marker

20

time range during which drug concentration exceeds MEC for desired response

Duration of action

21

dose that results in death of 50% of study population

LD50

22

dose necessary to establish effectiveness in 50% of population

ED50

23

Therapeutic index TI =

LD50 / ED50

24

LD50 sometimes replaced with

toxic dose TD
TI = TD50 / ED50

25

Wide TI implies

drug is generally safe--or large dif btwn lethal/toxic dose and ED

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narrow TI implies

drug has safety concerns-- will need close monitoring

27

Can there be more than one therapeutic index TI for a drug?

Yes--for drugs with multiple drug effects (i.e. ibuprofen for pain IN ADDITION TO inflammation) ED may be different depending on symp being treated--window may be narrower

28

measure for comparing 2+ drugs with equivalent pharm responses

Relative potency

29

refering to pharmacologic response generated at given receptor occupancy

potency of drug--EC50 compared

30

when 2 drugs produce equivalent responses the more potent drug on dose response curve is

the drug whose dose response curve lies to the left of the other--less drug required for same effect

31

chemical termed a "drug" when

supplied exogenously

32

#1 receptor-- lipid-soluble ligand--pg7 of outline

crosses plasma membrane to interact w/ intracellular receptor (enzyme or gene transcription regulator)

33

#2 R--Ligand (drug) binds extracellularly to transmembrane protein

activates enzymatic activity within cytoplasm--internal and external domains attached by hydrophobic segment.

34

enzyme that can transfer a P group from ATP to protein in cell

tyrosine kinase-- on/off switch for cellular functions

35

tyrosine kinase subclass of

protein kinase

36

#3 R--ligand (drug) binds extracell to transmem protein structurally bound to protein tyrosine kinase

becomes activated--same as #2 but tyrosine kinase not intrinsic w/ receptor

37

#4 R--Ligand binds to ion channel

activation = opening
1. mimic endogenous ligands--nt's
2. alter membrane potential
3. work quickly

38

#5 R--metabotropic--ligand attaches to receptor linked to G-protein--components:

1. surface receptor
2. G protein at cytoplasmic face
3. change to effector system (ion channel, 2nd mess)

39

second messenger ex's: _____, _______, and _______

cAMP, calcium, cGMP

40

affinity analogy

lock and key--skeleton keys (some keys fit into many locks)

41

if drug-receptor complex is irreversible its likely

covalent bond--

42

- molecule donates e- to + molecule -- treatment with "salt"

most drugs ionic

43

H+ on molecule attracted to negative on receptor

hydrogen bonding--

44

pregnancy risks

A: no risk
B: remote risk
C: benefits outweigh risks
D: evidence of risk--benefits may outweigh risks
X: Contraindicated

45

MEC

minimum effective concentration

46

only dif btwn transmembrane proteins 2 & 3

"machinery" integrated vs. separate, connected molecule that can detach respectively

47

ionotropic speed

miliseconds

48

metabotropic speed

fractions of second

49

#1 receptor ex

lipid soluble--ex. steroid-- approx 30 min lag for protein synth

50

agonist broken into

full and partial agonist--spectrum

51

partial agonist elicits

less than MAXIMUM EFFECT from same tissue as would elicited from total occupancy by full agonis

52

types of antagonists _______ and _______

competitive (reversible)--
noncompetitive (irreversible)-- typically covalent

53

drug that causes an action opposite to that of the agonist when bound

inverse agonist

54

antagonist type that will disallow full agonist rxn despite dose

noncompetitive--irreversible

55

iris sphincter muscle activation by parasymp NS

miosis--contriction

56

ANS integrated for male sexual function

symp=ejaculation
parasymp=erection

57

Always signals coming from ANS but which branch _____ will be based on internal and external environment

predominates

58

pt w/ tachicardia give

beta blocker--IV--antagonize of sympathetic NS

59

atropine for bradycardia--too much parasympathetic tone on SA node

antagonise parasympathetic w/ competitive antagonist for cholinergic muscarinic receptor

60

drug similar to normal functioning of involved receptors

-mimetic

61

drug that inhibits or blocks normal functioning of receptors involved

-lytic ("destroys")

62

______ can play part in pharmacokinetics of drug

Gender--sexual dimorphism

63

down-regulation of receptors

agonist given--body perceives strong signal

64

up-regulation of receptors

antagonist given--body perceives weak signal

65

rapid drug tolerance =

tachyphylaxis--rapid decrease in effectiveness of drug

66

exaggerated response, respectively, in pt when compared to most ppl

hyperreactivity

67

diminished response, respectively, in pt when compared to most ppl

hyporeactivity

68

"start low, go slow"

titration--when drug has ADR's that decrease tolerability of drug

69

titration leads to better _______ of drug

tolerance-- for drugs with low toxic level--i.e. anticoagulants

70

slowing weaning a patient off medication by lowering dose over time

tapering--avoid withdrawals--i.e. systemic steroids

71

if tapering pt off drug and symptoms emerge

slow taper--same for titration

72

mitigate tolerance by

1. taking break from drug
2. switch to drug with same effect by dif mechanism

73

Most drugs produce several effects, _____ _______, is wanted for treatment

therapeutic effect

74

tolerance vs tachyphalaxis

tolerance is blanket term for effect over time--tachyphalaxis happens w/in hours/ days/ mins

75

adverse drug rxns ADR's most appropriately for ________ as opposed to side effects which may be benign

unwanted, unpleasant, noxious, or potentially harmful drug effects

76

2 most common ADRs

* 1. GI disturbance (mostly PO drugs)
2.Allergic rxn

77

GI drug disturbances

exs. loss of apetite, nausea, bloating, constipation, and diarrhea --should be considered for ALL ORAL DRUGS

78

Allergic rxn to drug aka

hypersensitivity rxn

79

types of hypersensistivity drug rxn's -- all involve immune system

type ONE: rapid/immediate after 1st exposure-- mast-cell derived--IgE antibodies attach to drug--anaphylactic
type FOUR: rxn delayed--antigen presented to T helper cells-->macrophages and T killer cells destroy target cell.

80

Type four rxn to drug

Steven-Johnson syndrome & toxic epidermal necrosis presentation--deadly like burn--happens w/ 1st exposure but slow

81

Type one rxn to drug

IgE antibody--requires 1st exposure--presentation w/ urticaria, angioedema, and ANAPHYLAXIS

82

Drug-drug interaction

may increase or decrease concentration of other drug in body

83

D-D interaction--increase drug concentration as found by drug plasma concentration

1. inhibit liver enzyme production
2. slowing excretion by kidney
--drugs given based on normal liver function

84

D-D interaction--decreased drug concentration

1. decrease absorption of drug--i.e. lower stomach pH
2. increase metabolism-- ^ liver enzyme--may look like drug tolerance to clinician (dangerous)
3. increase excretion--

85

smoking can ________ activity of some ______ ________, thus decreasing effectiveness of some drugs

increase, liver enzymes

86

increasing urine acidity will

1. decrease acidic drug excretion
2. increase basic drug excretion

87

decreasing urine acidity will

1. increase acidic drug excretion
2. decrease basic drug excretion

88

drug-drug interaction in terms of pharmacodynamics

are those where the magnitude of the drug effect is changed

89

2+ drugs with same ingredient have added effect/ADR adverse drug rxn

DUPLICATING effect--particularly dangers with OTC drugs--risk toxicity

90

2+ drugs with same effect taken

DUPLICATING effect-- D-D interaction

91

2+ drugs taken with opposite action

OPPOSING effect--decreased efficacy of one or both

92

Anticholinergic side effects

hot as a hare
dry as a bone
blind as a bat
red as a beet
mad as a hatter

93

a ________ __________ or ________ _________ book can be checked for drug-drug interaction

reference book or computer program

94

most important drug-drug interaction DDI to think abt

hepatic enzyme INDUCTION or INHIBITION

95

pt taking multiple drugs--increase DDI risk

polypharmacy

96

age risk for DDI

newborns and elderly have lower physiological function

97

________and _________ diseases will greatly effect drug's ________and ________

liver and renal
metabolism and excretion