Pharm 4 Flashcards
1
Q
Pharmacodynamics
A
action of the drug inside the body. deals with physiological/biochemical effects of drugs, their mechanism of action at macromolecular/subcellular/organsystem levels
2
Q
how do drugs work
A
modifying underlying biochemical/physicological process_..NOT de novo
3
Q
physical properties of drugs
A
mass, adsorptive property, osmotic activty, radioactivty
4
Q
how do laxatives work
A
draw water into lumen
5
Q
mass examples
A
bulk laxatives –> bran,
methylcellulose
6
Q
adsorbtion
A
binding to a drug
7
Q
adsorptive property examples
A
charcoal, kaolin
8
Q
osmotic activity examples
A
magnesium sulfate, mannitol
9
Q
example of a diuretic
A
mannitol draws water into the kidney to remove water
10
Q
radioactivity example
A
iodine
11
Q
chemical properties
A
antacids like Al(OH)3,
Mg(OH)2 neutralize gastric HCL
12
Q
example of a drug acting on an enzyme
A
enalapril inhibits ACE
13
Q
example of drug acting on receptor
A
most durgs
14
Q
actions of drug receoptr interaction
A
molecular/conformational changes,
alteration of enzyme activity,
changes in permeability/transport processes,
cascade of changes leading to a response
15
Q
types of drug action
A
stimulation,
depression,
replacement,
cytotoxic
16
Q
stimulation
A
selective enhancement of the level of activity of specialized cells
17
Q
epinephrine stimulates
A
heart
18
Q
pilocarpine stimulates
A
salivary gland - PNS stimulant
19
Q
depression
A
selective diminution of activity of specialized cells
20
Q
barbiturates depress
A
cns reticular activating system and produce sleep
21
Q
quinidine depresses
A
heart - antiarrithemic
22
Q
drugh that stimulates one cell and depresses another cell type
A
acetylcholine
23
Q
replacement examples
A
insuline in diabetes mellitus,
levodopa in parkinsonism
24
Q
cytotoxic effects examples
A
anticancer drugs produe cytotoxic actions against neoplastic cells,
antibiotics produce cytotoxic action against microbes
25
most drugs act by
binding to receptors
26
functions of receptors
propagation of signals from outside to inside,
amplify the signal,
adapt to short term and long term changes
27
receptor families
channel linked/ligand gated,
g protein linked/coupled,
kinase linked,
intracellular receptor
28
channel linked (ligand gated)
ionotropic,
selective ion channel Na, K, Ca, Cl,
drug binding results in opening or closing of chnnel,
fastest (milliseconds)
29
g protein linked/coupled
metabotropic - cell membrane receptors linked through g proteins to effector mechanisms which include --adenylyl cyclase, phospholipase C,
channel regulation,
takes seconds to produce
30
kinase linked
(minutes) enzyme linked receptor,
phosphorylation of tyrosines .
Mst imp is to transport glucose receptors to surface
31
intracellular receptor
(hours) in cytosol or nucleus,
take longer time bc proteins need to be made,
eg steroids
32
channel linked examples
nicotinic cholinergic receptors,
| GABA a and NMDA receptors
33
g protein examples
alpha and beta adrenergic receptors,
| histamine receptors
34
kinase linked examples
insuline
35
intracellular receptor examples
steroids, tyroxine, vit-D
36
ligand gated ion channel example
cholinergic nicotinic receptors
37
affinity
the bility of the drug to bind to the receptors
38
intrinsic activity (IA)
ability of a drug to activate the receptor and produce the response
39
agonist
drug which binds to the receptor, activates it and produces the response
40
what has both affinity and intrinsic activity
agonist
41
examples of agonists
morphine, epinephrine, acetylcholine
42
antagonist
binds to the receptor but will not activate the receptor
43
what has affinity but no intrinsic activity
antagonist
44
examples of antagonists
prazosin (alpha rec), atenolol (beta rec), atropine (muscarinic rec)
45
partial agonist
it will activate the receptor but produce submaximal response (however, antagonizes the action of a full agonist)
46
example of a partial agonist
pentazocine --partial agonist at opioid receptor
47
what agonist will produce unsurmountable antagonism
noncompetitive binding at an alosteric site
48
inverse agonist
activates the receptors to produce an effect in the opposite direction to that of agonist
49
example of inverse agonist
beta carbolines produce the effects opposite to diazepam
50
affinity + IA (1)
agonist
51
affinity + IA (0)
antagonist
52
affinity + IA (0 to 1)
partial agonist
53
affinity + IA (0 to -1)
inverse agonist
54
drug potency
the amount of drug needed to produce the response (lower the doe required, higher will be the potency and vice versa)
55
drug efficacy
the maximum response of the drug (more important)
56
the position of the dose response curve on the dose axis is an index of
drug potency
57
the upper limit of the drug response curve is an index of
efficacy of the drug
58
steep slope in the DRC indicates
small increase in does markedly increases the response
59
the steepest part of the DRC is witing
25-75% of drug dose (30-70% is said to be linear)
60
types of dose response relationships
graded dose response, quantal(all or none) dose response
61
graded dose response
gradual increase in concentration and thereby response in one individual, animal, or tissue but only to a limit
62
ceiling effect
seen when further increase in dose does not exhibit the increase in response which occurs at a ceiling dose. Denotes all receptors are occupied.
63
shape of graded dose response relationship
hyperbolic curve plotting dose, sigmoid if plotting log dose
64
graded dose response relationship is significan in
studying the effect of drug on single tissue or animal,
determining the potency and efficacy of drugs,
studying the comparison between agonists and antagonists
65
quantal (all or none) dose response
studies the influence of the magnitude of the dose on the proportion of a population that response;
shows if the determined response is seen with a given dose or not at all
66
is quantal dose response a continuous relationship
no
67
quantal dose response is significant in determining
median effective dos (ED50) median lethal does (LD50) and therapeutic index (TI)
68
therapeutic index formula
TI = LD50/ED50
69
the gap btw the therapeutic and adverse DRC indicates
safety margin of the drug or therapeutic index
70
the higher the therapuetic index
the better bc a small increase won't lead to toxicity
71
combined effects of drugs
synergism and antactonism
72
interaction of drugs can occure on a
parmacokinetic level or pharmacodynamic level
73
synergism
when the action of one drug is faciitated or inreased by the other
74
types of synergism
additive and supraadditive (potentiation)
75
does a synergistic drug have to produce an effect if given alone
no
76
additive synergism
effect of (A + B) = effect of A + effect of B
77
additive synergism: asprine + acetaminophen
an analgesic/antipyretic
78
additive synergism: nitrous oxide + ether
general anesthetic
79
additive synergism:ephedrien + theophylline
bonchodialator
80
supraadditive (potentiation) synergism
```
when 2 or more drugs are given together the effecto of combination is greater than the individual effects of the comonents :
effect of (A + B) > effect of A + effect of B
```
81
supraadditive (potentiation) synergism: acetylcholine + physostigmeine
physostigmine prevents the breakdown of acetylcholine
82
supraadditive (potentiation) synergism: levodopa + carbidopa
carbidopa is a dopacecarboxylase inhibitor-->less levodopa metabolism/ dopamine prodicued in the periphery, more for CNS
83
supraadditive (potentiation) synergism: sulfamethoxazole + trimethoprim
sulfamethoxazole blcks folate synthase and trimethoprim blocks folate reductase. Individually they are bacteriostatic but together they are bacteriocidal (cotrimoxazoles). Sequential blockade/folate inhibition
84
antagonism
```
when one drug decreases or inhibits the action of another:
effect of (A + B) < effect of A + effect of B
```
85
types of antagonism
physico-chemical, physiological/functional, receptor/pharmacological
86
physicochemical antagonsim
two drugs that react chemicallly and form an inactive product
87
Physico-chemical example
EDTA (anticoagulant and metal chelator) complex with heavy metals
88
physiological/functional antagonism
tow drugs actig through different receptors or mechanisms produce opposite effects
89
physiological/functional antagonsim example
histamine and epinephrine on bronchial tissue (epi will reduce bronchoconstriction but they act on their own receptors), insuline and glucagon on blood glucose levels
90
receptor/pharmacological antagonism
two drugs action through the same receptors or mechanisms produce opposite effects or one prevents another from producing pharmacological effects
91
receptor/pharmacological antagonism example
beta blockers occupy beta receptors and preent epinephrine from binding and producing effects--stimulation of the heart is decreased
92
types of receptor/pharmacological antagonsim
competitive/equilibrium/reversible type, noncompetitive/nonequilibrium/permanent type
93
receptor - comp vs noncomp
same rec vs different allosteric site
94
compared to agonist - comp vs noncomp
resembles agonist vs does not resemble agonist
95
DRC - comp vs non comp
parallel rightward shift vs flattening
96
effect - comp vs noncomp
reduces affinity/potency by inactivating agonist molecules vs reduce intrinsic activity by inactivating receptors
97
intensity of response - comp vs noncomp
depends on concentration of both agonist and antagonist vs depends only on the concentration of the antagonist
98
competitive antagonist examples
Ach - atropine,
morphine - naloxone,
prazosin - epinephrine
99
noncompetitive antagonist
diazepam--bicuculline,
| phenoxybenzamine (irreversible alpha 1 blocker) and epinephrine
