Flashcards in pharmacodynamics Deck (85)
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1
Actions/effects of the drug on the body
Determines the group in which the drug is
classified and plays a major role in deciding
whether a group is appropriate therapy for
particular symptom or disease
pharmacodynamics
2
Specific molecules in a biologic system with
which drugs interact to produce changes in
the function of the system
RECEPTORS
3
Determine the quantitative relations between
dose or concentration of drug and
pharmacologic effects
RECEPTORS
4
Selective in choosing a drug molecule to bind
to avoid constant activation by promiscuous
binding of many different molecules
RECEPTORS
5
Changes its function upon binding in such a
way that the function of the biologic system
is altered in order to have pharmacologic
effect
RECEPTORS
6
Selective in ligand-binding characteristics
(respond to proper chemical signals and
not to meaningless ones)
Mediate the actions of both pharmacologic
agonists and antagonists
RECEPTORS
7
Majority are proteins which provide the
necessary diversity and specificity of
shape and electrical charge
RECEPTORS
8
Specific binding region of the macromolecule
High and selective affinity to the drug molecule
RECEPTOR SITE/RECOGNITION SITE
9
is the fundamental event that initiates the action
of the drug
Interaction between the drug and the receptor
10
CLASSIFICATION OF RECEPTORS
Best characterized drug receptors
Mediates the action of endogenous chemical
signals like neurotransmitters, autacoids and
hormones
Mediates the effects of the most useful
therapeutic agents
REGULATORY PROTEIN
11
CLASSIFICATION OF RECEPTORS
Inhibited (or less commonly, activated) by
binding a drug
Eg, dihydrofolate reductase, the receptor for
methotrexate
ENZYMES
12
CLASSIFICATION OF RECEPTORS
Eg, Na+/K+ ATPase, the membrane receptor
for digitali
TRANSPORT PROTEINS
13
CLASSIFICATION OF RECEPTORS
Eg, tubulin, the receptor for colchicine,
an anti-inflammatory drug
STRUCTURAL PROTEINS
14
Molecules that translate the drug-receptor
interaction into a change in cellular activity
Eg, adenyl cyclase
EFFECTORS
15
Response of a particular receptor-effector
system is measured against increasing
concentration of a drug
Graph of the response versus the drug
dose
GRADED DOSE-RESPONSE CURVE
16
Sigmoid curve
Efficacy (Emax) and potency (EC50) are
derived from this curve
The smaller the EC
50, the greater the
potency of the drug
GRADED DOSE-RESPONSE CURVE
17
Maximal response that can be produced
by a drug
All receptors are occupied
No response even if the dose is increased
Emax
18
Concentration of drug that produces
50% of maximal effect
Smaller EC
50–more potent
EC50
19
Total number of receptor sites
All receptors have been occupied
Bmax
20
Equilibrium dissociation constant
Concentration of drug required to
bind 50% of the receptors
KD
21
Measure of the affinity of a drug
for its binding site on the receptor
KD
22
Smaller KD
–greater affinity of drug to receptor
23
Transduction process between the occupancy
of receptors and production of specific effect
Highly efficient coupling can be elicited by a
full agonist and spare receptors
COUPLING
24
Maximal drug response is obtained at less
than maximal occupation of the receptors
Not qualitatively different from nonspare
receptors, not hidden or unavailable
SPARE RECEPTORS
25
Temporal in character, when occupied, they
can be coupled to respond, there is still effect
Drugs with low binding affinity for receptors
will be able to produce full response even at
low concentration
SPARE RECEPTORS
26
Compare concentration for 50% of maximal
effect (EC50) with concentration for 50%
maximal binding (KD)
KD > EC50 with spare receptors
SPARE RECEPTORS
27
Effect of the drug-receptor interaction may
persist for a longer time than the interaction
itself
Actual number of receptors may exceed the
number of effectors available
SPARE RECEPTORS
28
Non-regulatory molecules of the body
Binding with these molecules will result
to no detectable change in the function
of the biologic system
INERT BINDING SITES
29
Buffers the concentration of the drug
Bound drugs do not contribute directly
to the concentration gradient that drives
diffusion
Eg, albumin
INERT BINDING SITES
30
