Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharm Block 1 > Pharmacodynamics > Flashcards

Pharmacodynamics Flashcards

1
Q

Definition of pharmacodynamics

A

Mechanisms of action of a drug
Therapeutic uses
Adverse or side effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Definition of pharamcokinetics

A 
Mechanisms by which body handles the drug
Absorption
Distribution
Metabolism
Elimination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Theory of drug interactions

A

Drugs do not create effects, they modify ongoing functions
Effects of the body of most drugs are a result of interactions between the drug and functional macromolecular components of the organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Stages in receptor function

A

Binding (L+R LR)

Transduction (LR -> Effect)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Alternatives to receptor-mediated drugs

A

Enzyme inhibitors
Transport inhibitors
Ion channel inhibitors
Note all of these still tend to follow the same paradigm as receptor-mediation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Characteristics of receptors

A

Specificity: Receptors are targeted by specific drugs
Selectivity: Receptors target a specific subset of cell pathways
Sensitivity: Effects at receptors are amplified within the cell, therefore, only a small amount of drug is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pharmacological Classification Schema

A

Structural features of ligands (Muscarinic, Nicotinic cholinergic receptors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Biochemical Classification Schema

A

Based upon transduction mechanism (Metabotropic vs ionotropic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Molecular/Structural Classification Schema

A

Families of similar gene products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Definition of Kd

A

Dissociation constant at equilibrium
Kd = [L][R]/[LR] = k2/k1
Inverse of affinity
Units of M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Equation of [LR]

A

[LR] = Rt*[L]/(Kd + [L])

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Characteristics of Ionic Bonds

A

Receptors have charged amino acids
Ligands are weak acids or bases and are charged at physiological pH
Major determinant of k1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Characteristics of Hydrogen Bonds

A

Hydrogen bound to an electronegative atom will have a partial positive charge
Weaker than ionic bonds, and require close proximity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Characteristics of Van der Waals interactions

A

Hydrophobic interactions
Act only at very close distances
Greatly strengthen the binding interaction and are the major determinant of k2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Occupancy theory

A 
Effect is directly proportional to [LR]
E/Emax is proportional to [LR]/Rt
E = (Emax * C)/(Kact + C)
C = [Drug]
EC50 = Kact
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Efficacy in occupancy theory

A

Idea of intrinsic activity for a ligand (0 < α < 1)
E/Emax = α[LR]/Rt
Full agonist: α = 1
Antagonist: α = 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Spare receptors

A

Effector units are limiting factor, not receptors
Results in EC50 not being equal to KD
Increases a cell’s sensitivity to low ligand concentration and low activation time

18
Q

Classes of antagonists

A

Chemical: Combines with agonist to disallow interaction
Physiological: Activates an oppposing physiological target (ACh vs Norepi)
Pharmacological: Blocks effects of agonist at site of action

19
Q

Competitive Antagonist

A

Blocks target site of the drug
If reversible then it can be surmounted by agonist
Apparent affinity loss

20
Q

Equation for EC50’

A

EC50’ = EC50(1 + [I]/Ki)

21
Q

Implications of competitive therapeutic use

A

Dependence upon both its concentration and the agonist concentration
Antagonist with highest affinity for the receptor will produce the greatest inhibition

22
Q

Irreversible Competitive

A

Covalent binding to site or in an effectively irreversible rate
Reduces receptor pool
Assuming no spare receptors, no change in affinity (EC50), but efficacy decreases (Emax)

23
Q

Implications of irreversible therapeutic use

A

New receptor synthesis is the only way to overcome the effects of the antagonist
Degree of inhibition produced is not influenced very much by the concentration of agonist present

24
Q

Noncompetitive Antagonist

A

Binds to receptor at different target site

Decreases efficacy, completely irrespective of affinity even with spare receptors

25
Q

Implications of noncompetitive therapeutic use

A

Independent of agonist concentration of receptor
Can be used to inhibit the effects of multiple agonists that use the same signal transduction cascade (inhibition of voltage operated calcium channels)

26
Q

Partial agonist

A

Partial agonist decreases effect of agonist

27
Q

Tonic Activity

A

Equilibrium between active and inactive receptor states
True antagonist does not have effect so it does not alter basal equilibrium
Agonist and partial agonists shift equilibrium towards active state
Inverse agonist shift equilibrium toward inactive state

28
Q

Dose Response Theory

A

Ideally follows pharmacodynamical models in vitro

Issues from pharmacokinetics causes non-idealized behaviors (absorption, distribution, metabolism, excretion)

29
Q

Definition of potency

A

Drug response equivalent of affinity (EC50 => ED50)

Result from site affinity, delivery to site

30
Q

Definition of efficacy

A

Drug response equivalent of Ema
Determinants: intrinsic activity, characteristics of effector, limits on amount that can be actually given in dose (risks of adverse effects)

31
Q

Deviations from sigmoid response curve

A

Additive effects of the drug
Threshold effects
Antagonist effects
Need to be considered for therapeutic purposes

32
Q

Population dose response curves

A

Response frequency: Log-normal
Culmulative response: Log-sigmoid

You didn’t see that coming, did you?

33
Q

Causes for dose response variations

A

Pharmacokinetic differences
Variations in the amount of endogenous agonist present
Changes in the number of functioning of the drug target
Differences in a component distal to the drug target

34
Q

Definition of idiosyncratic drug responses

A

Unexpected based upon the mechanism of actions of the drug

35
Q

Definition of hyporeactive and hyperreactive

A

Tails of frequency distribution

36
Q

Definition of hypersensitivity

A

Allergic or inflammatory response to the drug

37
Q

Definition of tolerance

A

Slowly developing resistance to the drug

38
Q

Definition of tachyphylaxis

A

Rapidly developing resistance to the drug

39
Q

Quantal dose response curves

A

Culmulative frequency relationships between drug dose and population response
Shape of curve reflects the variability in response the population

40
Q

Parameters from quantal dose response curves

A 
ED50 - Median effective dose
TD50 - Median toxic dose
LD50 - Median lethal dose
Therapeutic index (Ti) = TD50/ED50

Pharm Block 1 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions