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Flashcards in Intro to Pharmacodynamics Deck (43):
1

Receptor:

what role does it play?

initiates what events?

regulatory role

interacts with a drug and initiates the biochemical events leading to drug effect

2

Drug-Receptor Interaction--> Covalent

-can it be reversed?

-reactivation requires?

Irreversible and reactivation requires resynthesis of the receptor or enzymatic removal of the drug

3

Drug Receptor Interaction--> Noncovalent

-is it reversible?

-how common

reversible, most drugs bind to receptors via non-covalent bonds

4

Strongest to weakest drug receptor interactions

(four)

Ionic>hydrogen>hydrophobic>Van der waals

5

Hyperbolic curve

x axis?

y axis?

drug dose on the x axis

drug effect on the y axis

6

how do you get a sigmoidal dose response curve?

-x, vs y axis

log of drug dose on x

response on y

more common than hyperbolic curve

7

Emax

-define

The maximal effect that can be produced by the drug

8

ED50

The dose of the drug that produces 50% of its maximal effect

9

Graded Response curve:

-what question does it answer?

-What varies continuously?

-represents mean value of what?

Answers the question how much

magnitude of a response varies continously

typically represents the mean value within a population or a single subject

10

Quantal Response:

-question it answers

-type of response

-requires what

-used for what?

all or none; yes-no binary response

-does the response occur or not?

-in how many?

-requires a pre-defined response (death, falling asleep, 10% reduction in bp)

-used to examine the frequency of the number of individuals showing a response within a large population

11

non-cumulative quantal dose-response curve

-define

number or percent of individuals responding at a certain dose of a drug and only at that dose

12

Cumulative quantal dose response curve

-define

number or percent of individuals responding at a certain dose of a drug AND at all doses lower than that dose

13

Therapeutic index:

-what ratio?

-meaning of the value?

TD50/ED50

higher the TI the safer the drug

14

Therapeutic window:

-define

range of doses of a drug or of its concentration in a bodily system that provides for the safe and effective therapy

15

KD:

-meaning of this value

-unit

-low vs high 

KD is the equilibirum dissociation constant, which is the drug concentration at which 50% of the drug receptor binding sites are occupied by the drug

-unit is molar concentration

-lower the value, higher the affinity of a drug for a receptor

Where [L], [R] and [LR] represent molar concentrations of ligand, receptor, and their complex

 

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16

What is the EC50

-how is it different than KD

-It is simply the concentration of agonist required to provoke a response halfway between the baseline and maximum responses. Because the EC50 defines the location of the dose-response curve for a particular drug, it is the most commonly used measure of an agonist’s potency.

-However, the EC50 is usually not the same as the Kd for the binding of agonist to its receptor -- it is not a direct measure of drug affinity.

17

-Magnitude of a drug's effects will be proportional to what?

proportional to the degreee of its interaction with a receptor

18

Drug selectivity:

-define

-measured how?

- property of a drug determined by its affinities at various binding sites

-measured by comparing affinities of a drug to different receprots

-a more selective drug would affect fewer targets over a specific concentration range (therapeutic range)

19

Intrinsic activity:

-define

ability of a drug to change a receprot function and produce a physiological response upon its binding to a receptor

 

20

Agonist

-definition, does it have intrinsiv activity?

bind to the receptor and stabilize it in a particular conformation (usually active), producing a physicological response

*have an intrinsic activity*

21

Antagonist

-define, does it have intrinsic activity?

-effect in absence of an agonist?

-receptor antagonists bind to the receprot but do not change its function. however, they prevent activation of the receport in the presence of an agonist

-don't have intrinsic activity

-don't change function of receptor upon binding

-no pharmacological effect in the absence of an agonist

22

Full agonist:

-when do they produce maximal pharm. effect?

-intrinsic activity levels?

fully activate receptors producing a max pharm effect when all receptors are occupied

-maximal intrinsic activity

23

partial agonist:

-describe activation of receptor

-pharm effect

-intrinsic efficacy

partially activate the receptor upon binding

-produce a sub-maximal pharm effect when all receptors are occupied

-intrinsic efficacy varies depending on drug, but ALWAYS submaximal

24

Inverse Agonists:

-effect on receptor signaling

-constitutive receptor activity?

-intrinsic activity, why?

-decrease receptor signaling

-decrease response at receprotrs with a significant level of constitutive receptor activity

-intrinsic activity is present and related to the inhibition of receptor function

25

Pharmacologic antagonism

Chemical antagonism

Physiologic antagonism

Pharm: (receptor) antagonism action at the same receptor as endogenous ligands or agonist drugs

Chemical: when chemical antagonist makes the other drug not available

Physiologic: occurs between endogenous pathways regulated by different receptors

26

Competitive antagonist:

-compete with what?

-can be displaced by what

-compete with endogenous chemicals or agonist drugs for binding to the receptor

-can be displaced from the receptor by other drugs (effects are surmountable)

27

Non-competitive antagonists:

types, define (x2)

-receptor inactivation is not surmountable

Irreversible antagonists: irreversibly bind to and occlude the agonist site on the receptor by forming covalent bonds

Allosteric antagonists: bind to a site other than the agonist site to prevent or reduce agonist binding or activation of the receptor

28

Competitive antagonism:

-EC50 effect

-Emax effect

-EC50 increases, Emax does not change

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29

Noncompetitive antagonism: 

-effect on EC50

-effect on Emax

EC50 does not change, but Emax decreases

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30

Drug Potency:

-define

-what drugs tend to be more potent

-what value represents drug potency? (lower vs higher)

-Potency describes the amount of drug required to produce a specific pharmacological effect

-drugs with higher affinities for a receptor--> lower KD tend to be more potent

-potency describes the amount of drug required to produce a specific effect and is represented by the ED50--> the lower the value, the more potent

*determines the drug dose that will be used clinically*

31

Drug Efficacy:

-define

-represented by what value?

-efficacy is related to total number of?

-determines clinical what?

-describes the maximal pharmacological effect the drug can produce

-represented by the Emax, the greater the Emax the more efficacious the drug

-efficacy is related to the total number of receptors available to bind a drug, and it determines the clinical effectiveness of a drug

32

Describe increasing potency vs increasing efficacy graphs

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33

microgram

-define

1/1000th of a milligram, which is 1/1000th of a gram

34

1 kg = how many pounds?

2.2

35

Volume:

-tsp, tbsp, ounce, cup

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36

Volume:

-ml/cc

-quart=how many ml? how many pints in quart?

-pint=ml? how many oz in one pint?

-gallon=how many L? quarts in a gallon? pints in gallon?

 

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37

Dosing Frequency abbreviations:

-qd

-bid

-tid

-qid

-qod

-q"x"h

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38

Dosing frequency:

-qam

-qpm

-qhs

-prn

-ac

-pc

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39

Routes of administration:

-od

-os

-ou

-ad

-as

-au

-gtt

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40

Routes of administration:

-po

-sl

-iv

-im

-sq

-pr

-NGT

-OGT

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41

abbreviations:

-ut.dict.

-tra

-kvo

-as directed

-to run at

-keep vein open

42

# of gms in 100ml

W/V%

43