Pharmacodynamics 2 Flashcards Preview

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Flashcards in Pharmacodynamics 2 Deck (14):
1

E-max

Efficacy or the maximal response to drug

2

Potency

Concentration of the drug at which 50% of the maximal response is observed

3

Partial agonist

Elicits a portion of the complete effect, may be more potent than the full agonist, however. Mechanism not fully understood, but probably doesn't completely elicit conformational changes

4

Antagonist

Binds receptor, but no response is seen when antagonist is applied independentaly

5

Physiological antagonist

Works at an independent site from agonist, but has opposing effects

6

Chemical antagonist

Combination of agonist and antagonist, with resulting inactivation of the agonist

7

Competitive antagonism

Binds reversibly to the active site, inhibiting the action of the agonist. Shifts log curve right, or EC50 shift to a decrease in potency

8

Noncompetitive antagonism

Binds active or allosteric site irreversibly, no effect on EC50, decrease in efficacy. Shift down on dose response curve

9

Inverse agonist

Decreases constitutive activity of the receptor activity, antagonist keeps activity at constitutive levels if applied with inverse agonist

10

Mechanism of spare receptors

Don't need 100% of receptors to be filled to get 100% of the response. 1) receptor remains activation after agonist departs. 2) Cell signalling pathways allow significant amplification

11

Quantal dose response curves

All or nothing response, frequency distribution of responders plotted versus the log dose

12

Therapeutic index

Lethal dose 50 / Effective dose 50, larger the TI - the safer the drug

13

Certainty safety factor

Ratio between the concentration of drug that is toxic to 1% of the population vs. the dose that is therapeutic for 99% TD1/ED99, greater the ratio, less toxic the drug

14

Tolerance and tachyphylaxis

Efficacy may change (read decrease) during therapy, if it happens rapidly this is tachyphylaxis.