Konorev Pharm Lect Pharmacodynamics Receptors

Question 1

what is an inert binding site?

Answer 1

a component of the biologic system to which a drug binds without changing any function

Question 2

covalent bonds are reversible or irreversible?

Answer 2

irreversible; in order to get rid of response, must get new receptor made

Question 3

which of the following processes are studied by pharmacodynamics?
A. metabolism of the drug in the liver
B. excretion of the drug with urine
C. relaxation of bronchial smooth m. by a drug
D. absorption of the drug from the site of administration

Answer 3

C

effect on body

Question 4

which of the bonds will most likely make binding of the drug to a receptor irreversible?

Answer 4

covalent

Question 5

what quantitatively describes the relationship between a drug and its effects?

Answer 5

dose-response curve

Question 6

what is the typical result of the plot of drug dose (x) vs. drug effect (y)?

Answer 6

hyperbolic curve

Question 7

what is the first portion of the dose-response curve? second?

Answer 7

linear phase; plateau phase

Question 8

what is a more common presentation of dose-response curve?

Answer 8

logarithmic drug dose, creates sigmoid curve

Question 9

what is Emax?

Answer 9

maximal effect that is produced by the drug

Question 10

what is ED50?

Answer 10

(effective dose 50) the dose of a drug that produces 50% of its maximal effect

Question 11

what does affinity describe?

Answer 11

how readily and tightly a drug binds to a receptor

Question 12

What is the constant for describing affinity?

Answer 12

Kd

Question 13

The lower the KD the ___ the affinity?

Answer 13

higher

Question 14

what is selectivity?

Answer 14

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

Question 15

what does intrinsic activity describe?

Answer 15

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

Question 16

what does an agonist do?

Answer 16

binds to receptor and induces a change that produces a physiological response
has intrinsic activity

Question 17

do antagonists have effect without presence of agonist?

Answer 17

no

Question 18

what do full agonists do?

Answer 18

fully activate receptors, maximal pharm effect when all receptors are occupied, maximal intrinsic activity

Question 19

what are inverse agonists?

Answer 19

decrease receptor signaling, decrease response at receptors with a significant level of constitutive receptor activity, intrinsic activity is present and related to the inhibition of receptor function

Question 20

In the absence of other drugs, Pindolol causes an increase in HR by activating B-AR. In the presence of highly effective B-AR stimulants Pindolol causes a decrease in HR. Therefore, Pindolol should be classified as…?

Answer 20

A partial agonist

– partial agonist replaces where full agonist binds

Question 21

the effect of an inverse agonist on a receptor activity in the absence of other ligands will be?

Answer 21

inhibition of the baseline receptor activity

Question 22

what do competitive antagonists compete with?

Answer 22

endogenous chemicals or agonist drugs for binding of the receptor, can be displaced from receptor by other drugs (effects are surmountable)

Question 23

are binding of non-competitive surmountable?

Answer 23

no

Question 24

cholestyramine is a bile-acid binding resin that is used for the treatment of hypercholesterolemia. It absorbs aspirin, preventing its absorption in GI tract and antagonizing its effects. What is cholesyramine an example of?

Answer 24

chemical antagonist

Question 25

Isoproteernol relaxes bronchial smooth m. by activating B-adrenergic receptors while pilocarpine causes contraction of this muscle by stimulating muscarinic receptors. What type of antagonism exists between isoproterenol and pilocarpine?

Answer 25

physiological antagonism

Question 26

what is a receptor?

Answer 26

a specific molecule in a biological system that plays a REGULATORY ROLE

Question 27

how do we control adverse effects of a drug?

Answer 27

avoid systemic administration

use highly selective drugs

Question 28

what does potency describe?

Answer 28

the amount of drug required to produce a specific pharmacological effect

Question 29

what does efficacy describe?

Answer 29

the maximal pharmacological effect that a drug can produce

related to the total number of receptors available to bind a drug= Bmax

Question 30

what is a quantal dose response?

Answer 30

binary answer yes or no,

did the pts on drug A lose 10+lbs

Question 31

what is an example of a graded response?

Answer 31

dose-response curve that depicts the mean amount of weight loss in a group of pts

Question 32

what is a therapeutic window?

Answer 32

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

Question 33

median effective concentration (ED50) in the example below is 0.4 while median toxic (TD50) is 40. The value of therapeutic index (TI) is:

Answer 33

100