Pharmacology and Agonists

Question 1

AGONIST

Answer 1

Activates the (β-2) like adrenaline

Mimic the key in the lock and key model

Question 2

Antagonist

Answer 2

Block the (β-1); decreases heart rate

Question 3

Adrenaline

Answer 3

Activates a and b adrenoceptors

Question 4

Dopamine

Answer 4

Binds to dopamine receptors

Question 5

Receptor, as molecular switch;

Answer 5

Receptor receives the drug > and then binds which activates it > response

Question 6

Salbutamol (anti-asthma) - AGONIST

Answer 6

acts on same site where adrenaline binds to the B-2 receptor and gives a SIMILAR physiological response

Question 7

Propanolol (Anti-hypertensive) - ANTAGONIST

Answer 7

Block B-2; decreases heart rate

it binds to the receptor where Receptor, as molecular switch
is meant to go = BLOCKS adrenaline

can’t occupy the receptor
will not be ay response for the adrenaline

Question 8

ability of drug to bind to receptor is

Answer 8

affinity

Question 9

Agonists have both ‘a_____’ and ‘e_____’

Answer 9

affinity
efficacy

Question 10

ability of drug to have a pharmacological response on receptor (activate the receptor)

Answer 10

efficacy

Question 11

Antagonists have only ‘affinity’ (no efficacy)

Answer 11

therefore does NOT activate the receptor - blocks receptor to chemicals

Question 12

Free drug and sub-drug will reach _____ .
Ratio will be equal.

Answer 12

equilibrium

Question 13

Drug action measures? Binding (association & dissociation)

Answer 13

D + R <> DR
Law of mass action
forward and backward reaction will be equal

Question 14

k

Answer 14

rate constant

Question 15

equation to measure drug action

Answer 15

[D] [R]/ [DR]= k reverse rate / k forward rate = kD

Question 16

kD

Answer 16

Equilibrium Dissociation Constant

Question 17

Drug action measures?
What is the equation for; Receptor occupancy?

Answer 17

X = DR
1-X = R

D + R <> DR

kD = [D][R] / [DR] = [D] (1-X) / X

kD = [D] (1-X) / X

X = [D] / [D] + kD

Question 18

What would be the receptor occupancy?

Answer 18

x = kD / kD = kD = 0.5

Question 19

kD ALSO defined as the conc of drug required to occupy __% of receptors: MEASURE OF DRUG AFFINITY

Answer 19

50

Question 20

the lower the conc the receptor the _____ the % measure of drug affinity

Answer 20

higher

Question 21

lower kD value; what kind of affinity

Answer 21

drug is well bound to receptor - better affinity

Question 22

parabolic curve

Answer 22

when arch is very steep and line goes straight at end

Question 23

how to easily figure out the 50% occupancy?

Answer 23

sigmoid curve

put drug conc in Log (M) - curve will be easier to identify when 50% is occupied

Question 24

1000 micromolar = millimolar

Answer 24

1 millimolar

Question 25

Rmax is the

Answer 25

maximum occupancy (saturated)

Question 26

Agonist Potency:

Answer 26

EC50 - Effective Concentration of agonist for 50% response

Question 27

Potency (EC50) is often lower than Affinity (kD)???
1. drug effect
2. drug binding

Answer 27

drug effect comes before (lower) drug binding

Question 28

receptor > response

Answer 28

amplification of signals

Question 29

Spare receptors/ receptor reserves

Answer 29

if there are antagonist (going to use them up)

agonist CANNOT bond to receptors

Question 30

if occupation is at 50% what will the percentage of response be?

Answer 30

100%

Question 31

if agonist produces less than 100% max response with maximal receptor occupation - the response:

Answer 31

40% (lower)

Question 32

partial agonist good or bad drug?

Answer 32

appears to be an effective and possibly a superior treatment option for patients with schizophrenia

Question 33

What is the best agonist - related to graphs

Answer 33

one showing a maximal response (steep line)

Question 34

Which drug is least potent?

Answer 34

calculate both on graph potency and compared

what is the drug conc when the response is at 50%?