03: Dose Response Relationship 3

Question 1

In a graded drug response, how does dose relate to effect?

Answer 1

Dose is related to the INTENSITY of the effect

Question 2

In a quantal drug response, how does the dose relate to the effect?

Answer 2

Dose is related to the FREQUENCY of the effect

Question 3

How is a drug’s quantal effect studied? (Single Biological Unit/Population Studies)

Answer 3

Population Studies

Question 4

Is a graded drug response measured on a continuous scale or in an “all or none” pharmacological effect?

Answer 4

Continuous Scale

Question 5

What does the term Potency mean in respect to drugs?

Answer 5

The amount of drug needed to produce a given effect

Question 6

What quality of the drug molecule has the largest influence on its potency?

Answer 6

Its affinity for the target receptor

Question 7

Is potency of great concern to clinicians?

Answer 7

Not really because the potency can be controlled through the dosage

Question 8

How is potency expressed?

Answer 8

EC50 (uM)

ED50 (mg/kg)

Question 9

This term describes the maximal effect that can be produced by a drug

Answer 9

Efficacy

Question 10

Which molecules have the lower maximal effect? Partial Agonists or Full Agonists?

Answer 10

Partial agonists

Question 11

What property of the drug has the largest influence on its efficacy?

Answer 11

The receptor-effector system

Question 12

What is more important clinically, the drugs potency or its efficacy?

Answer 12

Efficacy

Question 13

What is the difference between a Full Agonist and a Partial Agonist in terms of their ability to induce a conformational change in their target receptors?

Answer 13

A partial agonist can only induce some degree of receptor activation; but not enough to induce a maximal response

The full agonist leads to a conformational change that results in full activation of the receptor response

Question 14

What does the shape of the D-R curve describe?

Answer 14

The drug binding to its receptors

Question 15

What does the steepness of the curve indicate?

Answer 15

The useful dosage range

Question 16

What aspect of the drug is the slope of the curve related to?

Answer 16

The toxicity

Question 17

Are D-R curves with steep slopes more or less toxic?

Answer 17

More, because you get to the max with a smaller dose

Question 18

Change in efficacy with or without changing the ED50

Answer 18

Non-competitive Antagonist

Question 19

Change in ED50 without a change in Efficacy

Answer 19

Competitive Antagonist

Question 20

How are toxicity of drugs compared?

Answer 20

By their ED50

Question 21

The question, how many people got sick out of a group of 100 taking a drug? Would be an example of…..(Quantal/Graded)

Answer 21

Quantal

Question 22

When can partial agonists be useful?

Answer 22

When you don’t want to induce a maximal effect

Question 23

Agonist that locks a receptor in an inactive state but produces the opposite of the “real” agonist’s effect.

Answer 23

Inverse Agonist

Question 24

Are antagonists and inverse agonists the same thing?

Answer 24

No. Antagonists just lock up the receptor, they do not produce an effect

Question 25

What will the antagonist “block” from the receptor besides the agonist

Answer 25

Inverse agonists for that receptor as well

Question 26

What is the difference between a competitive antagonist and a non competitive antagonist

Answer 26

Competitive agonists bind in the same site on the receptor

Question 27

How can the effect of an antagonist be overcome?

Answer 27

Increasing the concentration of the agonist

Question 28

What produces a shift to the right (delta ED50/affinity/potency) without changing the Emax/Efficacy

Answer 28

Competitive antagonists

Question 29

With the introduction of a competitive antagonist, does the absolute affinity of the receptor change?

Answer 29

No, but you need to increase the dose of the agonist in order to get the same response; and therefore the relative affinity has been shifted to the right

Question 30

What will depress the Emax and shift the entire curve to the right?

Answer 30

Non-competitive antagonist

Question 31

The effect of what type of antagonist could be considered “taking receptors out of the pool”

Answer 31

Non-competitive antagonists