Drug Receptor Interaction.

Question 1

What are the strongest bonds that can be formed between drugs and their receptors?

Answer 1

Covalent bonds.

Question 2

What are the weakest bonds that can be formed between drugs and their receptors?

Answer 2

Hydrophobic interactions.

Question 3

What is drug binding?

Answer 3

When the drug binds to a receptor.

Question 4

What is meant when it is said that drug binding is reciprocal?

Answer 4

That certain drugs can only bind to certain receptors.

Question 5

How does the strength of the bond between the drug and receptor affect the activity of the drug?

Answer 5

The stronger the bond, the longer the drug is bound to the receptor and this means the drug will be active for longer.

Question 6

Will all receptors be able to interact with all drugs?

Answer 6

No, individual receptors will only recognise certain classes of drugs.

Question 7

What factor about receptor binding will lead to a strong effect from the drug?

Answer 7

The better the fit between the drug and receptor means the stronger the effect of the drug.

Question 8

Why is the structure of the drug very important?

Answer 8

As the better the drug fits into the receptor, the stronger the drugs effect on the receptor.

Question 9

What dictates the tightness of the binding between the drug and the receptor?

Answer 9

The type of bonds that are formed between the drug and the receptor.

Question 10

How does the strength of receptor binding affect a drugs duration of action?

Answer 10

The stronger the binding the, the longer the therapeutic effect.

Question 11

What is drug affinity?

Answer 11

The strength of attraction between a drug and a binding site.

Question 12

What kind of drug affinity will lead to short term binding?

Answer 12

Weak affinity.

Question 13

What kind of drug affinity will lead to long term binding?

Answer 13

Strong affinity.

Question 14

Does the affinity of a drug dictate the strength of the bodies response?

Answer 14

No, the affinity of the drug does not dictate the strength of the response.

I.e. a drug could have a low affinity by deliver a very large response.

Question 15

What do we use to measure drug affinity?

Answer 15

The KD constant.

Question 16

How do we use the KD constant to measure affinity?

Answer 16

The lower the KD, the higher the affinity.

Question 17

What is the KD constant that we use to measure affinity?

Answer 17

The point when 50% of the targets are occupied by the drug.

Question 18

What is the efficacy of a drug?

Answer 18

How strong the effect of the drug is.

Question 19

What effect are we always trying to achieve with a drug?

Answer 19

The maximum effect.

Question 20

What will be the characteristics of drugs with very strong efficacy?

Answer 20

A maximum effect, irregardless of dose.

Question 21

What characterises drugs with high potency?

Answer 21

They have a high affinity for receptors, even at low concentrations.

Question 22

What is used to compare different drugs within the same class?

Answer 22

Drug potency.

Question 23

Drugs with high potency will have what characteristic?

Answer 23

The higher the potency of the drug the higher the affinity to the receptor.

Question 24

How do we measure drug potency?

Answer 24

By using the EC-50 which is the concentration that leads to 50% of the maximum effect.

Question 25

What is binding selectivity?

Answer 25

The different affinities that drugs will have for different receptors.

Question 26

What is binding specificity?

Answer 26

The specific receptors that a drug will bind too.

Question 27

Will drugs bind to receptors regardless of the concentration of the drug?

Answer 27

No, some drugs will only bind to certain receptors at secific concentrations.

E.g. A certain drug may bind to histamine receptors at low concentrations, but at higher concentrations it may bind to histamine and monoamine receptors.

Question 28

If drug A is more potent than drug B should we give a larger or smaller dose of drug A to achieve the same effect?

Answer 28

If a drug is more potent we can give less of that drug as only a small amount is needed to bind to all of the receptors.

E.g. We need much more of drug B to achieve the same effect as drug A.

Question 29

If drug A is more potent than drug B will it be placed on the left or right of drug B in a graph?

Answer 29

A drug that has a higher potency will be placed to the left of a drug with lower potency as it achieves the same effects at a lower concentration.

Question 30

Do we need a small or large dose of a drug if it is very potent?

Answer 30

We need a smaller concentration a very potent drug to get the full effect of the drug.

Question 31

If drug B is less potent than drug A will it be placed on the left or right of drug A in a graph?

Answer 31

A less potent drug is placed to the right of a more potent drug on the graph.

Question 32

What is a drugs EC-50?

Answer 32

50% of the drugs maximum response.

Question 33

Can drugs with different potencies have the same EC-50?

Answer 33

Yes, as they can achieve their maximum response at different concentrations.

Question 34

What can we learn about a drug if we know its EC-50?

Answer 34

How potent a drug is and what its efficacy is.