L2 - Pharmacodynamics 2

Question 1

What is the function of an antagonist drug?

Answer 1

To occupy the binding site and inhibit agonist binding.

Question 2

What is the function of an agonist drug?

Answer 2

To activate the target and induce a conformational change.

Question 3

Receptors have 2 functions, what are they?

Answer 3

Recognition and transduction.

Question 4

The tendency of drugs to activate receptors is called…

Answer 4

Efficacy.

Question 5

The tendency of drugs to bind to receptors is called…

Answer 5

Affinity.

Question 6

Why is drug binding reversible?

Answer 6

Because of the weak chemical forces of attraction.

Question 7

There are other inhibitors of receptor-mediated effects such as chemical antagonists, neutralising antibodies and inverse agonists…what do they all have in common?

Answer 7

They all work by binding to the target.

Question 8

What are some other drug targets?

Answer 8

Enzymes, Ion Channels & Tranporters.

Question 9

What can the dose-response relationship tell you?

Answer 9

1. describe the therapeutic potencies. 2. describe the effectiveness of a drug. 3. describe the adverse effect of drugs.

Question 10

How can adverse effects be described on the dose-response curve? (hint: there are 3 ways)

Answer 10

Some drugs bind single targets….

1. but may produce adverse effects because the targets are widely distributed and multifunctional.
2. and produce few adverse effects but if taken too much can be bioconverted to metabolites and cause severe toxicity e.g. paracetamol
3. Some drugs are more likely to produce adverse effects because they bind to multiple targets (i.e. are non-selective)