Lecture 2: What Is a Drug?

Question 1

Explain how a drug works

Answer 1

1. Drug makes transient physical contact with the receptor
2. This causes signal transduction
3. The signal transduction causes a cellular response
4. The cellular response causes a tissue, organ or whole-body response

Question 2

Whats an example of a biological response to a drug?

Answer 2

1. Contraction of a muscle
2. Secretion of a hormone release or a mediator
3. Enzyme activity
4. Membrane depolarisation

Question 3

Whats the most effective way to plot drug dosages and effect of drug?

Answer 3

Plot it logarithmically to give a sigmoid relationship

Question 4

Whats a “wide” therapeutic index?

Answer 4

Means very few people taking an effective therapeutic dose will also experience toxic effects

Question 5

Are drugs and other agonists selective or absolutely specific?

Answer 5

Often selective, particularly for closely related receptors

Question 6

Whats the calculation for therapeutic index?

Answer 6