Pharmacology of the Nervous System

Question 1

What is pharmacology?

Answer 1

the study of how chemical agents (drugs) can influence the function of living systems.

Better definition:

A chemical substance that interacts with a specific target within a biological system to produce a physiological effect q

Question 2

What are the questions being asked in pharmacology?

Answer 2

How do individual drugs produce their effects?
1) Where is the effect produced?
2) What is the target for the drug?
3) What is the response produced after interaction with this target?

Question 3

Why do people take heroin?

Answer 3

Euphoria
Analgesia (pain relief)
Cough suppression

(this answers what is the response produced after interaction with this drug?)

Question 4

Where is the effect of heroin?

Answer 4

Peri-aqueductal grey region: analgesia

Ventral tegmental area: euphoria

Solitary nucleus (cough centre): cough suppression

Question 5

What is the target for heroin?

Answer 5

Opioid receptors

Question 6

What are the majortiy of drug targets?

Answer 6

Proteins

Question 7

What are the 4 main classes of the proteins being targeted?

Answer 7

1) Receptors
2) Enzymes
3) Transport proteins
4) Ion channels

Question 8

Drugs can act on targets to…

Answer 8

Enhance activation (stimulate an effect) Or
Prevent activation (block an effect from being produced).

Question 9

What is drug selectivity?

Answer 9

Another concept relating to drug targets = drug selectivity

To be an effective therapeutic agent, a drug must show a high degree of selectivity for a particular drug target

Question 10

Below are 4 of the most commonly prescribed drugs (both locally and globally). Which type of drug target do they act on?

1. Atorvastatin
2. Amlodipine
3. Salbutamol
4. Citalopram
   (Note – they are not all CNS drugs)

Answer 10

1. Atorvastatin= enzyme
2. Amlodipine= ion channel
3. Salbutamol= receptor
4. Citalopram= transport protein

Question 11

What is the role of these 4 drugs?
1. Atorvastatin
2. Amlodipine
3. Salbutamol
4. Citalopram

Answer 11

1. Atorvastatin= statin- lowers cholesterol
2. Amlodipine= hypertension
3. Salbutamol= asthma
4. Citalopram= antidepressant

Question 12

What 3 common neurotransmitters have a common structure?

Answer 12

Question 13

What is drug selectivity similar to, has similar concept?

Answer 13

Lock and key

Question 14

What is a side effect?

Answer 14

a side effect is an effect produced by the drug that is secondary to the intended effect.

Question 15

What is a negative side effect called?

Answer 15

If that side effect has negative health consequences, then it is also termed an adverse effect

Question 16

What is a dopamine receptor agonist?

Answer 16

Pramipexole

Question 17

What happens as dosage of pramipexole increases?

Answer 17

Low doses= mostly binds to dopamine receptors

Average doses= binds to serotonin receptors

High doses= binds to noradrenaline receptors

Question 18

What causes side effects?

Answer 18

Due to effects on:

• same target in other tissues
• Different targets
• dependent on the dose of drug administered

Question 19

pramipexole selectivity is what kind of example of a side effect?

Answer 19

off-target effects

Question 20

What organs have dopamine receptors?

Answer 20

Question 21

What are the ‘safest’ drugs?

Answer 21

The ‘safest’ drugs are those where there is a large difference between the dose required to induce the desired effect and the dose required to induce side effects/adverse effects

Drug safety is linked to dose required to induce adverse effect

Question 22

Side effects can be produced by drug action:

Answer 22

a) on other targets in the same tissue or other tissues
b) on the same target in other tissues
c) dependent on the dose of drug administered