Pharmacology of NS

Question 1

What is pharmacology?

Answer 1

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

Question 2

What is a drug?

Answer 2

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

Question 3

What are three main effects of heroin?

Answer 3

Euphoria
Analgesia
Cough suppression

Question 4

For each of the effects of heroin, where is it produced?

Answer 4

Euphoria → Ventral tegmental area
Analgesia → Peri-aqueductal grey region
Cough suppression → Solitary nucleus

Question 5

What is the main target of heroin?

Answer 5

Opioid receptors

Question 6

Difference between pharmacodynamics and pharmacokinetics [oversimplified]

Answer 6

Pharmacodynamics → what drugs do to the body
Pharmacokinetics → what body does to the drugs

Question 7

4 main drug target classes

Answer 7

→ Ion channels
→ Receptors
→ Enzymes
→ Transport proteins

Question 8

Example of drug that targets receptors

Answer 8

Salbutamol
Aerosolised beta-2 agonist given for asthma to cause airway dilation

Question 9

What is the target of salbutamol?

Answer 9

Beta-2 receptor

Question 10

Example of drug that targets enzymes

Answer 10

Atorvastatin
Given to reduce cholesterol levels → athlerosclerosis → cardiovascular risk

Question 11

What is the target of Atorvastatin?

Answer 11

HMV-CoA reductase (rate limiting step in cholesterol synthesis)

Question 12

Example of drug that targets transport proteins

Answer 12

Citalopram
SSRI (selective serotonin reuptake inhibitor) taken as antidepressant

Question 13

What is the target of citalopram?

Answer 13

Serotonin reuptake transport proteins

Question 14

Example of drug that targets ion channels

Answer 14

Amlodipine
Calcium ion channel blocker which stops vasculature from contracting
Given for high BP

Question 15

What is the target of amlodipine?

Answer 15

Calcium ion channel

Question 16

What does a drug need to have to be an effective therapeutic agent?

Answer 16

A high degree of selectivity for a particular drug target

Question 17

Why would the structural similarity of NTs like serotonin, dopamine, noradrenaline be more significant pharmacologically than physiologically?

Answer 17

Physiologically → NT are delivered to the very specifc part of the brain with the appropriate receptors by nerves

VS

Pharmacologically → drugs are given orally i.e. goes wherever the blood goes in the body i.e. everywhere

Question 18

Example of drugs utilising natural physiology for specificity

Answer 18

Parkinson’s → L-dopa can be absorbed directly into dopamine neuron to induce more dopamine production
[Not used in later stages due to degeneration and loss of dopamine neurones]

Question 19

What is a side effect?

Answer 19

An effect produced by a drug that is secondary to the intended effect

Question 20

What is an adverse effect?

Answer 20

A side effect with a negative health consequence

Question 21

What is Pramipexole?

Answer 21

→ Dopamine receptor agonist used to treat parkinson’s

Question 22

,What effect does increasing the dose of pramipexole have?

Answer 22

As dose increases, pramipexole can settle for fitting into serotonin and eventually NA receptors, producing side effects related to each NT (due to structural similarlity of dopamine to both NTs)

Question 23

What are the safest drugs?

Answer 23

Those where there is a large difference between the dose required to induce the desired effects and the dose required to induce side/adverse effects

Question 24

Side effects can be produced by drug action: [3]

Answer 24

1. On other targets in the same tissue or other tissues
2. On same target in other tissues
3. Dependent on dose

Question 25

What are the possible side effects of pramipexole hitting the intended targets but in other tissues?

Answer 25

Inhibitory effect

• May slow down gut function → e.g. constipation
• Mesolimbic pathway → hallucinations