Introduction To Pharmacology Of The Nervius System

Question 1

Pharmacology

Answer 1

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

Question 2

Drug

Answer 2

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

Question 3

What 3 questions should we ask when considering the pharmacology of a drug?

Answer 3

1) What is the target for the drug?

2) Where is the effect produced

3) What is the response produced after interaction with this target?
Eg opioid

1) Opioid receptors (normally detect endogenous opioids but also exogenous compounds like heroin and morphine)

2) Different areas depending on type of response- peri-aqueductal grey region for analgesia, ventral tegmental area for euphoria, solitary nucleus for cough suppression

3) Has different responses- euphoria, analgesia, cough suppression

Question 4

Safest drug

Answer 4

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

Question 5

What are the 4 main classes of proteins that drugs usually target?

Answer 5

• Receptors
• Enzymes
• Ion channels
• Transport proteins

Question 6

Describe the two effects that drugs can have on their target

Answer 6

Enhance activation of target

reduce/prevent activation of target

Question 7

What targets do atorvastatin, amlodipine, salbutamol and citalopram have?

Answer 7

• Atorvastatin → enzyme (HMGCoA reductase)
• Citalopram → transport protein (selective serotonin reuptake inhibitors that block serotonin re-uptake protein), resulting in longer serotonin expression- it’s an antidepressant
• Salbutamol → receptor (beta-2 adrenergic receptor in lung) which it activates which bronchodilates which helps with asthma
• Amlodipine → ion channel (calcium channel) and blocks it which causes vasodilation that reduces blood pressureThe drug blocks the calcium channel, stops contraction, vasoconstriction is reduced, lowering blood pressure

Question 8

Why is selectivity more important for drugs than endogenous compounds like dopamine

Answer 8

Neurotransmitters are very specifically delivered to their target e.g. dopaminergic nerve releases dopamine into synapse where it specifically interacts with a dopamine receptor

Drugs however are administered orally or intravenously so they need to be distributed to relevant tissue- that drug can be sent to any tissue in body- that is why they can’t be similar to other compounds or else they may produce unwanted effects in other tissues

Question 9

Side effect

Answer 9

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

Question 10

Adverse effectiveness

Answer 10

If that side effect has negative health consequences

2 terms often used interchangeably since most side effects have some sort of negative effect from minor e.g. runny nose to major e.g. heart attack

Question 11

Off target side effects

Answer 11

Side effects on areas of the body (either same tissue or different tissue) that aren’t the target area

Question 12

On target side effects

Answer 12

Drugs that act on intended target organ

Question 13

Which kind of effect increases as dosage of a drug increases?

Answer 13

Off target effects
Increasing dosage results in stimulation of alternative receptors