Principles of Pharmacology 1

Question 1

What does exogenous mean?

Answer 1

Originating externally…

Question 2

Are drugs exogenous or endogenous?

Answer 2

Exogenous.

Question 3

In what ways do drugs act like endogenous molecules?

Answer 3

They block or mimic their actions.

Question 4

Although from exogenous sources, are drugs always chemically distinct from endogenous molecules or can they be identical? Give examples.

Answer 4

They can be identical as well as distinct (e.g. noradrenaline or insulin).

Question 5

What is an agonist?

Answer 5

A drug that binds to a receptor to stimulate it.

Question 6

What is an antagonist?

Answer 6

A drug which binds to a receptor to block the action of an agonist (usually an endogenous agonist).

Question 7

What type of interaction makes a drug binding/interaction irreversible?

Answer 7

Covalent bonding.

Question 8

Explain primary vs secondary drug effect.

Answer 8

Primary = expected response to a drug

Secondary = a side effect response

Question 9

Differentiate between pharmacokinetics and pharmacodynamics.

Answer 9

Dynamics = what the drug does to the body

Kinetics = what the body does to the drug

Question 10

What are the 4 stages of pharmacokinetics?

Answer 10

Absorption
Distribution
Metabolism
Excretion

Question 11

Is it pharmacokinetics or dynamics which determines the speed at which a drug acts in a patient?

Answer 11

Kinetics

Question 12

What are the X3 names given to drugs in drug nomenclature? Give an example using the drug aspirin.

Answer 12

Proprietary name (brand name) = Disprin

Common name = Asprin

Chemical name = Acetylsalycylic acid

Question 13

What are the X2 ways in which drugs can be grouped?

Answer 13

Their therapeutic use (what they achieve)

• analgesics
• anti-emetics
• anti-pyretic

Their mechanism of action (how they work)
- cyclooxygenase inhibitors

Question 14

Using Prozac as an example, give it’s common name, therapeutic use and mechanism of action.

Answer 14

Proprietary (brand) name = Prozac
Common name = Fluoxetine
Therapeutic use = Antidepressant
Mechanism of action = SSRI (selective serotonin re-uptake inhibitor) as it blocks 5-HT (5-hydroxytryptamine) uptake.

Question 15

Describe phase 0 of a clinical drugs trial?

Answer 15

First ‘in-human’ test

Dose is sub-therapeutic

Provides some pharmacokinetic information

Can use humanised animals

Often skipped - straight to phase 1

Question 16

Describe phase 1 of a clinical drugs trial?

Answer 16

Small in scale (20-80 volunteers)

Testing for drug safety, side effects, tolerability and dose finding

Sub-therapeutic doses ascending to therapeutic doses

Determines if a drug can progress to phase 2 to test for efficacy

Question 17

Describe phase 2 of a clinical drugs trial?

Answer 17

Involves around (100-300 volunteers)

Tests drug efficacy (does the drug have any therapeutic effect)

Doses are therapeutic

Side effects monitored at every stage

Question 18

Describe phase 3 of a clinical drugs trial?

Answer 18

Larger in scale (1000-3000 volunteers)

Therapeutic doses used

Comparing drug to current available drugs/gold standard

Side effects monitored at every stage