Pharmacology, Drugs & Therapeutics

Question 1

What is pharmacology?

Answer 1

a branch of science that deals with the study of drugs and their actions on living systems

Question 2

What is a drug: ‘magic bullet’?

Answer 2

chemical with a selective therapeutic action

Chemical Structure
-defined

Physiological response
-CNS stimulant

Physiological Targets
-Adenosine receptors, -GABA &
-Phosphodiesterienes

Question 3

What are the TWO integral branches of Pharmacology??

Answer 3

Pharmacodynamics, PD = Drug action & Mechanisms

Pharmacokinetics, PK = Barriers (ADME - absorption, distribution, metabolism and excretion)

Question 4

“drug elicits specific physiological response”
What is specificity?

Answer 4

when referring to a medical test, specificity refers to the percentage of people who test negative for a specific disease among a group of people who do not have the disease

Question 5

Biological: “right target”
example&raquo_space;>

Answer 5

Adrenaline

Question 6

Adrenergic receptor- ‘beta’ (β-1)

What does it do in the heart?

Answer 6

Increases heart Rate

Increasing cardiac muscle’s force of contraction

Question 7

Adrenergic receptor- ‘beta’ (β-2)

What does it do in the lungs?

Answer 7

Relaxes the airway

Dilatate smooth muscles

Question 8

Chemical: “right target binding site”
Adrenaline
What does it do in the heart?

Answer 8

^ heart rate

^ cardiac muscle’s force of contraction

Adrenergic receptor - ‘beta’ (β-1)

Question 9

Chemical: “right target binding site”
Adrenaline
What does it do in the lungs?

Answer 9

Relaxes the airway

Dilatate smooth muscles

Adrenergic receptor - ‘beta’ (β-2)

Question 9

Chemical: “right target binding site”
Adrenaline
What does it do in the lungs?

Answer 9

Relaxes the airway

Dilatate smooth muscles

Adrenergic receptor - ‘beta’ (β-2)

Question 10

What are receptors made out of?

Answer 10

Protein - amino acid sequence

ONLY allow Adrenaline to BIND

(acetyl-choline/dopamine will be present but adrenaline g-protein-coupled-receptors will only recognise adrenaline)

Question 11

Binding - specific and types of receptors:

Answer 11

Adrenergic receptor- ‘beta’ (β-1)
Adrenergic receptor- ‘beta’ (β-2)

Target binding sites (receptors & its subtypes) provides the selectivity for the specific binding of drugs/ligands (LOCK & KEY system)

Question 12

Key drug binding sites

Answer 12

1) Drugs targeting enzymes
(Drugs as enzyme inhibitors)

2) Drugs targeting transporters

3) Drug targeting voltage-gated ion channels

Question 13

Process > Enzyme > Drug example

Answer 13

Intracellular > Phosphodiesterase

Neurotransmitter degration > Acetylcholine

Messenger synthesis > Cycle-oxygenase

Question 14

Give a drug example;
Intracellular > Phosphodiesterase

Answer 14

SILDENAFIL

Question 15

Give a drug example;
Neurotransmitter degration > Acetylcholine

Answer 15

NEOSTIGMINE

Question 16

Give a drug example;
Messenger synthesis > Cycle-oxygenase

Answer 16

IBUPROFEN (reversible)
ASPIRIN (irreversible)

Question 17

Reversible drug

Answer 17

The active site will not change and therefore the reaction is reversible

Question 18

Irreversible drug

Answer 18

The enzyme will not be able to bind to the substrate as the active site will change its shape - will not be able to make a lock and key model.

Reaction will only happen once (forward reaction&raquo_space;>)

Question 19

What is Competitive binding? (can be rev/irreversible)

Answer 19

drug competes for the ligand active site

Question 20

Neostigmine will COMPETE with _____ ________to bind yo the ACh Esterase (substrate).

Answer 20

Acetylcholine

Question 21

What is Non-competitive binding site? (rev/irreversible)

Example of drugs??

Answer 21

Drugs that binds at different site

Aspirin and Arachidonic Acid will not compete together as only ASPIRIN will bind with the cyclo-oxygenase (COX) substrate

Question 22

2. Drug targeting transporters - allows drug to get inside from extracellular to intercellular

Answer 22

Noradrenaline present in the transporter & released from pre-synaptic neurone > transport to the synapse > and move into the receptor (post-synaptic neurone) and stimulate a response

2nd example; glucose

Question 23

Why are transporters present?

Answer 23

recycle the adrenaline (neurotransmitters)

Question 24

Example - cocaine

Answer 24

NA uptake - block by cocaine e.g. TCAs The cocaine BLOCKS the transporters so LESS NA will be RECYCLED so there will be a GREATER response

Question 25

3. Drug targeting voltage-gated ion channels

Answer 25

Resting (outside) > Depolarised (inside)

Question 26

What happens in the process of DEPOLARISATION

Answer 26

Na+ comes inside the synapse membrane which increases the voltage as it's more +ive (graph inclines) Lidocaine- blocks Sodium channel Local anaesthetic

Question 27

What are the 4 main Key types of receptors?

Answer 27

1. Nuclear receptors 2. Ligand gated ion channel 3. Catalytic receptors 4. G-protein coupled receptors

Question 28

Drugs targeting receptors Messengers (endogenous ligands) E.g.

Answer 28

hormone, peptides, cytokines, neurotransmitters…

Question 29

Catalytic receptors -

Answer 29

outside of receptor catalysis the inside of the receptor

Question 30

G-protein coupled receptors:

Answer 30

G protein-coupled receptor (GPCR), also called seven-transmembrane receptor or heptahelical receptor, protein located in the cell membrane that binds extracellular substances and transmits signals from these substances to an intracellular molecule called a G protein (guanine nucleotide-binding protein).

Question 31

4 Major classes Binding?

Answer 31

- enzymes - voltage gated - receptors - transporters

Question 32

What are the General characteristics of receptors?

Answer 32

inactive receptor { selectivity of ligands/ Molecular switch} <> active receptor {response}

Question 33

Amplification of SIGNALS, what os the process?

Answer 33

Plenty of signalling molecules, ions flowing through a channel, second messengers (cAMP, Ca ions), mRNA molecules for new proteins and others

Question 34

Biological: “right target” + Chemical: “right target binding site” >>> RELATIVITY

Answer 34

Everything is poisonous, nothing is poisonous it is all a question of dose

Question 35

List the Benefits vs risk (Market authorisation of clinical drugs):::

Answer 35

RISK assessment is MORE critical than the benefit Pharmaceuticals spends huge (billions of £s) to develop a clinically safe drug

Question 36

Thalomid - treatment of nausea in pregnant women

Answer 36

THERAPEUTIC ACTION - RISK assessment is more critical than the benefit Pharmaceuticals spends huge (billions of £s) to develop a clinically safe drug ADVERSE/SIDE EFFECTS - gastric upset, bleeding & ulcer Reye’s syndrome: Liver & Brain damage (children, very rare) Contraindicated under 12 year*