Pharmacology

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?

Answer 2

A chemical with a selective therapeutic action.

Question 3

What is Pharmacodynamics (PD)?

Answer 3

What the drug does to the body.
Drug action and mechanisms.

Question 4

What is Pharmacokinetics (PK)?

Answer 4

What the body does to the drug.
Barriers (ADME).

Question 5

What is biological specificity?

Answer 5

Right target

Question 6

What is chemical specificity?

Answer 6

Right target binding site.

Question 7

What does the B1 receptor do?

Answer 7

Increases heart rate; Increasing cardiac muscle’s force of contraption.

Question 8

What does the B2 receptor do?

Answer 8

Relaxes the airway.
Dilatate smooth muscles.

Question 9

What do target binding sites provide?

Answer 9

The selectivity for the specific binding of drugs/ligands (LOCK and KEY system).

Question 10

What are the 3 key drug binding sites?

Answer 10

1. Drugs targeting enzymes.
2. Drugs targeting transporters.
3. Drug targeting voltage-gated ion channels.

Question 11

Drugs as enzyme inhibitors.

Answer 11

Intracellular breakdown - phosphodiesterase- sildenafil.
Neurotransmitter degradation - acetylcholine esterase - neostigmine.
Messenger synthesis - cyclo-oxygenase - ibuprofen (reversable) aspirin (irreversible).

Question 12

Drugs as enzyme substrates

Answer 12

dopamine precursor L-DOPA for Parkinson’s disease.

Question 13

What is meant by competitive binding?

Answer 13

Drug competes for the ligand active site.

Question 14

What is meant by non-competitive binding?

Answer 14

Drug binds at different site.

Question 15

Therapeutic action

Answer 15

Biological: right target.
Chemical: right target binding site.

Question 16

Adverse/Side effects

Answer 16

Biological: non-specific target.
Chemical: non-specific binding site.

Question 17

What is an agonist?

Answer 17

A drug that binds to the same active site as adrenaline and activates the B2 like adrenaline.

Question 18

What is an antagonist?

Answer 18

Drugs that oppose the agonist function.
Block the B1 receptor.

Question 19

What is Affinity?

Answer 19

How well a drug/ligand binds to it’s receptor.

Question 20

What is Efficacy?

Answer 20

How well a drug/ligand activates the receptor.

Question 21

Do agonists have affinity and efficacy?

Answer 21

Agonists have both affinity and efficacy.

Question 22

Do antagonists have affinity and efficacy?

Answer 22

Antagonists only have affinity.
THEY PRODUCE NO RESPONSE.

Question 23

What is kD?

Answer 23

The concentration req. to occupy 50% of receptor.

Question 24

What is EC50?

Answer 24

The effective concentration of agonist for 50% response.

Question 25

Which is usually higher, affinity(kD) or potency(EC50)?

Answer 25

Affinity (kD).

Question 26

What is antagonism?

Answer 26

Drug/ligand that reduces/blocks the agonist response

Question 27

Name a type of antagonism?

Answer 27

Receptor antagonism

Question 28

Why do antagonists only have affinity?

Answer 28

Binds to receptors, Null response, i.e. blocks agonist response.

Question 29

Competitive antagonism.

Answer 29

Orthosteric - same binding site of the endogenous hormone. Block the drug by occupying the B1 binding site.

Question 30

Non-competitive antagonism.

Answer 30

Blocks the response by by binding at a different binding site to the agonist. No need for them to have identical structures.

Question 31

Reversable and non-reversable

Answer 31

Reversable can dissociate from the receptor and binding sites can be re-occupied. Non-reversable antagonists cannot dissociate from the receptor.

Question 32

Reversable competitive antagonists

Answer 32

Max. response can still be achieved (surmountable antagonism).

Question 33

Irreversible competitive antagonists.

Answer 33

Form covalent link with receptor. Reduces the number of receptors available for the agonist to stimulate the response.

Question 34

Non-surmountable antagonism

Answer 34

EC50 declines as receptor reserves decrease. agonists maximum response drops.

Question 35

Receptor Tyrosine Kinase (RTK)

Answer 35

Receptors for growth factors (EGF, VEGF, Insulin etc.). Activation: Cell proliferation, differentiation, survival and metabolism. Hyperactivation: Polyps, tumours and cancer.

Question 36

Receptors for growth factors EGF, VEGF, IGF, PDGF

Answer 36

Epidermal growth factor. Vascular endothelial growth factor. Insulin-like growth factor. Platelet-derived growth factor

Question 37

RTK

Answer 37

Growth factor binding RTK leads dimerization and autophosphorylation

Question 38

RTK

Answer 38

One tyrosine kinase activates autophosphorylation of its partner and vice versa. signalling proteins recruited to RTK. Signalling proteins contains SH2 domain to sense and bind specific RTK.

Question 39

SH2 domain

Answer 39

some SH2 proteins are enzymes (phospholipase C) Some SH2 domain proteins are adaptors (Grb2).

Question 40

RTK - drugs

Answer 40

Very limited Insulin Many neurotrophin analogues couldn't pass through clinical trials. Monoclonal antibodies.

Question 41

Guanynyl cyclase receptors

Answer 41

Limited membrane bound released from atria, promotes vasodilation and urinary sodium excretion.