GBP1

Question 1

Define pharmacodynamics

Answer 1

effect of a drug on target cell/tissue

Question 2

Define pharmacokinetics

Answer 2

how the body controls drug concentration at the site of action

Question 3

Suggest 4 proteins that are drug targets

Answer 3

enzymes transporters/pumps, ion channels, recpetors

Question 4

What signalling can be activated by receptors

Answer 4

local mediators, hormones, meurotrasmitters, growth factors

Question 5

Name the four receptor types

Answer 5

ligand gated ion channel, g protein coupled receptor, catalytic receptors, nuclear receptors

Question 6

Which receptor type gives the fastest response

Answer 6

ligand gated ion channel

Question 7

Give 4 examples of drugs that use ligand gated ion channels.

Answer 7

anti-epiltics, anxiolytics, local anaesthetics, antiarrthymics

Question 8

Give 5 examples of drugs that use g protein coupled receptors as targets

Answer 8

b-blockers, b2-adrenoceptor agonists, anti-muscarinics, H2 antagonists, antipsychotics, anti-virals

Question 9

What g protein does activation of b2 adrenoceptor use, alpha2, alpha1

Answer 9

Gs, Gi, Gq

Question 10

Which g proteins effector is adenlyl cyclase

Answer 10

gi and gs

Question 11

What effector does Gq have?

Answer 11

phospholipase C

Question 12

What is the intracellular messenger for the G proteins

Answer 12

Gs-increase cAMP, Gi-decrease cAMP, Gq IP3 intracellular Ca2+

Question 13

What cAMP/Ca2+ sensors are there in with each Gprotein

Answer 13

protein kinase A (gi+gs) many Ca2+ dependant enzymes/channels (gq)

Question 14

What happens at catalytic receptor activation

Answer 14

enzyme activated by hormone binding, to eg tyrosine kinase receptors

Question 15

How do nuclear receptors act

Answer 15

ligands diffuse across membranes to intracellular receptor, create transcription factors.

Question 16

Give three examples where drugs target nuclear receptors

Answer 16

Asthma- corticosteroids, Sexual health, caner- tamoxifen

Question 17

Define Affinity

Answer 17

ability of a drug to bind its receptor

Question 18

Define efficacy

Answer 18

the ability of a drug once bound to activate the receptor by a conformational change

Question 19

What characterises a receptor agonist

Answer 19

Has both affinity and efficacy

Question 20

What characterises a receptor antagonist

Answer 20

Only has affinity for receptor not efficacy

Question 21

Define Kd

Answer 21

concentration of drug needed to occupy 50% of receptors (measure of binding affinity)

Question 22

How many moles in pM

Answer 22

10-12

Question 23

How many moles in nM

Answer 23

10-9

Question 24

How many moles in uM

Answer 24

10-6

Question 25

How many moles in mM

Answer 25

10-3

Question 26

What does Rmax represent

Answer 26

maximum response of a drug

Question 27

What does EC50 represent

Answer 27

effective concerntration of agonist for 50% of its maximal response (measure of potency)

Question 28

What determines EC50 and Rmax

Answer 28

drug receptor interaction, properties of functional response ( amplication etc)

Question 29

In what case does an assay have a receptor reserve for a drug

Answer 29

When maximum agonist response can only be obtained with only a few receptors occupied EC50

Question 30

In the presence of an competitve antagonist what happens to an agonists EC50 and Rmax

Answer 30

EC50 is reduced but Rmax stays the same

Question 31

In the presence of a non-competitive agonist what happens to an agonists EC50 and Rmax

Answer 31

Both are decreased

Question 32

What does p.r.n. mean

Answer 32

as required ( need to specify a minimum dosage interval)

Question 33

Give five benefits for the intravenous route of drug administration

Answer 33

``` rapid effects absorption circumvented useful in emergancy permits titration of dosage suitable for large volumes and for irritating substances when diluted ```

Question 34

Give four disadvantages for iv route of drug administration

Answer 34

increased risk of adverse effects risk from embolism not suitable for oily or insoluble substances requires iv access

Question 35

Give three advantages of subcutaneous route of drug administration

Answer 35

prompt from aqueous solution slow sustained release from repository prepartions suitable for some insoluble supsensions and implantation

Question 36

Give 2 disadvantages of subcutaneous route of drug administration

Answer 36

not suitable for large volumes | possibly painful/necrotic from irritating substances

Question 37

Give 3 advantages of intramuscular route of drug administration

Answer 37

prompt from aqueous solution slow sustained release from repository preps suitable for moderate volumes, oily vehicles and some irritating substances

Question 38

Give 2 disadvantages of intramuscular route of drug administration

Answer 38

Painful | danger from injecting at wrong site and causing damage

Question 39

Give 4 advantages of oral route of drug administration

Answer 39

most convenient safe economical no need for medical staff

Question 40

Give 3 disadvantages of oral route of drug administration

Answer 40

interpatient variation variable bioavailability compliance problems

Question 41

Describe 4 alternative routes of administration (exclude iv im po sc)

Answer 41

topical (eye drops/nasal spray/creams) inhalation (asthma spray/general anaesthesia) rectal (benzodiazepine) sublingual (glyceryl trinitrate)

Question 42

Why might blood levels not be a good measure of of concentration at site of action

Answer 42

irreversible drugs, active metabolites of drugs, drug kinetics in target compartment may be different to in blood