drug interactions

Question 1

what is a receptor

Answer 1

a component of a cell that interacts with a specific ligand and initiates a change of biochemical events to the ligands observed

Question 2

what are the 4 types of receptors

Answer 2

ligand gated ion channel
g protein couples
kinase linked receptors / enzyme linked
cytosolic/ nuclear receptors

Question 3

how do ligang gated ion channels work

Answer 3

Ion channelsare pore-formingmembrane proteinsthat allowionsto pass through the channel once a ligand binds to the receptor

so that the cell undergoes a shift inelectric chargedistribution

Question 4

most abundant type of receptor

Answer 4

G protein coupled receptor

Question 5

how do kinase linked receptors work

Answer 5

When a ligand binds to the receptor binding site on the extracellular domain the KLRs couple up to form pairs to become an active dimer

Begins the process of auto phosphorylation where tyrosine residues are phosphorylated which causes a cascade of reactions

Question 6

how do nuclear receptors work

Answer 6

can switch genes on or off

Work by modifying gene transcription

Question 7

define agonist

Answer 7

a compound that binds to a receptor and activates it

Question 8

define antagonist

Answer 8

a compound that reduces the effect of an agonist

Question 9

what is intrinsic activity

Answer 9

refers to the ability of a drug-receptor complex to produce a maximum functional response

Question 10

factors governing drug action

Answer 10

receptor related=
affinity efficacy

tissue related =
receptor number
signal amplification

Question 11

what is efficacy

Answer 11

describes how well a ligand activates the receptor

Question 12

affinity and efficacy with regards to agonist/ antagonists?

Answer 12

agonist= have affinity and efficacy

antagonists = have affinity but zero efficacy

Question 13

what is reverse agonism

Answer 13

When a drug that binds to the same receptor as anagonistbut induces a pharmacological response opposite to that of theagonist.

Question 14

what is tolerance

Answer 14

reduction in agonist effect over time
continuously, repeatedly, high concentrations

Question 15

what can desensitization involve

Answer 15

uncoupled
internalised
degraded

Question 16

What is a ligand

Answer 16

Molecules that bind to a receptor
Can be exogenous (drugs ) or endogenous (hormones , neurotransmitters)

Question 17

Describe the shape of a log dose response curve

Answer 17

Sigmoidal

Question 18

What does ec50 tell us about a drug and what is it

Answer 18

It’s potency !
The concentration of a drug that gives the maximal response

Question 19

What does emax tell you about a drug

Answer 19

Efficacy

Question 20

In terms of ionisation what happens to aspirin in the stomach

Answer 20

Weak acids so becomes less ionised in the stomach due to low gastric ph

Question 21

What is the effect of an increase in ph on a weak base

Answer 21

Weak base will become less ionised

Question 22

What is a therapeutic range

Answer 22

Upper and lower bounds of safe doses of a drug

Question 23

Main side effect of ace inhibitors and why

Answer 23

Dry cough due to bradykinin

Question 24

Main se of ccb’s

Answer 24

Oedema