Drug action

Question 1

What is a drug

Answer 1

“external substance that acts on living tissue to produce a measurable change in the function of that tissue”

Question 2

What is the difference between effects and side effects

Answer 2

effects - effects you want

side effects - effects you don’t want

Question 3

what do local anaestheics do

Answer 3

prevent pain

Question 4

what do antimicrobials do

Answer 4

treat and prevent infections

Question 5

what do anxiolytics do

Answer 5

reduce anxiety

Question 6

what do analgesics do

Answer 6

reduce postoperative pain

Question 7

What can drugs do?

Answer 7

• simulate normal body communications
• interrupt normal body communications
• act on non-host organisms to aid body defences

Question 8

where do hormone messages affect

Answer 8

all tissues

Question 9

where do neural messages affect

Answer 9

specific tissues

Question 10

name 4 types of hormones

Answer 10

thyroid hormones
insulin
cortisol
sex hormones

Question 11

what do thyroid hormones do

Answer 11

balance body’s metabolism

Question 12

too much thyroid hormone?

Answer 12

hyperthyroidism

Question 13

too little thyroid hormone?

Answer 13

hypothyroidism

Question 14

effects of inbalance of thyroid hormone?

Answer 14

cold intolerant
slow mentation
hair loss
slow pulse and low bp

Question 15

what does the thyroxine tablet do

Answer 15

replaces missing T3 and T4

Question 16

where does the thyroxine table act on

Answer 16

directly on tissues - no direct effect on thyroid gland

Question 17

What is the nerve control of the heart rate

Answer 17

Sympathetic - adrenergic stimulation
Speeds up the heart via Beta-receptors

Parasympathetic - cholinergic stimulation
Slows the heart via cholinergic receptors

Question 18

What are the ‘autonomic’ drugs and what do they do

Answer 18

epinephrine - beta agonist
atenolol - beta blocker

pilocarpine - cholinergic agonist
atropine - cholinergic blocker

Question 19

how do drugs interact with tissues

Answer 19

receptors
enzymes
ion channels

Question 20

why are receptors by themselves not enough to cause a change by a drug

Answer 20

because they are coupled to ion channels/ G proteins/ enzymes/ gene transcription ?

Question 21

What are the two components to drug-receptor interactions

Answer 21

drug-receptor interaction (affinity and occupancy)

drug reduced response (efficacy)

Question 22

What does affinity mean?

Answer 22

how keen drug and receptor are to be together

Question 23

What does occupancy mean?

Answer 23

time they are together

Question 24

What does efficacy mean?

Answer 24

the effect output of affinity and occupancy. E.g. high affinity and high occupancy gives high efficacy

Question 25

what is the law of mass action?

Answer 25

the principle that the rate of a chemical reaction is proportional to the concentrations of the reacting substances

Question 26

What is an agonist

Answer 26

fits to receptor and causes the effect you want the drug to cause

Question 27

what is an antagonist

Answer 27

fits to the receptor but doesn't cause an effect - blocks receptor

Question 28

whats a partial agonist

Answer 28

binds and causes a bit of change

Question 29

what effects can you get with partial agonists

Answer 29

more difficult to produce the drug/receptor effect than with an agonist. Increase partial agonist conc will improve efficacy for some but not for others

Question 30

What are the different types of antagonist

Answer 30

competitive and non-competitive

Question 31

what are the different types of responses you can get with antagonists

Answer 31

reversible Antagonist effect reduced by increasing the concentration of the agonist Example: atenolol (β1 blocker) irreversibe Binds and reduces available receptors for the agonist Example: phenoxybenzamine (α1 blocker)

Question 32

why can partial agonists be particularly helpful

Answer 32

by changing the conc you can change the response

Question 33

Enzymes | What is substrate antagonism

Answer 33

?

Question 34

Enzymes | What is reversible enzyme modification

Answer 34

(?)The other method of control is called reversible covalent modification. This involves the addition or removal of some type of group, most commonly the phosphoryl group, onto or from the enzyme. The addition of phosphoryl groups involves the use of ATP (energy source) and requires a protein called protein kinase

Question 35

Enzymes | What is irreversible modification

Answer 35

(?) Probably do to with the protein being changed permanently

Question 36

2 examples of drugs where enzymes have an effect

Answer 36

aspirin and simvastatin

Question 37

How do ions affect D/R interactions? | 2 examples?

Answer 37

electrical activity ion influx LAs and anti-diabetic drugs

Question 38

can both agonists and antagonists be competitiative?

Answer 38

yes - occupancy and affinity affect efficacy

Question 39

how do drugs act

Answer 39

through: receptors on cells influencing enzyme action disruption of ion conduction channels