NSAIDs

Question 1

what are the three most important properties of NSAIDS?

Answer 1

1. anti-inflammatory
2. analgesic
3. antipyretic

Question 2

what enzyme do NSAIDS inhibit the action of?

Answer 2

cycle oxegenase (produces prostaglandins, thromboxjnes and prostacyclins from arachidonic acid)

Question 3

which NSAID IRREVERSIBLY inhibits the action of cyclooxegenase?

Answer 3

ASPIRIN

Question 4

how does aspirin irreversibly inhibit the action of COX?

Answer 4

by acetylating the serine amino group of COX (forms a covalent bond)

Question 5

which drug binds irreversibly to COX and competes with the natural substrate?

Answer 5

ibuprofen

Question 6

what are three chemicals produced by the action of COX?

Answer 6

prostaglandins and thromboxanes and prostacyclins

Question 7

what is the effect of prostaglandins on the vasculature?

Answer 7

vasodilation

Question 8

what is the effect of thromboxanes on the vasculature?

Answer 8

vasoconstriction (they are also thrombotic)

Question 9

which enzyme liberates arachidonic acid from phospholipids?

Answer 9

phospholipase A2 (PLA2)

Question 10

what substance is produced as a by-product of arachidonic acid?

Answer 10

platelet activating factor (PAF)

Question 11

what are the two main types of COX enzymes?

Answer 11

COX-1 and COX-2

Question 12

which COX enzyme is constitutive ad is important in maintaining the GI tract integrity?

Answer 12

COX-1

Question 13

which COX enzyme is inducible and involved in inflammatory responses?

Answer 13

COX-2

Question 14

how do prostaglandins act on pain sensory nerves?

Answer 14

increase the sensitisation of nociceptive nerves to histamine and bradykinin

Question 15

how do prostaglandins promote the formation of oedema?

Answer 15

increase sensitivity of post capillary venues to histamine and bradykinin which increases venue permeability

Question 16

what is the effect of prostaglandins on temperature and why is this?

Answer 16

prostaglandins increase the thermostat ‘set point’ in the hypothalamus

Question 17

what causes the formation of prostaglandins in the brain?

Answer 17

release of interleukins from macrophages

Question 18

which class of drugs give a number of unwanted side effects including stomach ulcers, tinnitus, dizziness, nausea, vomiting, acid/base imbalances; haemostasis etc.?

Answer 18

salicylates (eg aspirin)

NB salicylic acid is formed from aspirin acetylating COX

Question 19

what class of drugs do ibuprofen and naproxen come under?

Answer 19

propionic acids

Question 20

which class of drugs have very similar properties to propionic acids?

Answer 20

fenemates (eg mefenamic acid)

Question 21

which drug is a good analgesic and antipyretic activity but is a poor anti-inflammatory; is a week COX inhibitor and is well-tolerated in the GIT?

Answer 21

paracetomol

Question 22

what is the major issue with paracetamol?

Answer 22

hepatotoxitiy due to overdose (enzymes in the liver can become saturated and toxic metabolites form)

Question 23

which type of drug is used for osteoarthritis and rheumatoid arthritis (also is restricted for use when traditional NSAIDs produce too sever GIT side effects) and is a selective COX-2 inhibitor?

Answer 23

coxibs eg celecoxib