Analgesics 2: NSAIDs as analgesics

Question 1

analgesic effects of NSAIDs

what 2 things do NSAIDs do

thing prostaglandins and spinal cord

Answer 1

• decrease production of prostaglandins (mainly PGE2) which sensitise nociceptors to inflammatory mediators
• have affects in spinal cord

Question 2

analgesic effects of NSAIDs

what are prostagladins decreased in production by NSAIDs likely to be mediated by?

Answer 2

likely to be mediated by COX-2

Question 3

Types of Cyclo-oxygenase

what is COX-2 and COX-1 associated with

Answer 3

COX-2: inflammatory roles/induced in inflammation

COX-1: physiological roles in stomach and kidneys

Question 4

Types of Cylo-oxygenase

what can COX-2 increase risk of?

Answer 4

myocardial infarcation (Heart Attack)

Question 5

Aspirin

what is the clinical use of aspirin now after being replaced by NSAIDs

Answer 5

• now used as an anti-platelet drug

Question 6

paracetamol

what shouldnt paracetamol be used as

Answer 6

• Shouldn’t be used as in anti-inflammatory, it is only an analgesic and antipyretic

Question 7

paracetamol

where is the action of paracetamol likely to be

Answer 7

likely to be in the CNS

Question 8

Paracetamol Overdose

outline what paracetamol overdose can lead to

think too much of a drug, liver issues that can occur because of this, and what these issues can thus result in.

Answer 8

1. overdose
2. potentially fatal hepatic necrosis through conversion to toxic metabolite (NAPQI) and then depleting of glutathione in liver.
3. this leads to oxidative stress and damage to the liver

Question 9

Paracetamol Overdose

how can a paracetamol overdose be treated

Answer 9

1. activated charcoal can be used within 4 hours if dose is below 7.5g
2. N-acetylcysteine can act as a glutathiole substitute and detoxifies NAPQI
3. if this doesnt work, a liver failure will occur and the only way this can be treated is with a liver transplant

Question 10

Ibuprofen

what are 3 drawbacks of ibuprofen

Answer 10

• short half life
• low solubility in water
• insoluble in the stomach

Question 11

ibuprofen

why is ibuprofen’s preparation for IV difficult

Answer 11

this is because it has low solubility in water

Question 12

ibuprofen

how can the drawbacks of ibuprofen be overcome if given orally

Answer 12

• controlled released formulatoins using liposomes, polymers or nanoparticles
• if ibuprofen is given orally, it allows for release in the intestine or even the colon.
• this means the plasma concentration will be low however it will be steady.