Analgesics

Question 1

Paracetamol
MOA
Dose
indication

Answer 1

Unsure

• May Inhibit COX-III
• Prevents release of prostaglandins
• also has anti-fever effect
• NO anti-inflammatory

2 500mg tablets every 4-6 hrs (max 4g daily)
onset about 30mins

Question 2

Paracetamol

Toxicity

Answer 2

Overdose:

• metabolised into N-acetly-p-benzoquinone imine
• inactivated by glutathione
• when this enzyme is saturated = toxicity
• MUST take acetycsyteine or methionine so body can produce more glutathione on its own

Question 3

HOW do NSAIDs work?

Answer 3

• COX Inhibitor

- prevents release of Prostaglandins thus inflammatory mediators

Question 4

Arlpropionic acids (iburprofen, naproxen ect)
Comparative info

Answer 4

Ibuprofen
= Metabolised in liver FIRST
= max 2400mg daily (2.4g)
=short half life 2hrs

Naproxen
= long half life (15hrs)
=

Question 5

Heteroaryl acetic acid (diclofenac)

comparative info

Answer 5

it accumulates in joints which is great for joint pain, but is has a high risk of fluid retention - avoid in HTN

Question 6

NSAID adverse effects

Answer 6

Triple whammy (diuretics, NSAID, ACE = decrease pressure in nephron leading to renal failure)

• fluid and NA retention - do not use in HTN/HF
• COX-11 platelet aggregation - increase clotting risk
• Aspirin stops platelet aggregation
• delays labour (avoid in last trimester)
• PG protect gastric lining thus increase risk of ulcers