Paracetamol

Question 1

Mechanism

Answer 1

Not fully known but some thoughts:

An indirect inhibitory effect on COX-2 in the CNS by reducing the availability of essential co-substrates.
Has some COX-3 activity - NOT IMPORTANT

Question 2

Uses

Answer 2

Reduce pain , Antipyretic (reduce fever),

Question 3

Overdose

Answer 3

metabolism paracetamol is normally conjugated with glucuronic acid and sulphate.
When toxic doses of paracetamol are taken (10-15g), these pathways become saturated, leading to metabolism by cyP450 enzymes (CYP2E1). = Production of toxic N-acetyl-p-benzoquinone, which can be inactivated by glutathione. However, once glutathione is depleted, N-acetyl-p-benzoquinone causes liver and kidney necrosis.

Irreversible liver damage usually reaches its peak by 72-96 hours

TREATMENT:
N-acetylcysteine must be administered within 8-10 hours of ingestion = speeds the replenishment of glutathione

IF liver damage too severe liver need replacing

Question 4

Common brand names

Answer 4

Calpol
Co codamol = codeine + paracetomal