Paracetamol is an aniline analgesic - the only one still in use today.

Acts by inhibiting COX enzymes (COX II-specific) and thus blocking prostaglandin synthesis.

Reduces oxidised form of COX.

Adult dosage - 1,000 mg single dose, maximum 4,000 mg/day (2,000 with alcohol).

Classed as a NSAID but lacks much anti-inflammatory activity.

Because of its selectivity for COX-2 it does not significantly inhibit the production of the pro-clotting thromboxanes.

Half-life 2-4 hours

Time to action 15 - 30 mins

Synthesis (NB no stereocentres):