Adults

2-4 tablets (500-1000 mg) every 4-6 hours as needed, not exceeding 16 tablets (4000 mg) in 24 hours.

Elderly

No specific dose adjustment is usually required, but caution is advised in those with hepatic or renal impairment.

Renal_impairment

Dose interval may need to be extended in severe renal impairment. Consult physician.

Onset

Pain relief usually within 30-60 minutes, fever reduction within 30 minutes.

Excretion

Mainly excreted in urine as glucuronide and sulfate conjugates; less than 5% is excreted unchanged.

Half life

1 to 4 hours, prolonged in liver dysfunction.

Absorption

Rapidly and almost completely absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 30 to 60 minutes after oral administration.

Metabolism

Primarily metabolized in the liver, mainly by conjugation with glucuronic acid and sulfate. A small amount is metabolized by cytochrome P450 to a toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by glutathione.

Alcohol

Increases the risk of hepatotoxicity.

Warfarin

May increase the anticoagulant effect, leading to increased bleeding risk with prolonged use of high doses.

Cholestyramine

Reduces absorption of paracetamol if given within one hour.

Metoclopramide, Domperidone

Increase absorption rate of paracetamol.