Acetyl cysteine has two important applications in palliative care, one as a mucolytic and the other parenterally for paracetamol toxicity.

It exerts mucolytic action through its free sulfhydryl group, which opens up the disulfide bonds in the mucoproteins, thus lowering mucous viscosity.
In paracetamol toxicity, it acts as a hepatoprotective agent by restoring hepatic glutathione, serving as a glutathione substitute, and enhancing the nontoxic sulfate conjugation of paracetamol.

As a mucolytic, oral
Adult: As candies, granules, or effervescent tab: 600 mg daily as a single dose or in 3 divided doses.
Child: 1 month to <2 yr 100 mg bid; 2-7 yr 200 mg bid; >7 yr same as adult dose.

Predominant side effect: nausea and vomiting.

Paracetamol poisoning, oral
Adult: As 5% solution: Initially, 140 mg/kg followed by 70 mg/kg 4 hrly for additional 17 doses.
Child: Same as adult dose.

Paracetamol poisoning, intravenous - See reference.

Adapted from CIMS India. Drug Information. Internet. Accessed on January 10, 2016.