UNDER REVIEW (April 2017)
Mechanism of Action:
NAC is a glutathione precursor that, unlike glutathione, has the potential to cross cell membranes and enter hepatocytes where it restores glutathione (GSH). GSH is necessary for the conversion of the toxic metabolite of paracetamol, NAPQI, to unreactive metabolites. When it is exhausted the toxix metabolites destroy the liver cells. Thus NAC is used to protect the liver from damage in paracetamol overdose. NAC also breaks disulphide bonds that holds mucus glycoproteins together (mucolytic).
Lecture and CAL materials:
- Lecture: Drugs affecting the respiratory system
Drug specifics
| Alternative drug name | N-acetylcysteine, NAC, Parvolex® |
| Effects | Prolonged intake of paracetamol may damage liver and kidney. Hepatic toxicity due to metabolite - normally combines with glutathione in liver, but excess metabolite (in overdose) starts binding to nucleophilic constituents (cell proteins) in liver cells, causing cell damage/death. Treatment of poisoning as soon as possible in first 12-48hr by increasing levels of gluathione (give N-acetylcysteine i.v. or methionine orally). see eBNF |
| Adverse actions | Anaphylactoid reaction in 10-15% of patients, usually in the first 30 minutes of administration, due to systemic histamine release. |
| Dose | See ToxBase and eBNF. |
| Interactions | See eBNF. |
| Contraindications | not specified |
| Comments | not specified |
| Contributors |
eDrug by