N-acetyl Cysteine in Treatment of Transaminitis

Effectiveness Based on Etiology

The American Gastroenterological Association (AGA) provides a strong recommendation for NAC use in acetaminophen-associated acute liver failure (ALF), despite the very low quality of evidence 1, 3
NAC is highly effective in preventing and treating acetaminophen-induced liver injury when administered early 1, 2, 3
NAC improves mortality in acetaminophen-induced liver injury (relative risk 0.65, 95% CI 0.43-0.99) 3
For non-acetaminophen-related transaminitis, the AGA recommends NAC use only in the context of clinical trials 1, 2, 3
Post-hoc analysis of one study showed mortality benefit in patients with stage 1 or 2 hepatic encephalopathy, but not in overall non-acetaminophen ALF patients 3

Intravenous regimen: 150 mg/kg for 1 hour, then 12.5 mg/kg/h for 4 hours, followed by 6.25 mg/h for 67 hours 4
Treatment should be initiated as soon as possible, ideally within 8-10 hours of ingestion 5

NAC should be administered to patients with hepatic failure thought to be due to acetaminophen, even without confirmed levels 8
In cases of ALF of indeterminate cause, NAC can be considered as some cases may be related to unrecognized acetaminophen toxicity 3
Patients may underreport their actual paracetamol intake, making clinical assessment challenging 6
For patients with severe transaminase elevation, paracetamol should be avoided if possible 6
If paracetamol is necessary in patients with elevated transaminases, limit dose to 2g/day with daily monitoring 6

Treatment timing is critical for effectiveness: NAC initiated within 8 hours: 2.9% risk of severe hepatotoxicity 5
NAC initiated within 10 hours: 6.1% risk of severe hepatotoxicity 5
NAC initiated after 10 hours: 26.4% risk of severe hepatotoxicity 5