Question: Is there any benefit in giving n-acetyl cysteine (NAC) in non-acetaminophen acute liver failure (ALF)?

Bottom Line:

• NAC has a relatively safe side effects profile with convincing evidence supporting its use in early ALF with minor encephalopathy (or no encephalopathy). 

• Both studies show a decreased LOS with administration of NAC. NAC shows improved outcomes with early use by decreasing encephalopathy, hospital LOS and need for transplant.

Study 1: Lee et al.

• prospective, randomized, double-blind, placebo-controlled study at 22 sites looking to measure overall survival at 3 weeks

Study 2: Darweesh et al.

• prospective, observational study at 3 centers looking to assess the effect of NAC on reducing transplantation rates and mortality in non-acetaminophen induced ALF

• administration of NAC significantly also decreased: development of encephalopathy (p=0.02), LOS (p=<0.001), ICU admission (p=0.01), bleeding (p=<0.01), abnormal renal function test (p=0.002) 

References:

1. Lee WM, et al. Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure. Gastroenterology 2009; 137(3): 856–864.

2. Darweesh SK, et al. Effect of N-Acetylcysteine on Mortality and Liver Transplantation Rate in Non-Acetaminophen-Induced Acute Liver Failure: A Multicenter Study. Clin Drug Investig 2017; 37:473–482.