Background

• N-acetyl cysteine (NAC) is made from the amino acid L-cysteine. It is a source of sulfhydryl (-SH) groups and, thus, may act as a strong antioxidant.
• Because it has the ability to thin mucus, NAC has been used traditionally as a decongestant. It has also been used to reduce poisoning associated with compounds such as acetaminophen and heavy metals.
• NAC has been used clinically for approximately 40 years and has shown benefit for treating bronchiolitis and chronic bronchitis. Recent study has investigated its role as an antioxidant with the potential to treat HIV infection, cancer, and heart conditions. There is a lack of evidence of benefit in using NAC to prevent kidney impairment or to treat hepatitis, cystic fibrosis, or erythropoietic protoporphyria (a disorder caused by a defect in making heme).
• NAC is generally well tolerated. The most frequent side effects are diarrhea, nausea, and vomiting. NAC is also well known for its unpleasant taste.

References

• Baker WL, Anglade MW, Baker EL, et al. Use of N-acetylcysteine to reduce post-cardiothoracic surgery complications: a meta-analysis. Eur J Cardiothorac Surg 2009;35(3):521-527.
  View Abstract
• Brok J, Buckley N, Gluud C. Interventions for paracetamol (acetaminophen) overdose. Cochrane Database Syst Rev 2006;(2):CD003328.
  View Abstract
• Charunwatthana P, Abul Faiz M, Ruangveerayut R, et al. N-acetylcysteine as adjunctive treatment in severe malaria: a randomized, double-blinded placebo-controlled clinical trial. Crit Care Med 2009;37(2):516-522.
  View Abstract
• Ghanei M, Shohrati M, Jafari M, et al. N-acetylcysteine improves the clinical conditions of mustard gas-exposed patients with normal pulmonary function test. Basic Clin Pharmacol Toxicol 2008;103(5):428-432.
  View Abstract
• Grandjean EM, Berthet P, Ruffmann R, et al. Efficacy of oral long-term N-acetylcysteine in chronic bronchopulmonary disease: a meta-analysis of published double-blind, placebo-controlled clinical trials. Clin Ther 2000;22(2):209-221.
  View Abstract
• Guijarro LG, Mate J, Gisbert JP, et al. N-acetyl-L-cysteine combined with mesalamine in the treatment of ulcerative colitis: randomized, placebo-controlled pilot study. World J Gastroenterol 2008;14(18):2851-2857.
  View Abstract
• Ho KM, Morgan DJ. Meta-analysis of N-acetylcysteine to prevent acute renal failure after major surgery. Am J Kidney Dis 2009;53(1):33-40.
  View Abstract
• Keays R, Harrison PM, Wendon JA, et al. Intravenous acetylcysteine in paracetamol induced fulminant hepatic failure: a prospective controlled trial. BMJ 1991;303(6809):1026-1029.
  View Abstract
• Minder EI, Schneider-Yin X, Steurer J, et al. A systematic review of treatment options for dermal photosensitivity in erythropoietic protoporphyria. Cell Mol Biol (Noisy-le-grand) 2009;55(1):84-97.
  View Abstract
• Moradi M, Mojtahedzadeh M, Mandegari A, et al. The role of glutathione-S-transferase polymorphisms on clinical outcome of ALI/ARDS patient treated with N-acetylcysteine. Respir Med 2009;103(3):434-441.
  View Abstract
• Nash EF, Stephenson A, Ratjen F, et al. Nebulized and oral thiol derivatives for pulmonary disease in cystic fibrosis. Cochrane Database Syst Rev 2009;(1):CD007168.
  View Abstract
• Nigwekar SU, Kandula P. N-acetylcysteine in cardiovascular-surgery-associated renal failure: a meta-analysis. Ann Thorac Surg 2009;87(1):139-147.
  View Abstract
• Shohrati M, Aslani J, Eshraghi M, et al. Therapeutics effect of N-acetyl cysteine on mustard gas exposed patients: evaluating clinical aspect in patients with impaired pulmonary function test. Respir Med 2008;102(3):443-448.
  View Abstract
• Stey C, Steurer J, Bachmann S, et al. The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review. Eur Respir J 2000;16(2):253-262.
  View Abstract
• Sutherland ER, Crapo JD, Bowler, RP. N-acetylcysteine and exacerbations of chronic obstructive pulmonary disease. COPD 2006;3(4):195-202.
  View Abstract