Acetylcysteine
Systematic (IUPAC) name
(R)-2-acetamido-3-mercaptopropanoic acid
Identifiers
CAS number	616-91-1
ATC code	R05CB01 S01XA08 V03AB23
PubChem	12035
DrugBank	n/a
Chemical data
Formula	C5H9NO3S
Mol. weight	163.19
Pharmacokinetic data
Bioavailability	6–10% (oral) <3% (topical)
Metabolism	hepatic
Half life	5.6 hours (adults) 11 hours (neonates)
Excretion	renal
Therapeutic considerations
Pregnancy cat.	B2 (Aus) Image File history File links Acetylcysteine. ... IUPAC nomenclature is a systematic way of naming organic chemical compounds. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences and alloys. ... The Anatomical Therapeutic Chemical Classification System is used for the classification of drugs. ... A section of the Anatomical Therapeutic Chemical Classification System. ... A section of the Anatomical Therapeutic Chemical Classification System. ... A section of the Anatomical Therapeutic Chemical Classification System. ... PubChem is a database of chemical molecules . ... DrugBank is a database available at the University of Alberta that provides information about thousands of products. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... In pharmacology, bioavailability is used to describe the fraction of an administered dose of medication that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. ... Overview of the citric acid cycle The citric acid cycle, one of the central metabolic pathways in aerobic organisms. ... The liver is an organ in vertebrates including humans. ... The elimination half-life of a drug (or any xenobiotic agent) refers to the timecourse necessary for the quantity of the xenobiotic agent in the body (or plasma concentration) to be reduced to half of its original level through various elimination processes. ... Excretion is the process of eliminating waste products of metabolism and other materials that are of no use. ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. ... Motto: None Anthem: Advance Australia Fair Royal anthem: God Save the Queen Capital Canberra Largest city Sydney Official languages English (de facto 1) Government Constitutional monarchy (federal)  - Queen Elizabeth II  - Governor-General Michael Jeffery  - Prime Minister John Howard Independence from the UK   - Constitution 1 January 1901   - Statute of Westminster 11...
Legal status	Schedule 4 (Aus) OTC or Rx (U.S.) The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction. ... Motto: None Anthem: Advance Australia Fair Royal anthem: God Save the Queen Capital Canberra Largest city Sydney Official languages English (de facto 1) Government Constitutional monarchy (federal)  - Queen Elizabeth II  - Governor-General Michael Jeffery  - Prime Minister John Howard Independence from the UK   - Constitution 1 January 1901   - Statute of Westminster 11... Over-the-counter substances, also abbreviated OTC, are drugs and other medical remedies that may be sold without a prescription and without a visit to a medical professional, in contrast to prescription only medicines (POM). ... A prescription drug (or POM Prescription Only Medicine, in UK) is a licensed medicine that is regulated by legislation to require a prescription before it can be obtained. ... For other uses, see United States (disambiguation) and US (disambiguation). ...
Routes	inhalation, IV, oral

Acetylcysteine (rINN) (IPA: [ˌæsɛtl̩ˈsɪstin, əˌsɛtl̩-, ˌæsətaɪl-]), also known as N-acetylcysteine (abbreviated NAC), is a pharmacological agent used mainly as a mucolytic and in the management of paracetamol overdose. For these indications, acetylcysteine is available under the trade names Mucomyst (Bristol-Myers Squibb), Acetadote (Cumberland Pharmaceuticals), Fluimucil and Parvolex (GSK). In pharmacology and toxicology, a route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body 1. ... IV may refer to: The Roman number for four — meaning one (I) less than five (V). ... An International Nonproprietary Name (INN) is the official non-proprietary or generic name given to a pharmaceutical substance, as designated by the World Health Organization. ... For information on how to read IPA transcriptions of English words see here. ... Any agent which dissolves thick mucus to help relieve respiratory difficulties. ... Paracetamol (INN) (IPA: ) or acetaminophen (USAN), is a common analgesic and antipyretic drug that is used for the relief of fever, headaches, and other minor aches and pains. ... Bristol-Myers Squibb (NYSE: BMY), colloquially referred to as BMS, is a pharmaceutical corporation, formed by a 1989 merger between pharmaceutical companies Bristol-Myers Company, founded in 1887 by William McLaren Bristol and John Ripley Myers in Clinton, NY (both were graduates of Hamilton College), and Squibb Corporation. ... GlaxoSmithKline plc (LSE: GSK NYSE: GSK) is a British based pharmaceutical, biologicals, and healthcare company. ...

Dosage forms

Acetylcysteine is available in different dosage forms for different indications:

• Solution for inhalation (Mucomyst, Mucosil) – inhaled for mucolytic therapy or ingested for nephroprotective effect
• IV injection (Parvolex) – treatment of paracetamol overdose
• Oral solution – various indications

The IV injection and inhalation preparations are generally prescription only, while oral solution is available over the counter in many countries. An intravenous drip in a hospital Intravenous therapy or IV therapy is the administration of liquid substances directly into a vein. ... Over-the-counter substances, also abbreviated OTC, are drugs and other medical remedies that may be sold without a prescription and without a visit to a medical professional, in contrast to prescription only medicines (POM). ...

Chemistry

Acetylcysteine is the N-acetyl derivative of the amino acid L-cysteine, and is a precursor in the formation of the antioxidant glutathione in the body. The thiol (sulfhydryl) group confers antioxidant effects and is able to reduce free radicals. Cysteine is a naturally occurring amino acid which has a thiol group and is found in most proteins, though only in small quantities. ... Skeletal formula of glutathione 3D model of glutathione Glutathione (GSH), whose IUPAC name is 2-amino-5-{[2-[(carboxymethyl)amino]- 1-(mercaptomethyl)-2-oxoethyl]amino}-5-oxopentanoic acid, is γ-glutamylcysteinylglycine, a tripeptide. ... // In organic chemistry, a thiol is a compound that contains the functional group composed of a sulfur atom and a hydrogen atom (-SH). ... Semi-accurate illustration of a redox reaction Redox reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed. ... In chemistry free radicals are uncharged atomic or molecular species with unpaired electrons or an otherwise open shell configuration. ...

Clinical use

Mucolytic therapy

Inhaled acetylcysteine is indicated for mucolytic ("mucus dissolving") therapy as an adjuvant in respiratory conditions with excessive and/or thick mucus production. Such conditions include: emphysema, bronchitis, tuberculosis, bronchiectasis, amyloidosis, pneumonia. It is also used post-operatively, as a diagnostic aid, and in tracheostomy care. It is considered ineffective in cystic fibrosis (Rossi, 2006). Oral acetylcysteine may also be used as a mucolytic in less serious cases. This article is about jesse because he is a dumbass and a fat kid. ... Tuberculosis (abbreviated as TB for Tubercle Bacillus) is a common and deadly infectious disease caused by the mycobacterium Mycobacterium tuberculosis or Mycobacterium bovis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system, lymphatic system, circulatory system, genitourinary system, bones and joints. ... It has been suggested that CURB-65 be merged into this article or section. ... Tracheotomy is a surgical procedure used to cut a hole in the trachea through which a small tube is inserted. ...

For this indication, acetylcysteine acts to reduce mucus viscosity by splitting disulfide bonds linking proteins present in the mucus (mucoproteins). In chemistry, a disulfide bond is a single covalent bond derived from the coupling of thiol groups. ...

Paracetamol overdose

Intravenous acetylcysteine is indicated for the treatment of paracetamol (acetaminophen) overdose. Oral acetylcysteine for this indication is uncommon as it is poorly tolerated owing to the high doses required (due to poor oral bioavailability), unpleasant taste/odour and adverse drug reactions (particularly nausea and vomiting). Paracetamol (INN) (IPA: ) or acetaminophen (USAN), is a common analgesic and antipyretic drug that is used for the relief of fever, headaches, and other minor aches and pains. ... In pharmacology, bioavailability is used to describe the fraction of an administered dose of medication that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. ... An adverse drug reaction (abbreviated ADR) is a term to describe the unwanted, negative consequences sometimes associated with the use of medications. ...

For this indication, acetylcysteine acts to augment glutathione reserves (depleted by toxic paracetamol metabolites) in the body and, together with glutathione to directly bind to toxic metabolites. These actions serve to protect hepatocytes in the liver from toxicity due to paracetamol overdose. Skeletal formula of glutathione 3D model of glutathione Glutathione (GSH), whose IUPAC name is 2-amino-5-{[2-[(carboxymethyl)amino]- 1-(mercaptomethyl)-2-oxoethyl]amino}-5-oxopentanoic acid, is γ-glutamylcysteinylglycine, a tripeptide. ... Hepatocytes make up 60-80% of the cytoplasmic mass of the liver. ...

Nephroprotective agent

Oral acetylcysteine is used for the prevention of radiocontrast-induced nephropathy (a form of acute renal failure). Some studies show that prior administration of acetylcysteine markedly decreases (90%) radiocontrast nephropathy (Tepel et al 2000), while others appear to cast doubt on its efficacy (Hoffman et al., 2004; Miner et al., 2004) Nevertheless, acetylcysteine continues to be commonly used in individuals with renal impairment to prevent the precipitation of acute renal failure. Radiocontrast agents (or simply contrast agents) are compounds used to improve the visibility of internal bodily structures in an X-ray image. ... Chronic renal failure (CRF, or chronic kidney failure, CKF, or chronic kidney disease, CKD) is a slowly progressive loss of renal function over a period of months or years and defined as an abnormally low glomerular filtration rate, which is usually determined indirectly by the creatinine level in blood serum. ...

Other uses

The following uses have not been well-established or investigated:

• NAC has been shown to reduce cravings associated with chronic cocaine use in a study conducted at the Medical University of South Carolina ( Kalivas, et al, 2006)
• It may reduce the incidence of chronic obstructive pulmonary disease (COPD) exacerbations (Pela et al., 1999)
• It has been proposed as a supplement for patients with AIDS, who generally have decreased glutathione levels. However, it does not appear to be effective in restoring glutathione levels (Witschi et al., 1995).
• An animal study indicates that acetylcysteine may decrease mortality associated with influenza (Ungheri et al., 2000)
• Animal studies suggest that NAC may help prevent noise-induced hearing loss (Kopke et al., 2005). A clinical trial to determine efficacy in preventing noise induced sensorineural hearing loss in humans is currently (2006) being jointly conducted by the US Army and US Navy.
• It has been suggested that NAC may help sufferers of Samter's triad by increasing levels of glutathione allowing faster breakdown of salicylates, though there is no evidence that it is of benefit (Bachert et al., 2003).
• There are claims that acetylcysteine taken together with vitamin C and B1 can be used to prevent and relieve symptoms of veisalgia (hangover following ethanol (alcohol) consumption). The claimed mechanism is through scavenging of acetaldehyde, a toxic intermediate in the metabolism of ethanol.

Cocaine (or crack in its impure freebase form) is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. ... The Medical University of South Carolina opened in Charleston, South Carolina in 1824 as a small private college for the training of physicians. ... Chronic obstructive pulmonary disease (COPD) is an umbrella term for a group of respiratory tract diseases that are characterized by airflow obstruction or limitation. ... Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... Influenza, commonly known as the flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). ... Samters triad is a medical condition consisting of asthma, aspirin sensitivity, and nasal polyposis. ... Salicylic acid is a colorless, crystalline organic carboxylic acid. ... A hangover is the after-effect following the consumption of large amounts of one drug or another. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless, slightly toxic chemical compound with a distinctive perfume-like odor, and is the alcohol found in alcoholic beverages. ... R-phrases , , S-phrases , , , Flash point −39 °C Autoignition temperature 185 °C RTECS number AB1925000 Supplementary data page Structure and properties n, εr, etc. ...

References

• Bachert C, Hormann K, Mosges R, et al. An update on the diagnosis and treatment of sinusitis and nasal polyposis. Allergy 2003;58(3):176-91. PMID 12653791
• Hoffmann U, Fischereder M, Kruger B, Drobnik W, Kramer BK. The value of N-acetylcysteine in the prevention of radiocontrast agent-induced nephropathy seems questionable. J Am Soc Nephrol 2004;15:407-10. Fulltext. PMID 14747387.
• Kopke R, Bielefeld E, Liu J, et al. Prevention of impulse noise-induced hearing loss with antioxidants. Acta Otolaryngol 2005;125(3):235-43. PMID 15966690
• Miner SE, Dzavik V, Nguyen-Ho P, Richardson R, Mitchell J, Atchison D, Seidelin P, Daly P, Ross J, McLaughlin PR, Ing D, Lewycky P, Barolet A, Schwartz L. N-acetylcysteine reduces contrast-associated nephropathy but not clinical events during long-term follow-up. Am Heart J 2004;148:690-5. PMID 15459602.
• Pela R, Calcagni AM, Subiaco S, et al. N-acetylcysteine reduces the exacerbation rate in patients with moderate to severe COPD. Respiration 1999;66(6):495-500. PMID 10575333
• Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006.
• Tepel M, van der Giet M, Schwarzfeld C, Laufer U, Liermann D, Zidek W. Prevention of radiographic-contrast-agent-induced reductions in renal function by acetylcysteine. N Engl J Med 2000;343:180-4. PMID 10900277.
• Ungheri D, Pisani C, Sanson G, et al. Protective effect of n-acetylcysteine in a model of influenza infection in mice. Int J Immunopathol Pharmacol 2000;13(3):123-128. PMID 12657201
• Witschi A, Junker E, Schranz C, Speck RF, Lauterburg BH. Supplementation of N-acetylcysteine fails to increase glutathione in lymphocytes and plasma of patients with AIDS. AIDS Res Hum Retroviruses 1995;11(1):141-3. PMID 7734187

The Australian Medicines Handbook or AMH is a medical reference text commonly used in practice by health professionals (particularly general practitioners and pharmacists) in Australia. ... The New England Journal of Medicine (NEJM) is a peer-reviewed medical journal published by the Massachusetts Medical Society. ...

See also

• Glutathione

Skeletal formula of glutathione 3D model of glutathione Glutathione (GSH), whose IUPAC name is 2-amino-5-{[2-[(carboxymethyl)amino]- 1-(mercaptomethyl)-2-oxoethyl]amino}-5-oxopentanoic acid, is γ-glutamylcysteinylglycine, a tripeptide. ...

External links

• MedlinePlus drug information: Acetylcysteine (inhalation) – information from USP DI Advice for the Patient
• Links to external chemical sources.