Description

Simple

A medication used to thin the mucus in certain lung conditions, and also as an antidote for acetaminophen overdose.

Clinical

A medication that can be used as a mucolytic in patients with certain lung conditions and as an antidote for acetaminophen overdose.

Overview

Acetylcysteine (also known as N-acetylcysteine or N-acetyl-L-cysteine or NAC) is primarily used as a mucolytic agent and in the management of acetaminophen poisoning. It is a derivative of cysteine with an acetyl group attached to the amino group of cysteine. NAC is essentially a prodrug that is converted to cysteine (in the intestine by the enzyme aminoacylase 1) and absorbed in the intestine into the blood stream. Cysteine is a key constituent to glutathione and hence administration of acetylcysteine replenishes glutathione stores. Acetylcysteine can also be used as a general antioxidant which can help mitigate symptoms for a variety of diseases exacerbated by reactive oxygen species (ROS). For instance, acetylcysteine is commonly used in individuals with renal impairment to prevent the precipitation of acute renal failure. Acetylcysteine has been shown to have efficacy in treating mild to moderate traumatic brain injury including ischemic brain injury, particularly in reducing neuronal losses, and also reducing cognitive and neurological symptoms when administered promptly after injury. N-acetylcysteine is now widely used in the treatment of HIV, and it has reported efficacy in chronic obstructive pulmonary disease and contrast-induced nephropathy. Acetylcysteine is also being successfully used to treat a variety of neuropsychiatric and neurodegenerative disorders including cocaine, cannabis, and smoking addictions, Alzheimer's and Parkinson's diseases, autism, compulsi... Read more

Pharmacology

Indication

Acetylcysteine is used mainly as a mucolytic and in the management of paracetamol (acetaminophen) overdose.

Pharmacodynamic

Acetylcysteine has been shown to reduce the extent of liver injury following acetaminophen overdose. It is most effective when given early, with benefit seen principally in patients treated within 8-10 hours of the overdose. Acetylcysteine likely protects the liver by maintaining or restoring the gl... Read more

Mechanism of action

Acetylcysteine protects against acetaminophen overdose-induced hepatotoxicity by maintaining or restoring hepatic concentrations of glutathione. It does this by producing the glutathione precursor L-cysteine. Glutathione is required to inactivate an intermediate metabolite (N-acetyl-p-benzoquinoneim... Read more

Absorption

Bioavailability is 6–10% following oral administration and less than 3% following topical administration.

Protein binding

83%

Volume of distribution

Information currently not available.

Clearance

Information currently not available.

Half life

5.6 hours (adults), 11 hours (neonates)

Route of elimination

Information currently not available.

Toxicity

Single intravenous doses of acetylcysteine at 1000 mg/kg in mice, 2445 mg/kg in rats, 1500 mg/kg in guinea pigs, 1200 mg/kg in rabbits and 500 mg/kg in dogs were lethal. Symptoms of acute toxicity were ataxia, hypoactivity, labored respiration, cyanosis, loss of righting reflex and convulsions.

Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Rash US
  • Kind: experimental
    • Percent: 0.2-21%
  • Unclassified
    Urticaria US
  • Kind: experimental
    • Percent: 0.2-21%
  • Unclassified
    Pruritus US
  • Kind: experimental
    • Percent: 0.2-21%
  • Unclassified
    Immune System Disorder US
  • Kind: experimental
    • Percent: 14-18%
  • Clinical Trial
    Gastrointestinal Disorder US
  • Kind: experimental
    • Percent: 10-15%
  • Clinical Trial
    Vomiting US
  • Kind: experimental
    • Percent: 2-10%
  • Clinical Trial
    Hypersensitivity US
  • Kind: experimental
    • Percent: 1-10%
  • Clinical Trial
    Urticaria US
    • children
  • Kind: experimental
    • Percent: 7.6%
  • Clinical Trial
    Facial Flushing US
    • children
  • Kind: experimental
    • Percent: 7.6%
  • Clinical Trial
    Skin disorder US
  • Kind: experimental
    • Percent: 6-7%
  • Clinical Trial
    Facial Flushing US
    • adult
  • Kind: experimental
    • Percent: 6.1%
  • Clinical Trial
    Urticaria US
    • adult
  • Kind: experimental
    • Percent: 6.1%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 1-6%
  • Clinical Trial
    Cardiac Disorder US
  • Kind: experimental
    • Percent: 3-5%
  • Clinical Trial
    Pruritus US
    • adult
  • Kind: experimental
    • Percent: 4.3%
  • Clinical Trial
    Pruritus US
    • adult
  • Kind: experimental
    • Percent: 4.3%
  • Clinical Trial
    Pruritus US
    • children
  • Kind: experimental
    • Percent: 4.1%
  • Clinical Trial
    Tachycardia US
  • Kind: experimental
    • Percent: 1-4%
  • Clinical Trial
    Rash US
  • Kind: experimental
    • Percent: 2-4%
  • Clinical Trial
    Vascular disorder US
  • Kind: experimental
    • Percent: 2-4%
  • Clinical Trial
    Respiratory reaction US
  • Kind: experimental
    • Percent: 2-3%
  • Clinical Trial
    Thoracic reaction US
  • Kind: experimental
    • Percent: 2-3%
  • Clinical Trial
    Mediastinal reaction US
  • Kind: experimental
    • Percent: 2-3%
  • Clinical Trial
    Pruritus US
  • Kind: experimental
    • Percent: 1-3%
  • Clinical Trial
    Flushing US
  • Kind: experimental
    • Percent: 1-3%
  • Clinical Trial
    Respiratory Symptoms US
    • children
  • Kind: experimental
    • Percent: 2.2%
  • Clinical Trial
    Respiratory Symptoms US
    • adult
  • Kind: experimental
    • Percent: 1.9%
  • Clinical Trial
    Edema US
    • adult
  • Kind: experimental
    • Percent: 1.6%
  • Clinical Trial
    Edema US
    • children
  • Kind: experimental
    • Percent: 1.2%
  • Clinical Trial
    Pharyngitis US
  • Kind: experimental
    • Percent: 1%
  • Clinical Trial
    Rhonchi US
  • Kind: experimental
    • Percent: 1%
  • Clinical Trial
    Rhinorrhea US
  • Kind: experimental
    • Percent: 1%
  • Clinical Trial
    Throat tightness US
  • Kind: experimental
    • Percent: 1%
  • Clinical Trial
    Anaphylaxis US
    • children
  • Kind: experimental
    • Percent: 0.2%
  • Clinical Trial
    Hypotension US
    • adult
  • Kind: experimental
    • Percent: 0.1%
  • Clinical Trial
    Anaphylaxis US
    • adult
  • Kind: experimental
    • Percent: 0.1%
  • Clinical Trial
    Hypotension US
    • children
  • Kind: experimental
    • Percent: 0.1%
  • Clinical Trial
    Chest tightness US
    Varying Reports
    Bronchoconstriction US
    Varying Reports
    Bronchospasm US
    Varying Reports
    Acquired sensitization US
    Varying Reports
    Irritation of the trachea US
    Varying Reports
    Clamminess US
    Varying Reports
    Drowsiness US
    Varying Reports
    Rhinorrhea US
    Varying Reports
    Fever US
    Varying Reports
    Vomiting US
    Varying Reports
    Nausea US
    Varying Reports
    Stomatitis US
    Varying Reports
    Rash US
    Post Marketing

    Contraindications

    Information currently not available.

    Food Interactions

    Information currently not available.