The modified amino acid acetylcysteine, sometimes referred to as N-acetylcysteine (NAC), is used as an antidote for paracetamol overdose to avoid liver damage. Hepatoprotective agent acetylcysteine has not been associated with clinically evident acute liver injury or with large increases in blood enzymes during therapy.
Liver injury and effects of acetylcysteine administration
A modified amino acid called acetylcysteine is used to stop acute liver failure and reverse the harmful consequences of an acetaminophen overdose. Because of its thiol side chain, which is capable of undergoing redox reactions, the amino acid cysteine possesses antioxidant properties. If there is a question of whether can liver disease individual take acetylcysteine drug (nac โรคตับกินได้ไหม, this is the term in Thai)?, here is a solution to it.
Crucially, cysteine is needed for the production of glutathione, a tripeptide made of cysteine, glycine, and glutamic acid. Glutathione is an intracellular antioxidant that protects against intracellular poisons such as drug metabolic intermediates and free radicals. While acetylated cysteine is more palatable and still supports glutathione production, pure cysteine has an unpleasant taste and smell. Patients suffering from chronic debilitating illnesses, malnourishment, and alcoholism can all experience glutathione depletion.
Patients who overdose on paracetamol may have acute glutathione depletion, which can result in the formation of lethal adducts of paracetamol metabolites with vital intracellular components. The damage that acetaminophen causes to cells is lessened when glutathione stores are restored.
Acetylcysteine, commonly known as N-acetylcysteine or NAC, when administered within 10 hours of an acetaminophen overdose has been shown in numerous clinical trials to effectively avoid major liver impairment. Even after 10 hours, dosing seems to be somewhat successful, according to further research, and it might even be helpful in cases of acute liver failure caused by non-acetaminophen causes, such as drug-induced liver damage.
In 1963, acetylcysteine was approved for use in humans as part of the Mucomyst inhalation solution, which helps patients with chronic bronchitis or pulmonary infections emulsify their respiratory secretions. Acetylcysteine also possesses mucolytic activity. In 1978, acetylcysteine in oral form and 2004 in intravenous form were approved for use as an antidote to acetaminophen. Acetylcysteine is available as an injectable solution in single-dosage vials containing 200 mg/mL and as effervescent tablets of 500 and 2500 mg for oral usage.
Dosage
Based on body weight, projected time of ingestion, and acetaminophen use, the appropriate dose of acetylcysteine should be determined. There is a nomogram (Rumack-Matthew Nomogram) that graphs the time after intake that the sample was obtained against the plasma levels of acetaminophen to determine the possibility of liver damage from acetaminophen. Usually, a loading dose is administered first, and then maintenance dosages every four hours for a few days. Side effects are typically dose-related. Antihistamines are often effective in treating hypersensitivity reactions.
Hepatotoxicity
A straightforward modified amino acid with potential hepatoprotective effects is acetylcysteine. The use of acetylcysteine in conjunction with acetaminophen overdose, as well as other conditions like pulmonary fibrosis, cystic fibrosis, ulcerative colitis, and contrast media nephropathy, has not been linked to episodes of liver injury that is clinically apparent or elevated serum enzymes during therapy, according to numerous studies.
There have been no documented cases of hepatotoxicity since the oral and intravenous versions of acetylcysteine were approved, and liver damage is not included as an adverse event on the product label. Although its current indications are restricted to acetaminophen overdose or acute liver injury related to acetaminophen, acetylcysteine may help treat liver problems in general.
