{
  "id": "paracetamol",
  "title": "Paracetamol",
  "lang": "en",
  "source_lang": "en",
  "summary": "Paracetamol, also called acetaminophen, is a medicine used to relieve pain and reduce fever; excessive exposure can cause severe liver injury.",
  "category": "health",
  "subcategory": "drugs",
  "type": "concept",
  "aliases": [
    "Acetaminophen",
    "APAP",
    "N-acetyl-para-aminophenol"
  ],
  "generated_at": "2026-10-11",
  "model": "pro/gpt-6.1-sol",
  "url": "https://aiwiki.page/en/paracetamol/",
  "translations": {
    "zh-Hans": {
      "url": "https://aiwiki.page/zh/paracetamol/",
      "json": "https://aiwiki.page/zh/paracetamol.json"
    }
  },
  "sections": [
    {
      "heading": "",
      "text": "Paracetamol, commonly called acetaminophen in the United States, is a medicine used to relieve pain and reduce fever. It is available both as a single active ingredient and in combination products, including cold remedies and prescription pain medicines. Its principal actions are analgesic and antipyretic: it reduces pain and elevated body temperature. Although generally well tolerated when used within approved dosing limits, excessive exposure can cause severe liver injury, liver failure, and death. (fda.gov)"
    },
    {
      "heading": "Names and chemical identity",
      "text": "Paracetamol and acetaminophen are names for the same chemical substance, not different medicines. “APAP” is an abbreviation that may appear on prescription labels. Paracetamol is the name commonly used outside the United States, while acetaminophen is the standard name used in American drug labeling. (fda.gov)\n\nThe compound has the molecular formula \\(\\mathrm{C_8H_9NO_2}\\). Its structure consists of a benzene ring bearing a hydroxyl group and an acetamide group in opposite, or para, positions. The chemical name N-acetyl-para-aminophenol describes this arrangement. (pubchem.ncbi.nlm.nih.gov)"
    },
    {
      "heading": "Pharmacological action",
      "text": "Paracetamol’s precise mechanism of action is not fully established. Its pain-relieving and fever-reducing effects are thought to involve actions primarily within the central nervous system. This uncertainty concerns the detailed biochemical mechanism rather than the existence of its analgesic and antipyretic effects, which have been demonstrated in human and animal studies. (accessdata.fda.gov)\n\nCompared with typical nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol has relatively little activity against peripheral inflammation. Pain relief therefore does not necessarily indicate suppression of the inflammatory process causing the pain. (ncbi.nlm.nih.gov)\n\nParacetamol also differs from some other pain medicines in its effects on blood clotting. Studies described in approved prescribing information found no significant effect on platelet aggregation or bleeding time under the conditions examined. (accessdata.fda.gov)"
    },
    {
      "heading": "Uses and formulations",
      "text": "Paracetamol is used for symptomatic relief of conditions such as headache, toothache, sore throat, and fever associated with a common cold or influenza. In these settings, it treats pain or elevated temperature rather than the underlying cause of the illness. (nhs.uk)\n\nAvailable formulations include tablets, capsules, oral liquids, powders, and rectal suppositories. Some oral products are chewable or extended-release. An intravenous formulation is also used in clinical care; its approved indications include mild-to-moderate pain, moderate-to-severe pain alongside opioid analgesics, and fever reduction. (fda.gov)\n\nCombination products are an important feature of its use. A medicine marketed primarily for cough, cold symptoms, or another complaint may contain paracetamol in addition to other active ingredients. Consequently, total exposure can come from several products and more than one route of administration. Approved labeling treats their combined contribution as relevant to the risk of overdose. (fda.gov)"
    },
    {
      "heading": "Metabolism",
      "text": "Paracetamol undergoes metabolism mainly in the liver through three principal pathways:\n\n- Glucuronide conjugation, which produces a metabolite excreted in urine.\n- Sulfate conjugation, which likewise produces a urinary metabolite.\n- Oxidation, mediated by the enzyme system cytochrome P450, particularly CYP2E1, which produces the reactive intermediate N-acetyl-p-benzoquinone imine, usually abbreviated NAPQI.\n\nNAPQI is normally detoxified through conjugation with glutathione. These pathways explain why the same substance can be tolerated at therapeutic exposure yet become markedly toxic when its detoxification capacity is exceeded. (dailymed.nlm.nih.gov)\n\nAfter a large overdose, the glucuronide and sulfate pathways become saturated, increasing the fraction processed through the oxidative pathway. More NAPQI is then produced, and glutathione may become depleted. The resulting reactive metabolite can damage liver tissue. (dailymed.nlm.nih.gov)"
    },
    {
      "heading": "Adverse effects and overdose",
      "text": "Liver injury\n\nThe principal serious dose-related hazard is liver injury. It can follow a single large ingestion or repeated exposure above therapeutic limits. Unintentional overdose may occur when several paracetamol-containing medicines are used together. Early symptoms can be absent or nonspecific, so the initial appearance of an affected person does not reliably indicate the eventual severity of poisoning. (fda.gov)\n\nPrescribing information identifies liver disease, alcoholism, chronic malnutrition, and severe renal impairment among conditions relevant to safety assessment. Some therapeutic-dose exposures can also produce transient elevations in liver enzymes without progressing to liver failure. These laboratory changes are distinct from the severe injury associated with overdose. (fda.gov)\n\nAcetylcysteine, also called N-acetylcysteine or NAC, is an antidote used to prevent or lessen liver injury following potentially toxic exposure. Its protective action involves restoring the capacity to detoxify the reactive metabolite. Clinical assessment distinguishes acute ingestion from repeated excessive exposure because their evaluation and treatment differ. (dailymed.nlm.nih.gov)\n\nHypersensitivity and skin reactions\n\nRare adverse reactions include severe allergic reactions and serious skin reactions. The latter include Stevens–Johnson syndrome, toxic epidermal necrolysis, and acute generalized exanthematous pustulosis. These reactions can occur during first use or after previous exposure without problems, and can be fatal. Unlike dose-related liver toxicity, they are not simply consequences of taking an excessive amount. (nhs.uk)"
    }
  ],
  "links": [
    "medicine",
    "pain",
    "fever",
    "central-nervous-system",
    "inflammation",
    "platelet",
    "headache",
    "common-cold",
    "metabolism",
    "enzyme"
  ],
  "sources": [
    {
      "title": "Acetaminophen",
      "url": "https://www.fda.gov/drugs/safe-use-over-counter-pain-relievers-and-fever-reducers/acetaminophen"
    },
    {
      "title": "Acetaminophen: PubChem compound record",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/acetaminophen"
    },
    {
      "title": "Acetaminophen for injection: prescribing information",
      "url": "https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/206610s000lbl.pdf"
    },
    {
      "title": "Acetaminophen — LiverTox",
      "url": "https://ncbi.nlm.nih.gov/books/NBK548162/"
    },
    {
      "title": "Paracetamol for adults",
      "url": "https://www.nhs.uk/medicines/paracetamol-for-adults/"
    },
    {
      "title": "Acetaminophen injection: prescribing information",
      "url": "https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=88c29438-3648-4b09-bd43-70ad7a35bcb5"
    },
    {
      "title": "Acetaminophen injection: clinical pharmacology and prescribing information",
      "url": "https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=0f67c1bd-915b-4681-88dd-22f5154a80b3&type=display"
    },
    {
      "title": "Acetaminophen warnings and precautions",
      "url": "https://www.fda.gov/media/121203/download"
    },
    {
      "title": "Acetylcysteine injection: prescribing information",
      "url": "https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8cca4e4c-85a2-d575-e053-2995a90a6599&type=display"
    },
    {
      "title": "Acetylcysteine injection: indications and prescribing information",
      "url": "https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=277963a0-8ab2-4305-a688-28e47e87c584&type=display"
    },
    {
      "title": "Don’t Overuse Acetaminophen",
      "url": "https://www.fda.gov/consumers/consumer-updates/dont-overuse-acetaminophen"
    },
    {
      "title": "Questions and Answers: FDA warns of rare but serious skin reactions with the pain reliever/fever reducer acetaminophen",
      "url": "https://www.fda.gov/drugs/drug-safety-and-availability/questions-and-answers-fda-warns-rare-serious-skin-reactions-pain-relieverfever-reducer-acetaminophen"
    }
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/"
}