• Molecular NameAcetaminophen
  • SynonymAcetaminofen; APAP; Paracetamol; Paracetamolo; Paracetanol
  • Weight151.165
  • Drugbank_IDDB00316
  • ACS_NO103-90-2
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  • LogP (experiment)0.46
  • LogP (predicted, AB/LogP v2.0)0.54
  • pkaN/A
  • LogD (pH=7, predicted)0.54
  • Solubility (experiment)15.4 mg/ml
  • LogS (predicted, ACD/Labs)(ph=7)-0.93
  • LogSw (predicted, AB/LogsW2.0)4.55
  • Sw (mg/ml) (predicted, ACD/Labs)17.85
  • No.of HBond Donors2
  • No.of HBond Acceptors3
  • No.of Rotatable Bonds1
  • TPSA49.33
  • StatusFDA approved
  • AdministrationOral, rectal, intravenous
  • PharmacologyA widely used over-the-counter analgesic (pain reliever) and antipyretic (fever reducer). It is commonly used for the relief of fever, headaches, and other minor aches and pains, and is a major ingredient in numerous cold and flu remedies.
  • Absorption_value85.0
  • Absorption (description)Rapid and almost complete
  • Caco_2N/A
  • Bioavailability88.0
  • Protein binding25.0
  • Volume of distribution (VD)0.95 L/kg
  • Blood/Plasma Partitioning ratio (D_blood)N/A
  • MetabollsmParacetamol is metabolised primarily in the liver, into non-toxic products. Three metabolic pathways are notable: (1) * Glucuronidation is believed to account for 40% to two-thirds of the metabolism of paracetamol; (2) Sulfation (sulfate conjugation) may account for 20–40%; (3) N-hydroxylation and rearrangement, then GSH conjugation, accounts for less than 15%. The hepatic cytochrome P450 enzyme system metabolizes paracetamol, forming a minor yet significant alkylating metabolite known as NAPQI (N-acetyl-p-benzo-quinone imine).[42] NAPQI is then irreversibly conjugated with the sulfhydryl groups of glutathione.Production of NAPQI is due primarily to two isoenzymes of cytochrome P450: CYP2E1 and CYP1A2.
  • Half life2 h
  • ExcretionRenal
  • Urinary Excretion3
  • Clerance5 ml.min-1.kg-1
  • ToxicityExcessive use of paracetamol can damage multiple organs, especially the liver and kidney. In both organs, toxicity from paracetamol is not from the drug itself but from one of its metabolites, N-acetyl-p-benzoquinoneimine (NAPQI).
  • LD50 (rat)N/A
  • LD50 (mouse)N/A