Paracetamol is although a safe drug in therapeutic doses, toxic doses can cause Acute Liver Failure is following absorption of therapeutic doses , 90% is metabolized by glucuronidation and sulfation to form nontoxic metabolites, which are excreted in the urine by kidneys. A small fraction of paracetamol undergoes oxidation by the enzyme "Cytochrome P 450 situated in the mitochondrial system to form the reactive metabolite N-acetyl-p-benzoquinoneimine (NAPQI)" . NAPQI reacts with glutathione, forming conjugates that are excreted in urine by kidneys.
With a large amount of paracetamol hepatic glutathione is depleted and NAPQI accumulates. It combines with intracellular proteins affecting energy production. The first 24 hours after ingestion of toxic dose usually more than 7 grams nonspecific gastrointestinal irritation with symptoms of nausea commuting, abdominal pain, anorexia, lethargy…
