Paracetamol belongs to the group of analgesics: other analgesics and antipyretics. The mechanism of action of paracetamol has not been fully specified. It is assumed that by inhibiting cyclooxygenase 2 and cyclooxygenase 1, paracetamol prevents the synthesis of prostaglandins from arachidonic acid. There are oral and parenteral formulations of paracetamol on the Croatian market. Paracetamol is an effective analgesic and antipyretic. Clinical use of paracetamol includes headache, tension headache, migraine, toothache, sore throat, back pain, dysmenorrhea, pyrexia, transient myalgia and arthralgia during colds, pain after injury and after therapeutic procedures. The toxic dose varies among individuals with respect to baseline glutathione levels and clinical factors below. In the case of a single dose of less than 7.5 to 10 g in an adult or 150 mg/kg in a child, the probability of toxicity is low. Toxicity is likely to occur with a single ingestion of a dose greater than 250 mg/kg or greater than 12 grams in a 24-hour period. The basis for diagnosing acute paracetamol poisoning and determining the need for treatment is the serum concentration of paracetamol. Treatment of a patient poisoned by paracetamol includes stabilization, decontamination and administration of N-acetylcysteine, a specific antidote. The initial treatment of paracetamol poisoning is determined by the patient's symptoms. The duration of treatment with N-acetylcysteine is determined by the type of intake and the presence or absence of elevated serum ALT concentrations