Signs and Symptoms of Overdose: Hepatobiliary Disorders: If a paracetamol extended-release product is involved or if the exact formulation is not known, it is recommended to obtain an additional plasma paracetamol level 4 to 6 hours following the initial paracetamol level as these levels will continue to rise with the extended release products and may alter treatment decisions.
In adults and adolescents (2:12 years of age), hepatic toxicity may occur following ingestion of greater than 7.5 to 10 g over a period of 8 hours or less. Fatalities are infrequent (less than 3-4% of untreated cases) and have rarely been reported with overdoses of less than 15 grams. In children (<12 years of age), an acute overdosage of less than 150 mg/kg has not been associated with hepatic toxicity. Early symptoms following a potentially hepatotoxic overdose may include: Anorexia, nausea, vomiting, diaphoresis, pallor and general malaise. Clinical and laboratory evidence of hepatic toxicity may not be apparent until 48 to 72 hours post-ingestion. Serious toxicity or fatalities have been extremely infrequent following an acute paracetamol overdose in young children, possibly because of differences in the way they metabolize paracetamol.
Table 1 shows the clinical events associated with paracetamol overdose that if seen with overdose are considered expected, including fatal events due to fulminant hepatic failure or its sequelae. (See Table 1.)
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The following clinical events are sequelae to acute hepatic failure and may be fatal. If these events occur in the setting of acute hepatic failure associated with paracetamol overdose (adults and adolescents: >12 years of age: >7.5 g within 8 hours; children <12 years of age: >150 mg/kg within 8 hours), they are considered expected.
Expected sequelae to acute hepatic failure associated with paracetamol overdose include the following: Bacterial infection, fungal infection, sepsis, coagulopathy, disseminated intravascular coagulation, thrombocytopenia, hypoglycaemia, hypophosphatemia, lactic acidosis, metabolic acidosis, brain oedema, coma (with massive paracetamol overdose or multiple drug overdose), encephalopathy, cardiomyopathy, hypotension, respiratory failure, gastrointestinal haemorrhage, pancreatitis, acute kidney injury, and multiple organ dysfunction syndrome.
Blood and Lymphatic Disorders: Haemolytic anaemia (in patients with glucose-6-phosphate dehydrogenase [G6PD] deficiency): Haemolysis has been reported in patients with G6PD deficiency, with use of paracetamol in overdose.
In the event of overdose, get medical help or contact a Poison Control Center right away.
What to do when the patient have taken more than the recommended dosage: Overdose warning: Taking more than the recommended dose (overdose) may result in liver damage. In case of overdose, get medical help immediately. Quick medical attention is critical for adults as well as for children even if they do not notice any signs or symptoms.
When should the patient consult the doctor: If pain or fever persists or gets worse, or if new symptoms occur, a physician should be consulted.