PARACETAMOL

Children are more resistant to paracetamol induced liver damage than adults.¹ Chronic overdosage is more likely to result in harm than the acute effects of ingestion. Special care should be taken with children who are malnourished or on cytochrome P450 enzyme inducing drugs.

Toxic paracetamol concentrations associated with the accidental ingestion of paracetamol suspension are extremely rare. A careful history can often obviate the need for investigation or treatment. The volume, and paracetamol concentration, of the formulation should be established from the packaging. The volume remaining should be measured. No allowance should be made for spillage during the course of the accident or poor parental recall as to the amount remaining in the bottle prior to ingestion. In this way, the maximum possible dose of paracetamol consumed can usually be established. If the potential dose of paracetamol consumed can be established with absolute certainty as being below 150 mg/kg, no further action is required.

Where deliberate ingestion is reported or suspected, or the dose accidentally ingested cannot be confirmed, the blood paracetamol concentration should be measured. Paracetamol concentration must be measured at least four hours following ingestion. Samples taken prior to this may be unreliable because of the possibility of continuing absorption and changing drug distribution.

Paracetamol concentration should be compared with the standard adult normogram to determine the need for treatment. A lower treatment threshold (50% of the standard concentration at which treatment would be instigated) is recommended for patients in high risk groups. Children at high risk include those who are malnourished (for example, anorexia, failure to thrive) …