Intravenous paracetamol (Perfalgan ▼): risk of accidental overdose

Risk of accidental overdose, particularly in infants and neonates.

Article date: July 2010

Cases of accidental overdose have been reported during treatment with intravenous paracetamol 10 mg/mL solution for infusion (Perfalgan ▼). In most cases, this occurred in infants and neonates due to confusion between the prescription of Perfalgan being issued in mg and then administered in mL; in most of these cases, a 10-fold overdose was reported.

Perfalgan is indicated for the short-term treatment of pain and fever, when there is a clinical need of paracetamol administration intravenously. It is available as a solution for infusion of 10 mg paracetamol per 1 mL solution in 50 mL vials and 100 mL vials. The 50 mL vial is only for use in term newborn infants, infants, toddlers, and children who weigh less than 33 kg.

The recommended dose of Perfalgan depends on the weight of the patient, and is summarised in the table below.

Note that irrespective of dose, the dosing schedule is up to four infusions a day with a minimum of 4 hours between each administration (6 hours for those with renal impairment).

Term newborn infants, infants, toddlers, and children weighing <10 kg

  • Dose (per administration): 1 intravenous infusion of 7·5 mg/kg; i.e., 0·75 mL solution per kg
  • Maximum daily dose: 30 mg/kg (ie, 3 mL/kg)

Children weighing >10 kg and <33 kg

  • Dose (per administration): 1 intravenous infusion of 15 mg/kg; i.e., 1·5 mL solution per kg
  • Maximum daily dose: 60 mg/kg (ie, 6 mL/kg) without exceeding 2 g (ie, 200 mL) in total

Children, adolescents, and adults weighing >33 kg and <50 kg

  • Dose (per administration): 1 intravenous infusion of 15 mg/kg; i.e., 1·5 mL solution per kg
  • Maximum daily dose: 60 mg/kg (i.e., 6 mL/kg) without exceeding 3 g (i.e., 300 mL) in total

Adolescents and adults weighing >50 kg

  • Dose (per administration): 1 intravenous infusion of 1 g; i.e., 100 mL solution
  • Maximum daily dose: Must not exceed 4 g (i.e., 400 mL) in total

Note: maximum daily dose in each dose range refers to that for maximum weight in each range.

Infants and children

Up to May 31 2010, 23 cases of accidental overdose with Perfalgan have been reported worldwide in children younger than 1 year, one of which was fatal. In the UK, there have been seven reports of overdose in infants and neonates. In most of these cases, a 10-fold overdose was reported.

See Information sent to healthcare professionals in May 2010 about the safety of medicines

A dosing table for infants and children of different weights is provided below:

Paracetamol dose Weight (kg) Calculated dose (mg) Volume of solution (mL)
Infants and children weighing ≤10 kg      
7·5 3 22.5 2.25
  5 37.5 3.75
  7 52.5 5.25
  10 75 7.5
Children weighing >10 kg      
15 15 225 22.5
  20 300 30
  30 450 45

Advice for healthcare professionals:

  • vigilance is advised when prescribing and administering Perfalgan to ensure that the correct dose is given, especially in infants and neonates where there is a risk of confusion due to prescription in mg and administration in mL
  • for all patients on the basis of their weight, adhere to the recommended dose as outlined above and in the product information; the dosing schedule is up to four infusions a day with a minimum of 4 hours between each administration, 6 hours for those with renal impairment
  • for infants and children who weigh less than 33 kg, the 50 mL vial should be used
  • in order to avoid overdose, intravenous paracetamol should not be given concomitantly with oral paracetamol, including combination products

Reporting of suspected adverse reactions

Perfalgan is under intensive monitoring (▼) by the MHRA, and healthcare professionals are reminded to report all suspected adverse reactions promptly via the Yellow Card Scheme (see www.yellowcard.gov.uk).

Article citation: Drug Safety Update July 2010, vol 3 issue 12: 2.

Published 11 December 2014