Survey of i.v. paracetamol (acetaminophen) use in neonates and infants under 1 year of age by UK anesthetists

The license for i.v. paracetamol has recently been extended to include term neonates and infants aged 1 year, at a uniform dose across this age range of 7.5 mg.kg(-1), total daily dose 30 mg.kg(-1).day(-1). We were interested to survey current i.v. paracetamol prescribing practices of anesthetists in the UK, in neonates and infants under 1 year of age. We conducted an online survey of 94 linkmen of the Association of Pediatric Anesthetists of Great Britain and Ireland Linkmen representing both general and specialist hospitals and 90 members of the British Pediatric Pain Travelling Club representing the pediatric acute pain teams throughout the UK and Ireland. A total of 105/184 (57%) responded to the survey on behalf of 78 regions and 27 pediatric acute pain teams. Over half (54%) of the respondents indicated i.v. paracetamol use in infants under 1 year of age. A wide range of loading and maintenance doses were used. Total daily doses exceeded the license for age 1-12 months in 70% of cases; for the 36 week postconceptional age (PCA)-1 month age range the proportion was 50%. Over 80% of total daily dosing from age 36 weeks PCA to 1 year fell within dosing suggested by pharmacokinetic studies. Close to 40% of respondents who used i.v. paracetamol in infants, also indicated use in preterm age groups. The total daily dose used in preterm neonates was within the range suggested by pharmacokinetic studies, in over 90% of cases in the age range 32-36 weeks PCA, and for 60% in the under 32 weeks PCA age group. This survey demonstrates i.v. paracetamol dosing in infants in the UK and Ireland is frequently above the licensed dose and outside the licensed age range but is in keeping with doses suggested by pharmacokinetic studies.