Pharmacokinetics of single dose intravenous propacetamol in neonates: effect of gestational age
- K Allegaert1,2,
- C D Van der Marel2,
- A Debeer1,
- M A L Pluim3,
- R A Van Lingen4,
- C Vanhole1,
- D Tibboel2,
- H Devlieger1
- 1Neonatal Intensive Care Unit, Department of Paediatrics, University Hospitals, Gasthuisberg, Herestraat 49, Leuven, Belgium
- 2Department of Paediatric Surgery, Sophia’s Children’s Hospital, Rotterdam, the Netherlands
- 3Department of Pharmacy, Sophia’s Children’s Hospital
- 4Department of Paediatrics, the Isala Clinics, Zwolle, the Netherlands
- Correspondence to:
Dr Allegaert
Neonatal Intensive Care Unit, Department of Paediatrics, University Hospitals, Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium; karel.allegaertuz.kuleuven.ac.be
- Accepted 20 February 2003
Abstract
Aim: To investigate the pharmacokinetics and pharmacodynamics of single dose propacetamol in preterm and term infants on the first day of life.
Methods: Neonates were stratified by gestational age. Preterm (< 37 weeks) and term (37–41 weeks) infants received a single dose of propacetamol in the first 24 hours of life when they had minor, painful procedures or as additional treatment in infants receiving opioids. Blood samples were taken from an arterial line, and pain was evaluated by a multidimensional pain scale. Results were reported as mean (SD). Student’s t and Wilcoxon tests were used to compare the groups.
Results: Thirty neonates were included, 10 of which were term infants. Serum half life was 277 (143) minutes in the preterm infants and 172 (59) minutes in the term infants (p < 0.05). Clearance was 0.116 (0.08) litre/kg/h in the preterm infants and 0.170 (0.06) litre/kg/h in the term infants (p < 0.05). Gestational age correlated with serum half life (r = −0.46). No effect of sex or administration of prenatal steroids was found on the pharmacokinetics of paracetamol. In neonates who only received propacetamol (n = 15), the level of analgesia seemed to be associated with the therapeutic (> 5 mg/l) level.
Conclusions: A correlation was found between gestational age and the serum half life of propacetamol. The maturational trend of clearance and half life in preterm and term neonates is in line with data on the pharmacokinetics of propacetamol beyond the newborn period.
Footnotes
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These results were partially presented at the biannual congress of the European Society of Developmental Pharmacology (ESDP) Liège, 25–28 October 2002.
