Objective To determine the extent to which recommended paracetamol loading doses are administered in an academic paediatric hospital and to determine whether paracetamol loading doses are necessary to achieve the therapeutic target concentration of 10 mg/L in (pre)term neonates and children.

Methods A retrospective study was performed including (pre)term neonates and children who were hospitalised between 1 January 2023 and 1 January 2024 and received at least one dose of intravenous or rectal paracetamol. The number of treatments with and without a paracetamol loading dose was evaluated. Pharmacokinetic simulations were performed to determine the effect of the loading dose on paracetamol steady-state concentrations (C_ss).

Results We included 911 intravenous and 1402 rectal treatment periods, with loading doses administered in 21% and 1% of the cases, respectively. Pharmacokinetic simulations show that an intravenous or rectal loading dose reaches C_ss concentrations within the first dose, while without a loading dose, C_ss is only reached after 12 hours for intravenous and 18 hours for rectal administration.

Conclusion Our results indicate that in most cases, paracetamol loading doses are not administered in an academic paediatric hospital, which will strongly delay paracetamol C_ss. We conclude that the treatment of (pre)term neonates and children with paracetamol can and should be improved.