Evidence-based morphine dosing for postoperative neonates and infants.

Area of Science:

• Pharmacology
• Pediatric Medicine
• Clinical Pharmacy

Background:

• Paediatric population pharmacokinetic models are crucial for optimizing drug dosing in children.
• Morphine dosing in neonates and infants requires careful consideration due to pharmacokinetic variability.
• Previous models suggested non-linear dosing strategies for improved morphine administration.

Purpose of the Study:

• To prospectively evaluate a model-derived morphine dosing algorithm in postoperative neonates and infants.
• To compare the efficacy and safety of the new dosing algorithm against traditional methods.
• To assess morphine and metabolite concentrations and the need for rescue medication.

Main Methods:

• Prospective evaluation of a model-derived morphine dosing algorithm in term neonates and infants up to 1 year.
• Utilized a previously validated paediatric population pharmacokinetic model for dosing.
• Assessed efficacy through rescue medication requirements and actual average infusion rates.

Main Results:

• The paediatric pharmacokinetic morphine model accurately predicted morphine and metabolite concentrations.
• Neonates with postnatal age <10 days required significantly less rescue medication (27.8%) compared to older patients (90%).
• Median morphine rescue doses and infusion rates were substantially lower in younger neonates.

Conclusions:

• Morphine paediatric dosing algorithms, adjusted for pharmacokinetics, effectively prevent over-dosing in neonates <10 days old.
• The current algorithm requires further optimization for neonates and infants ≥10 days old who still need rescue medication.
• Pharmacodynamic studies are recommended to refine dosing for older infants.