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Postmenstrual age and CYP2D6 polymorphisms determine tramadol o-demethylation in critically ill neonates and infants

Karel Allegaert1, Ron H N van Schaik, Steve Vermeersch

  • 1Neonatal Intensive Care Unit, University Hospitals, campus Gasthuisberg, B-3000 Leuven, Belgium. karel.allegaert@uz.kuleuven.ac.be

Pediatric Research
|March 5, 2008
PubMed

Insights

Postmenstrual age and CYP2D6 genetic variations significantly impact tramadol O-demethylation in neonates. This pharmacogenetic insight is crucial for optimizing drug metabolism and administration in this vulnerable population.

Area of Science:

  • Pharmacology
  • Neonatal Medicine
  • Genetics

Background:

  • Neonates exhibit variable drug metabolism due to developmental immaturity.
  • O-demethylation is a key metabolic pathway for drugs like tramadol.

Purpose of the Study:

  • To identify factors influencing tramadol O-demethylation in critically ill neonates and infants.
  • To investigate the roles of postmenstrual age and CYP2D6 activity in drug metabolism.

Main Methods:

  • Quantified tramadol and O-demethyl tramadol concentrations in urine and plasma samples.
  • Analyzed correlations between drug concentrations, postmenstrual age, and CYP2D6 activity scores.
  • Utilized forward multiple regression modeling.

Main Results:

  • Significant negative correlations were found between postmenstrual age and the M/M1 ratio in both urine and plasma.
  • Increasing CYP2D6 activity scores were associated with decreased M/M1 ratios.
  • Postmenstrual age and CYP2D6 activity score were significant predictors of O-demethylation activity.

Conclusions:

  • Postmenstrual age and CYP2D6 genetic polymorphisms are key determinants of tramadol O-demethylation in neonates and infants.
  • Pharmacogenetics significantly influences drug metabolism in neonates, though variability persists.
  • Understanding CYP2D6 ontogeny aids in safer drug administration for neonates.

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