Related Experiment Video
Updated: May 10, 2026

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Putative association of ABCB1 2677G>T/A with oxycodone-induced central nervous system depression in breastfeeding
Jessica Lam1, Lauren Kelly, Ilan Matok
1Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada.
Objective:
To assess the effect of maternal CYP2D6, CYP3A5, ABCB1, and OPRM1 polymorphisms in predicting both neonatal and maternal central nervous system depression after oxycodone use during lactation.
Study Design:
A nested case-control study in 67 breastfeeding mother-infant pairs exposed to oxycodone was conducted. Cases were defined as parental reports of lethargy in the infant temporally related to oxycodone exposure via breastmilk. Maternal saliva samples were analyzed for 18 polymorphisms in 4 genes, CYP2D6, CYP3A5, OPRM1, ABCB1, involved in oxycodone metabolism and response.
Results:
Mothers of symptomatic infants were using oxycodone for a longer period of time during breastfeeding compared with those of asymptomatic infants (P < 0.0001). None of the maternal genetic variants in the 4 genes were associated with oxycodone-induced depression in neonates. However, mothers carrying at least one copy of the ABCB1 2677 T variant had an increased risk of experiencing sedation themselves (odds ratio, 2.35; 95% confidence interval, 1.06-5.28; P = 0.03).
Conclusions:
The ABCB1 2677 T variant may predict oxycodone-induced central nervous system depression in breastfeeding mothers.
Related Concept Videos
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Analgesia and Pain Management
Drug Toxicity: Risk factors
Drug Abuse and Addiction: Pharmacological Phenomena
Therapeutic Drug Monitoring: Affecting Factors
ABC Transporters: Exporter