The Effects of P‐glycoprotein Inhibition on Norbuprenorphine‐induced Neonatal Abstinence Syndrome (NAS)

Abstract

Treating pregnant, opioid‐addicted women with the opioid buprenorphine improves mother‐child outcomes, but can cause neonatal abstinence syndrome (NAS), a potentially life‐threatening withdrawal syndrome newborns often develop following chronic prenatal exposure to opioids. NAS severity is independent of maternal buprenorphine dose, suggesting that inter‐individual variance in the pharmacokinetics of buprenorphine may influence NAS. We previously showed that prenatal exposure to the major active metabolite of buprenorphine, norbuprenorphine (NorBUP), can induce NAS. NorBUP is a substrate of the highly polymorphic placental efflux transporter P‐glycoprotein, which transports its substrates from fetal to maternal circulation. We tested the hypothesis that inhibiting P‐glycoprotein increases NorBUP‐induced NAS severity. We administered a subthreshold dose of NorBUP or vehicle to pregnant rats from gestation day (GD) 9 until post‐delivery and treated them twice daily with the p‐glycoprotein inhibitor Elacridar or vehicle on GD18‐21. After delivery, pups were observed for precipitated withdrawal signs following administration of naltrexone or saline. NorBUP and Elacridar together, but not individually, increased naltrexone‐precipitated withdrawal signs, providing the first evidence that P‐glycoprotein activity can substantially modulate the effects of NorBUP on the fetus and may therefore contribute to the uncoupling of maternal buprenorphine dose and NAS severity.Support or Funding InformationThe project described was supported by a Summer Undergraduate Research Fellowship from the American Society for Pharmacology and Experimental Therapeutics, the UAMS Fellow‐to‐Faculty Award (Arkansas Biomedical Institute, Tobacco Settlement Funds), a UAMS Research Scholar Pilot Grant Award in Child Health, and the Translational Research Institute (TRI), grants 1U54TR001629‐01A1 and KL2TR000063 through the National Center for Advancing Translational Sciences of the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.