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Updated: Aug 3, 2026

A Swine Model of Neonatal Asphyxia
Published on: October 11, 2011
Neonate With Intrauterine Xylazine Exposure: A Case Report
Cera E Cissna1, Hayley M Grzych, Megan K Kalinowski
1Department of Pediatrics, Saint Louis University, St. Louis, MO (CEC, HMG, MKK, JBJ).
Background:
Fentanyl is a rising cause of morbidity and mortality in the United States, affecting neonates exposed in utero. Xylazine, an alpha-2 receptor agonist, is a non-narcotic sedative that is becoming an increasingly common adulterant. There are case reports describing the clinical manifestations of xylazine exposure and toxicity in adult populations; however, cases involving neonatal populations are not described in the literature. Limitations of toxicology analyses for neonates cause delays in the identification and treatment of affected patients.
Case Summary:
We present the case of a term neonate who presented to the neonatal intensive care unit with a strong foul-smelling odor, diffuse rash, hypertonicity, irritability, and inconsolability. This case describes additional symptoms that presented over the subsequent 120 hours of life, including sustained bradycardia, significant peripheral vasoconstriction, and focalization of odor to breath, urine, feces, and umbilical stump. Mass spectroscopy toxicology of the neonate's serum confirmed the presence of methamphetamine, fentanyl, multiple fentanyl metabolites, and xylazine. Management strategies are discussed, including the role of alpha-2 receptor agonists in treating withdrawal.
Clinical Significance:
This case report presents clinical manifestations of xylazine toxicity and withdrawal in neonatal populations and highlights the need for additional attention on the effects of adulterants to improve management strategies. There is a need for improved toxicology testing to identify affected populations in a timely manner.

