"Tranq dope" in infancy: A 19- day-old with life-threatening poisoning due to fentanyl/xylazine

ABSTRACT

Background: More and more, young children are victims of the ongoing epidemic of opioid use disorder. Xylazine, an alpha-2 adrenergic agonist with notorious use as a veterinary tranquilizer, is an increasingly encountered component of the illicit opioid supply in the US, but has been rarely documented in biological samples obtained from children. We report a 19-day-old infant with classic manifestations of central nervous system and respiratory depression associated with fentanyl and xylazine poisoning. Case report A 19-day-old boy was taken to the emergency department (ED) by his parents for episodes of straining, breathholding, and his eyes rolling backwards. The formula-fed boy was born of an uncomplicated full-term spontaneous vaginal delivery and had previously been thriving. During ED triage assessment he had a period of apnea, then bradypnea, with pulse-oximetric oxygen saturation drop to 55%. He was supported with stimulation and supplemental oxygen via nonrebreather mask but remained lethargic, with temperature 96F, heart rate 166/min, and brisk capillary refill. Point of care blood dextrose testing was 88mg/dL. Analysis of respiratory secretions for common viruses by polymerase chain reaction was negative for respiratory syncytial virus, influenza, or SARS-CoV-2. Computed tomography imaging of the brain was unremarkable. A urine drug immunoassay (Vitros 4600 Chemistry , Ortho- Clinical Diagnostics) resulted positive for fentanyl (cutoff 1 ng/ mL), but negative for amphetamine, barbiturate, benzodiazepine, cannabinoids, cocaine, heroin, morphine, buprenorphine, methadone, or oxycodone. Liquid chromatography tandem mass spectroscopy analysis of the urine confirmed the presence of fentanyl (25 ng/mL) and norfentanyl (245 ng/mL). Gas chromatography with mass spectrometry also detected the presence of xylazine (qualitative result based on spectra matching). Over the ensuing hours the boy recovered fully and the family was connected with child protection services;an exposure route was not identified. Discussion(s) This 19-day-old infant suffered fentanyl/xylazine poisoning. The infant's age and urine fentanyl concentrations exclude pre-natal exposure as an explanation for the drug test findings, and the baby was bottle-fed excluding drug transmission through breast milk. Xylazine has been known to be in this hospital's regional heroin supply since the early 2000s, and in 2019 xylazine was implicated in more than 31% of opioid-associated deaths at the city's medical examiner's office. In 2022, many fentanyl samples tested by regional law enforcement find more xylazine than fentanyl. Until recently, xylazine was an uncommon finding in our testing of pediatric opioid poisoning victims. Similar to fentanyl, xylazine may cause pupillary miosis and CNS depression;unfortunately it may be resistant to reversal with naloxone. Conclusion(s) This case is remarkable for the young age of this infant ill from post-natal fentanyl poisoning and for the detection of xylazine in his urine. Healthcare providers may not immediately consider opioid poisoning in the differential diagnosis of infants with altered mental status, and proper toxicological testing is important for appropriate child protection support. Detection of xylazine is a marker for a non-medical, or "street," source of fentanyl.