Opioid use disorder is associated with significant morbidity and mortality during pregnancy. However, a new threat has emerged in recent years that is causing growing concern – xylazine. This veterinary sedative has become an increasingly common adulterant in the illicit opioid supply, posing unique risks to pregnant individuals and their developing fetuses.
What is Xylazine?
Xylazine is a potent alpha-2 adrenergic agonist used as a sedative and muscle relaxant in veterinary medicine. It is not approved for human use.
In recent years, xylazine has been increasingly detected as an adulterant in illicit opioids, particularly fentanyl. Its sedative effects are thought to prolong and enhance the effects of opioids.
The prevalence of xylazine as an adulterant has risen dramatically since 2015. In 2020, xylazine was detected in 25.8% of overdose deaths involving fentanyl in Philadelphia, up from just 2% in 2015. Similar trends have been observed in other regions of the country.
Risks to Pregnancy and the Developing Fetus
Xylazine poses several unique risks to pregnant women beyond those associated with opioid use alone. Xylazine can cause severe respiratory depression, especially when combined with opioids. This increases the risk of maternal hypoxia. Xylazine also causes bradycardia and hypotension, which may compromise uteroplacental blood flow. The sedative effects of xylazine can be profound and long-lasting, increasing the risk of accidents and injuries.
Xylazine withdrawal is not well characterized but may include severe anxiety, agitation, and hypertension.
There is little information regarding the effects of xylazine on the developing fetus. Decreased placental blood flow may contribute to intrauterine growth retardation. Limited data from human studies indicate that xylazine may cause respiratory depression, bradycardia, and central nervous system depression in the newborn.
Clinical Implications and Recommendations
Several factors complicate the detection and management of xylazine exposure in pregnancy. Routine drug screens do not detect xylazine. Specialized testing is required but not widely available.
In addition, we lack specific treatments to manage xylazine toxicity and overdose. While naloxone reverses the effects of opioid overdose, naloxone does not reverse the effects of xylazine, potentially leading to incomplete reversal of overdose symptoms.
Given the rising prevalence of xylazine and its potential risks, healthcare providers caring for pregnant women should:
1. Maintain a high index of suspicion for xylazine exposure in patients with known or suspected opioid use.
2. Consider xylazine exposure in cases of apparent opioid overdose that respond incompletely to naloxone.
3. Be prepared to provide prolonged supportive care for respiratory depression and sedation in suspected xylazine toxicity.
4. Monitor closely for signs of fetal distress and growth restriction in patients with known or suspected xylazine exposure.
5. Counsel patients about the risks of xylazine and provide education on harm reduction strategies.
6. Consider specialized testing for xylazine when clinically indicated and available.
7. Be aware of potential xylazine withdrawal symptoms and manage supportively, as there are no approved pharmacological treatments.
8. Collaborate with specialists in addiction and maternal-fetal medicine in managing complex cases.
Xylazine represents a new and significant threat to pregnant women with opioid use disorder and the developing fetuses. While much remains unknown about its specific effects in human pregnancy, the available evidence suggests cause for serious concern. Healthcare providers must be aware of this emerging issue and prepared to adapt their clinical approach accordingly. A multidisciplinary approach involving obstetrics, addiction medicine, and pediatrics will be crucial in addressing this evolving challenge and mitigating potential harm to mothers and babies.
Ruta Nonacs, MD PhD
References
Pregnant women and babies face ‘terrifying’ threat from xylazine addiction (NPR)
Clinical Advisory on Presence of Xylazine in the Massachusetts Drug Supply April 12, 2023
Implications of xylazine exposure in pregnancy: a narrative review
