A class of novel synthetic opioids, nitazenes, have infiltrated the illicit drug market worldwide. Their high potency leading to overdose and fatality is a public health concern. Xylazine is a non-opiate sedative typically used for veterinary applications. The drug has recently appeared as an adulterant in the informal drug market, particularly within opioid drugs such as fentanyl and heroin. Determining the extent of use of t...