Xylazine and Benzodiazepines in the Unregulated Drug Supply
Current Situation
Hamilton Public Health Services (PHS) is notifying healthcare providers of recent information regarding the unregulated supply of drugs in Ontario. On February 28th, 2023, the Office of the Chief Medical Officer of Health and the Office of the Chief Coroner for Ontario shared a memo regarding the presence of xylazine and benzodiazepines in the current drug supply and risks of drug toxicity.
Data from the Office of the Chief Coroner for Ontario, Health Canada’s Drug Analysis Service, and Toronto’s Drug Checking Service all indicate frequent benzodiazepine presence in the unregulated drug supply, along with a recent increase in the presence of xylazine. These substances are often found present with opioids and may lead to symptoms like those associated with opioid-related drug poisonings. However, neither xylazine or benzodiazepines respond to Naloxone administration.
Preliminary data from the Office of the Chief Coroner for Ontario show that xylazine was detected in 2-4% of opioid toxicity deaths between 2021 Q1 and 2022 Q3. Additionally, benzodiazepines were detected in 63% of opioid toxicity deaths in 2021 and 41% in 2022.
Xylazine and Benzodiazepines
Xylazine, commonly known as “tranq” or “horse tranquilizer”, is a non-opioid sedative, muscle relaxant and pain medication typically used in veterinary settings. It is not approved for human use in Canada or the United States.
Xylazine is associated with several harms, including:
- severe skin lesions (with injection drug use),
- central nervous system depression,
- respiratory depression,
- cardiovascular effects (e.g. low blood pressure/ slowed heart rate)
- death
Benzodiazepines are classified as central nervous system depressants or sedative-hypnotics. Several benzodiazepines (e.g. etizolam, bromazolam and flubromazepam) have been identified within the unregulated drug supply. Like xylazine, acute exposure to benzodiazepines may cause central nervous system depression, respiratory depression, and death.
The use of xylazine and benzodiazepines alone is associated with a risk of toxicity, however this risk can increase significantly when these substances are combined with depressants like opioids.
Medical Advisory: Xylazine and Benzodiazepines in the Unregulated Drug Supply