Veterinary tranquilizers found in majority of Toronto fentanyl samples: drug testing service
Combination of tranquilizers and opioids poses deadly threat, front line workers say
Veterinary tranquilizers are being found in a large amount of downtown Toronto's fentanyl supply, according to a drug testing service.
Between Feb. 22 and March 7, toxic drug samples taken by Toronto's Drug Checking Service, a free and anonymous public health service that collects toxic drug samples for testing from 10 sites around the city's downtown, found 81 per cent of what users expected to be fentanyl included xylazine and medetomidine.
It's a dangerous mix, says Hayley Thompson, the managing director of Toronto's Drug Checking Service.
"Both of these are veterinary tranquilizers that are central nervous system and respiratory depressants that, particularly in combination with high potency opioids like fentanyl, would work to suppress people's vitals," Thompson said.
It's not entirely clear why these tranquilizers are added to fentanyl, but Thompson says she believes it is to sustain the short-acting opioid's effect for a longer period of time.
Thompson says seeing fentanyl combined with veterinary tranquilizers, especially xylazine, isn't new, but the drug checking service hasn't seen numbers like these since it started testing samples in 2020.
The presence of these tranquilizers adds multiple health risks, front line workers say.
Naloxone can't reverse veterinary tranquilizers: advocate
For instance, Thompson says naloxone, which reverses the effects of fentanyl, doesn't reverse the effects of veterinary tranquilizers.
Frontline worker Sarah Greig says she suspects the mix of tranquilizers and fentanyl is also behind a rise in paramedic calls related to cardiac arrests at the Moss Park Consumption Treatment Service over the past few months.
Greig, director of substance use and mental health at South Riverdale Community Health Centre, says supervised consumption sites aren't equipped for that.
"Our sites are set up to respond to opioid overdoses or respiratory issues," Greig said. "We're not set up for cardiac issues."
According to data provided by Ontario's chief coroner, Dirk Huyer, the presence of xylazine in opioid-related deaths didn't change much from 2023 to 2024, going up only 3.6 per cent.
Huyer says Toronto's Drug Testing Service has the more relevant numbers for the moment, since coroner data only comes in well after someone has died.
"It's really, I think, the most effective way to understand what's happening now," he said.
Consumption site closures could limit future testing
But the service's sampling size is about to decrease.
That's because five of Toronto's supervised consumption sites are slated to close at the end of March as a result of new provincial legislation.
Toronto's Drug Testing Service collects testing samples at these sites — and their closures could decrease the amount of toxic drugs the service checks by up to 60 per cent, according to Thompson.
That's a big concern for front line workers at other supervised consumption sites, like Greig at Moss Park, who says the drug testing service makes a big difference.
"It actually helps us, you know, figure out what the best response is to those types of adverse drug reactions," Greig said. "More and more people are accessing the drug checking service, and they are making informed decisions about their drug use."
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With files from Dale Manucdoc