Health officials are advising that two fentanyl-related drugs have been discovered in Yellowknife wastewater for the first time.
A notice from the Office of the Chief Public Health Officer details the two new drugs which are often found cut with fentanyl.
"This is the first time these substances have been detected anywhere in the NWT. Both substances can cause harmful effects in humans based on potency," said NWT Health and Social Services Authority communications manager Andrew Wind on July 21. "Neither can be detected with a fentanyl test strip.
One of the substances discovered is isotonitazene, an experimental opioid which was synthesized in the 1950s but never put into medical use as it was considered too unstable compared to other opioids. While they cannot be detected with a fentanyl test strip, an overdose can be countered with Naloxone. In April 2025, Fort Smith reported three deaths related to isotonitazene.
The other substance, Xylazine, is a veterinary tranquilizer which is often cut with opioids. It is not an opioid itself, and an overdose cannot be countered with Naloxone, nor will it show up on a fentanyl test strip. Deaths by overdose due to fentanyl cut with Xylazine have been popping up since 2024. The drug is typically found to make fentanyl overdoses worse and limit the ability of Naloxone to counter the effects. Skin lesions have also been seen on parts of the body where the drug is injected.
There are no visual cues fentanyl could be mixed with either substance, nor do they have any smell or taste.
"While Naloxone, an opioid-reversing agent, will not stop effects of Xylazine, it should still be used as it will reverse the effects when opioids are also consumed," said Wind. "It is important to know that Xylazine may cause sedation that will last even after Naloxone has restored normal breathing. Additional doses may not be required but emergency responders (9-1-1) should still be called to help.
"We cannot tell how these drugs are appearing on the street just from information gathered from wastewater. They are most commonly used as additives to alter illegal opioids, but users of all drugs are urged to take extra precaution," Wind added.
In light of this development, residents should be on the lookout for the signs of an overdose and call 9-1-1 or their local health centre if they suspect they are witnessing one. Signs include difficulty walking, talking or staying awake; dizziness and confusion; very small pupils; unresponsiveness (unable to wake up, even when shaken or shouted at); signs of hypoxia (bluish skin); slow, weak or no breathing; blue, purple or grey lips or nails; cold and clammy skin and choking, gurgling or snoring sounds.
Officials are also reminding residents that the Good Samaritan Drug Overdose Act protects people involved in an overdose from being charged with possession of a controlled substance SA国际影视传媒� this is to encourage users to come forward in an emergency to get the medical help needed to stay alive.
Wastewater samples in Yellowknife have been monitored for illegal substances since July 2024.
