Interior Health has issued a drug alert for the Kootenays, warning of multiple overdoses involving down containing high amounts of fluorofentanyl and medetomidine.
The drugs may also contain benzodiazepines and are being sold as down, dope, tranq or fentanyl.
Medetomidine can slow breathing and heart rate, making overdoses more complex and prolonged.
The health authority warns that the combination of these substances can also cause heavy sedation that may last even after naloxone is administered.
Other possible effects include dizziness, nausea, confusion and prolonged sleepiness.
Interior Health recommends getting drugs checked before use, carrying naloxone and avoiding using alone.
The alert remains in effect until Oct. 26.
