The health authority said there have been “numerous” fatal and non-fatal drug poisonings in Castlegar, Trail, and Nelson although they did not attribute it to any specific substance.
The warning was initially issued Aug. 26 and was in effect until Thursday.
A separate alert has been issued about a light yellow powder being sold in Nelson as down or fentanyl. Interior Health says it contains 21 per cent flurofentanyl, whose potency is not well understood.
“It can be more potent than standard fentanyl,” they said. “This means this drug could be very strong.”
It presents a high risk of fatal overdose or loss of consciousness, they said.
That warning is also in effect until Sept. 17.