KITCHENER -- The Waterloo Region Drug Strategy is warning the public about reports of fentanyl causing "extreme sedation" in the area over the past few days.

In a notice, the drug strategy said there have been reports of purple/dark red and white/clear fentanyl. People have reported they feel fine, but then lose consciousness, wake up and speak, and then lose consciousness again quickly, according to the notice.

Waterloo Region Drug Strategy says people should be careful and suggests using the Consumption and Treatment Services (CTS) site at 150 Duke Street West, which is open daily from 9 a.m. to 9 p.m.

The group also suggests having naloxone on hand, which can be administered to someone who overdoses.

Anyone who believes they or someone else has overdosed should call 911.