Should pot users carry Naloxone? London's medical health officer says yes

Pot users should carry Naloxone kits in case their marijuana is laced with fentanyl, Middlesex-London Health Unit Medical Officer of Health Chris Mackie says.

Mackie issued the warning after fentanylwas found in the urine of heroin and marijuana users who were being screened at the Addiction Services Thames ValleySuboxoneClinic in July, health officials said.

But one man who tested positive for fentanylat that clinic last weektells CBC News he's never used the drug, and he didn't test positive for marijuana, either.

"In my case, I've had easily half a dozen false positives," said DavidCowen, a patient of the Suboxoneclinic where people tested positive for fentanyl.

"They say it's probably in your marijuana, or they think you're actually using the drug. I've never used that in my life, and I also don't smoke marijuana, so I know it's wrong."

• Fentanyl showing up in heroin, marijuana users' urine

Mackiesaid people often misrepresent what they take. The drug lab, at St. Joe's, is very reputable, he said.

But Cowen said it's wrong for health officials to cause panic about pot, a drug half of Canadians say they've used at some point in their lives.

"It's very inflammatory. It's not logical for someone to be lacing very expensive [fentanylin]pot. It's just inflammatory and it's not true. It's going to make parents very worried,"Cowensaid. "I don't have a bone to pick. It just kind of blows me away.

'A very disturbing finding'

But Mackie said parents should be worried as should casual drug users.

"It's a very disturbing finding because a whole new subset of people who are using drugs could be exposed to a very dangerous chemical," Mackie said.

"We have multiple people who are saying this is happening."

It's unknown if the fentanyl was found in pot that was smokedor eaten.

Suboxone is a drug therapy for recovering opioidaddicts. The Suboxone clinic's Dr. Ken Lee said it looks like dealers are adding fentanyl to other drugs.

And Mackie told CBC's London Morninghe's worried that the laced drugs could seriously harm someone who is not expecting it.

"This is very, very concerning. A whole new level of drug user, people who are not hardcore users, are not experiences with fentanyl or opioidsat all are going to be exposed. I'm really worried that some young person who thinks they're just experimenting is gong to end up taking an overdose of something that kills them."