One pill was all it took for 18-year-old Anthony Hampton to end up in a hospital, barely able to speak or move.

Just weeks after graduating from high school, the Calgary teen was looking to buy pot with some friends, his parents said. When the teens couldn’t get marijuana, they opted for what they believed was oxycodone.

But Calgary Police say the pill Hampton took was likely laced with fentanyl, a potent painkiller blamed on a recent spike in overdoses.

Hampton was rushed to hospital on July 17, after his mother found him unresponsive in his bed.

Pat Forgio said her son’s hands, feet and lips were blue. The pill he took, she said, “completely stopped his heart.”

Hampton was in a coma and on life support for several days before he started showing signs of improvement.

“From all accounts, he tried this once,” said the teen’s father, CTV journalist Reg Hampton. “He just tried this pill that he thought was oxy, one time.”

Hampton’s parents are speaking out because they want to warn others about the dangers of fentanyl.

Last Sunday alone, police in Vancouver responded to 16 fentanyl-related overdoses.

And according to the Canadian Centre on Substance Abuse, more than 650 Canadians have died from fentanyl-related overdoses between 2009 and 2014.

“It can happen to anyone,” Reg Hampton said. “Anthony wasn’t a drug user, really. Yeah, he had the pot and stuff, but this was a one-time mistake.”

A veteran journalist, the teen’s father has covered stories about drug use. Still, he’s struggling to understand why his son took such a chance.

“I keep saying to myself, ‘I should have just had one more conversation with him,’” he said.

Tests show that Hampton suffered extensive brain damage. While he has made progress in hospital, a full recovery is not guaranteed.

“Maybe we’ll get our Anthony back,” his father said. “We just don’t know.”

With a report from CTV’s Vancouver Bureau Chief Melanie Nagy