In the last two days, seven people were treated in Christchurch Hospital for severe synthetic cannabis toxicity prompting local health officials, Canterbury District Health Board, to issue a warning about the latest bad batch of the illegal drug in Christchurch.

Health officials say there's a noticeable increase of people turning up to hospital with side effects.

Corrections Minister Kelvin Davis says to combat the spread of synthetic drugs in prisons, dogs are being used to detect the drugs.

"We know that psychoactive substances are out in the streets, in our communities and we would be naive to think people are trying to get them into our prisons."

Christchurch Emergency Physician Doctor Mark Gilbert says seven people were hospitalised with extreme symptoms.

“They generally start off with some agitation and confusion and then can proceed to coma. Also, seizures and in severe cases cardiac rhythm or heart rhythm disturbances. This can proceed with what we call a cardiac arrest and death.”

Ngaetu Grover was the girl who was in last year’s video of a disturbing drug-fuelled video that went viral online.

She says, the synthetics made her already fragile state, worse.

“A year ago, I was in a dark bubble and I could only see synthetics and always finding the drive to have another hit or another smoke. Always wanting to be in that mind state of being high.”

Grover has been cleaned for 15 months and says, she stayed clean for her whānau and daughter.

“I haven't been to rehab no I didn't take up the opportunity to go I just ended up going cold turkey I guess just going right off it.”

Plenty more videos have surfaced and in the past year, up to 45 people are thought to have died in relation to synthetic drugs.

Massey University Associate Professor Chris Wilkins is calling for an early warning drugs system needs to be put in place.

“It's just as simple as having an agency that engages with all the different people that interact with drug users and different communities throughout NZ.”

Grover is wanting to help those to get off synthetic drugs.

“I only really want to reach out to the ones who are in this really bad bubble where drugs are clouding their minds and making bad decisions and bad choices.”