Toxic synthetic drugs have killed dozens of people in the past year, a huge spike compared to previous years, the Coroner says.
The Coroner's office told Newshub there have been 40 to 45 deaths which provisionally appear to have been caused by "synthetic cannabis toxicity" since 2017.
In the previous five years, there were two deaths linked to the synthetic drugs and others suspected but not yet confirmed.
In April, St John ambulances responded to 121 synthetic-drug related incidents - twice the number of the previous month.
The synthetic cannabis killing people is "very different" to the kind New Zealanders used to be able to buy from dairies, Ross Bell, executive director of the NZ Drug Foundation told Newshub.
"While they were making people sick, they weren't killing. This is more dangerous, more potent," Mr Bell said. He said people manufacturing the drugs are either knowingly or unknowingly selling "really highly concentrated" drugs.
One of the men killed after smoking synthetic drugs was Andrew McAllister, who collapsed on the ground after drinking methylated spirits and smoking synthetics, a Coroner's report found.
"I thought he was sleeping because that's what they normally do [after smoking the drug]," the Coroner was told by one of Mr McAllister's friends. After a few minutes, they checked on him, began CPR and called an ambulance. He had suffered a sudden cardiac event, leading to brain injury.
Synthetic cannabis is found right across the country, but there have been clusters of fatal toxicity - the first being seven deaths in quick succession in Auckland in 2017.
In west Auckland, young people - particularly those not engaged in school - were accessing the drug. In central Auckland, it was the homeless. Mr Bell said for that reason, responses need to be localised.
People may choose to smoke synthetic drugs because it's cheaper than other drugs and more accessible. People who use it are often in "vulnerable circumstances who just want to collapse and forget about the world," Mr Bell said.
Government urged to act
The Drug Foundation is calling on the Government to ask community providers what help they need and to have agencies co-ordinate so that information and warnings are shared about dangerous drugs.
Health Minister David Clark said it's "deeply concerning" to hear of the deaths.
"Those who are peddling these substances are doing it illegally and knowingly doing it illegally and people are dying.
"The full thrust of the law needs to be thrown at those pushing those substances that are killing people," he said.
He said agencies are already sharing information.
Government support party the Greens say prohibition and punishment isn't working.
"We need to take a health-based approach, which means collaborating and developing a sustainable strategy. I believe the best way to do that is to work across the House," spokesperson on drugs Chloe Swarbrick told Newshub.
Meanwhile, National Party's Simeon Brown has a Member's Bill before Parliament that would increase the penalty for supplying synthetic drugs from a maximum of two years in prison to a maximum of eight years.
Mr Brown told Newshub harsher sentences for suppliers will bring down the number of deaths.
"When National was in power we invested a huge amount of new money into addiction support… but at the same time we need to tackle the supply," he said.
"There needs to be harsher sentences so those found guilty of supplying these drugs know they will face harsher penalties."