A total of 31 patients have been treated at Christchurch Hospital for the effects of taking synthetic drugs since September 20, with two people remaining in ICU.
A spokesperson for the Canterbury and West Coast DHB said 12 more people have presented or were admitted to Christchurch Hospital just this week.
"Three more patients have received intensive care following synthetic cannabinoid use, but are no longer in ICU. Two of the original three remain in ICU."
It comes a spate of admissions to Christchurch Hospital over the last three weeks of people who had taken synthetic drugs.
"There have been no synthetic cannabinoid-related deaths in Christchurch hospital during this time," the spokesperson said.