Two people are in an induced coma and a further 14 people have been hospitalised this weekend after taking unknown substances on the Gold Coast. The patients were all found to be hallucinating.
Police are trying to track down the source of the mystery drugs.
Seven ambulances were called to a night club in Surfer's Paradise early on Sunday morning and another to a residence in Labrador. The callouts follow the eight people taken to hospital with overdose symptoms early on Saturday.
Senior Queensland Ambulance Service operations supervisor Stephen Burns said at a press conference that is was the largest number of people found with similar drug overdose symptoms in his 24-year career on the Gold Coast.
"I have seen worse, but my concern is the numbers — it seems to be more widespread out there," he said.
There is no evidence that all 16 people took the same drug and toxicology reports have not yet determined what the drugs were. Police believe the patients took a variant of MDMA (ecstasy). There are also fears that it could be the drug flakka, a synthetic hallucinogen known as 'the zombie drug' in the U.S.
Superintendent Michelle Stenner urged anybody with information on the source of the drugs to contact Crimestoppers or their local police station.
There are fears that the batch could surface during the V8 carnival and Schoolies in the coming months, with thousands of teenagers set to flock to the Gold Coast to celebrate the end of exams.
The Queensland Ambulance Service has issued a warning to party-goers that "drugs will kill".