Synthetic opioid protonitazene is suspected to have played a role in the death of an Adelaide man, while a young woman has been hospitalised after being exposed to the lethal drug.

This follows two confirmed overdose cases last week in Adelaide, with two young men requiring hospital treatment.

The woman is still being treated at the Royal Adelaide Hospital (RAH). The man’s death is being investigated by the coroner.

These cases confirm that protonitazene has entered the South Australian illicit drug market, and in addition may be contaminating other non-opioid illicit drugs, such as methamphetamine.

Acting State Director, Drug and Alcohol Services South Australia, Dr Victoria Cock says "We are once again reminding all South Australians that the effects of protonitazene and drugs that it could be disguised in are capable of causing an overdose that could be fatal."

"There is major concern that this drug is being mixed with other illicit drugs, particularly methamphetamine, and that people are being accidentally exposed to it. Even if used knowingly by a regular opioid user, there is a high chance of overdose and death." 

Individuals exposed to protonitazene are at a high risk of opioid poisoning, and the drug can produce life-threatening toxic effects at low doses.

People using drugs while unsupervised or alone are at particular risk.

Protonitazene effects may be reversed by giving the affected person naloxone (Nyxoid spray or Narcan).

This is available at most pharmacies without a prescription and at no cost.

Illicit drug users are strongly encouraged to ensure they have access to naloxone but should not anticipate that this will remove the risk of death associated with drug use.

Protonitazene has also recently been detected in Victoria, Queensland, and Western Australia.

Last week was the first detection in a clinical environment in South Australia.

Anyone who has taken a recreational drug and the effects are unexpected should call Triple Zero (000) or present to their closest Emergency Department immediately.