The brown powder, which contains methylamphetamine (MDMA, otherwise known as ecstasy) and paramethoxymethamphetamine (PMMA) was seized for the first time in Cork yesterday.
Toxicology tests are expected to confirm that the same substance led to the deaths of Liam Coffey and Michael Coleman in Kinsale on Sunday.
The concoction, if mixed with other drugs or alcohol, can lead to heart and liver failure, and has been associated with multiple deaths worldwide.
The HSE has alerted doctors in the region, as well as community and voluntary groups, about the dangers of the substance.
Symptoms of its use include high fever, rapid heart rate, and agitation.
Chris Luke, consultant in emergency medicine at Cork University Hospital and the Mercy University Hospital, said the substance was an example of the “chemical chaos” facing doctors on the front line.
“It is a new world order out there, and chemical chaos is the name of the game. There are hundreds of these kinds of agents out there.
“Those of us working in Irish emergency departments have tests for maybe six to 10 kinds of illegal drugs. But there is no test, or even a possibility, of identifying which novel recreational drugs people presenting at the [emergency department] have taken.
“In terms of managing patients who may have taken these kinds of drugs, we just have to deal with what’s in front of us, and treat the patient as we find them.”
The warning came last night as gardaí investigating the deaths of Mr Coleman and Mr Coffey, both aged 22, made a fourth arrest.
The friends, from Co Waterford, were found dead in a cottage Mr Coleman shared with his girlfriend, Ciara Drummey, in Kinsale at about 6am on Sunday.
Gardaí, who have been examining the men’s mobile phone records and who traced those they believe supplied the drugs, arrested a man in his 20s in Cork City yesterday. He was taken to Bandon Garda Station for questioning about the alleged sale and supply of drugs. He is being detained under the provisions of section 4 of the Criminal Justice Act 1984, and can be held for up to 24 hours.
Three people held since Sunday on suspicion of drug dealing — two men and a woman, who are all in their 20s and all with addresses in Cork City — were released without charge on Monday.
Gardaí are preparing files for the DPP in relation to the those cases.
Meanwhile, Mr Coleman’s family are preparing for his funeral today.
The first-class honours graduate from CIT, who began a job at the Eli Lilly pharmaceutical plant in Dunderrow last week, will be buried after 11am funeral Mass at St Augustine’s Church in Abbeyside, Co Waterford, today.
He is survived by his parents, Anne and Kevin, and brother Shane.