Substance more deadly than fentanyl linked to spate of Dublin overdoses

A substance found in contaminated heroin that has been linked to an unprecedented spike in overdoses in Dublin can be more deadly than fentanyl, the HSE has warned.

A substance found in adulterated heroin that has been linked to an unprecedented spike in overdoses in Dublin can be more deadly than fentanyl, the HSE has warned.

Nitazenes, a substance found in heroin samples linked to these overdoses, have emerged in Europe as an increasingly popular and dangerous synthetic opioid, said Professor Eamon Keenan, the national clinical lead for the HSE's addiction services.

Fentanyl cannot yet be ruled out as contributing to the spate of overdoses but it has not been identified in samples so far.

Synthetic opioids may be increasingly common in Europe because the Taliban has led a clampdown on the production of opioids in Afghanistan – the main opium poppy producer – leading to a 95% reduction in cultivation of the drug, Prof Keenan warned.

“This [sudden spike in overdoses] is not going to be an isolated incident,” he said. 

“I think that we may well be facing situations like this over the next months and years.” 

Some 57 overdoses have been reported since Thursday. 

Numbers started falling rapidly from Friday following a public information campaign about the potential dangers of a batch of brown powder being sold as heroin.

Nitazenes were synthesised about 60 years ago as an alternative to morphine but never marketed because of the risk of overdose and its high potency, Prof Keenan said.

Despite this, nitazenes, which are even more potent than fentanyl, have emerged as a drug of abuse, he said.

“Over the last number of years, we've seen a lot of opioid drugs coming in the European market. Up to about 2020, they would have predominantly been the fentanyl drugs but since 2021 it is these nitazenes which are emerging,” he said.

“So I think if we were going to get synthetic opioids in Ireland, we were much more likely to get nitazenes rather than fentanyl.” 

He warned that nitazenes “have been associated with overdose and death” and said: “Fentanyl is less of an issue here in Europe than it is in the United States.” 

However, naloxone, the opioid neutraliser, can and has saved lives from synthetic opioid overdose, he said. 

“So we've given out over 4,000 units of naloxone this year and we've trained over 1,000 people in the administration of naloxone [including family and peers of drug users],” he said.

Meanwhile, people using heroin in Dublin are fearful, according to Tony Duffin, the chief executive of the national addiction service, AnaLiffey.

“It is very difficult, it is very worrying,” he said. 

“We are talking about a very vulnerable group of people who do not want to overdose. They are worried and frightened themselves.” 

The number of overdoses over such a short time is “highly unusual”, he said.

"At one point it was being described as 42 overdoses in 36 hours. I’ve been working with AnaLiffey for 18 years and we have never known such a spike in overdoses.” 

Those affected are among the homeless population in Dublin, he said.

“It is frightening. The people who are most affected by this are the people who use drugs, we shouldn’t forget that. They’re people who have had significant trauma in their lives or have trauma in their lives.

"The concern now is how this will pan out. We don’t know. We need to stay on top of it.”