Lethal synthetic alternatives to heroin are posing a growing threat across Europe, with rising reports of overdoses and deaths, including in Ireland, according to the EU drugs agency, Cormac O'Keeffe.

Some 25 of these synthetic opioids have been detected since 2009, including nine last year.

One of these drugs, known as fentanyls, are the most prevalent and, as reported by the Irish Examiner last year, were behind five deaths in Dublin and Cork in 2016.

Gardaí continue to warn unsuspecting users that fentanyl is being mixed in with heroin and cocaine.

The European Drug Report 2017, using 2015 Irish data, also shows that:

Ireland continues to have one of the highest drug mortality rates, with 71 fatalities per million people, the fourth highest in Europe (average 21 deaths);

Ireland, along with Czech Republic, has the highest rate of recent (last year) use of new psychoactive substances by young adults (15-34) at 1.6%;

Ireland has the second- highest rate of recent use of ecstasy (MDMA) at 4.4%, compared to an average of 1.8%;

Ireland has the fourth- highest rate of recent cocaine use at 2.9%, compared to an average of 1.9%;

Ireland’s recent rate of cannabis use was the same as the European average (14%), but it has increased from 8% since 2003;

Ireland has the fourth- highest expected prison sentence for supplying 1kg or more of heroin or cannabis at 12 years

The report, compiled by the European Monitoring Centre for Drugs and Drug Addiction, said that of the 25 new synthetic opiates detected since 2009, 18 were fentanyls and that they make up eight of the nine new opiates detected in 2016.

“Although currently playing a small role in Europe’s drug market, the new fentanyls are highly potent substances that pose a serious threat to individual and public health,” states the report.

We need to protect the health of our citizens &stop huge profits from drugs ending up in the pockets of organised crime groups @Avramopoulos pic.twitter.com/S8EJFn7AB0 — European Commission 🇪🇺 (@EU_Commission) June 6, 2017

It says only a small volume is needed to produce many thousands of doses, making them easy to conceal and transport and difficult to intercept, as well as providing considerable profits to criminal gangs.

“In Europe, problems related to highly potent synthetic opioids appear to be growing, as indicated by increasing reports of non-fatal intoxications and deaths,” it read.

Three people died in Dublin and two in Cork after consuming drugs containing fentanyl between March and July 2016.

The report states that historically high potency levels of cannabis continue and that cannabis is responsible for the greatest share of new entrants to drug treatment.

Figures supplied to the European Monitoring Centre by the Irish Health Research Board show cannabis comprised 45% of first-time treatment cases and that the number had risen from 1,107 cases in 2009 to 1,693 in 2015.

Launch of the European Drug Report 2017: what are the latest trends and developments in Europe's drug situation? https://t.co/eLJWMbW0k3 pic.twitter.com/x5anREWwTC — European Commission 🇪🇺 (@EU_Commission) June 6, 2017

The board said MDMA was implicated in 15 deaths in 2014, compared to five in 2010, and that cocaine was implicated in 40 deaths in 2014, compared to 32 the previous year.

The European Monitoring Centre report says there were 66 new psychoactive drugs detected in 2016, down from previous years, bringing to 620 the total number of detections.

It expressed particular concern at the danger posed by synthetic cannabis, which is “highly potent” and could cause “serious, potentially lethal, consequences”.

The report says a “lively debate” is taking place in relation to legal approaches to cannabis. “There is a need to wait for robust evaluations before the relative costs and benefits of differing cannabis policy approaches can be assessed,” it states.

This article first appeared in the Irish Examiner newspaper.