"With a total of 38 different opioids reported, the number of synthetic opioids has grown rapidly in Europe since the first substance was reported in 2009. In fact, most of these substances have been reported for the first time during the past two years, with 9 reported in 2016 and 13 during 2017. Although they play a small overall role in Europe’s drug market, many of the new opioids are highly potent substances that pose a risk of life-threatening poisoning because an overdose can cause respiratory depression (slowing down of breathing), which can lead to respiratory arrest (stopping breathing) and death. The public health importance of this risk is reflected in the fact that most deaths involving illicit opioid use are caused by respiratory depression (White and Irvine, 1999). Of particular concern are the new fentanils. These substances currently dominate this group, with a total of 28 reported since they first appeared in 2012.

"Reflecting their small share of the market as well as their high potency, new opioids accounted for only around 2% of the total number of seizures of new substances and about 0.2% of the total quantity reported to the EU Early Warning System during 2016. New opioids are found mainly in powders but also in tablets and, since 2014, liquids. For the most part, seizures are dominated by fentanils. There were around 1,600 seizures of new opioids reported by law enforcement during 2016, of which 70% were related to fentanils. These included 7.7 kg of powders (of which 60% contained fentanils), approximately 23,000 tablets (of which 13% contained fentanils) and 4.5 litres of liquids (of which fentanils accounted for 96% of the total). Some of these liquids are from seizures made by police and customs of nasal sprays, which appear to be growing in popularity as a way of using these substances."

Source

European Monitoring Centre for Drugs and Drug Addiction (2018), Fentanils and synthetic cannabinoids: driving greater complexity into the drug situation. An update from the EU Early Warning System (June 2018), Publications Office of the European Union, Luxembourg.