European drug users at risk from illicit fentanyls mix

The increase of overdose deaths involving licit and illicit fentanyl analogs (FAs), recently observed in North America, has shifted toward Europe posing a serious public health menace (Mounteney et al., 2015). The widespread appearance of these synthetic opioids, between 50 and 100 times more potent than morphine and in many cases not approved for medical use, has been reported by the European Monitoring Centre for Drugs and Drug Addiction (European Drug Report, 2017).. Indeed, in the last few years a number of FAs, (e.g., despropionyl-2-fluorofentanyl, furanylfentanyl, valerylfentanyl, acryloylfentanyl, carfentanyl, butyrfentanyls) has appeared for the first time on the European illicit market having caused more than 100 fatalities, when used alone or in association to other drugs (UNODC, 2017). Due to the low cost of the required materials and equipment for producing these compounds in clandestine laboratories inside and outside Europe, they are sold by drug dealers in place of heroin or mixed with it as cutting agents. In this context, the possibility of fatal overdoses is extremely high because of the narrow range between a safe and a lethal dose and the manufacturing of quantitatively inaccurate and contaminated products