Understanding the availability, prevalence of use, desired effects, acute toxicity and dependence potential of the novel opioid MT-45

Introduction. 1-Cyclohexyl-4-(1,2-diphenylethyl) piperazine (MT-45) is a novel psychoactive substance available over the Internet. MT-45 is an opioid-like compound. This study provides an overview of availability, use and desired and unwanted effects of MT-45 through triangulation of available data sources. Methods. Searches of the published scientific literature and 'grey' information sources, using the keywords 'MT 45', 'MT-45' and '1-cyclohexyl-4-(1,2-diphenylethyl) piperazine' were undertaken in June 2014 to identify information on the availability, prevalence of use and desired/unwanted effects of MT-45. In addition an Internet snapshot survey in English was undertaken in May 2014 to determine the availability and cost of MT-45. Results. In June 2014 we were unable to identify any studies reporting the prevalence of use of MT-45. The Internet snapshot study identified 17 Internet sites selling MT-45. Information on price was available from 9 sites, with the mean price of MT-45 decreased with increasing purchase amounts from US$57.60 +/- 19.37 per gram for a 1-g purchase to US $3.36 +/- 1.83 per gram for a 1-kg purchase. We identified one published scientific paper reporting on the acute harms in nine cases of analytically confirmed MT-45 toxicity, one US government report relating to two MT-45-related deaths and 20 user reports on Internet discussion forums relating to the use of MT-45. All these suggest that the desired and unwanted effects of MT-45 are similar to those seen with other opioids, and that the opioid-like unwanted effects may be reversed with the opioid antagonist naloxone. There were user reports of MT-45 being used in heroin withdrawal and of 'withdrawal symptoms' after use, suggesting that long-term use may be associated with dependency as seen with other opioids. Conclusions. Combining published scientific literature and 'grey' information sources, we have demonstrated that MT-45 has opioid-like desired and unwanted effects. Whilst the information is limited at the moment, it has the potential to have similar dependence liability to other opioids.