MT-45, a new psychoactive substance associated with hearing loss and unconsciousness

Background. MT-45 (1-cyclohexyl-4-(1,2-diphenylethyl)piperazine) is an opioid analgesic drug candidate developed in the 1970s that has recently been introduced as a new psychoactive substance (NPS) on the "recreational" drug market. We describe a case series of non-fatal intoxications associated with MT-45 within the Swedish STRIDA project. Study design. Observational case series of consecutive patients with admitted or suspected intake of NPS presenting to hospitals in Sweden from November 2013 to February 2014. Patients and methods. Blood and urine samples were collected from intoxicated patients presenting to emergency departments and intensive care units over the country. NPS analysis was performed by an LC-MS/MS multi-component method. Clinical data were collected when caregivers consulted the Poisons Information Centre and also retrieved from medical records. Case series. Among nine intoxications where MT-45 was detected in the biological samples, four cases were indicated to only involve MT-45, while one or several psychoactive substances were found along with MT-45 in the others. All patients were men aged 17-32 years and they commonly presented with opioid-like adverse symptoms, such as unconsciousness and respiratory depression. Naloxone appeared to have utility in the treatment of MT-45 intoxication in several cases. Three patients complained of bilateral hearing loss that in one case persisted after two weeks. Conclusion. MT-45 should be added to the growing list of harmful NPS causing life-threatening poisonings, and rapid actions taken to make it a controlled substance.