From “Special K” to “Special M”: The Evolution of the Recreational Use of Ketamine and Methoxetamine

Abstract

This article reviews the recreational use of ketamine ("Special K"; KET) and explores the recent diffusion of its new derivative methoxetamine ("Special M"; MXE). The literature search on the nonclinical/recreational use of KET and MXE was carried out in a range of medical databases. Considering the limitations of peer-reviewed information, data were integrated with a qualitative assessment of a range of websites, drug fora, and other online resources including e-newsgroups, chat rooms, mailing lists, e-newsletters, and bulletin boards. The recreational use of KET has started since its discovery in 1962. This was due to its rapid onset, short duration of action, and peculiar psychotropic effects ("K-hole"). The latter effect ranges from confusion to dissociation and depersonalization (near-death experience). However, KET abuse is often associated with physical and psychological side effects, of which the worst is urological/bladder toxicity. Recently, MXE has emerged as a legal and "bladder-friendly" KET alternative. MXE presents with the same dissociative effect of KET, but with slower onset and longer duration of action. However, MXE seems to be associated with worse side effects than KET, ranging from mood disturbances/suicidal attempts to acute cerebellar toxicity. After 50 years of its discovery, KET has led to the emergence of MXE. However, this latter derivative does not appear to be a safer alternative to KET itself.

Neuropharmacological characterization of the new psychoactive substance methoxetamine

“…Other desired effects include euphoria, feelings of peacefulness, increased empathy and social interaction and a sense of going deeper inside the self (Zawilska, 2014). These intended effects are similar to those of ketamine, but much longer lasting and with a delay in the effects (Corazza et al, 2013(Corazza et al, , 2012. As a consequence of this delay, users more frequently take a second dose, increasing the risk for adverse effects.…”

“…MXE-induced toxicity includes psychiatric, cognitive, neurological and cardiovascular symptoms. These include drowsiness, slurred speech, anxiety, reduced ability to focus and concentrate, tremor, impaired motor coordination, aggression, hypertension and tachycardia (for review see Zawilska, 2014) as well as depressive thoughts and suicide attempts (Corazza et al, 2013).…”

Bladder leiomyosarcoma in a patient with chronic ketamine abuse: A case report

“…10 Ketamine is a dose-dependent dissociative anesthetic with a short duration of action. It is metabolized by hepatic microsomal enzymes.…”

New Synthetic Drugs in Addictovigilance

“…[59,63] The doses used range from 20 to 100 mg orally and 10 to 50 mg in intramuscular administration, but doses can reach more than 100 mg among patients who have become tolerant of the effects of the substance. [60] MXE differs from ketamine by the time lapse before it acts and the duration of the effects. The effects seem to appear later (after 30 minutes) than with ketamine (less than 10 minutes) so that there is a risk of repeat administrations among users who are accustomed to the use of ketamine.…”

“…[59,60] In vitro, these hypotheses on the mechanisms appear to be only partly confirmed, since MXE does indeed exhibit affinity with NMDA receptors, but no affinity at all for dopamine transporters or receptors. [61] It does however exhibit affinities with serotonin transporters, which could explain, at least in part, certain serotoninergic clinical signs observed among users (agitation, trembling, hyperthermia).…”