Ketamine-related – The Arylcyclohexylamines

This entry is part 6 of 7 in the series The Ketamine Konnection

Arylcycloheylamine structure

Ketamine numbers many relatives in the arylcyclohexylamine class (of which it is itself a member), though not all are dissociative in effect, or indeed pharmacologically active. Arylcyclohexylamines are useful tools for chemists and pharmacologists, due to their application in research on NMDA receptors, dopamine reuptake inhibitors, and opioid receptors. Other chemical classes with dissociative effect include Adamantane/ memantine, L-Arg, APV, Opioids, peptides, and simple gases.

With the explosion in popularity of ketamine (and latterly it’s cousin methoxetamine 1 across the UK recreational drug scene over the last decade, 2 it seems logical to at least briefly delve into the range of other active arylcyclohexylamines. After a patchy drought lasting several years, 2016 has seen reports of a resurgence in the illicit ketamine market, thought to be mostly emanating from China, 3 rather than via the traditional Indian supply chain. Further, recent news of further clinical trials and “breakthroughs” in drug giant Johnson & Johnson’s research aimed at bringing ketamine to market as a treatment for depression 4 – not to mention the surge in buyers from ‘Deep Web’ markets from around 2010 onwards – provide even more reason to learn a little about these hitherto relatively unexplored compatriots of the Great Odd K…


Benocyclidine (Benzothiophenylcyclohexylpiperidine, BCP, BTCP, BTPC, GK 13)

First discovered in 1997, 5 unlike related compounds such as ketamine and PCP, BTPC “lacks any anticonvulsant, anesthetic, hallucinogenic, or dissociative effects”, due to negligible affinity for the NMDA receptor, 6 instead acting as a potent and selective dopamine reuptake inhibitor (DRI), 7 and as a psychostimulant. Used to label the dopamine transporter in mice for neurological research, 8 the drug has also reportedly been found as an ingredient of several batches of ‘ecstasy’ tablets. 9

Dieticyclidine (PCDE, diethylphenylcyclohexylamine)

A drug with a relatively low potency, used medically alongside eticyclidine, 10 in combination with which it acts as a prodrug. 11

Eticyclidine (PCE, CI-400)

PCE is a less common (though still controlled) dissociative, similar in effects to PCP, yet “slightly more potent”. First developed in the 1970s by Parke-Davis, as an anaesthetic (under the name ‘CI-400’), research was discontinued subsequent to the development of ketamine, due to its perceived attractiveness over that of PCE.

Rarely encountered in the modern recreational drugs scene, although briefly abused throughout the 1970s and 1980s (where users soon learnt to loathe the drug’s smell, taste, and nausea-inducing properties). 12

Methoxetamine (MXE, MKET, Mexxy/Mexi, Minx, Jipper, 3-MeO-2-Oxo-PCE)

Allegedly first synthesized circa 2010, by an underground arylcyclohexylamine chemist looking for “…something fantastic…the perfect dissociative…a stress-free version of ketamine”, 13 MXE did not undergo any legal medical trials before entering into the illegal market. Not to be confused with its cousin Methoxyketamine, or 2-MeO-2-deschloroketamine, until an April, 2012, Temporary Class Drug Order (TCDO) by the government, 14 no license was required in the UK to buy, sell or otherwise utilise MXE; however, in November, 2012 it was classified as a Class B drug. 15

MXE has been administered via the nasal, rectal, oral, intravenous, and intramuscular routes, as well as by smoking (in freebase form). Unsurprisingly, users report that the injection, nasal and rectal methods are fastest to peak and hardest hitting, with oral administration being “approximately 75% as efficient”. Most routes of ingestion result in the first effects being felt after 10-20 minutes, main effects occurring between 1-3 hours in and a further 3-6 hours of after effects. Duration of effect is strongly dose dependent, with larger doses leaving users feeling residuals for up to 24 hours. Compulsive redosing has been reported during high dose trips too, resulting in “automatic” overdose.

Like most active arylyclohexylamines, effects vary widely, and include; convulsions, hyperventilation, dissociation, unconsciousness, euphoria, nausea, depression/derealisation, stimulation, dysphoria, mania, hallucinations (visual, auditory, tactile and olfactory), suicidal ideation, panic/anxiety, increased enjoyment of music, muscular relaxation, ataxia, numbness, double vision, out of body experiences, hallucinations, time distortion, vertigo, insomnia, and spastic muscle movements.

There have been some hospitalisations attributed to MXE overdoses (often due to acute cerebellar toxicity). Several deaths have been reported in the UK in which intoxication by the drug has been claimed as a significant factor and one death in Sweden due to cardiac problems resulting from intravenously injected MXE (100mg) and MDAI (400mg). Avoid mixing the drug with other stimulants (due to a tendency for mania and recklessness), or CNS depressants (alcohol, GHB, ketamine, etc). Consider also asking someone to look after any remaining MXE once you have decided upon dose (to avoid the risk of automatic overdose).

Phencyclamine (PCPr)

PCPr is another dissociative anaesthetic with hallucinogenic and sedative effects, of roughly the same potency to PCP, although slightly less potent than eticyclidine. 16 It has been available to recreational users (although rarely) as a ‘designer drug’ since the late 1990s, being sold in Germany and several other European countries. 17

Phencyclidine (PCP, Angel Dust)

PCP was first synthesized in 1926, 18 before being brought to market in the 1950s as an anaesthetic pharmaceutical drug by Parke-Davis under the name Sernyl. In 1965, human use was discontinued due to PCP’s strongly dissociative effects, resulting in an increase in clandestine laboratories producing the drug. Today PCP is rarely used as a veterinary medicine, yet is an infrequent but definite presence on the fringes of the black markets. It is active via most traditional routes of ingestion, with a tendency toward more euphoric/less anaesthetic effects when insufflated.

Rolicyclidine (PCPy)

Rolicyclidine is similar in effect to PCP, but with a lesser tendency towards stimulation, instead producing a sedative effect reportedly “somewhat similar to a barbiturate, but with additional PCP-like dissociative, anaesthetic and hallucinogenic effects”. 19 PCPy has never been widely available to the drug-using public, and as of the time of writing is seldom seen on the black market.

Tenocyclidine (TCP, Thienylcyclohexylpiperidine)

Discovered in the 1950s by Parke-Davis employees, 20 TCP is reportedly similar in effects to PCP (and is treated the same way in law), but exhibits more potency. Now commonly used in research into the NMDA receptor’s PCP site, TCP was seemingly briefly used recreationally during the 1970s and 1980s, but is currently almost unknown on the grey and black markets. Anecdotal reports suggest that tenocyclidine possesses “less euphoric and more insightful [effects] as a dissociative” than PCP. 21


On a scale of potency, “tiletamine is between ketamine and phencyclidine with ketamine being the weakest and phencyclidine the most potent.” 22 It is used in veterinary medicine (as part of an equal mix of tiletamine and the tranquiliser zolazepam 23) as an anaesthetic for cats and dogs, 24 and is used in combination with xylazine to tranquilize larger mammals, such as polar bears and wood bison. 25 Recreational abuse has been reported. 26

Other Active Arylcyclohexylamines

Esketamine | Ethylketamine | Gacyclidine | Metaphit | Methoxydine (4-MeO-PCP) | Neramexane | Phenylhexylcyclopyrrolidine | 2-Chloro-PCP | 2-Oxo-PCP | 3-HO-PCP | 3-Amino-PCP | 4-Fluoro-PCP | 4-HO-PCP | 2-MeO-PCP | 3-MeO-PCE | 3-MeO-PCP | 3-MeO-PCPr | 3-MeO-PCPy | 4-Methyl-PCP | 4-Oxo-PCP | PCA | PCBu | PCiPr | PCM | TCPy

Series Navigation<< Indian Ketamine Smuggling, 2000-2009Notable Users of Ketamine >>


  1. Reported by VICE as being first synthesised circa 2010 by an underground chemist named Karl.)
  2. According to government figures, the illegal use of ketamine increased from 0.8 percent to 1.4 percent of the UK population between 2006 and 2015
  3. Max Daly – ‘How Ketamine Has Made Its Way Back Into the UK’ (VICE, 18 February 18 2016)
  4. ‘Esketamine Receives Breakthrough Therapy Designation from U.S. Food and Drug Administration for Major Depressive Disorder with Imminent Risk for Suicide’ (Johnson & Johnson, 16 August 2016)
  5. World Patent 9712513 Myers Bigel Sibley & Sajovec
  6. (
  7. (
  8. Maurice, T., Vignon, J., Kamenka, J., et al. – ‘In vivo labelling of the mouse dopamine uptake complex with the phencyclidine derivative [3H]BTCP’
  9. (
  10. Wikipedia (
  11. Wikipedia (
  12. Wikipedia (
  13. Hamilton Morris – ‘Interview with a ketamine chemist’ (
  14. ‘Government bans methoxetamine or ‘mexxy’’ (
  15. Drugscope (
  16. Maddox VH, Godefroi EF, Parcell RF – ‘The Synthesis of Phencyclidine and Other 1-arylcyclohexylamines’ (
  17. Sauer C, Peters FT, Staack RF, Fritschi G, Maurer HH – ‘Metabolism and toxicological detection of a new designer drug, N-(1-phenylcyclohexyl)propanamine, in rat urine using gas chromatography-mass spectrometry’ (
  18. Phencyclidine (PCP) (
  19. Phencyclidine (PCP) (
  20. Heterocyclic compounds and methods for producing the same‘ (
  21. ‘PCP Analogs – Cumulative'(
  22. Christopher J. Cording, Robert DeLuca, Thomas Camporese, and Elizabeth Spratt – ‘A Fatality Related to the Veterinary Anesthetic Telazol’ (
  23. This product is sold as Telazol (USA), and Zoletil (Australia, Belgium, France, Italy, Luxembourg, Norway, New Zealand, South Africa and Switzerland.
  24. Drugs (
  25. Wikipedia (
  26. M. T. Quail, P. Weimersheimer, A. D. Woolf, B. Magnani – ‘Abuse of telazol: an animal tranquilizer’ (