Here's the facts as far as I can divine them.
Tiletamine is not used in "pure" form like ketamine is, so "diverted tiletamine" is mostly or entirely zoletile (50mg/ml each of tiletamine and zolazepam, Telazol) which has a much different qualitative response than plain arylcyclohexylamines (I think). Zoletile interferes much less with serotonin SERT/5-HT2a and dopaminergic DAT/D2 receptors when compared to ketamine/xylazine. (ref:
http://www.ncbi.nlm.nih.gov/pubmed/12715241 - In layman's terms, this means TLE is much closer to a "pure dissociative" like mk-801 with less fun/magical/enlightening/euphoric activity.)
Tiletamine potently displaced the binding of [3H]1-(2-thienyl)cyclohexylpiperidine with an IC50 of 79 nM without affecting sigma-, glycine, glutamate, kainate, quisqualate, or dopamine (DA) receptors. Like other PCP ligands acting via the NMDA-coupled PCP recognition sites, tiletamine decreased basal, harmaline-, and D-serine-mediated increases in cyclic cGMP levels and induced stereotypy and ataxia. Tiletamine was nearly five times more potent than PCP at inhibiting the binding of 3-hydroxy[3H]PCP to its high-affinity NMDA-uncoupled PCP recognition sites. However, following parenteral administration, dizocilpine maleate (MK-801), ketamine, PCP, dexoxadrol, and 1-(2-thienyl)cyclohexylpiperidine HCl, but not tiletamine, increased rat pyriform cortical DA metabolism and/or release, a response modulated by the NMDA-uncoupled PCP recognition sites.
http://www.ncbi.nlm.nih.gov/pubmed/1847186
Tiletamine is more potent than MK-801 or ketamine at inhibiting calcium channel activity. (
http://www.ncbi.nlm.nih.gov/pubmed/1338108)
Doses are typically "comparable to ketamine" if you're using it for anesthetia, but Erowid experiences suggest it's 3-4x as potent as ketamine, and doses start at ~5mg IM, possibly as high as 20mg IM. (well, starting with 5mg of each til and zolazepam, or 0.1ml Telazol) I cannot find a good figure for the half life of the compound, but it's similar to MXE (~2x longer than K). Since abuse is mostly by veterinarians from diverted Telazol there are very few "clean" tiletamine experiences. I did see it being sold on the UK "research chemical" scene but I trust that shit about as far as I can throw it. The few Erowid experiences with tiletamine also suggest that it's not very pleasant at all.
A semi-related drug, TCM (thienyl cyclohexyl methylamine), was known to be sold as "MXE". Someone tested it via GC/MS and found that the compound was likely TCM in high purity. I think it's more likely that other freakish drugs like TCM are being sold as MXE or used to curt MXE, rather than tiletamine - if you're going so far as to make tiletamine you may well be making MXE.
Metabolism of the thienyl compounds to thiones (thioketones) is one route of elimination, oxidisation of the amine might be another, glucuronidation and hydroxylation like with ketamine is another possiblity.
re: MXE, It's my personal belief that MXE has very small or insignificant affinity for the mu-opioid receptor. I think it does have considerable activity at dopamine DAT and d2/d3 receptors due to the 3-methoxy addition. (evidence for this includes mood lifts, compulsive usage, euphoria/mania, strong stimulation in some.) Perhaps it is also 4' hydroxylated in vivo, like with PCP? Compared to tiletamine, MXE is definitely preferable to some extent simply because it is more pleasurable.
