Pharmacology - Cross-tolerance between dissociatives?

[Niteflights]

I was speaking to my lab monkey who relayed a rather strange phenomenon. Back in the day SWIM used to occasionally use pure DXM powder. 400-500mg orally would always take swim to a heavy 2nd plateau or even third plateau. SWIM would not use DXM more than once a month so tolerance was not an issue.

Last year SWIM came into a quantity of Ketamine and began using ketamine. During one period SWIM developed a habit of using ketamine daily IM for a period of about two weeks. After that excessive binge SWIM decided to retire from ketamine use.

Several months have passed since SWIM used ketamine, DXM or anything other than the occasional joint. One night the feeling of nostalgia was overwhelming and nothing was on hand so SWIM picked up a package of decline and took 20 30mg caps for a total of 600mg.

SWIM expected a strong 3rd plateau experience from this does as he had in the past, but instead SWIM only achieved a slight 2nd if that. Mostly just a drunken stoned feeling with little of the classic DXM magic.

SWIM concludes that apparently DXM and ketamine are cross tolerant. What's worse is the ketamine tolerance seems to be permanent. SWIM wonders if anyone else has experienced a permanent tolerance to DXM as a result of substantial ketamine use.

Best regards,
Niteflights

[Niteflights]

just a quick correction to my post above... the brand SWIM picked up recently was DEXALONE (not decline).
cheers,
niteflights

[Forthesevenlakes]

SWIM has had a similar thing happen, but the order of the substances used was reversed. SWIM was using DXM fairly regularly, at doses of 350 to 500 mg, and when he used K during that period, found that it took larger amounts than most people he was with in order to attain a decent high.

DXM and ketamine both act as NMDA receptor antagonists, among other ways. It is most likely through upregulation of these receptors after heavy dissociative use that tolerance to both drugs would occur. Additionally, after many trips on either DXM or K alone, the "magic" seems to vanish as the user gets tolerant to the more pleasurable effects of the drugs, leaving the user with just a "stoned" feeling if he/she uses them again.

However, SWIM doubts that any tolerance to these drugs are permanent. SWIM can vouch for the fact that DXM takes a while for tolerance to drop after abstaining. Possibly on the order of months. SWIM had to take a year hiatus in order to recapture the euphoria of the DXM trip, and imagines that the same timeframe would hold true for ketamine.