I do not think that combining DXM, or indeed, any related NMDA antagonist with stimulants is advisable on a long term basis - Memantine and similar compounds (if any exist) will still allow normal functioning of the receptors they antagonise but prevent over-excitation, while DXM, Ketamine and other similar compounds will cause a blanket antagonism which isn't dependant on the level of receptor activation.
This may indeed be more effective for tolerance prevention but is likely not conducive to optimal cognitive performance, especially long term. In addition, while there is a fairly extensive body of research demonstrating Memantine's inhibiting effects on the formation of tolerance to a wide array of other substances, and even some hints that Memantine may have some nootropic benefits in it's own right, there is next to no research on the effects of DXM in this regard. As far as NMDA antagonists go, DXM does seem to be a dirtier one, with a much wider profile of effects and multiple active metabolites. Ketamine might be a safer bet purely because there is much more research on it, but this has just as wide an effect profile and some actual proven potential for harm such as bladder damage through a mechanism which is not fully understood.
Granted the very low, sub-threshold doses suggested may mean that the risk of unwanted side effects or dependence is minimal, but nonetheless both DXM and Ketamine have definite abuse potential themselves, and almost definitely no nootropic benefit.
Given these facts it does not seem to me to be worth the risk of any potential (and unproven) incremental benefit to using DXM (or Ketamine, or indeed any other less-researched dissociative) for prevention of tolerance to anything, compared to Memantine for which, at least, the evidence would seem to suggest that most combinations are at the very least unlikely to be actually harmful.
Edited by Xenthide, 04 May 2015 - 07:53 PM.
LongeCity
