Memantine prevents MDMA-induced neurotoxicity

[Holy_cow]

Neurotoxicology. 2008 Jan;29(1):179-83. Epub 2007 Sep 22.
Memantine prevents MDMA-induced neurotoxicity.

Chipana C, Camarasa J, Pubill D, Escubedo E.
Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Nucli Universitari de Pedralbes, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.

MDMA (ecstasy) is an illicit drug causing long-term neurotoxicity. Previous studies demonstrated the interaction of MDMA with alpha-7 nicotinic acetylcholine receptor (nAChR) in mouse brain membranes and the involvement of alpha-7 nicotinic acetylcholine receptors (nAChR) in dopaminergic neurotoxicity induced by MDMA in mice. The aim of the present study was to investigate the utility of memantine (MEM), an alpha-7 nAChR antagonist used for treatment of Alzheimer's disease patients, to prevent neurotoxicity induced by MDMA in rats and the oxidative effect of this amphetamine derivative in mice striatal synaptosomes. In isolated mouse striatal synaptosomes (an in vitro model of MDMA neurotoxicity of dopaminergic origin), MDMA (50muM)-induced reactive oxygen species (ROS) production that was fully inhibited by MEM (0.3muM). This effect of MEM was fully prevented by PNU 282987 (0.5muM), a specific agonist of alpha-7 nAChR. The preventive effect of MEM on this oxidative effect can be attributed to a direct antagonism between MDMA (acting probably as agonist) and MEM (acting as antagonist) at the alpha-7 nAChR. In Dark Agouti rats (an in vivo model of MDMA neurotoxicity of serotonergic origin), a single dose of MDMA (18mg/kg) induced persistent hyperthermia, which was not affected by MEM pre-treatment. [(3)H]Paroxetine binding (a marker of serotonergic injury) was measured in the hippocampus of animals killed at 24h and 7 days after treatment. MDMA induced a significant reduction in [(3)H]paroxetine binding sites at both times of sacrifice that was fully prevented by pre-treatment with MEM. Since previous studies demonstrate that increased glutamate activity is not involved in the neurotoxic action of MDMA, it can be concluded that the effectiveness of MEM against MDMA-induced neurotoxicity would be the result of blockade of alpha-7 nAChR, although an indirect mechanism based on the interplay among the various neurotransmission systems leading to an increase in basal acetylcholine release should also be taken into account.

PMID: 17980434 [PubMed - in process

Thus putting memantine in MDMA pills could be an excellent way to make it a safer recreational drug.

 

[UnfortunateSquid]

Shame memantine costs a ridiculous factor more than MDMA dose for dose!

 

[Jamshyd]

It is basic drug-lore that taking Ketamine after E makes the negative after-effects much less severe.

It is well known that both memantine and Ketamine have neuroprotective effects against excitotoxicity, and thereore the above study probably applies to Ketamine as well.

 

[MeDieViL]

It is basic drug-lore that taking Ketamine after E makes the negative after-effects much less severe.

It is well known that both memantine and Ketamine have neuroprotective effects against excitotoxicity, and thereore the above study probably applies to Ketamine as well.

Apperantly this wouldnt be the case as this neuroprotective effect has been connected to its nicotinic receptor antagonism.

Memantine protects against amphetamine derivatives-induced neurotoxic damage in rodents.
Neuropharmacology. 2008 Jun;54(8):1254-63.
We hypothesize that 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine (METH) interact with alpha-7 nicotinic receptors (nAChR). Here we examine whether memantine (MEM), an antagonist of NMDAR and alpha-7 nAChR, prevents MDMA and METH neurotoxicity. MEM prevented both serotonergic injury induced by MDMA in rat and dopaminergic lesion by METH in mice. MEM has a better protective effect in front of MDMA- and METH-induced neurotoxicity than methyllycaconitine (MLA), a specific alpha-7 nAChR antagonist. The double antagonism that MEM exerts on NMDA receptor and on alpha-7 nAChR, probably contributes to its effectiveness. MEM inhibited reactive oxygen species production induced by MDMA or METH in synaptosomes. This effect was not modified by NMDA receptor antagonists, but reversed by alpha-7 nAChR agonist (PNU 282987), demonstrating a preventive effect of MEM as a result of it blocking alpha-7 nAChR. In synaptosomes, MDMA decreased 5-HT uptake by about 40%. This decrease was prevented by MEM and by MLA but enhanced by PNU 282987. A similar pattern was observed when we measured the dopamine transport inhibited by METH. The inhibition of both transporters by amphetamine derivatives seems to be regulated by the calcium incorporation after activation of alpha-7 nAChR. MDMA competitively displaces [(3)H]MLA from rat brain membranes. MEM and METH also displace [(3)H]MLA with non-competitive displacement profiles that fit a two-site model. We conclude that MEM prevents MDMA and METH effects in rodents. MEM may offer neuroprotection against neurotoxicity induced by MDMA and METH by preventing the deleterious effects of these amphetamine derivatives on their respective transporters. [

 

[Jamshyd]

^ Sure, but why are other NMDA-antagonists proven several times over to be neuroprotective against a variety of things? While Memantine VS MDMA may indeed require a nicotinic component, it still doesn't disprove that NMDA-atnagonists in general, including K, may be able to help against MDMA/Meth toxicity.

Besides, do we know for sure that Ketamine has no affinity for that particular nicotinic receptor?

 

[MeDieViL]

^ Sure, but why are other NMDA-antagonists proven several times over to be neuroprotective against a variety of things? While Memantine VS MDMA may indeed require a nicotinic component, it still doesn't disprove that NMDA-atnagonists in general, including K, may be able to help against MDMA/Meth toxicity.

Besides, do we know for sure that Ketamine has no affinity for that particular nicotinic receptor?

I am a big proponent op NMDA antagonists so you dont have to convince me of the benefits.
I cant answer your question about ketamine, it may be possible.

 

[zekethemusicman]

It is basic drug-lore that taking Ketamine after E makes the negative after-effects much less severe.

It is well known that both memantine and Ketamine have neuroprotective effects against excitotoxicity, and thereore the above study probably applies to Ketamine as well.

Jam buddy, i think everything applies to ketamine when it comes to you lol

Not that theres anything wrong with that.

 

[shamus]

I thought it a good idea to see what bluelight had to say on memantine & MDMA before trying it tomorrow.


Good enough for me, I'll report back with this tomorrow. I'm worried memantine's inhibitory effects might give poor Mandy the frights.


You've gotta treat Mandy right

 

[MeDieViL]

I tried flephedrone on memantine and it worked as a charm. The inhibitory effects will go away after a few days as A7 receptors quickly upregulate.