Posted by JohnX2 on March 24, 2002, at 17:41:56
In reply to Re: NMDA antagonist neurotoxicity » christophrejmc, posted by JohnX2 on March 24, 2002, at 17:22:54
I've read some papers by Olney.
I get confused by the theories surrounding schizopherenia. He suggests that it is caused by hypofunctional NMDA receptors. Also, he believes that 5ht-2a antagonists will exacerbate hypofunctioning NMDA receptors. He suggests in one paper I read using a 5ht-2a agonist to protect against NMDA antagonist (hypofunctioning) neurotoxicity. If this is the case, why do antipsychotic medicines block the 5ht-2a receptor?The neurotoxicity comes from regions of the brain where the NMDA receptors stimulate GABA neurons which in turn protect other neurons.
John
>
> I've seen reports of it happening with the more competitive antagonists. I haven't seen anything indicating that Memantine would cause an olney's lesion? Could you direct me to some info on that?
> That medicine (memantine) has been in Germany for like 10 yrs+ and I don't think there has been case reports of Olney lesions from it.
>
> DXM (dextromethorphan) on the other hand is quite toxic at strong doses. That medication with dxm in it better monitor the blood levels very closely. I would be leary about the neurotoxicity, yes.
>
> John
>
> > What is your take on NMDA antagonist neurotoxicity ("Olney's Lesions")? I could only find a few articles on MedLine, but I haven't looked too hard. Have you seen any reports of this with NMDA antagonist use? I believe it has been shown to happen with memantine/dextromethorphan/etc. As far as I know, it's only theoretically possible in humans, but it is kind of scary.
> >
> > -chris
poster:JohnX2
thread:99188
URL: http://www.dr-bob.org/babble/20020322/msgs/99921.html