One can work with NMDA receptors. Magnesium is useful for this and also is a good vasodilator.

Here is a wiki article that lists drugs that work as antagonists:

http://en.wikipedia.org/wiki/NMDA_receptor

Avoidance of MSG (monosodium glutamate) may help and avoidance of aspartic acid (in nutrasweet and some supplements) may help too. These two amino acids stimulate the NMDA receptors. MSG is in many processed foods, especially soups and snacks, gravies, etc. Restaurants use it heavily.
Q-doba mexican really pours it on....I can't eat there. Some new soups are on the market as NO MSG...and the difference is striking to the body! I have met people who eat MSG containing foods 3 or more times a day! We are just not designed to handle a flood of non protein bound glutamate this way. We were designed to consume glutamate that is normally in foods which is slowly cleaved off the carriers as needed.

MSG and NMDA receptor stimulation is a very common trigger for peripheral neuropathy. I've posted many many times on this subject over there. I am finding many similarities to PN while reading here. We have several posters with full body burning, for example.

I am new here and all of this information is mind blowing. I have had TOS for 10 years and just diagnosed with RSD last month. I have been taking percocet for the pain and recently neuronting. Absolutely no help from neurontin, that I have seen. I am only on 600 mg per day so far. My pain has spread and gotten consistently worse. Thank you for all the information. I am very interested to see how I should proceed with this diagnosis. Linda

I'm not sure MSG bothers me but do know I have a waxing and waning hypersensitivity to sodium nitrite. This is a deadly poison used in small quantities to preserve the color in all processed meats. Usually a sandwich won't bother me but in a sensitive stage even a single slice can exascerbate my pain.

I'll pay more attention to the MSG.