While conventional analgesic pain killers such as paracetamol (acetaminophen) or NSAIDs provide initial relief for some sufferers, the pain is often more neuralgic in nature, which often does not respond well to these drugs.[11]
An alternative approach is for pain modification, for which off-label use of low-doses of Tricyclic antidepressant that have anti-muscarinic properties (e.g. Amitriptyline or the less sedative Nortriptyline) generally prove more effective.
I haven't really thought about NMDA antagonists, I will have to look into them though: anything that will help reduce my tolerance would be a huge help. DXM really does not agree with me very well though.