Low Dose Ketamine and Memantine for Neuropathic Pain

I recognize and respect the frustration that doctors and nurses must experience when patients delve into the internet to obtain medical information, and then bring that "research" in to appointments in full "eureka!" mode.

That said (ar! ar! ar!), one of my MedWorm news feeds, on ketamine, turned this up:
ultra-low dose ketamine and memantine treatment for chronic pain -- specifically, neuropathic pain. As usual, the non-malignant neuropathic pain is represented by diabetic peripheral neuropathy. This use of memantine is off-label (of course) -- the drug is usually used in moderate to severe Alzheimer's disease (Namenda).

In the October 2008 issue of Anesthesia and Analgesia, doctors from the Anesthesia Department of the University of Washington published "Ultra-low dose ketamine and memantine treatment for pain in an opioid-tolerant oncology patient."

This is the abstract of the article that the authors submitted to PubMed:

Patients taking high-dose opioids chronically for tumor-related or neuropathic pain may develop pain that is refractory to opioids. One option for control of such pain is the use of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine. We describe a case of opioid-refractory pain that responded to a low-dose IV infusion of ketamine in the inpatient setting. The patient was then successfully transitioned to oral memantine for long-term outpatient management, in a novel use of this oral NMDA receptor antagonist. We present recent findings from basic research on pain mechanisms to explain why opioid tolerance, as in this patient, may contribute to the analgesic benefit of NMDA receptor antagonists.


"Memantine Significantly Reduces Peripheral Neuropathy Pain in Diabetics" was the next thing I turned up -- yes! I released the hounds! I let the dogs out! And I dare to call it research... But will I dare to stalk my internist, neurologist, and pain management doctor-dude with the information that I have culled, and will continue to cull?

Yes, I think so. It has been several years, actually, since I have dragged in any articles. Mostly, I read and then present anything interesting in a very brief oral report that inevitably results in the same reaction of "uh-huh." That is not to say there is no interest -- no, the problem lies elsewhere. The problem is that "no one knows" how CRPS / RSD really comes about, sticks around, or is best treated. I feel myself on almost equal footing with some of the more speculative researchers out there, with the difference that I cannot afford -- neither by bank account nor by insurance coverage -- the treatments that are in the pipeline.

Bitter? Moi? Of course not.

Shoot, we just added Forteo as an off-label use -- why not give this ketamine-transition-to-memantine idea a go? I think sometimes that they give me way too much credit. There is this tacit assumption that Retired Educator, succored by Fred, the felines, and La Belle Bianca Castafiore, and living the luxe in Marlinspike Hall, Tête de Hergé, can handle any amount of pain.

Not so. More and more "not so" with each passing day.

(Oh -- for those who don't know, MedWorm is a "medical RSS filter engine" and proves *occasionally* helpful in turning up germane articles -- but only if you feed the worm with very specific and well-thought out search guidelines. You must then bring the full power of your intellect to bear upon the results and vett the weird and unfounded, the scientistic and the industry-driven.)