Serotonin Mediated Neuropathy and Possible Treatments

[irobeth]

I have, for a few years, been waging a chemical war against what I had only known until this year as 'burning in my arms and legs'

I've visited a neurologist who suspected MS, but the MRI came up negative for this. I've been prescribed pregabalin (lyrica) at the 75 and 100mg levels which alleviated some of the symptoms (but they're still present.) Blood tests have not turned up any results nor shown it may be diabetic.

The following factors didn't have a strong effect on the pain:
Neck/back pain, sleep habits, diet
Cannabis
NSAIDs (Aspirin, APAP/IBP, Ketorolac)
Opiates
'Z' drugs/Benzodiazepines (this was an early guess that it may have been related to quitting Ambien cold tukey)

The following factors did:
DXM during 2nd+ doses
High doses of caffeine aggravates it, but not having caffeine didn't help it any.
Lyrica reduced the 'volume' of the pain but not the fact that it existed.

I've noticed Cymbalta being prescribed to treat diabetic neuropathy so on a hunch I started taking 5-HTP 3-4 times daily and the pain is gone as long as I can presume the dose is 'active' (being actively metabolized.) Operating on the theory that it's serotonergic, I've been ~11 days without lyrica and without major pain now, which is promising.

Thus my question is: Is there a known association with serotonin deficiency and neuropathy? Besides the S*RI classes, are there any ideas for treatment?

 

[yuppu]

I havnt a clue to your question.
But recently started taking methylcobalamin or methyl b-12 for neuropathy in my legs, incurable by a majority of what you spoke of, and it works alright.

(lyrica, some what well. opiates well. and an anti epileptic made it in different locations.)



I lost my medical insurance so I don't take anything prescribed anymore but think it could maybe help especially if combined with stuff.

 

[seep]

Besides the S*RI classes, are there any ideas for treatment?

Freighter-fulls. For instance,

1. Curr Mol Pharmacol. 2008 Nov;1(3):255-69.

TRPV1: on the road to pain relief.

Jara-Oseguera A, Simon SA, Rosenbaum T.

Departamento de Biofísica, Instituto de Fisiología Celular, Universidad Nacional
Autónoma de México, Mexico.

Historically, drug research targeted to pain treatment has focused on trying to prevent the propagation of action potentials in the periphery from reaching the brain rather than pinpointing the molecular basis underlying the initial detection of the nociceptive stimulus: the receptor itself. This has now changed, given that many receptors of nociceptive stimuli have been identified and/or cloned. Transient Receptor Potential (TRP) channels have been implicated in several physiological processes such as mechanical, chemical and thermal stimuli detection. Ten years after the cloning of TRPV1, compelling data has been gathered on the role of this channel in inflammatory and neuropathic states. TRPV1 activation in nociceptive neurons, where it is normally expressed, triggers the release of neuropeptides and transmitters resulting in the generation of action potentials that will be sent to higher CNS areas where they will often be perceived as pain. Its activation also will evoke the peripheral release of pro-inflammatory compounds that may sensitize other neurons to physical, thermal or chemical stimuli. For these reasons as well as because its continuous activation causes analgesia, TRPV1 has become a viable drug target for clinical use in the management of pain. This review will provide a general picture of the physiological and pathophysiological roles of the TRPV1 channel and of its structural, pharmacological and biophysical properties. Finally, it will provide the reader with an overall view of the status of the discovery of potential therapeutic agents for the management of chronic and neuropathic pain.

PMCID: PMC2802457
PMID: 20021438 [PubMed - in process]

Full text here.

Some grad student at the University of Iceland almost singlehandedly wrote a very good wikipedia article on the discovery and development of TRPV1 antagonists.

 

[onmyway]

thanks for the wiki article. great stuff in there.

 

[dread]

Reuptake inhibitor.

 

[dread]

http://www.ncbi.nlm.nih.gov/pubmed/9075493

Tramadol is a synthetic analogue of codeine that binds to mu opiate receptors and inhibits norepinephrine and serotonin reuptake.

 

[Thray]

I have, for a few years, been waging a chemical war against what I had only known until this year as 'burning in my arms and legs'

I have similar problems in my feet (sometimes rising to the lower legs) and hands since 4 years. It varies, burning, stabbing or undefined pain. In the last years mostly the last two.

The weird part is I had pain free intervals of 8-12 months. And even during a day the pain can be gone for half of the time.

I've visited a neurologist who suspected MS, but the MRI came up negative for this. I've been prescribed pregabalin (lyrica) at the 75 and 100mg levels which alleviated some of the symptoms (but they're still present.) Blood tests have not turned up any results nor shown it may be diabetic.
...
Lyrica reduced the 'volume' of the pain but not the fact that it existed.

I had the same examinations coming up negative. I take Lyrica for 2 months now (the pain has been there for 6 months), and it really helped a lot. In my case it decreased the pain intensity only slightly but mostly the frequency of the pain . I can go for days without pain now. But it is still not completely gone.

I've noticed Cymbalta being prescribed to treat diabetic neuropathy so on a hunch I started taking 5-HTP 3-4 times daily and the pain is gone as long as I can presume the dose is 'active' (being actively metabolized.) Operating on the theory that it's serotonergic, I've been ~11 days without lyrica and without major pain now, which is promising.

I have tried Cymbalta it did not help much, but I also could not handle it very well. Interestingly I started 5-HTP a couple of days ago(I have trouble with my energy and motivation), and I have the feeling that the pain is getting more frequent again.

Thus my question is: Is there a known association with serotonin deficiency and neuropathy?

Besides the S*RI classes, are there any ideas for treatment?

I had phases where B vitamins helped a lot. Around 3-4 times the recommended daily allowance (and not extended release). It helped and really fast (half an hour). Unfortunately it only lasted 4-5 hours, higher doses did not help more or even made it worse. I tried to narrow it down which vitamin it was. 2 years ago it was Niacin(B3), this year the pain reappeared and Niacin did not help at all, now Pyridoxine(B6) often helps (around 6mg). I am still not sure if it is just the placebo effect (then it is impressively consistent), but who cares as long as it stops the pain for a while.

PS: I just noticed I am replying to an old thread , sorry. Hopefully your problem is better by now.