As many of you know, I suffered from a “demyelinating polyneuropathy” that gradually worsened last year. My symptoms were ataxia (inability to walk a straight line), loss of proprioception (inability to judge where parts of my body existed in space), and horrible paresthesias (pins and needles) in the extremities. My neurologist basically said “oh well, nothing we can do to fix this!” Frustrated, I did some research on my own and found some medications and nutritional supplements that actually have data behind them to support their use in neuropathies. Below is some of the information I found…maybe it’ll help someone you know.
For patients with cancer who are experiencing Chemotherapy Induced Peripheral Neuropathy (CIPN), duloxetine has the best evidence to recommend it (Grade 2B).
There is insufficient evidence to support a strong recommendation for any other treatment. However, in keeping with the recommendations from ASCO, a therapeutic trial of gabapentin/pregabalin or a tricyclic antidepressant (eg, nortriptyline or desipramine) is reasonable given the limited therapeutic options and the demonstrated efficacy of these drugs for other neuropathic pain conditions. Given the single borderline positive trial in patients with CIPN, it is also reasonable to try a compounded topical gel containing baclofen, amitriptyline HCl, and ketamine, understanding that this can only be manufactured by a compounding pharmacy and that ideally confirmatory results from other randomized trials regarding this treatment are needed.
In a situation where evidence based medicine has failed, it it sometimes appropriate to try, as a last resort, methods that have less strong evidence as long as the treatment plan meets the following criteria:
1) the treatment does not replace a possibly efficacious treatment that has good evidence
2) the treatment’s risk/benefit ratio is favorable
3) there is at least some positive evidence
Other dietary supplements that have some positive data (though none of them have class A evidence (double blind, placebo controlled reproducible trials) and are likely to do little or no harm include:
1) Acetyl L-Carnitine (ALC)
Http://www.sciencedirect.com/science/article/pii/S0959804905004296
[Curr Pain Headache Rep. 2015 Dec;19(12):56.]
However in one study, ALC was found to worsen chemotherapy induced neuropathy at the 24 week mark
[J Clin Oncol. 2013 Jul 10;31(20):2627-33.]
but this remains controversial:
[J Pain Symptom Manage. 2013 Dec;46(6):887-96.]
2) Alpha Lipoic Acid (ALA)
http://onlinelibrary.wiley.com/doi/10.1111/j.1464-5491.2004.01109.x/full
[J Fam Pract. 2015 Aug;64(8):470-5.]
3) Myo-Inositol
http://www.sciencedirect.com/science/article/pii/002604957990060X
4) Gamma E Complex
Http://www.sciencedirect.com/science/article/pii/S0140673683925989
[Pharmacol Rep. 2014 Feb;66(1):44-8.]
[Int J Vitam Nutr Res. 2013;83(2):101-11]
5) Glutamine (specifically for Chemo Induced Peripheral Neuropathy)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3385273/
6) Vitamin K2-7
http://www.jpharmacol.com/article.asp?issn=0976-500X;year=2018;volume=9;issue=4;spage=180;epage=185;aulast=Mehta
On the “alternative medicine” front, there is some early evidence that Corydalis may be effective in neuropathic pain. Though this remedy has been used for hundreds of years, studies are only now being done and are still murine and murid-based only.
[PLoS One. 2016 Sep 13;11(9):e0162875.]
It should be noted that much of the evidence regarding dietary supplements and neuropathic pain is related to diabetic neuropathy (with the exception of glutamine, noted above), which may require different treatment than chemotherapy induced neuropathy. Solid evidence continues to be lacking, and patients must be given information regarding the scientific method and how nutritional supplements or off-label drugs may or may not be effective.
Methadone can also be considered in patients with neuropathic pain that is refractory to the above. The advantages of using methadone for refractory pain in cancer patients or in those who could not tolerate the side effects of other opioids are well-cited in recent literature. Advantages of methadone over other opioids include but are not limited to: dual elimination without active metabolites allowing safe use with renal and liver failure, delta receptor activity in addition to mu receptor agonism, multiple routes of administration, rapid onset of action, long half-life, low cost and fewer adverse effects. In particular, methadone has salutary effects on hyperalgesia due to neuropathy, due to its antagonistic effect on NMDA receptors.
Disadvantages of methadone include the large variation in interindividual pharmacokinetics, potential for delayed toxicity,resistance of providers to write this medication, emerging state restrictions on its use, and its association with addiction therapy. Patients need to be screened for congential prolonged QT syndrome prior to initiation of therapy, and need to be followed periodically with EKGs to ensure the QTc is less than 450ms. Patients are counseled to avoid drugs and foods (e.g., ketoconazole or grapefruit juice) that can similarly prolong QT or inhibit CYP450. [Am J Hosp Palliat Care. 2011 Mar;28(2):135-40.]
Fortunately, in my case, my symptoms resolved nearly completely (I still have some hand numbness, but all of the other symptoms are gone) with the nutritional supplements alone. Obviously, my experience is anecdotal, but there’s enough decent evidence in the literature to support at least trying these supplements in refractory patients, because the chance of harm from them is so low. As always, DON’T DO ANYTHING WITHOUT A DISCUSSION WITH YOUR MEDICAL PROVIDER.
So there you go, email me if you have questions regarding the information above, and good luck!
yr obt svt,
Dr Steve
(PS: You can check out the supplements above by going to THIS LINK or click one of the images below.)
