Just dx'd with genetic variant of sodium channel blocker
 

I just found out that there is an actual reason for my neuropathic pain - I was tested for the genetic variant that affects my sodium channel blockers. I was wondering if anyone else has received this diagnosis and what they have received for treatment. I am told there is a medication that may help me to feel better. It is called Mexiletine. Has anyone been prescribed this? Has it worked?

Hi Mamadebski

My understanding is that Mexiletine is no longer available. It was initially indicated for management of irregular heartbeat and was sometimes used for management of neuropathy.

It seems that it had many possible adverse side-effects - this is discussed in this old NeuroTalk thread; http://neurotalk.psychcentral.com/ar...hp/t-3441.html.

Which sodium channel mutant do you have - the most common of those linked to peripheral neuropathy are those in Nav1.8 (SCN10A) and Nav1.9 (SCN11A)?

Apparently drugs which may help in this context are under development but it seems that none have been approved yet; http://www.neurologyadvisor.com/pain...rticle/380020/.

[QUOTE=kiwi33;1197915]Hi Mamadebski

My understanding is that Mexiletine is no longer available. It was initially indicated for management of irregular heartbeat and was sometimes used for management of neuropathy.

It seems that it had many possible adverse side-effects -
Which sodium channel mutant do you have - the most common of those linked to peripheral neuropathy are those in Nav1.8 (SCN10A) and Nav1.9 (SCN11A)?



Hello & thank you for your reply. Mexiletine is indeed still being prescribed here in the US because I have been seeing it listed in all of the formularies for prescription insurance companies. I am also currently taking it. It has been 6 days & there are definitely side effects. I have yet to get to a therapeutic dose & still do not have any positive results from taking it, so the jury is out for me.

The sodium channel variant that I have been found to have is the Nav1.7 SCN9a. It is linked to Erythromelalgia & SFN. Has anyone out there been diagnosed with this?

This drug is still available here in US... by Teva company.
You can verify this at FDA.gov Search Orange Book there and put its name into the keyword search to find any drug in the US.

We have had some posters try this on our PN forum, but all seem to get the terrible erosive esophagus side effects and had to discontinue.

You can search it on PN forum and find those posts.

An alternative would be a lidocaine infusion...so you could discuss this alternative which may work. Members on RSD forum have sometimes posted this treatment.

If your pain is in a small targeted area, Lidoderm patches may work for you as well. These are RX only as is the lidocaine infusion, which is done in a hospital setting.