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View Full Version : Mexiletine anyone? mrsd? Jim S?




janster
10-11-2006, 12:52 PM
I just had this med added to my list for my worsening PN. I am to take 150mg 2 x's/day. (I am also on Topamax 100mg 4 x's/day) Does anyone have any experience with it?

http://millercenter.uchicago.edu/learnaboutpn/treatment/pain_med/mexiletine.shtml

I find THIS part quite interesting: "Mexiletine reduces pain by adhering to peripheral nerves and reducing pain signals carried from the peripheral nerves to the central nervous system and brain. Over time, as mexiletine bonds to the peripheral nerves, the feeling of pain is diminished."

THIS is the part that bothers me: "was originally approved to treat irregular heartbeats." I did have to have an ECG, but...

Anyone?
Thanks,
Jan




mrsD
10-11-2006, 01:10 PM
This drug is not commonly used... There were a few posts a very long
time ago on our old BT board back in 2000 I think...

The side effect profile is very poor (common) and since the antiarrthymic
value of this drug is low, it is just not used much anymore.

It is sort of a last resort thing, I think.
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Mexiletine. Long-term efficacy and side effects in patients with chronic drug-resistant potentially lethal ventricular arrhythmias

N. Z. Kerin, E. Aragon, G. Marinescu, K. Faitel, H. Frumin and M. Rubenfire
Department of Medicine, Sinai Hospital of Detroit, Mich 48235-2899.

The antiarrhythmic efficacy of mexiletine hydrochloride (Mexitil) was evaluated in 100 patients with potentially lethal and drug-resistant ventricular arrhythmia. The efficacy of arrhythmia suppression was assessed by Holter monitoring. The overall arrhythmia suppression of ventricular premature contractions of 70% and greater was low and seen in only 22% of patients, with an additional 16% responding to a combination of mexiletine and an additional antiarrhythmic drug. The suppression of high-grade forms, couplets of 90% and greater, and complete abolition of nonsustained runs of ventricular tachycardia was achieved in 22% of patients, with 9% responding to the addition of another antiarrhythmic agent. Ventricular premature contractions, couplets, and nonsustained ventricular tachycardia were suppressed in only 16% of the cohort. The drug was poorly tolerated, with intolerable side effects developing in 49% of patients receiving mexiletine alone and in 57% of patients receiving a combination of antiarrhythmic agents. Tolerable adverse effects were relatively common but transient and dose related.

This is a good description of this drug:
http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=1642

Mostly GI disturbance and CNS effects are predominate.

This is a study that is fairly recent:
June 04, 2005

J Orthop Sci. 2005;10(3):315-20.
We studied the efficacy of mexiletine as a sodium channel blocker for neuropathic pain by investigating the effect of mexiletine on the pathological ectopic firing pattern in a chronic constriction nerve injury (CCI) model. The experiment was conducted with 60 male Wistar rats. The CCI model was created by loosely ligating the sciatic nerve. After breeding 7 days, the frequency and pattern of ectopic firing antidromically recorded from the sural nerve and the amplitude of antidromic sensory nerve-evoked potential were analyzed. The CCI rats were given an intravenous injection of normal saline and mexiletine (5 or 15 mg/kg). Mexiletine significantly suppressed spontaneous firing frequency, an on-off firing pattern that consisted of cyclic bursting spikes and ectopic firing generation under the hypoxic condition. Mexiletine did not influence the amplitude of A-delta component in the antidromic sensory nerve-evoked potential. Mexiletine suppressed ectopic firing by blocking activity of the abnormal sodium channel at the nerve-injured site and dorsal root ganglion without blocking nerve conduction. This study suggests that mexiletine is useful for treating neuropathic pain in peripheral neuropathy.
from http://www.dejerine-sottas.com/archives/news_you_can_use/neuropathic_pain_management/index.php

All of these agents that affect heart rhythm can impact even a normal patient. Hence they are not used frequently. You will need to be monitored carefully, while on this drug. Also the GI effects can be huge..usually they are the reason people discontinue it.

And a warning for people with ocular issues (vision)
http://www.blackwell-synergy.com/links/doi/10.1046/j.1526-4637.2001.01027.x/abs/

Most drug stores do not carry this as a regular item..you might have to have it special ordered...so a delay may occur in receiving it.

I tried searching the old board for you, but I don't get any hits on this drug.
It was a LONG TIME ago that I saw someone with PN posting about it.

Is this a result of your recent visit to Mayo?

janster
10-11-2006, 05:26 PM
Thanks for all the good info mrsd....you are a Godsend! I hope you know how much we appreciate all you do for us!

Yeah, my Neuro wants me to try a low dose of Mexiletine. We discussed the side effects, but she thinks it's worth the shot. We are kinda running out of options....

You were right about my Pharmacy not stocking it. I will get it tomorrow afternoon, so we'll see how I tolerate it. Thanks again.
Hugs,
Jan

mrsD
10-11-2006, 05:32 PM
Please keep us posted about how you are doing...

And report ANY GI problems ASAP to your doctor, before they turn into
some awful erosive eosphagial thing. Okay?

janster
10-11-2006, 07:14 PM
Shall do--thanks!
Hugs,
Jan

LizaJane
10-11-2006, 11:57 PM
You know, depending on the level of pain management you've been getting, this is either a very thoughtful and creative choice, or off the wall.

I don't know what you've been on for your pain, and what has helped, but I'd hope that all the routine meds have been tried: The anti-epileptics, anti-depressants (remember, these stabilize nerves and are not only active in the one diagnosis they were first approved for), opioids, and maybe Rebuilder, TENS and the like. I believe there's a sticky here with a pretty complete list of what's being used for neuropathic pain these days.

Some doctors are excellent with sticking with us, and working their way through the menu of drugs, but some are not. If you've a good one, and s/he has been working methodically, then I'd say you've got someone who cares, and is willing to be creative about what to use.

Are you doing all the non-drug things that various people here recommend? From supplements to exercise (yoga, t'ai chi, meditation, stress reduction, etc). They, too, are an integral part of pain management.

Right now, the newest ingredient on my list is Feldenkrais therapy. It's geared at finding ways of moving which reduce pain, and it is helpful.

Keep us posted on how it works, promise?

beth
10-12-2006, 04:04 AM
This med is an oral version of lidocaine, it was used more widely in the past I believe, but if the side effects are tolerated can be very effective. I see neurologist Dr Robt Schwartzman from Drexel University in Philly, he is a leading researcher into RSD and other neuropathic disorders. I have full-body RSD due to a vaccine reaction, and one treatment he tried to put my RSD into remission was an in-patient IV-lidocaine infusion. I wasn't able to tolerate it; as the dose was slowly increased I became nauseous and the room started spinning. Despite pausing, then restarting from a lower dose, I wasn't able to continue.

I was sent home, though, with an RX for mexiletine, which I took for several months until starting a different treatment involving an even stronger med with a higher side-effect profile. I didn't suffer any bad results from either treatments or from the mexiletine. I think I got some benefit from it, but at the time my pain was just raging, so it seemed that nothing really touched it.
My Drs at home were not familiar with it's use, either, and may not have increased it to the desired dose for effectiveness, a drawback to being treated by Drs from away unfortunately. :(

I hope you see good results with it, and no side effects. Because of the treatments I've had, I am assured my heart is in VERY good shape, at least that's one body part that I can rest easy about! ;)

beth

janster
10-12-2006, 09:41 AM
LizaJane~
I went through the list in the sticky again--I remember reading it when it was posted--very good information.

My Neuro and I have experimented at length with many meds, as most everyone has. I am on what I can tolerate, what seems to help, and what doesn't interfere with my other meds.

I am on no Narcotics for pain; Mayo is Narcotic-phobic. I am on Tramadol.

I've tried the "normal" non-drug things: physical therapy, tens and supplements. Mrsd & heyjoe helped me with supplements last year, so I know I'm good to go there.

The other things you mention I have not tried. I live in a very rural area where the closest instructors would be in the metropolitan area, which is over 2 hours away. I don't drive there because people drive like they're nuts. (Sorry people whom live there--I know, you think it's people like ME that do...) Hey, I like our two stop lights!

I will keep you posted. My pharmacy will have my med in later this afternoon.

Beth~
Thank you for your first hand experience with the med. It's comforting to know someone has taken the drug and has gotten some relief from it.

I guess I'm kinda excited about it because of reading how it attaches to the nerve and acts as lidocaine. That makes sense to me that it would help take care of pain, but, we'll see.

Thanks again!
Hugs,
Jan

Wittesea
10-12-2006, 10:07 AM
Jan,

Do you remember FiberoWendy from the chronic pain forum? If I remember correctly, she took (or might still take) Mexiletine for pain/fibromyalgia.

She posted in the fibromyalgia forum here recently.... so she may be able to shre some personal experience.

Take care,
Liz

janster
10-12-2006, 10:13 AM
Thanks Liz, I'll look her up.
HUgs,
Jan

janster
11-08-2006, 01:15 PM
Update:
After wearing a Halter Monitor for 24 hours, my Cardiologist said I am having extra beats coming out of the top and bottom of my heart, evidently from the Mexiletine. I didn't notice anything before starting it. The ECG was normal.

I hope I'm saying this right. The beats are coming in twos, so while it's not normal, it's OK as long as we don't increase the dosage, and if the symptoms get worse, we stop. The Mexiletine has taken care of about 80- 90% of the new "zaps" to my feet, so I would like to stay on it, but not if it means damaging my heart. The cardiologist said at this point I am safe.

Hugs,
Jan

mrsD
11-08-2006, 01:20 PM
I was just thinking about you, and was going to post soon!

What dose are you on?

No heartburn/reflux yet?

Sounds like you are being supervised well. That is a good thing, that you
had the 24hr monitor, too.

janster
11-08-2006, 02:18 PM
What dose are you on?

No heartburn/reflux yet?
Mrs D~
I'm on 150mg 2x's/day. I asked if the heartburn could be from the new med and the Resident said no, so I didn't ask the Cardiologist. So, it probably is from it...... thought so.

I should have known to ask the "real" doctor as well as the Resident. :( I'm sure that question wasn't relayed when the Resident prepped the Cardiologist about me.
Hugs,
Jan

dahlek
11-08-2006, 02:22 PM
well, plain old 'STICKY'? I went that route, totally neg., which, I guess is a good thing, but....what else is going der heck on? Everyone just scratches their heads [maybe other areas out of eye-shot] and goes: DER WHAT?

All I can say is a sort of Dirk Gently -Psychic Detective [book series by Douglas Adams of Python fame] in that you go where you need to go, even tho you've no idea of where you are going,....because that is where you need to BE!...???? As with all our conditions, and the issues that stack up on it all, well, you never know when/where/why or by what accident you find--the answer.


Hugs, fuzzies and pain free moments however few! - j

mrsD
11-08-2006, 03:05 PM
This drug is not frequently used. And if the doctor does NOT refresh his/her
memory... or learn about it.. you have to find these facts yourself:

http://www.rxlist.com/cgi/generic3/mexiletine_ad.htm

GI side effects are huge with this drug..and it is they that lead to the
majority of treatment failures.
41% of upper GI side effects is a very large number.

And this is an interesting factoid:
Additionally, in one controlled study in five normal subjects and seven patients, the clearance of caffeine was decreased 50% following the administration of Mexitil®. So be careful with coffee/tea consumption.

janster
11-08-2006, 05:08 PM
GI side effects are huge with this drug..and it is they that lead to the majority of treatment failures. 41% of upper GI side effects is a very large number.

And this is an interesting factoid: So be careful with coffee/tea consumption.
mrsd~
The GI side effects that I experience are infrequent. Now anyway. Thanks for the heads up on the coffee consumption.

well, plain old 'STICKY'? I went that route, totally neg., which, I guess is a good thing, but....what else is going der heck on? Everyone just scratches their heads [maybe other areas out of eye-shot] and goes: DER WHAT?

All I can say is a sort of Dirk Gently -Psychic Detective [book series by Douglas Adams of Python fame] in that you go where you need to go, even tho you've no idea of where you are going,....because that is where you need to BE!...???? As with all our conditions, and the issues that stack up on it all, well, you never know when/where/why or by what accident you find--the answer.

Hugs, fuzzies and pain free moments however few! - j
dahlek~
Huh?
Hugs,
Jan

Silverlady
11-08-2006, 10:27 PM
I think my brain links are totally not working. Dahlek..I didn't understand a thing you said. I just couldn't relate it. Am I losing it??

Billye

nancy-h
11-09-2006, 04:25 PM
Dear Dahlek;

It's your first sentence that throws me off. Could you explain because it sounds worth repeating with just a few revisions so we can understand.

Hope all is well with you today...

nancy-h