Hi. Sorry to be late on this, but I've been given something that's nothing short of awesome for flairs.

In addition to the backdrop of Oxycontin/oxycodone, Xanax and Baclofen, I've been using - as discussed here months ago - Neudexta, a combination of 20 mg of dextromethorphan HBr (DM) and 10 mg of quinidine sulfate. DM - widely used as an over the counter cough suppressant - just happens to be a powerful NDMA-receptor antagonist, second only the ketamine. Its downside in pain relief is that it's quickly metabolized by the liver. But, it turns out that quinidine - widely used in substantially larger doses years ago as a tricyclicate antidepressant before it was found to cause cardiac arrhythmia in too many people - completely blocks the metabolism of DM, for 4 - 6 hours at a time. To which my doctor adds a prescription for compounded DM in capsules, 30 mg each. (While Neudexta is covered by my insurance, DM is not, but its pretty cheap: 60 capsules costs $56.)

So, with the worst of flairs, as I was having a few minutes ago, I just take the foregoing - including 90 mg of DM - and I'm right as rain, and heading out to see a movie in few minutes!

One note of caution: even with only 10 mg of quinidine, Neudexta is contraindicated for anyone throwing a "long Q - T interval" on their EKG. So "pre-clearance" from your internist is a good idea.

I hope this is useful.

Mike

Hi Mike,

I am curious, who is your doc who came up with this protocol?

Mon frère –

I basically started out on my own, after reading the posts of SandyS regarding how well her daughter tolerated DM and raised the issue with a pharmacist, who advised me that 100% USP dextromethorphan HBr was – at that time – available OTC as Zicam Cough MAX, which dispensed it at 6 mg/spray, with a suggested maximum adult daily dose of 120 mg. I then mentioned it to my psychiatrist/psychopharmacologist who suggested Neudexta, which I then augmented with my continued use of Zicam Cough MAX.

Unfortunately, I wasn’t alone in becoming aware of the possibilities of Zicam Cough MAX. Turns out that kids were buying the stuff in bulk and then taking it in doses a full order of magnitude or more beyond anything I was taking – 1,000 to 2,000 mg at a pop – which was enough to induce a true “dissociative state,” and get the attention of the DEA. At which point the manufacturer was persuaded to pull it off the market. At which point I went back to my psychiatrist, who then added the prescription for compounded DM capsules.

One final item of clarification is still in order. In order to “function” (as best I can) with what could otherwise be a stultifying brew of Baclofen, analgesics and benzodiazepines - as well as the ground fog of RSD - I take significant amounts of both Provigil and Wellbutrin, as well as a standard 30 mg dose of Namenda (mementine). Although, truth be told, my psychiatrist believes that Neudexta has as significant an effect on alertness as any of the other meds.

And lastly, a couple of points as far as Provigil is concerned: first, because its patent is expiring, the manufacturer, Avanir Pharmaceuticals, Inc., is pushing patients to a newly tweaked molecule of essentially the same drug, marketed under the name of Nuvigil, which I tried as well but found that it profoundly raised my blood pressure. Secondly, even though the standard dose of Provigil is 400 mg/day, I’m on 600 mg, but it’s taken carefully because it too raises blood pressure, although, at least for me, not nearly as much as Nuvigil. So I take two 200 mg tablets in the morning, with a third allowed in the afternoon, but before taking it, I use a blood pressure cuff to insure that it’s dropped into a normal range. And if it hasn’t, I wait.

Apologize for the long response to a short question, but I wanted to be as clear as I could.

Mike

According to my psychiatrist, the quinidine in Nuedexta also blocks the metabolism of, and in doing so "potentiates," Namenda as well as DM.

Giving me, in effect, two for the price of one.

1) Please correct the following statement in your post:

"And lastly, a couple of points as far as Provigil is concerned: first, because its patent is expiring, the manufacturer, Avanir Pharmaceuticals, Inc., is pushing patients to a newly tweaked molecule of essentially the same drug, marketed under the name of Nuvigil"

Provigil and Nuvigil ARE NOT MANUFACTURED BY AVANIR PHARMA. They're products of Cephalon.

2) As you have mentioned Nuedexta does work for neuropathic pain. A large scale new trial is ongoing but still enrolling patients. For info please see Avanir ** for details.

3) The compounding pharmacy is breaking the law and is subject to prosecution and fines. Please remind your doctor you can obtain Nuedexta at a very good price by either using your insurance (millions of lives are covered) or if you can't afford it you can contact Avanir and they work with charities which provide assistance **

Thank you and good luck.

@fmichael:

I found your doctor's statement that Namenda would be increased by the quinidine in the Nuedexta, strange. So I looked it up:

This combo did not appear on the standard drugchecker at drugs.com to have interactions. This monograph explains why:

from http://www.drugs.com/pro/namenda.html
In fact even moderate hepatic impairment does not appreciably affect Namenda metabolism. The most significant factor is renal damage and poor clearance there.
In fact if the urine pH increases...the drug may not be cleared well:
Also quinidine is not a "tricyclic antidepressant"....it is a heart drug for arrhythmias:
http://en.wikipedia.org/wiki/Quinidine

This is a list from drugs.com of drugs that interact with quinidine considered MAJOR:
http://www.drugs.com/drug-interactio...&generic_only=

This list includes major and moderate interactions:
http://www.drugs.com/drug-interactio....html?filter=2

The drugchecker at www.drugs.com is very good. I suggest you check all your medications against quinidine just for safety's sake.

mrsD -

I thank you for your post. It appears you may be correct, although I will see my doctor again on Friday for his reposte. First, I was pretty sure I had heard of quinidine's past use as a tricyclic antidepressant, but looks to be incorrect. My assertion must have been based on something of a false memory on my part.

But I was/am certain of my doctor's comment vis-a-vis blocking the metabolism of memantine. Until I looked it up at your instigation. Turns out that quinidine is an inhibitor of the cytochrome P450 enzyme 2D6, which is what gives it its effect as a potentiator of dextromethorphan. NUEDEXTA™ Full Prescribing Information. That said:

Memantine [Namenda] is predominantly renally eliminated, and drugs that are substrates and/or inhibitors of the CYP450 system are not expected to alter the pharmacokinetics of memantine. A clinical drug-drug interaction study indicated that bupropion did not affect the pharmacokinetics of memantine.

NDA 22525 - NAMENDA XR Full Prescribing Information.

I'll try to clear this up on Friday. Thank you again.

Mike

PS And good point re searching for patterns of known interactions on quinidine, as with any med. And as far as quinidine is concerned, I've come across at least one, but was told that it was dose dependent, and at only 10 mg of quinidine, I shouldn't worry about it.

One can never be sure about individual drug metabolism potential.

It is genetically determined, and now can be tested.
One of our PNers had 23andMe testing that revealed her
problems with several liver enzymes:

http://neurotalk.psychcentral.com/post855377-6.html

The price is certainly not that high like it used to be!
Something to think about!

Dear Visitor -

1) The wonders of reputation.com, what can I say? Thank you for the clarification regarding the manufacturer of Provigil/Nuvigil, I had too many screens open at the time and confused it with the manufacturer of Nuedexta.

2) I look forward to reading the results of the pending study.

3) I fear you may have misread my post. My pharmacy is NOT compounding dextromethorphan HBr WITH quinidine sulfate - Avanir has a not entirely uncontroversial patent on that - but SOLELY dextromethorphan HBr, an OTC medication. How that steps on anyone's toes is beyond me. In fact, it's my understanding that the literature linking DM and quinidine goes back some time, to the point that I'm a little surprised the patent isn't subject to challenge for obviousness. Just kidding. At least I'm not one of those to-be-left-unnamed senior Members of Congress who - one fine morning a couple of years back - got out of bed with folks holding short positions on Avanir, inflammatory press-releases in hand. [Citation available upon request.] And as you may sense, I don't particularly like the hedge fund business.

Cheers!

Mike

fmichael,

I am new here and by no means an expert on meds. I am, nonetheless, very concerned about the number of meds you are on. Please excuse me If I am being intrusive but just coming off a similarly long laundry list of meds I cannot express how negatively they effected me mentally and cognitively. The meds had slowly been added over the years, predominantly by a psychiatrist. I now wish that I had listened to the advice of my pain management doctor to withdraw and then revisit what I really needed.

The only thing that finally forced me to come off meds was beginning tDCS. I wanted to know if the treatment could take the place of meds. The bonus was the rapid rebound of the cognitive issues that had dogged me.

Additionally the suggestion of my pain management doctor that narcotics would, in the long run, only serve to increase my neuropathic pain, in addition to causing other nasty long term issues, made me rethink things.

I see from other posts that you are considering tDCS. Maybe, in conjunction with tDCS, an outside opinion about your med list could be helpful.

Just a thought.
Best to you with tDCS.