i and others have detailed some compelling evidence for the efficacy of this drug, and i think the trialees are doing a good job of helping us all figure out if it actually has any efficacy. i am open to any evidence against its efficacy, especially if it were to reference some scientific article. i have not seen any on this thread.
Fair enough.
Let's first look at the "evidence" in favor of Retigabine's purported pharmacological efficacy against tinnitus generated on this board. We have a cadre of individuals who are truly suffering from tinnitus and are seeking relief. So these folks manage to find a source for Retigabine (no easy task in many cases) and take the drug specifically in the hopes that they will at long last achieve an appreciable degree of relief. And a fair percentage do report improvement in their tinnitus rating, which basically is their own subjective measure of their own subjective symptom. Please bear in mind that this is an improvement they were specifically looking for and hoping to achieve. There is no randomization. There are no controls. Now we all know that tinnitus is a subjective condition and as such cannot be directly measured, but even so we do not even have a reliable set of before and after tinnitus pitch and loudness matches. What we have is totally subjective data regarding a totally subjective condition, data generated from a group of very highly motivated individuals looking for (and hoping for) any suggestion of improvement. In another post I referred to it as quite likely the result of a combination of placebo effect, coincidence, desperation, wishful thinking, and mob mentality. Nevertheless, many here refer to the above circumstance as evidence. Is it evidence? It might be, but for now I choose to look at it as data points and nothing more. Especially in view of the compelling evidence
against efficacy that I am about to describe.
OK. Let's for now take Retigabine completely out of the equation. Just for now. Instead, let's talk about herpes.
Approximately 20% of the population of the US has tinnitus, but the vast majority of those are for one reason or another not significantly affected by it. Maybe because it's not loud. Maybe because it occurs only sporadically. Maybe because they have fantastic coping skills. Maybe because they have habituated it. Whatever. Still and all they'd rather not have it. I know I would! But 20% of the 20% (i.e., approximately 4% of the population of the US) have severe tinnitus. And for whatever reason
their lives are markedly disrupted by it. They truly suffer in every sense of the word. Maybe because it is so loud. Maybe because it is so relentless. Maybe because ... well, why am I telling you? This board is absolutely
loaded with people who have severe tinnitus. This board is loaded with people who suffer. This board is loaded with people whose lives to a greater or lesser degree revolve around their tinnitus. The composition of this board is reflective of what that 4% of the US population experiences every day of their lives. And if one day - for whatever reason - your tinnitus improved by 50%, you would recognize that blessed state of affairs immediately. Right?
Acyclovir (Zovirax) is a commonly prescribed anti-herpes medication with absolutely no known pharmacological activity against tinnitus. Millions of people have been prescribed Zovirax for cold sores, genital herpes, shingles, and chickenpox. Many take it chronically to decrease the frequency of recurrent herpes outbreaks. Of course 4% of individuals on Zovirax have severe intrusive tinnitus, and another 16% have tinnitus that is not particularly severe - just like in the general population. Now if my own doctor put me on Zovirax for herpes and within a week or two my tinnitus (which has been screaming now for more than 20 years) settled down to an appreciable degree, I would be on the phone with him thanking him not for what the medication did for my herpes, but rather for the totally unexpected effect it apparently had on my tinnitus. And so would anybody else in my shoes. If any of the 4% ... hell, if most anybody in the entire 20%, actually found meaningful tinnitus relief from a herpes pill, the prescribing doctor would get a call from the appreciative patient the very next day. Not only that, if only 50% of tinnitus sufferers found appreciable unexpected tinnitus relief while on Zovirax, word would get around pretty quickly in the medical community that finally we have a pill that truly shows promise against tinnitus. There would be case report after case report. We wouldn't have to beg our internists, family doctors, and ENTs for off-label prescriptions of Zovirax ... because they would be expecting our calls and would willingly prescribe it. The stock of the company that manufacturers the drug would soar. And the whole story would of course be all over the Internet.
The operative word in the above paragraph is
unexpected.
Back to Retigabine ...
Some three million Americans have epilepsy, most of whom are on medication and a goodly number of whom since 2011 have been on Retigabine, if only as a trial. So where are all the case reports of unexpected tinnitus relief from those epileptics on Retigabine who happen also to have tinnitus - severe or otherwise? Sure, we have the hardly unbiased
Tinnitus Talk data from those who took the drug specifically looking for relief - but where are the hundreds of case reports we should have by now from those epileptics on Retigabine who also suffer from tinnitus and who finally found their long-sought-after tinnitus relief
unexpectedly while on the drug. I do not know of hundreds of cases. I do not know of dozens of cases. Indeed I do not know of even one. And
that is what I consider to be convincing evidence at this point in time - the lack of phone calls to prescribing physicians from those who unexpectedly found relief and the lack of the case reports that those phone calls would surely generate.
Now let me make it clear where I stand on the issue of off-label prescribing of Retigabine. Even though I feel strongly that ultimately a properly done study will fail to show pharmacological efficacy (just like with Campral and all the other supposed silver bullets), I would have trouble saying no to a patient of mine who asked for it - if for no other reason that I personally know what it is like to be in the bottom of that snake-infested pit where many tinnitus sufferers dwell day in and day out. Some physicians may not understand tinnitus suffering - perhaps most do not understand tinnitus suffering - but I surely do.
There are, however, mitigating factors in my situation. First of all, I see only 40 patients a year and do not prescribe any medications for any reason whatsoever. If I did, I would have to take call (which at the age of 66 is no longer on my radar), and my malpractice insurance rates (which are predicated on my not prescribing any medications) would more than double.
The original question from
@john2012 had to do with whether or not I would be willing to prescribe Retigabine off-label to a patient of mine who asked for it. In view of what I wrote in the above paragraph, I would be willing to discuss it in detail with my patient's own primary care physician and (in spite of my opinion that any "effect" is not pharmacological) argue in favor of it purely on a compassionate basis, but I would not prescribe it myself.
Dr. Stephen Nagler
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