Gabapentin was developed as a focal seizure medication and has been found to be effective for neuropathic pain syndromes in diabetic neuropathy and postherpetic neuralgia.
Gabapentin is also widely used in America for a variety of pain syndromes including sciatica. The well done wikipedia article has a good overview of what we know about these uses. In general the benefits of gabapentin for many pain syndromes are not clear; as usual more research is needed. The evidence for nerve healing benefit is weak. I am confident we would almost never use gabapentin for chronic sciatic pain if opioids were not cursed by tolerance, dependence, dosage escalation, respiratory suppression, and diversion to recreational use. Without opioids we have acetominophen and ibuprofen and not much else.
In addition to doubts about efficacy some patients report significant persistent side-effects of somnolence and fatigue, sleep disruption, and a withdrawal syndrome that resembles benzodiazepine withdrawal. In my own life I've taken gabapentin for months for spinal stenosis* and I have not experienced either obvious benefits or problems, but I believe reports that some people have unpleasant withdrawal syndromes.
The combination of unclear benefit outside of diabetic neuropathy and idiosyncratic withdrawal syndromes would be enough to make gabapentin unpopular. Beyond that there's a significant group of chronic pain patients who feel they would do much better on opioids; they believe they are getting a defective substitute because of an excessive reaction to physician overuse of opioids in the 1990s. It's easy to see why gabapentin is not loved.
Which brings me to the point of this post. I have seen claims from the community of chronic pain patients who have legitimate suspicion about the value of gabapentin that "gabapentin causes Alzheimer's" based on an article published out of Taiwan - The association between Gabapentin or Pregabalin use and the risk of dementia: an analysis of the National Health Insurance Research Database in Taiwan. The authors conclude "Patients treated with gabapentin or pregabalin had an increased risk of dementia. Therefore, these drugs should be used with caution, particularly in susceptible individuals".
Long ago I was an academic family physician who did the tedious work of evaluating research publications. Back then I'd have had to point out that this is an outrageous conclusion to draw from data mining a health insurance data set. If all the right boxes were checked and procedures followed the most one could conclude from this type of study is that maybe there's some signal that should be researched in animal models and maybe one day in a range of increasingly expensive and complex studies. In those days that conclusion in an abstract would be the end of my interest in the publication.
Sadly, these days, we don't even have to look that deeply. We start with looking at where an article was published. Front Pharmacol is a pay-to-publish eJournal. That's why you can read their articles without paying - the authors paid for you to read it.
You can find the publishers of this article in www.frontiersin.org and read about them in a wikipedia article on Frontiers Media. Nobody, absolutely nobody, would publish in Frontiers if they could get through peer review anywhere else. Derek Lowe is the most publicly accessible writer about this class of publication, you can read two of his recent pieces here and here. The garbage output of these fake journals to qualify for academic promotion is so bad that even PRC academic centers are turning against them: "... January 2023, Zhejiang Gongshang University (浙江工商大学) in Hangzhou, China, announced it would no longer include articles published in Hindawi, MDPI, and Frontiers journals when evaluating researcher performance."
In short, in our broken modern world, we don't have to dig into the particulars of this article. We don't have to even look at the absurd abstract conclusion. All we have to know is that the authors of this article paid to get it published by an enterprise that is almost certainly fraudulent.
It's not impossible that any substance that interacts with the human body might in some way increase the risks of Alzheimer's dementia. That, I suppose, includes cosmic rays. But there's no particular reason to suspect gabapentin more than other medications. This is a bullshit result published in a bullshit journal.
So why, a reasonable person would say, was this crap indexed by the National Library of Medicine, a division of the National Institute of Health funded by the American tax payer? That's a damned good question. I can guess why the NLM is effectively promoting fraud, and I can suggest workarounds for the problems I'm guessing they have, but I honestly don't know. I am, however, angry. As you might guess. I'm sick of this academic fraud.
* I'm now post-decompression surgery. That's a story for another day.
