Memantine (aka Namenda) is Food and Drug Administration–approved for Alzheimer’s disease, though its benefits are modest, at best.
It’s also, 18 years after first coming to market, relatively inexpensive.
I occasionally use it off label, as neurologists tend to do with a wide variety of medications. There are small studies that suggest it’s effective for migraine prevention and painful neuropathies. It also has a relatively benign side-effect profile.
As a result, once in a while I prescribe it for migraines or neuropathy where more typical agents haven’t helped. Like any of these drugs, sometimes it works, sometimes it doesn’t. A lot of neurology, as one of my colleagues puts it, is “guessing and voodoo.”
Since I’ve started this, however, I’ve noticed an unusual, and somewhat scary, side effect – one that has nothing to do the drug reactions.
While I don’t use any type of commercial chart system, most doctors in my area do, as well as all the hospitals. So I often see my patients’ notes from their general practitioners or after they’ve been in the hospital for whatever reason.
Those notes often list – as they should – current medications. Which includes the memantine I’ve prescribed.
But in the patient problem list I often then see “Alzheimer’s disease” or “dementia” show up, even in people who clearly have no history of such.
I’ve seen it way too many times to think it’s an accident. So one of two things is happening:
1. The computer chart system, when it sees “memantine” entered, searches its database, finds what it’s FDA-approved for, and automatically puts that in a list of current diagnoses.
2. The person entering the data, upon hearing the patient takes memantine, just enters the more commonly used indication as well, without bothering to ask the patient why they’re taking it.
Neither of these is good.
At the very least, they show a lack of proper history taking (or interest in doing so) by the person entering things in the chart (which these days could be someone with no medical training at all). It doesn’t take that much effort to say “what are you on this for?” I do it several times a day. It’s part of my job.
It’s bad form for any incorrect diagnosis to get into a chart. It can have serious repercussions on someone’s ability to get health, disability, or life insurance, not to mention the immediate impact on their care when that shows up. Someone who doesn’t know the patient opens the chart and immediately assumes it’s what they’ve got. I mean, it’s the chart. People treat it like it’s infallible and inviolable.
This isn’t a new issue – I trained at the VA when sometimes an H&P simply said “see old chart” and there were four volumes of it. But now, in the age of digital records, entries are forever. The toe you fractured surfing 8 years ago still shows up as a “current problem,” and will likely follow you to the grave. The same with any other diagnosis entered – it’s yours to keep, regardless of accuracy.
Medicine, like life, is mostly gray. But computers, and many times those who enter their data, only see things as black and white. In this field that’s liable to backfire. I’m just seeing the tip of the iceberg by using memantine off-label.
Dr. Block has a solo neurology practice in Scottsdale, Ariz.