Gabapentin (Neurontin)

The author is not medically trained, and not advising one way or the other on this medication.

It is very easy to end up with only a part of the information available when trying to find out about a medication. Without more information from more than one viewpoint we have far less of a secure foundation to make a decision which is ultimately going to affect our health. I am not writing this to sway you one way or the other. I would always want any patient to make-up their own mind. That is our moral and legal right to do so.

Any medication has pros and cons. The key is weighing up the odds and deciding what works for our particular body with our particular condition(s), symptoms, medical history and so on. This is something for you to discuss with your doctor / medical team and a pharmacist, and not the right of anyone else to tell you what to do (especially people who are not medically trained or do not understand your condition, hence the inclusion of pharmacist at the reminder of a good friend coz they’re the experts when it comes to meds. I always talk to my local pharmacist before talking to my doctor about a meds issue).

I have friends who have taken Gabapentin in the past, a friend who is currently taking it and finds it helps their pain, and I have at least one friend who wouldn’t touch it with a bargepole, and each of those people is doing what is right for them. So first of all – please do not worry. If you have autonomic dysfunction (and that includes CRPSers) worrying is more likely to set off the fight or flight system and make it harder to process information, make decisions etc. So be kind to yourselves, whatever you, your doctor and pharmacist decide is fine. It is your choice to make, xx

file000303654817 from morguefile

The go-to medication for many doctors when treating pain is Gabapentin (brand name: Neurontin). It is a drug which was approved in Canada for treatment of epilepsy back in 1993. It was never approved for treatment of pain, migraines or bipolar disorder, and yet the company who produce the drug (Pfizer) promoted it for these conditions anyway.

Why would they do such a thing?

Well, in 1998 a study into neuropathic pain in diabetes (Backonja et al) concluded that Gabapentin seemed to include positive effects on neuropathic pain, sleep, and even on mood and quality of life. In the same year a study by Rowbotham et al into the treatment of persisting pain after having shingles (postherpetic neuralgia) concluded pretty much the same thing. These are the pain conditions most commonly used for testing drugs for neuropathic pain, so…. the outcomes sound pretty awesome, eh?

Kaboom! Suddenly, and unsurprisingly, Gabapentin became the drug of the moment and really widely used.

pills-out-of-bottle, stock exchange

Two years later a drug assessment was carried out by the Therapeutics Initiative in Canada. Their intention is to provide up-to-date and, crucially, evidence-based drugs information to doctors. Therapeutic Letter #33 (1999-2000) informed that it had been found that Gabapentin is actually removed by the kidneys and has no painkilling (analgesic) effect after all. It concluded that, at best, it may assist with the two conditions in those studies to a small extent (less than 1 point of pain improvement on a 10 point scale) and only for a small percentage of patients (15%). This drug would therefore not be likely to be approved for the treatment of pain, it just isn’t effective enough to do so. And the reason it can only be said to have a small effect on these two conditions is simply because it cannot be assumed that something that works on diabetic neuropathic pain and postherpetic neuralgia would work on other types of pain condition. Pain conditions vary and so much about underlying mechanisms is still unknown – there just isn’t any foundation to be able make that assumption. Interestingly, this last point was made by one of the authors mentioned above (Michael Rowbotham writing about the design of clinical trials in 2005).

The same assessment also found that all that varying doses of Gabapentin did not vary pain relief at all. The only thing that varied with dose was toxicity to the body. Additionally, about 15% of patients also experienced detrimental effects from the drug.

The final conclusion of the assessment was that “Gabapentin has no role in acute nociceptive pain” and they noted Pregabalin (Lyrica) as being similar in pros and cons but even worse for detrimental effects.

research, test tube, from morguefile

After this, a litigation in the USA resulted in a court ordering all unpublished studies about this drug to be released. Funnily enough, as is sadly still the norm in medical research, the company who created the drug had only published the research that said the drug was helpful. All the research with negative outcomes and conclusions were never made available outside the company. (I have issues with this ‘norm’ and want it to change – all info’ should be available or else how are we and our medical team supposed to make informed decisions about medications? More about this at the end of this post).

More on the negative effects of Gabapentin have turned up in more recent research. For example Eroglu et al, 2009, who found that it stops new synapses being formed in the brain (as does Lyrica / Pregabalin). We used to think that adult brains didn’t do this anyway, but now we know better.

Many pain patients are still on this med, and many new patients are still being prescribed it.

What I was not aware of until recently was that Pfizer was fined for drug fraud over this, 3 and a half years ago.

So why is it still prescribed?

Well, Pfizer still defends its actions and still purports that the drug should be prescribed for these unapproved uses (despite the research showing otherwise).

So the outcome is that there are cons to taking Gabapentin for the two types of neuropathic pain researched, there is no research into CRPS and Gabapentin, it doesn’t relieve pain for most patients because the kidneys remove the active ingredient, but a small number of patients with diabetic neuropathic pain and postherpetic neuralgia do experience some pain relief.

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I said to some fellow patients that I would share this information in case anyone wanted a broader view because we all deserve to make informed decisions. If no-one informs us we’re scuppered from the off. What I don’t want to do is worry you. All medications require consideration of the pros and cons by you and your doctor. There is never a magic pill that fixes everything and has no side effects. If you experience good effects and assistance from being on the drug then you could be one of the lucky patients who has enough overlap with the assessed conditions and also falls into the 15% who experience benefit. If it helps you, it helps you. And we need to make sure we have effective medication for our condition(s). If it’s effective then that’s good. If you want to double check with your doc’ and pharma’ to reassure you then of course do so, but don’t worry.

If you are a patient who has not experienced any help from this drug then you now have back-up to be able to ask your doctor for something that is more effective for your body and your condition. If you are a patient who wants to come off the drug for other reasons, well, you could just throw this in there as well as part of your reasons if you want to. What works for one patient doesn’t necessarily work for another. Neuropathic pain is neurological, and we each develop a uniquely wired and linked brain in the womb so it’s not surprising that what works for one doesn’t work for another. The key thing to remember is that neurological illness means variation between patients.

So some patients will stick with Gabapentin, and others may not. It depends what is right for each of us. Though the research suggests that anyone who finds it helps their pain is in the minority.

I hope that this helps, x

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Thank-you to Lili over at Taming the Beast who originally alerted me to Gabapentin issues.

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A note about research publication
It is the norm’ that research gets published if there is a positive outcome, it does not get published if the end result is negative data. So we cannot gain access to the other side of the story which we need to make an informed decision.

It is a simple but crucial difference to publish all data.

And this is what Dr Goldacre and his team is trying to change internationally to help us patients by getting our doctors access to all of the info’.

The website and petition is here (at 58,783 signatures when I wrote this, and it needs more to have more impact). And here’s all of the companies who are already on board with the idea. (Yep, I am openly biased on this one! I’m all for having access to all of the information. Otherwise it leaves doctors and patients second-guessing medication which is downright silly)!