|Taming the Beast: Gabapentin|
|By Jeffrey E. Keller MD|
A reader recently wrote:
At our facility, one of the most abused drugs in Neurontin. I am the trying to formulate when this medication will be continued. My question is if the following is acceptable in your opinion:
Neurontin will not be given for any indication not approved by the FDA. The only indications approved by the FDA is for epilepsy and PHN after shingles. Now the question remains how can you tell what the indication of prescribing the Neurontin was? The therapeutic dose for the treatment of epilepsy is 900 to 1800mg a day divided into three times a day not to exceed 3600 mg per day. If you come to our facility on 300mg at night, this clearly indicates that the drug was not given for the two recommended doses so therefore, it can be assumed it was given for insomnia- which we do not treat at our facility. The Neurontin would be canceled and we would observe for signs and symptoms of withdrawal for the next 5 days.
Does this sound reasonable and do you know of a substitution for the treatment of diabetic neuropathy that is less abused in the jail setting?
Well, you’re not alone, Christy! Gabapentin is one of the most abused and diverted drugs at all correctional facilities that I know of! (I’m going to use the generic term “gabapentin” interchangeably with the brand name “Neurontin” in this article). In fact, I was recently in a meeting with the commissioner of a certain state’s Department of Corrections to give an update on medical services in his prisons and the very first question he asked was about gabapentin. Gabapentin! Think of all the things he could have been concerned about—Hepatitis C for example—and instead, he asked about the security problems caused by gabapentin diversion.
In my experience, gabapentin is one of the “Big Three” non-DEA regulated drugs with the potential for diversion and abuse in a prisons and jail. The other two are Seroquel and Trazodone. The important difference is that Seroquel and Trazodone both allow easy substitution of another, less abused, cousin. Gabapentin, not so much. More on that later.
In order to get a handle on gabapentin, I think it is important to understand where it came from and why it has not approved by the FDA for most of the reasons it is prescribed nowadays. B_beuRNW8AEYOgn
Gabapentin was originally introduced in the 1990s as the seizure medication Neurontin. Pfizer also sought FDA approval to use Neurontin as a treatment for post-herpetic neuralgia. Once a drug is approved by the FDA, however, it can be legally prescribed for any indication that medical practitioners want. This practice is known as “off label” prescribing and is commonly done, not just for gabapentin, but for many, many other drugs as well.
It turns out that Neurontin never took off as a seizure drug. So in the late 1990s, Pfizer began aggressively marketed Neurontin for other neuropathic pain syndromes (besides post-herpetic neuralgia), for chronic pain, as a psychiatric drug, sleep aid, really “for everything.” Gabapentin quickly became a blockbuster drug.
However, while it may be legal for medical practitioners to prescribe medications for off label uses, it is illegal in the US for manufacturers to market medications for off label uses. They are instead supposed to submit to the FDA the data for the efficacy of their drug for the new indication to the FDA and let the FDA evaluate this data. Pfizer never did this. As a result, Pfizer has paid almost a billion (yes, “Billion” with a “B”) dollars in fines to the FDA and others for illegally marketing Neurontin.
Whether ethically marketed or not, in the end, gabapentin has become VERY widely prescribed in the US medical community–in fact, a blockbuster drug–almost all for off label uses. In fact, there were more gabapentin prescriptions written in 2012 than, say, lisinopril or citalopram. I’m going to bet that gabapentin is even more prescribed today than it was in 2012. It seems to be used everywhere. Inmates show up at my jails all the time with gabapentin on their current medication list.
The dark side of gabapentin
As everyone in correctional medicine (including my DOC commissioner!), gabapentin can be used to get high, despite not being categorized by the DEA as a controlled substance. This fact is now receiving some attention in the medical literature and CME conferences. Through its effects on both the GABA and dopaminergic reward system, it produces euphoria, a marijuana-like high, sedation, and, at high enough doses, dissociative/psychedelic effects. It works so well that it is used in the drug community to mellow out methamphetamine tweaking and to cut heroin. Since drug abusers know about these illicit uses of gabapentin on the streets, once they get to jail they often view gabapentin as an obtainable “jail substitute” for their preferred drugs.
Of course, we correctional physicians must keep the abuse potential of any medication in mind when we weigh the potential benefits versus the potential harms of using that medication in our facility. Besides the benefits and harms to the patient, we must also consider the safety and security of the institution, as my prison commissioner pointed out. Gabapentin is very high on the list of non-DEA regulated drugs with this potential.
Unfortunately, the abuse potential of gabapentin is not recognized much outside of jails and prisons. Community prescribers are generally unaware that gabapentin can be misused and (in my experience) are often incredulous and even disbelieving when told about “the dark side” of gabapentin.
So what are the potential benefits of gabapentin?
Well, the issue here is that it is hard to know exactly what the evidence for gabapentin efficacy is because, although Pfizer sponsored several Placebo Controlled Double Blinded Trials, Pfizer fudged the resulting data in a variety of ways. First, they simply didn’t publish negative trials. Second, they distorted and manipulated data in the trials they did publish to imply that gabapentin was more effective than it really was.
Fortunately, however, independent researchers without an axe to grind (or a drug to sell) have analyzed the gabapentin data. Here are their conclusions:
Although the quality of the evidence is pointed out as being poor, it appears that gabapentin is modestly effective in treating neuropathic pain from diabetes, post-herpetic neuralgia and central neuropathy. The number needed to treat (NNT) in blinded trials to produce one good outcome is around seven, which means that the other six got no benefit. This is actually not bad and similar to other potential treatments for neuropathic pain, such as antidepressants. Interestingly, capsaicin cream has similar efficacy. By the way, the number needed to harm (HHH) using gabapentin was eight.
Probably the most important take away point from these analyses is this: The benefits were seen at low doses. Large doses did not increase benefit but did markedly increase harms, such as sedation. Memorize this fact. It is critically important. The other critically important factor to note is this quote from the Cochrane Review of the subject: “Only a minority of people achieved acceptably good pain relief with either drug, but . . . quality of life and function improved.” In other words, pain control is not the ultimate goal when using gabapentin. Improved quality of life and function is the goal.
In these studies, gabapentin performs no better than other therapies for neuropathic pain such as antidepressants. Some antidepressants like amitriptylline and venlafaxine that can be used to treat neuropathic pain also have abuse and diversion risks, though maybe not as much as gabapentin. Other antidepressants that you could substitute, like duloxetine, are less risky. Capsaicin cream worked as well as gabapentin in these studies.
In placebo-controlled trials, gabapentin performed no better than placebo for the treatment of fibromyalgia.
Pfizer studied the effects of gabapentin on various types of regular pain (called nociceptive pain in the literature): dental extractions, orthopedic surgery and chronic pain due to osteoarthritis. These studies were all negative and Pfizer never published them. Bottom line: gabapentin is a poor choice for treating acute pain and musculoskeletal pain.
Other chronic pain syndromes
The Cochrane Review concludes that gabapentin does not work well for the prophylactic treatment of migraine headaches or postoperative pain.
Restless leg syndrome
Gabapentin is listed as a potential therapy for restless leg syndrome. (Here is one example) However, it is not the preferred therapy. The best therapies for RLS are exercise, stretching and stopping drugs that exacerbate RLS, like caffeine and SSRIs. If you are going to use a drug, ropinerole is cheap and has much less abuse and diversion potential.
There are lots of references that document this fact : that gabapentin is not a useful psychiatric drug–for anything. Here is the best single supporting document that I can find. It is the Medical Letter’s Drugs for Psychiatric Disorders. You will note that gabapentin is not mentioned anywhere in this document.
The bottom line is that gabapentin is not used much for its original FDA approved indications. It is mainly prescribed nowadays for a variety of off-label indications. The only one of these off-label uses that has a decent evidence base is diabetic and central neuropathic pain. However, gabapentin prescriptions are also common in community practice for regular, nociceptive chronic pain, fibromayalgia, restless legs and lots of other things. In fact, gabapentin is the non-opiate “go-to” drug in many pain clinics. Most outside practitioners do not appreciate gabapentin’s abuse potential. Most outside practitioners do not appreciate that most of gabapentin’s legitimate benefits occur at low doses. Most outside practitioners do not understand why correctional facilities would have any problem with this drug.
So, Christy, this is the hand you have been dealt with regard to forming a gabapentin policy for your facility. I will discuss different potential policies in my next JailMedicine post. I think it makes a big difference whether you are working in a jail or a prison.
Mandatory disclaimer: What I have written here is my opinion based on my personal experience and understanding. I could be wrong! Please read this critically. If you think I have made a mistake or error in judgment, please comment!
Is gabapentin a problem in your facility? Please comment!
Corrections.com author, Jeffrey E. Keller is a Board Certified Emergency Physician with 25 years of practice experience before moving full time into the practice of Correctional Medicine. He is the Chief Medical Officer of Centurion. He is also the author of the "Jail Medicine" blog
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