Gabapentin ‘Free for All’ in Substance Use Disorder Treatment
/By Pat Anson
The nerve drug gabapentin is increasingly being prescribed to patients undergoing treatment for substance use disorder (SUD), according to two new studies that highlight how the drug is being abused and used to treat health conditions it was never intended to treat.
The first study, published in the journal Drug and Alcohol Dependence, looked at over 200,000 urine drug test results from patients undergoing SUD treatment in all 50 U.S. states.
Over the past decade, gabapentin (Neurontin) prescribing nearly doubled, from 3.9% of patients undergoing addiction treatment in 2016 to 7.6% in 2023. In addition, nearly one in ten patients being treated for SUD tested positive for gabapentin, even though they didn’t have a prescription for it.
“A lot of that use is off label, and in the context of substance use, we're seeing it being prescribed to manage withdrawals, or for insomnia, pain, and anxiety. It’s just sort of a free-for-all in how it's prescribed,” says lead author Matthew Ellis, PhD, an Assistant Professor of Psychiatry at Washington University School of Medicine.
“I think one of the big findings was that the positivity rate for those without a prescription for gabapentin was twice as big as those prescribed gabapentin.”
Gabapentin was originally developed as an anti-convulsant. It was first approved by the FDA as a treatment for epilepsy and later for neuropathic pain caused by shingles. But it is also routinely prescribed off-label for migraine, fibromyalgia, bipolar disorder, cancer pain, postoperative pain, and many other conditions.
Its off-label use as a pain reliever grew after the CDC recommended gabapentin in 2016 as an alternative to opioid analgesics. By 2024, gabapentin was prescribed to 15.5 million Americans, making it the fifth most prescribed drug in the U.S.
Due to the nature of the study, Ellis says it’s difficult to know if patients were prescribed gabapentin before entering SUD treatment or if they started taking it after treatment started to help manage symptoms of withdrawal. Gabapentin prescribing increased to all patients, whether they were being treated for alcohol, cannabis, stimulant, sedative or opioid abuse.
Another possibility is that patients take gabapentin to heighten the effects of addiction treatment drugs like buprenorphine (Suboxone) or methadone. Gabapentin is prized as a street drug because it helps increase the euphoria or “high” that comes from psychoactive substances.
“I don't want to give gabapentin a bad name at all. I think there's definitely potential for it. I think my biggest issue is that there's just so little evidence base for its use in substance use treatment settings,” Ellis told PNN.
“And to have so many people using it outside of a prescription, it just may be a call to recognize that, one, there may be untreated comorbid conditions that people are self managing, or two, we need to do a lot better about building an evidence base to see what exactly is or could be the benefit of gabapentin in substance use treatment.”
One positive trend uncovered by the study is that the use of gabapentin without a prescription has declined in drug treatment settings, from 15.2% of patients to 9.9%.
The second study, published in the same journal, also found that gabapentin prescribing has significantly increased over the past decade, but that its “nontherapeutic” use (another term for misuse) appears to be declining.
Despite the decrease in misuse, FDA researchers found that the number of cases reported to U.S. poison control centers involving gabapentin greatly exceeded those for pregabalin (Lyrica) and the anti-anxiety drug diazepam. Most of the gabapentin cases involved other substances, particularly opioids.
