In a bid to stop abuse and diversion of the anticonvulsant gabapentin, a watchdog group is petitioning federal regulators to make the drug a controlled substance.
Gabapentin is a generic drug, best known under the brand name Neurontin. The petition also covers the related drug gabapentin enacarbil (Horizant).
Public Citizen requested that gabapentin come under the DEA’s Schedule V category, which already includes the similar drug pregabalin (Lyrica). Schedule V is the lowest rung on the DEA’s drug schedule, meaning it has lower potential for abuse then Schedule I through IV drugs. This tier also includes cough preparations with less than 200 milligrams of codeine.
Classifying gabapentin as a Schedule V drug would facilitate better tracking of the drug’s use and misuse and put in place educational and limitation requirements to mitigate the risk of addiction, overdose, and death, Michael Abrams, MPH, PhD, senior health researcher with Public Citizen’s Health Research Group, and colleagues write in the petition.
‘Widespread misuse’
There is “substantial evidence of widespread misuse” of gabapentin, plausibly helped by “extraordinary levels of off-label prescribing,” Public Citizen said in the petition.
Some estimates have pegged off-label use at more than 90%, with gabapentin prescribed for indications such as chronic cough, hiccups, postoperative pain, and postmenopausal hot flashes, the group said.
“Moreover, there are numerous reports indicating that gabapentin is widely used and diverted on the street to induce ‘highs’ or otherwise self-medicate,” Public Citizen said. “Both gabapentin and pregabalin have been empirically linked to the opioid overdose epidemic as drugs that potentiate the activity of these oftentimes deadly analgesics.”
This news organization tried several times to reach Azurity for comment but did not receive a response. Pfizer included gabapentin in the portfolio of drugs used to create the Viatris spin-off, which took place in 2020. Pfizer referred this news organization to Viatris for comment, but it also did not respond.
It is unclear how the FDA and DEA will respond to the petition. Public Citizen has received a reply from the FDA, in which the agency acknowledged receipt of the petition. However, the “acceptance of the petition for filing is a procedural matter and in no way reflects the agency’s decision on the substantive merits of the petition,” the FDA said in a letter.
As is common practice, the agency assigned a docket number for the petition, FDA-2022-P-0149. The docket’s website allows interested parties to track the issue.
‘Unnoticed’ abuse
There have been rising concerns about risks and abuse of gabapentin in recent years. In its petition, Public Citizen noted that the United Kingdom and several U.S. states have already sought tighter control of gabapentin prescriptions.
In 2019, the United Kingdom announced it would reclassify both pregabalin and gabapentin as class C controlled substances because of the rising numbers of deaths linked to the drugs.
As of November 2020, seven states – Alabama, Kentucky, Michigan, North Dakota, Tennessee, Virginia, and West Virginia – had classified gabapentin as a schedule V drug, while another 12 states required prescription monitoring of the drug, Public Citizen noted.
In 2018, researchers at the University of Louisville, Kentucky, a state that has been hit particularly hard by the opioid crisis, tried to draw more attention to the risks of gabapentin.
“Amid the opioid epidemic, abuse of a different prescription painkiller has widely gone unnoticed,” the University said in a press release at the time.
The release highlighted a study led by Rachel Vickers Smith, PhD, assistant professor in the University of Louisville School of Nursing that was published in Psychology of Addictive Behaviors.
It included 33 individuals who reported recent recreational use of gabapentin. Use of the drug was combined with buprenorphine, other opioids, cocaine, and caffeine to produce effects such as muscle relaxation, pain reduction, sleep induction, feeling drunk, and feeling “high.”
In the press release, Dr. Vickers Smith said individuals who abuse gabapentin often mix it with opioids, marijuana, cocaine, and opioid treatment medication, compounding side effects to the central nervous system that include euphoria and sedation.
In addition, some individuals who primarily abused opioid pain medication have turned to gabapentin after law-enforcement actions made it more difficult to obtain prescription opioids, she noted.
“People are looking for other drugs to substitute for opioids, and gabapentin has filled that place for some,” Dr. Vickers Smith said. “Some have said it gives them a high similar to opioids.”
FDA 2019 warning
In 2019, the FDA issued a warning about serious breathing difficulties associated with gabapentin and pregabalin in patients with respiratory risk factors.
These factors include opioid use and other drugs that depress the central nervous system, as well as conditions such as chronic obstructive pulmonary disease that reduce lung function. Older patients are also at higher risk, the FDA said.
The agency noted that gabapentinoids are often co-prescribed with opioids for for medical conditions and abused in combination with opioids. Data collected in 2016 from an office-based physician survey showed 14% of patient encounters involving gabapentin also involved opioids, the FDA said.
“Our evaluation shows that the use of these medicines, often referred to as gabapentinoids, has been growing for prescribed medical use, as well as misuse and abuse,” the agency said in its 2019 alert.
A version of this article first appeared on Medscape.com.