Opioid users may be misusing and abusing the anti-seizure medication gabapentin, known by the brand names Neurontin, Gralise and Horizant, according to a study presented at the American Association for Clinical Chemistry.
Researchers looked at test results for 323 patients who were prescribed opioids and who were being treated at pain or rehabilitation clinics in Arizona, Indiana, Massachusetts, and other states. About a fifth tested positive for gabapentin but did not have a prescription for the drug.
Among the patients taking gabapentin without prescription, more than half (56 percent) were taking it with an opioid, and more than a quarter (27 percent) were taking it with an opioid and a muscle relaxant or anxiety medication. The rest (17 percent) were taking gabapentin with other substances.
Gabapentin is approved by the Food and Drug Administration (FDA) to treat epilepsy and postherpetic neuralgia. It is often prescribed off-label to treat other pain syndromes, anxiety and mood disorders, restless leg syndrome, alcohol withdrawal, and other conditions.
Gabapentin is not scheduled as a controlled substance because it is thought to have little potential for abuse and addiction. However, the medication shares characteristics associated with drugs that are misused and abused, such as withdrawal syndrome and certain psychoactive effects, according to Medscape. A study published in the journal Anesthesia & Analgesia has found that gabapentin can enhance the analgesic effect of opioids.
“The high rate of misuse of this medication is surprising and it is also a wake-up call for prescribers,” said study author Poluru Reddy, PhD, medical director of ARIA Diagnostics and ARCTIC Medical Labs. “Doctors don’t usually screen for gabapentin abuse when making sure patients are taking medications, such as opioids, as prescribed. These findings reveal that there is a growing risk of abuse and a need for more robust testing.”