By Pat Anson, PNN Editor

Opioid medication significantly reduces low back pain, but opioids should not be used in combination with gabapentin (Neurontin) because of their limited effectiveness and potential for abuse, according to the authors of a small new study presented at the annual meeting of the American Academy of Pain Medicine.

"In these days, when we are focusing on reduction of opioids due to opioid crisis in the U.S., gabapentin could be an important part of multimodal non-opioid pain management," N. Nick Knezevic, MD, of the University of Illinois in Chicago told MedPage Today. "However, it should not be given to all patients since the effectiveness in chronic pain patients, particularly in those with low back pain, is limited."

In a retrospective study, Knezevic and his colleagues looked at 156 patients with low back pain; half of whom were treated with opioids alone and the other half with a combination of opioids and gabapentin.

“According to our study, the combination of gabapentin with opioids was not statistically superior in providing pain relief, in contrast to opioids alone, in patients with chronic pain. Our results are in line with recent guidelines for low back pain treatment that reflect the need to assess the recommendation of gabapentinoids for chronic pain in patients already taking opiods to mitigate risk factors of abuse and overdose,” researchers found.

Gabapentin is an anticonvulsant that was originally developed as a treatment for epilepsy, but is now widely prescribed for a variety of chronic pain conditions. Its use in primary care as a treatment for chronic back and neck pain has risen by 535% in the last decade, despite little evidence of its effectiveness.

"The fact that anticonvulsants are often advertised to be effective for 'nerve pain' may mislead the prescriber to assume efficacy for low back pain or sciatica," Oliver Enke, MD, of the University of Sydney, told MedPage.

A 2018 study by Australian researchers found that gabapentinoids did not reduce back pain or disability and often had side effects such as drowsiness, dizziness and nausea. Another recent study found that combining gabapentin with opioid medication significantly raises the risk of dying from an overdose than opioid use alone.

There have been increasing reports of gabapentin being abused by drug addicts, who have learned they can use the medications to heighten the high from heroin, marijuana, cocaine and other substances.

The CDC’s opioid prescribing guideline recommends gabapentin as a safer alternative to opioids, without saying a word about its potential for abuse or side effects.

A 2017 commentary in the The New England Journal of Medicine warned that gabapentinoids -- a class of nerve medication that includes both gabapentin and pregabalin (Lyrica) -- are being overprescribed.

"We believe… that gabapentinoids are being prescribed excessively — partly in response to the opioid epidemic,” wrote Christopher Goodman, MD, and Allan Brett, MD. “We suspect that clinicians who are desperate for alternatives to opioids have lowered their threshold for prescribing gabapentinoids to patients with various types of acute, subacute, and chronic noncancer pain."