By Pat Anson, Editor

The use of gabapentin (Neurontin) and pregabalin (Lyrica) has soared in the United States, with little attention paid to their safety and effectiveness, according to a research letter published in JAMA Internal Medicine.

Gabapentin and pregabalin belong to a class of nerve medication known as gabapentinoids, which are increasingly prescribed as alternatives to opioids in treating neuropathy, fibromyalgia and other types of chronic pain.

In an analysis of health data for nearly 350,000 patients, researchers found that the use of gabapentinoids more than tripled in the past decade, from 1.2% of patients in 2002 to 3.9% in 2015.

Use of the drugs was concentrated in older patients with numerous other health problems, who were often co-prescribed opioids or benzodiazepines, a class of anti-anxiety medication.

“The combination of a dearth of long-term safety data, small effect sizes, concern for increased risk of overdose in combination with opioid use, and high rates of off-label prescribing, which are associated with high rates of adverse effects, raises concern about the levels of gabapentinoid use,” wrote lead researcher Michael Johansen, MD, of OhioHealth, a large non-profit health system based in Ohio.

“While individual clinical scenarios can be challenging, caution should be advised in the use of gabapentinoids, particularly for those individuals who are long-term opioid users, given the lack of proven long-term efficacy and the known and unknown risks of gabapentinoid use.”

Johansen’s research adds to a growing body of evidence that pregabalin and gabapentin are overprescribed and being abused. A recent study by Canadian researchers found that there was “no clear rationale” for the off-label use of the drugs and warned that they have a “significant risk of adverse effects” such as dizziness, fatigue and diminished mental activity.

Lyrica (pregabalin) and Neurontin (gabapentin) are both made by Pfizer and are two of the company’s top selling drugs, generating billions of dollars in annual sales. Lyrica is approved by the FDA to treat diabetic nerve pain, fibromyalgia, post-herpetic neuralgia caused by shingles and spinal cord injuries; while Neurontin is approved to treat epilepsy and post-herpetic neuralgia. Both drugs are also widely prescribed off label to treat back pain, depression, migraine and other conditions.

Sales of pregabalin and gabapentin have risen steadily in recent years, in part because of CDC prescribing guidelines that recommend the two drugs as alternatives to opioid pain medication. About 64 million prescriptions were written for gabapentin in the U.S. in 20l6, a 49% increase in just five years.

“We believe… that gabapentinoids are being prescribed excessively — partly in response to the opioid epidemic,” Christopher Goodman, MD, and Allan Brett, MD, recently wrote in a commentary published in The New England Journal of Medicine. “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.

Gabapentinoids are increasingly being used recreationally by addicts who have found the medications enhance the effects of heroin and other opioids. Lyrica and Neurontin have been linked to heroin overdoses in the United Kingdom, where prescriptions for both drugs have soared in recent years.