The Painkiller Used for Just About Anything

Mary Peart, 67, a retired nurse in Manchester, Mass., began taking gabapentin a year and a half ago to reduce the pain and fatigue of fibromyalgia. The drug helps her climb stairs, walk her dog and take art lessons, she said.

With it, “I have a life,” she said. “If I forget to take a dose, my pain comes right back.”

Jane Dausch has a neurological condition called transverse myelitis and uses gabapentin as needed when her legs and feet ache. “It seems to be effective at calming down nerve pain,” said Ms. Dausch, 67, a retired physical therapist in North Kingstown, R.I.

Amy Thomas, who owns three bookstores in the San Francisco Bay Area, takes gabapentin for rheumatoid arthritis. Along with yoga and physical therapy, “it’s probably contributing to it being easier for me to move around,” Ms. Thomas, 67, said.

All three are taking the non-opioid pain drug for off-label uses. The only conditions for which gabapentin has been approved for adult use by the Food and Drug Administration are epileptic seizures, in 1993, and postherpetic neuralgia, the nerve pain that can linger after a bout of shingles, in 2002.

But that has not stopped patients and health care providers from turning to gabapentin (whose brand names include Neurontin) for a startling array of other conditions, including sciatica, neuropathy from diabetes, lower back pain and post-surgery pain.

Also: Agitation from dementia. Insomnia. Migraines. Itching. Bipolar disorder. Alcohol dependence. Evidence of effectiveness for some of these uses is thin.

“It’s crazy how many indications it’s used for,” said Dr. Michael Steinman, a geriatrician at the University of California, San Francisco, and a co-director of the U.S. Deprescribing Research Network. “It’s become a we-don’t-know-what-else-to-do drug.”

(The related but less often used drug pregabalin — brand name: Lyrica — is also F.D.A.-approved for several conditions, including fibromyalgia.)

What has fueled this multipurpose popularity? “The history of gabapentin is really a history of uses getting ahead of the evidence,” said Dr. Joseph Ross, an internist and health policy researcher at Yale School of Medicine.

Early on, Warner-Lambert, the manufacturer of gabapentin, pushed off-label prescriptions of the drug through aggressive marketing methods that the Justice Department deemed illegal and fraudulent; the company settled the government’s suit for $430 million in 2004. Still, gabapentin use tripled between 2002 and 2015.

It received another boost as opioid use and misuse grew to crisis proportions. “People were searching for alternatives, and this was often the drug they landed on,” Dr. Steinman said.

Using Medicare data, he calculated that in 2020, five million seniors with Part D plans received at least one prescription for gabapentin — 12.2 percent of that population. The next year, the proportion hit 12.8 percent.

By 2022, the most recent year for which data is available, 5.7 million older adults had received a gabapentin prescription. It has become one of the nation’s most widely prescribed drugs.

It is also one that geriatricians and other researchers have cautioned about for years, however. That’s partly because of its side effects — including drowsiness, dizziness and confusion — but also because it can interact with other frequently prescribed medications.

The Beers Criteria, a directory of potentially inappropriate drugs for older adults, warned last year that gabapentin was associated with an increased risk of falls and fractures when used concurrently with at least two other drugs that act on the central nervous system, like antidepressants, anti-psychotics, benzodiazepines and muscle relaxants.

It’s particularly risky to combine gabapentin with opioids, which can lead to “severe sedation-related adverse effects, including respiratory depression and death,” according to the Beers Criteria.

Like any drug, gabapentin can also set off a “prescribing cascade,” in which problematic side effects lead to treatment with yet another drug. For instance, 2 to 16 percent of gabapentin users experience swelling in their legs, for which a diuretic like Lasix is sometimes prescribed, said Dr. Matthew Growdon, a geriatrician at U.C.S.F. But diuretics have their own side effects: dizziness, falls, dehydration, abnormal electrolyte levels. The swelling could also prompt a health care professional who is unaware of the patient’s gabapentin use to suspect heart failure.

If so, “you’d want an echocardiogram,” Dr. Growdon said. “And then you’re off to the races.”

Nanci Cartwright got a taste of this when her nurse practitioner suggested that she take gabapentin for restless legs syndrome, which led to uncomfortable, involuntary movements that awakened her and forced her out of bed several times a night.

The resulting insomnia was worsening, said Ms. Cartwright, 73, a retired executive assistant in Santa Fe, N.M. Her nurse practitioner thought the drug might also relieve her pain in one leg, presumably from a compressed nerve.

With gabapentin, Ms. Cartwright enjoyed eight uninterrupted hours of sleep. “Unfortunately, I also slept the next day,” she recalled.

She became groggy and needed naps. It was “like being underwater,” she said. “I hated that feeling.” She no longer cared about activities she used to enjoy, like needlework and walks on local trails. Her ankles and calves swelled.

Unable to find a dose strong enough to relieve her symptoms without the unwelcome side effects, she tapered off gabapentin. Within three weeks, she had stopped the drug.

Often, however, older patients continue gabapentin for years or even decades, past the point at which they remember why they started it or what it was supposed to do.

Dr. Steinman called it a “sticky” drug. He was an author of a 2022 study on older adults who were prescribed gabapentin after surgery, most commonly hip and knee replacements. One in five refilled the prescription more than three months later, when “presumably their surgical pain has long since resolved,” he said.

Long-term gabapentin users should talk with their prescribers, Dr. Growdon said. Why are they taking it? Is it still helping? Might it be causing symptoms or interacting with other drugs they take? Can they lower the dose?

Prescribing a drug, or renewing a prescription, is fast and easy, he said, but “to stop something or lower the dose is fighting upstream,” requiring far more time and discussion.

Patients should not stop gabapentin abruptly, he added, as that can lead to withdrawal symptoms like irritability, anxiety and insomnia. Tapering off gradually, as Ms. Cartwright did, is safer. It may take a few weeks or, at higher doses, a couple of months.

As older patients seek to find relief from chronic pain, “we don’t have a lot of great options,” Dr. Steinman said of health care providers. Prescribers try to avoid opioids, and nonsteroidal anti-inflammatories like ibuprofen are recommended only for short-term use.

Some find relief from medical cannabis, topical medications like creams and patches, and non-pharmacological approaches such as acupuncture, therapeutic massage and exercise.

“Often the single best thing I can do for patients with pain is to get them to physical therapy,” Dr. Steinman added.

A variety of mind-body interventions, like meditation and cognitive behavioral therapy, can also make pain more manageable by changing the way the brain responds to it, he said.

This is where Ms. Cartwright is now. Without gabapentin, her restless legs syndrome and insomnia have returned. “I think I need to focus more on non-drug solutions,” she said. She’s trying an online app that teaches techniques for managing chronic pain.

As for the leg pain attributed to a compressed nerve, further diagnosis showed that what she needed was not a drug but hip replacement surgery, which she underwent a year ago. “It was fantastic,” she said. “Took my leg pain away completely.”