Huge numbers of older people are taking the non-opioid pain medication gabapentin for a variety of conditions, including itching, alcohol dependence and sciatica, with one expert calling it “crazy”.
One 67-year-old retired nurse started taking gabapentin a year and a half ago to reduce the pain and fatigue of fibromyalgia, saying the drug helps her climb stairs, walk her dog and take art lessons, while another, also 67, has the neurological condition transverse myelitis and uses gabapentin as needed when her legs and feet ache, saying “it calms down nerve pain”.
A third woman takes gabapentin for rheumatoid arthritis.
All three are taking the pain drug for off-label uses, and yet, the only conditions for which gabapentin has been approved for adult use by the US 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.
However, reports The New York Times, that has not stopped patients and healthcare 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.
Evidence of effectiveness for these conditions is all over the map. The drug appears to provide relief for some patients with diabetic neuropathy but not with some other kinds of neuropathic pain.
Several small studies indicate that gabapentin can reduce the itching associated with kidney failure. But the data for its effectiveness against low back pain or a number of psychiatric disorders are limited and show no meaningful impact.
“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 US 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 FDA-approved for several conditions, including fibromyalgia.)
What has fuelled this multi-purpose 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 medication through aggressive marketing methods that the Justice Department deemed illegal and fraudulent; the company settled the government’s suit for $430m 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,” Steinman said.
Using Medicare data, he calculated that in 2020, 5m seniors received at least one prescription for gabapentin – 12.2% of that population. The next year, the proportion hit 12.8%.
By 2022, the most recent year for which data are available, 5.7m 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% of gabapentin users experience swelling in their legs, for which a diuretic like Lasix is sometimes prescribed, said a geriatrician at UCSF.
But diuretics have their own side effects: dizziness, falls, dehydration, abnormal electrolyte levels. The swelling could also prompt a healthcare professional, who is unaware of the patient’s gabapentin use, to suspect heart failure.
If so, “you’d want an echocardiogram”, Growdon said. “And then you’re off to the races.”
Nanci Cartwright got a taste of this when her nurse practitioner suggested 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 Cartwright (73) and the nursing practitioner thought the drug might also relieve her pain in one leg, presumably from a compressed nerve.
With gabapentin, she enjoyed eight uninterrupted hours of sleep. Unfortunately, she also slept the next day, became groggy and needed naps. 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.
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 to their prescribers, 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 is safer.
As older patients seek to find relief from chronic pain, “we don’t have a lot of great options”, Steinman said. Prescribers try to avoid opioids, and non-steroidal 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,” Steinman added.
Various mind-body interventions, like meditation and cognitive behavioural therapy, can also make pain more manageable by changing the way the brain responds to it, he said.
The New York Times article – The Painkiller Used for Just About Anything (Restricted access)
See more from MedicalBrief archives:
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Study backs guidelines for meds to treat diabetic neuropathy pain