Gabapentin for Fibromyalgia

How it Works, Side Effects, and More

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Gabapentin is somewhat commonly prescribed as a fibromyalgia treatment. It's available as a generic and is also sold under the brand names Neurontin, Horizant, and Gralise.

Gabapentin is not FDA approved for treating this condition, so it's prescribed off-label. However, the drug is chemically related to Lyrica (pregabalin), which is approved for fibromyalgia. In fact, Lyrica is sometimes referred to as the "son of Neurontin."

Gabapentin is classified as an anti-seizure drug. It's used to treat epilepsy, neuropathy (pain from damaged nerves), restless legs syndrome, and hot flashes.

Fibromyalgia pain is similar to neuropathy, but whether this condition involves nerve damage still isn't clear.

How Gabapentin Works

Gabapentin is believed to work by altering the release of glutamate and other neurotransmitters in your brain. Neurotransmitters send messages from one brain cell to another.

Glutamate is really helpful for certain things, like learning new information. That's because it gets your brain cells stirred up and active.

Kind of like a toddler with chocolate, though, if you have too much glutamate running around up there, your brain cells can become over stimulated. That can make all kinds of things go wrong.

Glutamate has more than one job, though. It also helps transmit pain signals in your brain and nerves. Too much glutamate may play a role in hyperalgesia, which is basically turning up the volume of pain.

To counter the effects of glutamate, you have another neurotransmitter called gamma-aminobutyric acid (GABA). It calms your cells and quiets your brain. When GABA and glutamate exist in balance with each other, things go well. (It's likely out of balance in fibromyalgia, though.)

Some diseases and conditions—including fibromyalgia—may interrupt this balance and let glutamate run amok. Gabapentin is believed to reduce your brain's release of glutamate so the cells can calm down and your brain can function better.

Gabapentin for Fibromyalgia

Research suggests that people with fibromyalgia have too much glutamate in certain parts of their brain, so gabapentin has long been prescribed for it.

But is it effective? Research is mixed.

Two reviews of the evidence disagree. One released in 2016 found that gabapentin is an effective fibromyalgia treatment, but another, published in 2017, reported only low-quality evidence.

A 2014 review of gabapentin for fibromyalgia and neuropathy found that about 35 percent of study participants saw their pain drop by at least 50 percent while on this drug. It's important to note, though, that 21 percent saw similar drops when taking a placebo.

In studies comparing gabapentin with pregabalin (the drug in Lyrica), including one published in The Journal of the American Medical Association, pregabalin appeared to perform better.

An extended-release form of gabapentin showed promise in one small trial published in Pain Practice. Researchers say it improved pain, sleep, and quality of life. This was a preliminary trial, though, so more work needs to be done before we'll know for sure whether it's safe and effective long term.

Gabapentin Dosage

Gabapentin is usually started at a low dose and then gradually increased. Be sure to follow your doctor's instructions.

A typical dose ranges between 900 mg and 1,800 mg daily, divided into three doses.

You shouldn't stop taking gabapentin suddenly. Be sure to talk to your doctor about the proper weaning procedure for the dose you're taking.

Gabapentin Side Effects

Like all drugs, gabapentin comes with a risk of side effects. Some are potentially dangerous while others are not.

If you have any of the following side effects while taking gabapentin, call your doctor immediately:

  • Severe weakness of tiredness
  • Upper stomach pain
  • Chest pain
  • New or worsening cough along with fever
  • Difficulty breathing
  • severe tingling or numbness
  • Rapid, back-and-forth eye movements
  • Pain or difficulty with urination, or no urination
  • Fever
  • Sore throat
  • Swelling in the face or tongue
  • Burning eyes
  • Rash

Side effects that aren't cause for immediate concern include:

  • Fatigue
  • Dizziness
  • Headache
  • Falling asleep
  • Weight gain

Children taking gabapentin may experience a different set of side effects. Contact your doctor immediately for the following:

  • Changes in behavior
  • Memory problems
  • Inability to concentrate
  • Restlessness, hostility, or aggression

Gabapentin may react negatively with other drugs. Be sure your doctor and pharmacist know everything you're taking.

Is Gabapentin Right for You?

With evidence being weak and mixed, gabapentin has one clear advantage over Lyrica—it's generic, and therefore it's much less expensive. The price difference leads some people to try gabapentin in spite of a weaker showing in studies.

Also, we all react differently to medications. Some people who fail on other drugs, including Lyrica, may find relief from gabapentin.

If you're interested in trying gabapentin, talk to your doctor about the pros and cons of the drug as well as how it may fit into your overall treatment regimen.

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