Gabapentin for Fibromyalgia How It Works

Gabapentin is often prescribed as an off-label treatment for fibromyalgia. Also sold under brand names Neurontin, Horizant, and Gralise, gabapentin works to balance the neurotransmitters glutamate and gamma-aminobutyric acid (GABA). Fibromyalgia is believed to be caused in part by altered glutamate levels.

Research on gabapentin for fibromyalgia is mixed, but some people find it helps to relieve symptoms like widespread pain and insomnia. This article discusses gabapentin for fibromyalgia, including dosage and side effects.

What Is Gabapentin?

Gabapentin is somewhat commonly prescribed as a fibromyalgia treatment, however, it is not approved by the Food and Drug Administration (FDA) for this condition. It’s often 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.¹ Neurotransmitters send messages from one brain cell to another. Glutamate is helpful for certain things, like learning new information. That’s because it makes your brain cells more active.

Though, if you have too much glutamate, your brain cells can become overstimulated. That can make all kinds of things go wrong.

Glutamate also helps transmit pain signals in your brain and nerves. Too much glutamate may play a role in hyperalgesia, which essentially turns up the volume of pain.

To counter the effects of glutamate, you have another neurotransmitter called gamma-aminobutyric acid (GABA).² 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,³ while another, published in 2017,⁴ reported only low-quality evidence.

A 2014 review of gabapentin for fibromyalgia and neuropathy found that about 35% of study participants saw their pain drop by at least 50% while on the drug.⁵ It’s important to note, though, that 21% saw similar drops when taking a placebo.

In studies comparing gabapentin with Lyrica (pregabalin), 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.³ 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 healthcare provider’s instructions. A typical dose ranges between 900 milligrams (mg) and 1,800 mg daily, divided into three doses.

You shouldn’t stop taking gabapentin suddenly. Be sure to talk to your healthcare provider 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.⁵ Some are potentially dangerous, while others are not. If you have any of the following side effects while taking gabapentin, call your healthcare provider immediately:

• Severe weakness or 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 healthcare provider immediately for the following:

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

Gabapentin may interact negatively with other drugs. Be sure your healthcare provider 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 much less expensive. Price, however, is far less important than efficacy.

We all react differently to medications. Some people who don’t get relief with other drugs, including Lyrica, may have better results from gabapentin. Talk to your healthcare provider about the benefits and drawbacks gabapentin may have for your overall treatment regimen.