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Need To Know: Top 9 Facts About Gabapentin

Medically reviewed by L. Anderson, PharmD. Last updated on Jan 10, 2018.

Gabapentin: A Versatile Medication

Gabapentin, in the drug class of anticonvulsants, is known by brands names such as Gralise, Horizant, and Neurontin. It is one of the most highly prescribed drugs as it has so many uses.

Gabapentin affects chemicals and nerves in the body that are involved in the cause of seizures and some types of nerve pain.

Gabapentin was FDA-approved in 1993 and it treats many different types of medical conditions, for example:

Gabapentin Use for Seizures

If you are familiar with Neurontin (gabapentin), you remember it was first FDA approved for patients with seizures.

  • Gabapentin is used to treat seizures in adults and children who are at least 3 years old. It also comes in a liquid dose form for small children who have trouble swallowing capsules.
  • You can take gabapentin with or without food. But wait at least two hours after taking an antacid that contains magnesium, calcium or aluminum and taking your gabapentin dose. This drug interaction between the antacid and gabapentin may prevent proper absorption of the anti-seizure medication and lower its effectiveness
  • You should avoid or limit the use of alcohol while being treated with gabapentin.
  • If you take gabapentin three times a day for seizures, do not allow more than 12 hours to pass between any two gabapentin doses.

In 2017, the U.S. Centers for Disease Control and Prevention (CDC) reported that record numbers of Americans are living with epilepsy. According to the data, 1.2 percent of the population, or about 3 million adults and 470,000 children, were being treated for epilepsy or had experienced recent seizures in 2015. Reasons for the increased numbers include population growth, better diagnosis, and longer life span.

What is Postherpetic Neuralgia?

Most people are familiar with the seizures that occur with epilepsy, but what is postherpetic neuralgia (PHN)?

Postherpetic neuralgia can occur due to an outbreak of shingles. Most cases of shingles clear up within a few weeks. However, postherpetic neuralgia is a burning pain that lasts for more than a month after the rash and blisters have cleared up. In fact, the burning pain that affects the nerves may last for months or even years.

The risk of postherpetic neuralgia increases with age, primarily affecting people older than 60 years of age. You may be more at risk for the lingering pain of PHN if the shingles breaks out on your face, too.

What is Restless Legs Syndrome?

Restless legs syndrome (RLS) results in an uncontrollable urge to move your legs around, usually due to leg discomfort.

The symptoms typically occur in the evenings or at night while you're sitting or lying down, or trying to sleep. Moving around eases the leg discomfort, but only temporarily.

Restless legs syndrome generally worsens as you age, but it can happen at any age. It can disrupt sleep - leading to daytime drowsiness - and make traveling, like air travel or long car rides - difficult.

How Does Gabapentin Come at the Pharmacy? The Immediate-Release Form

Gabapentin comes in many different forms and doses. Use only the brand and form of gabapentin prescribed by your doctor. It is wise to check your medicine at the pharmacy each time you get a refill to be sure you have the correct form.

  • Gabapentin immediate-release (IR) comes in capsules (100, 300, 400 mg), tablets (600, and 800 mg) and as a liquid oral solution (250 mg per 5 mL).
  • Doses of the IR form are usually given three times per day. The IR form of gabapentin (Neurontin) is also available generically.
  • If you are able to use the generic immediate-release form of gabapentin for your condition (ask your doctor as this may not always be possible), it could save you hundreds of dollars each month or might be cheaper than your copay.
  • But remember, prices can fluctuate wildly, so check with other pharmacies if the price seems out of reach. Be sure to check for online coupons, too, that can save you money on both generics and brands.

The Extended-Release (ER) Forms: What's the Difference?

  • Gralise (gabapentin) comes as a 300 and 600 milligram (mg) extended-release (ER) tablet and in a in a convenience dose start pack of 78 tablets.
  • Horizant (gabapentin enacarbil) is available in a 300 and 600 mg ER tablet.

For both brands, the total dose is given only once or twice daily, which can be more convenient and improve your ability to stick with the correct dosing. Doses are usually increased gradually to help prevent side effects.

  • Gralise, as a brand, is FDA-approved only to treat post-herpetic neuralgia.
  • Horizant is used for restless leg syndrome and post-herpetic neuralgia.
  • No generics exist yet for these brands.
  • It is important you use only the brand or the generic form of gabapentin that your doctor has prescribed. Check your medicine each time you get a refill at the pharmacy; be sure you have received the correct type.
  • Because these products are extended-release, it is important not to chew, crush, split or try to dissolve the pills. Take your medication with food.
  • When your doctor determines that you should stop or change this medication, it should be slowly discontinued over at least one week.
  • Patients with kidney disease may need to have their doses adjusted.

Off-Label Uses of Gabapentin

Unapproved, or "off-label" uses of gabapentin are uses that have not been approved by the FDA and are not in the professional package labeling. However, some doctors may have had good experience using gabapentin in an off-label fashion, and it may be an accepted use even if not specifically FDA-approved.

For example, gabapentin has been used off-label in the treatment of:

However, the FDA turned down the approval for menopausal hot flashes due to lack of effectiveness and side effects like dizziness, fatigue and balance problems.

A 2017 study published in JAMA Surgery noted that gabapentin has been used in surgical patients to help reduce the amount of opioid painkillers required for pain. When patients received gabapentin before and after surgery, the need for continued opioid painkillers was reduced by 24 percent, according to researchers at Stanford University School of Medicine.

Only use a drug for an off-label use if your doctor has specifically written you a prescription with appropriate dosing.

Gabapentin Side Effects and Abuse Potential

Gabapentin is usually well-tolerated but there may be side effects that occur more commonly, especially at the beginning of treatment.

  • Drowsiness and dizziness can be common side effects and it's important to know how the drug will affect you before driving. You should avoid or limit the use of alcohol with gabapentin as it can worsen these effects.
  • Depression and suicide tendencies have been associated with seizure medications.
  • Call your doctor right away if you notice signs of an allergic reaction, such as: a rash, hives, itching; red, swollen, blistered, or peeling skin, difficulty breathing, unusual hoarseness; or swelling of the face or throat.
  • Increased appetite and weight gain have been reported, too, so keep an eye on the scale if you are concerned about adding pounds.

In an alarming report, it was recently noted that 1 in 5 opioid medication users may also be abusing and misusing gabapentin. Gabapentin can be abused to boost the high a person gets from opioid painkillers like oxycodone, muscle relaxants like Soma, and anxiety medications, such as Valium and Xanax.

Don't Abruptly Stop Gabapentin

Thinking of stopping your gabapentin? Think again, and contact your doctor first.

Abruptly stopping any form of gabapentin can lead to worsened seizures and unpleasant withdrawal side effects, so it's best to slowly stop the drug over a period of time. Your doctor will direct you on how to do this appropriately. Doses may need to be reduced if you have or develop kidney disease, too.

Bottom line? It's important to review the medication guide that comes with your gabapentin prescription, whether it be the generic, or the brand Neurontin, Horizant or Gralise. There are many side effects, and most you will not experience; however, it's still important to be aware of them and discuss with your doctor.

To learn more about gabapentin, join the gabapentin Support Group and Q&A Section. Ask questions, stay on top of the news, and contribute your experiences to patients just like you.

Finished: Need To Know: Top 9 Facts About Gabapentin

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  • 1 in 5 Opioid Users Also Might Be Abusing Seizure Drug: Study. August 3, 2016. Accessed 1/10/2018 at
  • Gabapentin [package insert]. Revised: 10/2015. Greenstone. Accessed 1/10/2018.
  • Gabapentin: Patient drug information. Up To Date (Lexicomp). Accessed 1/10/2018 at
  • Gabapentin May Help Surgical Patients Stop Opioids Sooner. Dec. 13, 2017. Accessed 1/10/2018 at
  • Number of Americans With Epilepsy at Record Level. August 10, 2017. Accessed Jan. 10, 2018 at

Further information

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