Gabapentin (By mouth)


Gabapentin (gab-a-PEN-tin)

Treats certain types of seizures. Also treats Restless Legs Syndrome (RLS) and pain caused by shingles (postherpetic neuralgia).

Brand Name(s)

Neurontin, Therapentin-90, Therapentin-60, FusePaq Fanatrex, Gralise, Gabarone

There may be other brand names for this medicine.

When This Medicine Should Not Be Used

Do not use this medicine if you have had an allergic reaction to gabapentin.

How to Use This Medicine

Capsule, Liquid, Tablet, Long Acting Tablet

  • Your doctor will tell you how much of this medicine to use and how often. Your dose may need to be changed several times in order to find out what works best for you. Do not use more medicine or use it more often than your doctor tells you to.
  • If you have epilepsy and take gabapentin 3 times per day, do not allow more than 12 hours to pass between any 2 doses. The medicine works best if a constant amount is in the blood.
  • You may break the scored Neurontin® tablets into 2 pieces, but make sure you use the second half of the tablet as the next dose. Ask your doctor or pharmacist if you have any questions.
  • Swallow the Gralise® tablet or the Horizant® extended-release tablet whole. Do not crush, break, or chew it. The Gralise® tablet should be taken with the evening meal. The Horizant® extended-release tablet should be taken with food at about 5 PM.
  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
  • Gabapentin may be used together with other seizure medicines. Do not stop using any of your medicines unless your doctor tells you to.
  • This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions. Ask your pharmacist for the Medication Guide if you do not have one.

If a dose is missed:

  • If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.Horizant® extended-release tablets: If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Store the Neurontin® oral liquid in the refrigerator. Do not freeze.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you also use hydrocodone (Vicodin®), morphine, or naproxen (Naprosyn®). Tell your doctor if you drink alcohol regularly.
  • If you take an antacid (such as Di-Gel®, Gaviscon®, Gelusil®, Maalox®, or Mylanta®), wait at least 2 hours before you take gabapentin.
  • Tell your doctor if you are using any medicines that make you sleepy. These include sleeping pills, cold and allergy medicine, narcotic pain relievers, and sedatives.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding. Tell your doctor if you have kidney problems or a history of cancer or tumors, depression, or mental illness. Tell your doctor if you are receiving kidney dialysis.
  • This medicine can increase thoughts of suicide. Tell your doctor right away if you start to feel more depressed and have thoughts about hurting yourself. Report any unusual thoughts or behaviors that trouble you, especially if they are new or getting worse quickly. Let the doctor know if you or anyone in your family has a mental illness or has tried to commit suicide.
  • Do not stop using this medicine suddenly without asking your doctor. You may need to slowly decrease your dose before stopping it completely.Your seizures may return or occur more often if you stop this medicine suddenly.
  • Check with your doctor right away if you develop a fever, rash, swollen or tender lymph glands, unusual bleeding or bruising, or yellow eyes or skin. These may be symptoms of a serious and life-threatening reaction to this medicine.
  • This medicine may make you dizzy, drowsy, or sleepy. Do not drive, use machines, or do anything else that could be dangerous until you know how this medicine affects you.
  • Your doctor will need to check your progress at regular visits while you are using this medicine. Be sure to keep all appointments.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Behavior problems, hostility, restlessness, trouble concentrating, moodiness (especially in children)
  • Blistering, peeling, or red skin rash
  • Blood in the urine, back or side pain
  • Clumsiness, problems with coordination, shakiness, tremors
  • Depression, thoughts of hurting yourself
  • Extreme tiredness
  • Fever, cough, sneezing, sore throat, stuffy nose, and body aches
  • Rapid weight gain
  • Swelling in your hands, ankles, or feet
  • Swollen or tender lymph glands in the neck, armpit, or groin
  • Uncontrolled eye movements
  • Unusual bleeding or bruising
  • Yellow skin or eyes

If you notice these less serious side effects, talk with your doctor:

  • Dizziness
  • Headache
  • Nausea, vomiting
  • Unusual sleepiness, drowsiness, tiredness, or weakness

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last Reviewed on 06/12/2013

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This page was last updated: July 31, 2013

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