Gabapentin is an anti-epileptic medication, also called an anticonvulsant. It affects chemicals and nerves in the body that are involved in the cause of seizures and some types of pain.
Gabapentin is used in adults to treat nerve pain caused by herpes virus or shingles (herpes zoster).
The Horizant brand is also used to treat restless legs syndrome (RLS).
The Neurontin brand is also used to treat seizures in adults and children who are at least 3 years old.
Use only the brand and form of gabapentin that your doctor has prescribed. Check your medicine each time you get a refill at the pharmacy, to make sure you have received the correct form of this medication.
Gabapentin may also be used for purposes not listed in this medication guide.
Important information
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Before taking this medicine
You should not use this medication if you are allergic to gabapentin.
To make sure this medicine is safe for you, tell your doctor if you have:
Some people have thoughts about suicide while taking this medicine. Your doctor will need to check your progress at regular visits while you are using gabapentin. Your family or other caregivers should also be alert to changes in your mood or symptoms.
FDA pregnancy category C. It is not known whether gabapentin will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.
See also: Pregnancy and breastfeeding warnings (in more detail)
Gabapentin can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
How should I take gabapentin?
Take gabapentin exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
The Horizant brand of gabapentin should not be taken during the day. For best results, take Horizant with food at about 5:00 in the evening.
Both Gralise and Horizant should be taken with food.
Neurontin can be taken with or without food.
If you break a Neurontin tablet and take one half of it, take the other half at your next dose. Any tablet that has been broken should be used as soon as possible or within a few days.
Measure liquid medicine with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
If your doctor changes your brand, strength, or type of gabapentin, your dosage needs may change. Ask your pharmacist if you have any questions about the new brand you receive at the pharmacy.
Do not stop using gabapentin suddenly, even if you feel fine. Stopping suddenly may cause increased seizures. Follow your doctor"s instructions about tapering your dose.
Wear a medical alert tag or carry an ID card stating that you take gabapentin. Any medical care provider who treats you should know that you take seizure medication.
This medication can cause you to have a false positive urine protein screening test. If you provide a urine sample for testing, tell the laboratory staff that you are taking gabapentin.
Store at room temperature away from light and moisture.
Store the liquid medicine in the refrigerator. Do not freeze.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Be sure to take the medicine with food. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid?
This medication may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.
Avoid taking an antacid within 2 hours before or after you take gabapentin. Antacids can make it harder for your body to absorb this medicine.
Drinking alcohol can increase certain side effects of this medicine.
Gabapentin side effects
Get emergency medical help if you have any of these signs of an allergic reaction to gabapentin: hives; fever; swollen glands; painful sores in or around your eyes or mouth; difficulty breathing; swelling of your face, lips, tongue, or throat.
Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, depression, or if you feel agitated, hostile, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.
Call your doctor at once if you have:
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increased seizures;
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fever, swollen glands, body aches, flu symptoms;
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skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;
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upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
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chest pain, irregular heart rhythm, feeling short of breath;
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confusion, nausea and vomiting, swelling, rapid weight gain, urinating less than usual or not at all;
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new or worsening cough, fever, trouble breathing;
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rapid back and forth movement of your eyes; or
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severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Some side effects are more likely in children taking gabapentin. Contact your doctor if the child taking this medication has any of the following side effects:
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changes in behavior;
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memory problems;
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trouble concentrating; or
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acting restless, hostile, or aggressive.
Common gabapentin side effects may include:
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
Gabapentin Dosing Information
Usual Adult Dose of Gabapentin for Epilepsy:
Initial dose: 300 mg orally on day one, 300 mg orally twice a day on day two, then 300 mg orally 3 times a day on day three.
Maintenance dose: 900 to 1800 mg orally in 3 divided doses. If necessary, the dose may be increased using 300 mg or 400 mg capsules three times a day up to 1800 mg/day. Dosages up to 2400 mg/day have been well tolerated in long-term clinical studies. Doses of 3600 mg/day have also been administered to a small number of patients for a relatively short duration, and have been well tolerated. The maximum time between doses in the three times a day schedule should not exceed 12 hours.
The safety and effectiveness of gabapentin available under the trade name Gralise (R) or Horizant (R) in patients with epilepsy has not been studied.
Usual Adult Dose for Postherpetic Neuralgia:
Initial dose: 300 mg orally on day one, 300 mg orally twice a day on day two, then 300 mg orally 3 times a day on day three.
The dose may be titrated up as needed for pain relief to a daily dose of 1800 mg.
Maintenance dose: 900 to 1800 mg orally in 3 divided doses.
Efficacy was demonstrated in clinical studies over a range of 1800 mg/day to 3600 mg/day. However, no additional benefit was demonstrated from the use of doses over 1800 mg/day.
Gabapentin available under the trade name Gralise (R):
Maintenance dose: Gralise (R) should be titrated to 1800 mg orally once daily with the evening meal.
Recommended titration schedule:
Day 1: 300 mg orally with the evening meal
Day 2: 600 mg orally with the evening meal
Days 3 through 6: 900 mg orally with the evening meal
Days 7 through 10: 1200 mg orally with the evening meal
Days 11 through 14: 1500 mg orally with the evening meal
Day 15: 1800 mg orally with the evening meal
Gralise (R) is not interchangeable with other gabapentin products because of differing pharmacokinetic profiles that affect the frequency of administration.
Gabapentin enacarbil extended release tablets available under the trade name Horizant (R):
The recommended dosage is 600 mg orally twice daily. Therapy should be initiated at a dose of 600 mg orally in the morning for 3 days of therapy, then increased to 600 mg twice daily (1,200 mg/day) on day four.
Gabapentin enacarbil extended release tablets available under the trade name Horizant (R) and gabapentin are not interchangeable.
Usual Adult Dose for Restless Legs Syndrome:
Gabapentin enacarbil available under the trade name Horizant (R):
600 mg orally once daily with food at about 5 PM
Usual Pediatric Dose for Epilepsy:
Less than 3 years: Effectiveness has not been established.
Greater than or equal to 3 and less than 12 years:
Starting Dose: ranges from 10 to 15 mg/kg/day in 3 divided doses.
Effective Dose: reached by upward titration over a period of approximately 3 days. The effective dose of gabapentin in patients 5 years of age and older is 25 to 35 mg/kg/day and given in divided doses (three times a day). The effective dose in pediatric patients ages 3 and 4 years is 40 mg/kg/day and given in divided doses (three times a day). Gabapentin may be administered as the oral solution, capsule, or tablet, or using combinations of these formulations. Dosages up to 50 mg/kg/day have been well tolerated in a long term clinical study. The maximum time interval between doses should not exceed 12 hours.
Greater than 12 years:
Initial dose: 300 mg orally on day one, 300 mg orally twice a day on day two, then 300 mg orally 3 times a day on day three.
Maintenance dose: 900 to 1800 mg orally in 3 divided doses. If necessary, the dose may be increased using 300 mg or 400 mg capsules three times a day up to 1800 mg/day. Dosages up to 2400 mg/day have been well tolerated in long term clinical studies. Doses of 3600 mg/day have also been administered to a small number of patients for a relatively short duration, and have been well tolerated. The maximum time between doses in the three times a day schedule should not exceed 12 hours.
What other drugs will affect gabapentin?
Taking gabapentin with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking gabapentin with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.
Tell your doctor about all medicines you use, and those you start or stop using during your treatment with this medicine, especially:
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hydrocodone, (Lortab, Vicodin and others);
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morphine (Kadian, MS Contin, Oramorph, and others); or
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naproxen (Naprosyn, Aleve, Anaprox, and others).
This list is not complete and other drugs may interact with gabapentin. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.
