Tag: Gabapentin dosage

Gabapentin Dosage

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 2 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.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (capsules, liquid, and tablets):
    • For epilepsy:
      • Adults and teenagers 12 years of age and older—At first, 300 milligrams (mg) 3 times per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 1800 mg per day.
      • Children 3 to 12 years of age—Dose is based on body weight and must be determined by your doctor. The starting dose is 10 to 15 milligrams (mg) per kilogram (kg) of body weight per day and divided in 3 doses. Your doctor may adjust your dose as needed.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.
    • For postherpetic neuralgia:
      • Adults— At first, 300 milligrams (mg) as a single dose in the evening. Your doctor may adjust your dose as needed. However, the dose is usually not more than 1800 mg per day.
      • Children—Use and dose must be determined by your doctor.
  • For oral dosage form (extended-release tablets):
    • For postherpetic neuralgia:
      • Adults— At first, 600 milligrams (mg) in the morning. Then, your doctor will increase your dose to 600 mg 2 times per day.
      • Children—Use and dose must be determined by your doctor.
    • For restless legs syndrome:
      • Adults—600 milligrams (mg) as a single dose at about 5 PM.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

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 should Gabapentin be used?

Gabapentin comes as a capsule, a tablet, an extended-release (long-acting) tablet, and an oral solution (liquid) to take by mouth. Gabapentin capsules, tablets, and oral solution are usually taken with a full glass of water (8 ounces [240 milliliters]), with or without food, three times a day.

Gabapentin should be taken at evenly spaced times throughout the day and night; no more than 12 hours should pass between doses. The extended-release tablet (Horizant) is taken with food once daily at about 5 PM. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take gabapentin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Gabapentin extended-release tablets cannot be substituted for another type of gabapentin product. Be sure that you receive only the type of gabapentin that was prescribed by your doctor. Ask your pharmacist if you have any questions about the type of gabapentin you were given.

Swallow the extended-release tablets whole; do not cut, chew, or crush them.

If your doctor tells you to take one-half of a regular tablet as part of your dose, carefully split the tablet along the score mark. Use the other half-tablet as part of your next dose. Properly throw away any half-tablets that you have not used within several days of breaking them.

If you are taking gabapentin to control seizures or PHN, your doctor will probably start you on a low dose of gabapentin and gradually increase your dose as needed to treat your condition. If you are taking gabapentin to treat PHN, tell your doctor if your symptoms do not improve during your treatment.

Gabapentin may help to control your condition but will not cure it. Continue to take gabapentin even if you feel well. Do not stop taking gabapentin without talking to your doctor, even if you experience side effects such as unusual changes in behavior or mood. If you suddenly stop taking gabapentin tablets, capsules, or oral solution, you may experience withdrawal symptoms such as anxiety, difficulty falling asleep or staying asleep, nausea, pain, and sweating. If you are taking gabapentin to treat seizures and you suddenly stop taking the medication, you may experience seizures more often. Your doctor may decrease your dose gradually over at least a week.

Your doctor or pharmacist will give you the manufacturer’s patient information sheet (Medication Guide) when you begin treatment with gabapentin and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs) or the manufacturer’s website to obtain the Medication Guide.

Gabapentin Overview
Gabapentin Overview

Abuse of Gabapentin

The stance of the DEA is that gabapentin is not a significant drug of abuse and does not have a significant capability to produce physical dependence. Similar drugs to gabapentin, such as pregabalin (brand name Lyrica), are classified as controlled substances; Lyrica is classified as Schedule V. Research evidence has indicated that there are some isolated reports of individuals abusing gabapentin; however, these appear to be rather extreme cases.

The Substance Abuse and Mental Health Services Administration (SAMHSA) reports that as an overall estimate, 80 percent of people with prescriptions for medications do not abuse them. The actual figures of misuse vary from medication to medication with prescription opiate drugs, benzodiazepines, and some sedatives having higher rates of misuse. However, it is clear from the research that the majority of people who are prescribed medications do not abuse them, even if they do develop some level of physical dependence on them as a result of using them for medicinal reasons.

The risk of a person abusing a prescription medication increases if the person’s use of the medication is not closely monitored by their physician. For instance, individuals now prescribed narcotic medications in the United States have difficulty legally obtaining more of the medication if they use their prescription up too quickly. Likewise, an individual abusing gabapentin who has a prescription for the medication would most likely use significantly more of the drug than prescribed, and physicians should recognize this and take steps to assist the person (e.g., discuss substance abuse with them, limit the amount of the drug they have access to, etc.). Thus, while any medication can be abused, gabapentin abuse is most likely not a major issue for individuals who are prescribed the drug, and individuals who have a prescription for the drug and abuse it should be relatively easy to recognize.

Unlike prescription opiate medications, gabapentin is not a drug that is in large demand by potential drug abusers. There is research evidence that use of high doses of gabapentin or very long-term use of the drug may produce a mild form of physical dependence. Withdrawal symptoms from gabapentin appear to be mild in the same way that withdrawal from antidepressant medications is relatively mild compared to withdrawal from other drugs.