Gabapentin Side Effects

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:

  • increased seizures;
  • fever, swollen glands, body aches, flu symptoms;
  • skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;
  • upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
  • chest pain, irregular heart rhythm, feeling short of breath;
  • confusion, nausea and vomiting, swelling, rapid weight gain, urinating less than usual or not at all;
  • new or worsening cough, fever, trouble breathing;
  • rapid back and forth movement of your eyes; or
  • 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:

  • changes in behavior;
  • memory problems;
  • trouble concentrating; or
  • acting restless, hostile, or aggressive.

Common gabapentin side effects may include:

  • dizziness, drowsiness;
  • dry mouth, blurred vision;
  • headache;
  • diarrhea; or
  • swelling in your hands or feet.

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.

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.