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Below are the general guidelines for dosing gabapentin. Note that these dosages may be adjusted on a case-by-case basis for individual patients by provider. Always follow your prescribing physician’s instructions for taking gabapentin.

The following information comes from DailyMed, the official FDA label information provider for drugs.

Usual Adult Dose for:

Dosage for Postherpetic Neuralgia

In adults with postherpetic neuralgia, gabapentin capsules may be initiated on Day 1 as a single 300 mg dose, on Day 2 as 600 mg/day (300 mg two times a day), and on Day 3 as 900 mg/day (300 mg three times a day). The dose can subsequently be titrated up as needed for pain relief to a dose of 1,800 mg/day (600 mg three times a day). In clinical studies, efficacy was demonstrated over a range of doses from 1,800 mg/day to 3,600 mg/day with comparable effects across the dose range; however, in these clinical studies, the additional benefit of using doses greater than 1,800 mg/day was not demonstrated.

Dosage for Epilepsy with Partial Onset Seizures

Patients 12 years of age and above

The starting dose is 300 mg three times a day. The recommended maintenance dose of gabapentin capsules is 300 mg to 600 mg three times a day. Dosages up to 2,400 mg/day have been well tolerated in long-term clinical studies. Doses of 3,600 mg/day have also been administered to a small number of patients for a relatively short duration, and have been well tolerated. Administer gabapentin three times a day using 300 mg or 400 mg capsules. The maximum time between doses should not exceed 12 hours.

Pediatric Patients Age 3 to 11 years

The starting dose range is 10 mg/kg/day to 15 mg/kg/day, given in three divided doses, and the recommended maintenance dose reached by upward titration over a period of approximately 3 days. The recommended maintenance dose of gabapentin capsules in patients 3 to 4 years of age is 40 mg/kg/day, given in three divided doses. The recommended maintenance dose of gabapentin capsules in patients 5 to 11 years of age is 25 mg/kg/day to 35 mg/kg/day, given in three divided doses. 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.

Dosage Adjustment in Patients with Renal Impairment

Dosage adjustment in patients 12 years of age and older and adolescents with renal impairment or undergoing hemodialysis is recommended, as follows (see dosing recommendations above for effective doses in each indication):

TABLE 1.  Gabapentin Capsules Dosage Based on Renal Function

Renal FunctionCreatinine Clearance (mL/min)Total DailyDose Range(mg/day)Dose Regimen(mg)
≥ 60900 to 3,600300 TID400 TID600 TID800 TID1,200 TID
> 30 to 59400 to 1,400200 BID300 BID400 BID500 BID700 BID
> 15 to 29200 to 700200 QD300 QD400 QD500 QD700 QD
15a100 to 300100 QD125 QD150 QD200 QD300 QD
Post-Hemodialysis Supplemental Dose (mg)b
Hemodialysis125b150b200b250b350b
TID = Three times a day; BID = Two times a day; QD = Single daily dosea For patients with creatinine clearance < 15 mL/min, reduce daily dose in proportion to creatinine clearance. b Patients on hemodialysis should receive maintenance doses based on estimates of creatinine clearance as indicated in the upper portion of the table and a supplemental post-hemodialysis dose administered after each 4 hours of hemodialysis as indicated in the lower portion of the table.

The use of gabapentin capsules in patients less than 12 years of age with compromised renal function has not been studied.

Dosage in Elderly

Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and lowest doses should be started if therapy is needed, and dose should be adjusted based on creatinine clearance values in these patients.

*Some experts recommend avoiding gabapentin in patients who are >65 years of age, however, it remains up to the clinician and patient scenario for that recommendation.

Dosage Forms and Strengths

Capsules (oral):

  • 100 mg
  • 300 mg
  • 400 mg

Solution (oral):

  • 250 mg/5mL

Tablet (oral):

  • 600 mg
  • 800 mg

What if I miss a dose of Gabapentin?

If you miss a dose of Gabapentin, take it as soon as you can. If it’s almost time for your next dose, however, skip the missed dose and revert back to your regular schedule. Be sure not to double your doses.

What if I overdose on Gabapentin?

A lethal dose of gabapentin was not identified in mice and rats receiving single oral doses as high as 8,000 mg/kg. Signs of acute toxicity in animals included ataxia, labored breathing, ptosis, sedation, hypoactivity, or excitation.

Acute oral overdoses of gabapentin up to 49 grams have been reported. In these cases, double vision, slurred speech, drowsiness, lethargy, and diarrhea were observed. All patients recovered with supportive care. Coma, resolving with dialysis, has been reported in patients with chronic renal failure who were treated with gabapentin.

Gabapentin can be removed by hemodialysis. Although hemodialysis has not been performed in the few overdose cases reported, it may be indicated by the patient’s clinical state or in patients with significant renal impairment.

If overexposure occurs, call your poison control center at 1-800-222-1222.

How is Gabapentin administered?

Administer gabapentin capsules orally with or without food.

Gabapentin capsules should be swallowed whole with water.

If the gabapentin capsules dose is reduced, discontinued, or substituted with an alternative medication, this should be done gradually over a minimum of 1 week (a longer period may be needed at the discretion of the prescriber).

How is Gabapentin supplied?

Capsules

  • 100 mg
  • 300 mg
  • 400 mg

Tablets

  • 300 mg
  • 600 mg
  • 800 mg

Oral Solution

250 mg per 5 mL

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.


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