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)|
|≥ 60||900 to 3,600||300 TID||400 TID||600 TID||800 TID||1,200 TID|
|> 30 to 59||400 to 1,400||200 BID||300 BID||400 BID||500 BID||700 BID|
|> 15 to 29||200 to 700||200 QD||300 QD||400 QD||500 QD||700 QD|
|15a||100 to 300||100 QD||125 QD||150 QD||200 QD||300 QD|
|Post-Hemodialysis Supplemental Dose (mg)b|
|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
- 100 mg
- 300 mg
- 400 mg
- 250 mg/5mL
- 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?
- 100 mg
- 300 mg
- 400 mg
- 300 mg
- 600 mg
- 800 mg
250 mg per 5 mL