Maximum Daily Dose of Gabapentin

The maximum recommended daily dose of gabapentin is 3600 mg per day, typically divided into three doses. 1, 2

FDA-Approved Dosing Guidelines

The FDA-approved maximum daily dose of gabapentin is 3600 mg/day, though clinical efficacy has been demonstrated across a range of doses from 1800 mg/day to 3600 mg/day 2
For postherpetic neuralgia, the FDA notes that while efficacy was demonstrated across doses from 1800-3600 mg/day, additional benefit of using doses greater than 1800 mg/day was not demonstrated in clinical studies 2
For epilepsy with partial onset seizures in patients 12 years and older, dosages up to 2400 mg/day have been well-tolerated in long-term clinical studies, while doses of 3600 mg/day have been administered to a small number of patients for a relatively short duration 2

For neuropathic pain, the maximum single dose is generally 1200 mg, as part of the maximum daily dose of 3600 mg divided into three doses 3
For epilepsy treatment, the recommended maintenance dose is 300 mg to 600 mg three times a day, with total daily doses up to 3600 mg 2
For unexplained chronic cough, a maximum tolerable daily dose of 1800 mg in two divided doses may be considered 3

Initial dosing should start at 100-300 mg at bedtime or 100-300 mg three times daily, with increases by 100-300 mg every 1-7 days as tolerated 3
Treatment should be initiated at low dosages with gradual titration until pain relief, dose-limiting adverse effects, or the maximum dose of 3600 mg/day in 3 divided doses is reached 3
The maximum time between doses should not exceed 12 hours 2

Dose adjustment is required for patients with renal impairment as gabapentin is primarily excreted unchanged by the kidneys 2
For patients with creatinine clearance 30-59 mL/min, the maximum daily dose range is 400-1400 mg 2
For patients with creatinine clearance 15-29 mL/min, the maximum daily dose range is 200-700 mg 2
For patients with creatinine clearance <15 mL/min, the maximum daily dose range is 100-300 mg 2

Lower doses may be more appropriate in older adults due to potential for decreased renal function 3
The effective dose in older adults may be lower than standard ranges due to increased sensitivity to side effects 3
The FDA recommends dose adjustment based on creatinine clearance values in elderly patients 2

Higher doses of gabapentin are associated with increased risk of adverse events, including dizziness (19%), somnolence (14%), peripheral edema (7%), and gait disturbance (14%) 4
Adverse event withdrawals are more common with gabapentin (11%) than with placebo (8.2%) 4
Side effects typically occur around the onset of dosing and may be transient 5
Increasing gabapentin doses may not provide better therapeutic outcomes but can increase the risk of adverse events 6

For postherpetic neuralgia and peripheral diabetic neuropathy, gabapentin at doses of 1800 mg to 3600 mg daily can provide good levels of pain relief to some people 4
Studies suggest improved seizure control at higher gabapentin maintenance dosages (up to 3600 mg/d) without necessarily increasing the incidence of adverse reactions 5
Gabapentin exhibits dose-dependent bioavailability due to a saturable transport mechanism, with plasma concentrations essentially proportional to dosages up to 1,800 mg daily 7