What is the recommended dosage of Gabapentin (Neurontin)?

From the Guidelines

Gabapentin should be started at a low dose of 100-300 mg nightly and increased to 900-3600 mg daily in divided doses 2 to 3 times a day, with dose increments of 50%-100% every few days, as this approach has been shown to be effective in managing neuropathic pain while minimizing side effects 1.

Key Considerations

• The dosage of gabapentin may need to be adjusted for patients with renal insufficiency, with a slower titration for the elderly or medically frail 1.
• For neuropathic pain, an adequate trial of treatment with gabapentin can require 2 months or more, with increases in dosage until pain relief, dose-limiting adverse effects, or 3600 mg/d in 3 divided doses is reached 1.
• Common side effects of gabapentin include dizziness, drowsiness, and fatigue, which often improve with time, and the medication should never be stopped abruptly due to potential withdrawal symptoms; dosage should be gradually tapered over at least one week.

Dosage Recommendations

• Starting dose: 100-300 mg nightly
• Effective dose range: 900-3600 mg daily, divided into 2 to 3 doses
• Dose increments: 50%-100% every few days
• Maximum dose: 3600 mg daily in 3 divided doses
• Special considerations:
  • Elderly patients and those with kidney impairment require lower doses, starting at 100-300 mg daily with slower titration.
  • Gabapentin should be taken with food to improve absorption and reduce gastrointestinal side effects.

Evidence-Based Practice

The recommended dosage of gabapentin is based on the most recent and highest quality study available, which suggests that a gradual increase in dosage can help minimize side effects while achieving effective pain management 1.

From the FDA Drug Label

Dosage and Administration 2. 1 Dosage for Postherpetic Neuralgia In adults with postherpetic neuralgia, gabapentin 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 1800 mg/day (600 mg three times a day) 2. 2 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 tablets is 300 mg to 600 mg three times a day. 2. 3 Dosage Adjustment in Patients with Renal Impairment Dosage adjustment in patients 12 years of age and older with compromised renal function or undergoing hemodialysis is recommended, as follows (see dosing recommendations above for effective doses in each indication): TABLE 1 Gabapentin Tablets Dosage Based on Renal Function Renal Function Creatinine Clearance (mL/min) Total Daily Dose Range (mg/day) Dose Regimen (mg) ≥60 900-3600 300 TID 400 TID 600 TID 800 TID 1200 TID

The recommended dosage of Gabapentin (Neurontin) is as follows:

• Postherpetic Neuralgia: 300 mg on Day 1,600 mg/day on Day 2, and 900 mg/day on Day 3, titrated up to 1800 mg/day as needed.
• Epilepsy with Partial Onset Seizures:
  • Patients 12 years and above: 300 mg three times a day, with a recommended maintenance dose of 300 mg to 600 mg three times a day.
  • Pediatric Patients:
    • Age 3 to 4 years: 40 mg/kg/day, given in three divided doses.
    • Age 5 to 11 years: 25 mg/kg/day to 35 mg/kg/day, given in three divided doses.
• Dosage Adjustment in Patients with Renal Impairment:
  • Creatinine Clearance ≥60 mL/min: 900-3600 mg/day.
  • Creatinine Clearance 30-59 mL/min: 400-1400 mg/day.
  • Creatinine Clearance 15-29 mL/min: 200-700 mg/day.
  • Creatinine Clearance <15 mL/min: reduce daily dose in proportion to creatinine clearance. 2

From the Research

Recommended Dosage of Gabapentin

The recommended dosage of Gabapentin varies depending on the condition being treated.

• For adults with epilepsy, Gabapentin may be initiated at a dosage of 900 mg/d and titrated to maintenance dosages of 3600 mg/d or more 3.
• For children with epilepsy, Gabapentin may be treated with 23 to 78 mg/kg per day 3.
• For adults with neuropathic pain, treatment should be started at a dose of 900 mg/d (300 mg/d on day 1,600 mg/d on day 2, and 900 mg/d on day 3), with additional titration to 1800 mg/d recommended for greater efficacy, and doses up to 3600 mg/d may be needed in some patients 4, 5.
• For postherpetic neuralgia and painful diabetic neuropathy, Gabapentin at doses of 1200 mg to 3600 mg daily can provide good levels of pain relief to some people 4, 6.

Titration and Administration

• Titration to effect can be accomplished rapidly, but optimal seizure control may take months to achieve 3.
• More frequent drug administration (q.i.d. versus t.i.d.) may increase Gabapentin bioavailability, especially at higher doses (4800 mg/day) 7.
• The effective dose should be individualized according to patient response and tolerability 5.

Adverse Effects

• Adverse events occurred significantly more often with Gabapentin, including dizziness, somnolence, peripheral oedema, and gait disturbance 4, 6.
• Serious adverse events were no more common with Gabapentin than with placebo 4, 6.