What is the recommended dose and frequency of Gabapentin (Neurontin)?

From the Guidelines

Gabapentin should be started at a low dose of 300 mg once daily and gradually increased to minimize side effects, with a maximum tolerable daily dose of 1800 mg a day in two divided doses, as recommended by the most recent guideline 1. The effective dose ranges from 900-3600 mg daily, divided into three doses, with common maintenance regimens including 300-600 mg three times daily.

• For neuropathic pain, doses often range from 1200-2400 mg daily
• For seizure disorders, doses may reach 1800-3600 mg daily. Elderly patients and those with renal impairment require lower doses, with adjustments based on creatinine clearance, as noted in the earlier study 1. Gabapentin should be taken with food to improve absorption and reduce gastrointestinal side effects. The medication should never be stopped abruptly due to potential withdrawal symptoms; tapering is essential when discontinuing. Common side effects include dizziness, drowsiness, and peripheral edema. Gabapentin works by binding to calcium channels in the nervous system, modulating neurotransmitter release and reducing neuronal excitability, which explains its effectiveness for both pain and seizure management. It is essential to discuss the potential side effects and the risk-benefit profile with patients before use of the medication, and there should be a reassessment of the risk-benefit profile at 6 months before continuing the drug, as suggested by the guideline 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

30-59 400-1400 200 BID 300 BID 400 BID 500 BID 700 BID 15-29 200-700 200 QD 300 QD 400 QD 500 QD 700 QD 15a 100-300 100 QD 125 QD 150 QD 200 QD 300 QD

The recommended dose and frequency of Gabapentin (Neurontin) are as follows:

• For postherpetic neuralgia: 300 mg on Day 1,600 mg/day (300 mg two times a day) on Day 2, and 900 mg/day (300 mg three times a day) on Day 3, titrated up to 1800 mg/day (600 mg three times a day) as needed.
• For epilepsy with partial onset seizures in patients 12 years and older: starting dose of 300 mg three times a day, with a recommended maintenance dose of 300 mg to 600 mg three times a day.
• Dosage adjustment is recommended for patients with renal impairment, with specific dose regimens based on creatinine clearance. 2

From the Research

Recommended Dose and Frequency of Gabapentin

The recommended dose and frequency of Gabapentin (Neurontin) vary depending on the patient's condition and kidney function.

• For patients with normal kidney function, the typical starting dose is 300 mg every 8 hours, which can be rapidly titrated to an effective dose 3.
• The effective dose for postherpetic neuralgia can range from 1800 to 3600 mg/day, with higher doses providing greater pain relief but also increasing the risk of adverse events 4.
• For patients with decreased kidney function, the dose should be adjusted based on creatinine clearance (CrCl), with lower doses recommended for patients with CrCl <60 mL/min 5, 6.
• The frequency of administration can also impact the bioavailability of Gabapentin, with more frequent dosing (e.g., q.i.d.) potentially increasing bioavailability at higher doses (e.g., 4800 mg/day) 7.

Dose Adjustment for Kidney Function

• Patients with CrCl ≥60 mL/min can typically receive the standard dose of Gabapentin 5, 6.
• Patients with CrCl <60 mL/min may require dose reduction to avoid adverse effects, with the exact dose adjustment depending on the individual patient's kidney function and response to treatment 5, 6.
• For patients with CrCl 15-29 mL/min and <15 mL/min, inappropriately high doses of Gabapentin were prescribed in 48.8% and 45% of cases, respectively, highlighting the need for careful dose adjustment in these patients 5.

Formulations and Dosing Regimens

• Different formulations of Gabapentin, such as extended-release Gabapentin and Gabapentin enacarbil, may have different dosing regimens and efficacy/safety profiles 4.
• Gabapentin enacarbil at doses of 1200 mg/day and 2400 mg/day was found to be safe and effective in treating postherpetic neuralgia, while higher doses (3600 mg/day) increased the risk of adverse events 4.