Recommended Dosing of Gabapentin for Various Conditions
The recommended dosing of gabapentin varies by condition, with postherpetic neuralgia requiring 1800-3600 mg/day, epilepsy requiring 900-3600 mg/day in adults, and all regimens requiring gradual titration starting at 300 mg/day with dose adjustments based on renal function. 1
Dosing by Condition
Postherpetic Neuralgia
- Initial titration schedule:
- Day 1: 300 mg once daily
- Day 2: 300 mg twice daily (600 mg/day)
- Day 3: 300 mg three times daily (900 mg/day)
- Maintenance dose: 1800 mg/day (600 mg three times daily)
- While doses up to 3600 mg/day have been studied, clinical trials showed no additional benefit beyond 1800 mg/day 1
Epilepsy with Partial Onset Seizures
Adults and Children ≥12 years:
- Starting dose: 300 mg three times daily (900 mg/day)
- Maintenance dose: 300-600 mg three times daily (900-1800 mg/day)
- Doses up to 2400 mg/day are well-tolerated in long-term studies
- Maximum doses of 3600 mg/day have been administered for short durations 1
Children 3-11 years:
- Starting dose: 10-15 mg/kg/day in three divided doses
- Maintenance dose:
- Ages 3-4 years: 40 mg/kg/day in three divided doses
- Ages 5-11 years: 25-35 mg/kg/day in three divided doses
- Doses up to 50 mg/kg/day have been well-tolerated 1
Neuropathic Pain (Off-label)
- Typical dosing: >1200 mg/day in divided doses
- Starting dose: 300 mg once daily
- Maintenance dose: 1800-3600 mg/day in three divided doses 2
- Evidence shows good pain relief at doses of 1800-3600 mg/day for diabetic neuropathy and postherpetic neuralgia 3
Dosing Considerations
Titration
- Gabapentin requires slower titration than pregabalin, typically over weeks rather than days 2
- For optimal efficacy in neuropathic pain, treatment should start at 900 mg/day (300 mg on day 1,600 mg on day 2,900 mg on day 3) with additional titration to 1800 mg/day for greater efficacy 4
Renal Impairment Dosage Adjustment
| Creatinine Clearance (mL/min) | Total Daily Dose Range (mg/day) | Dose Regimen |
|---|---|---|
| ≥60 | 900-3600 | 300-1200 mg TID |
| >30-59 | 400-1400 | 200-700 mg BID |
| >15-29 | 200-700 | 200-700 mg QD |
| ≤15 | 100-300 | 100-300 mg QD |
- Patients on hemodialysis require supplemental post-hemodialysis doses 1
Elderly Patients
- Dose adjustment based on creatinine clearance is necessary as elderly patients are more likely to have decreased renal function 1
Administration Guidelines
- Gabapentin can be taken with or without food
- Maximum time between doses should not exceed 12 hours
- If discontinuing gabapentin, taper gradually over at least 1 week to minimize withdrawal effects 1
Efficacy and Side Effects
- In postherpetic neuralgia, approximately 32% of patients achieve at least 50% pain relief with gabapentin ≥1200 mg/day compared to 17% with placebo 3
- In diabetic neuropathy, about 38% of patients achieve at least 50% pain relief with gabapentin ≥1200 mg/day compared to 21% with placebo 3
- Common side effects include:
Clinical Pearls
- For epilepsy, higher maintenance doses (≥3600 mg/day) may provide improved seizure control without increasing adverse reactions 5
- For neuropathic pain, individualizing the dose based on patient response and tolerability is essential, with doses up to 3600 mg/day sometimes needed 4
- When used for sciatica (off-label), doses ranging from 300-900 mg three times daily have shown benefit 6
- Gabapentin has fewer cardiovascular side effects than tricyclic antidepressants and a more favorable side effect profile than opioids for neuropathic pain 2