Gabapentin Dosing for Peripheral Neuropathy
For peripheral neuropathy, gabapentin should be initiated at 100-300 mg at bedtime or 100-300 mg three times daily, then gradually titrated by 100-300 mg every 1-7 days as tolerated until adequate pain relief is achieved or a maximum dose of 3600 mg/day in divided doses is reached. 1
Initial Dosing and Titration Schedule
Gabapentin requires careful titration due to its nonlinear pharmacokinetics (saturable absorption):
- Starting dose: 100-300 mg at bedtime or 100-300 mg three times daily
- Titration: Increase by 100-300 mg every 1-7 days as tolerated
- Maximum dose: 3600 mg/day in 3 divided doses
- Duration of adequate trial: 3-8 weeks for titration plus 2 weeks at maximum dose 1
This slow titration approach helps minimize dose-dependent side effects such as dizziness and sedation, which can be particularly problematic when starting therapy.
Dose Adjustments for Special Populations
- Renal impairment: Dose reduction required as gabapentin is primarily eliminated by renal excretion (98%) 2
- Elderly patients: Consider lower starting doses and slower titration to minimize adverse effects 1
Efficacy and Response Assessment
Gabapentin has demonstrated efficacy in several neuropathic pain conditions:
- In diabetic peripheral neuropathy, approximately 38% of patients achieve substantial pain relief (at least 50% reduction) compared to 21% with placebo 3
- Pain relief typically requires 2-4 weeks to become apparent, with full effect potentially taking up to 2 months 1, 4
Monitoring and Side Effects
Common adverse effects to monitor for include:
- Dizziness (occurs in approximately 19% of patients)
- Somnolence (14%)
- Peripheral edema (7%)
- Gait disturbance (14%) 3
These side effects are typically dose-dependent and can often be managed with dose reduction rather than discontinuation 2.
Important Clinical Considerations
Nonlinear pharmacokinetics: Gabapentin has saturable absorption, making careful titration necessary 1
Realistic expectations: Set a goal of 30-50% pain reduction rather than complete pain elimination 5
Adequate trial duration: An adequate trial requires 3-8 weeks for titration plus 2 weeks at the maximum tolerated dose 1
Common pitfall: Inadequate dosing - many patients require doses of 1800-3600 mg/day for optimal effect 4
Follow-up timing: Schedule follow-up within 2-4 weeks of starting treatment to assess efficacy and side effects 5
If gabapentin monotherapy provides inadequate relief, combination therapy with amitriptyline may be considered, as this combination has shown greater efficacy than either medication alone 5.