Gabapentin Titration Schedule
The recommended titration schedule for gabapentin starts with 100-300 mg at bedtime or 100-300 mg three times daily, with dose increments of 100-300 mg every 1-7 days as tolerated, aiming for an effective dose range of 900-3600 mg/day in divided doses. 1
Initial Dosing and Titration
- For postherpetic neuralgia in adults, the FDA recommends initiating gabapentin on Day 1 as a single 300 mg dose, on Day 2 as 600 mg/day (300 mg twice daily), and on Day 3 as 900 mg/day (300 mg three times daily), with subsequent titration up to 1800 mg/day (600 mg three times daily) as needed for pain relief 2
- For epilepsy in patients 12 years and older, the starting dose is 300 mg three times daily, with a recommended maintenance dose of 300-600 mg three times daily 2
- The maximum time between doses should not exceed 12 hours due to gabapentin's relatively short half-life 1, 2
- An adequate trial requires 3-8 weeks for titration plus 2 weeks at maximum dose to properly assess efficacy 3, 1
Dosing Considerations
- Gabapentin has nonlinear pharmacokinetics due to saturable absorption, which necessitates careful titration 3, 1
- The maximum recommended dose is 3600 mg/day in 3 divided doses, though clinical efficacy has been demonstrated across a range of 1800-3600 mg/day 3, 2
- Higher doses (1800-3600 mg/day) may provide greater efficacy in some patients, particularly those with drug-resistant conditions 4
Special Populations
- For elderly patients, consider lower starting doses and slower titration due to increased risk of adverse effects and potential changes in renal function 1, 2
- Dosage adjustment is required in patients with renal impairment based on creatinine clearance values 2:
- CrCl ≥60 mL/min: 900-3600 mg/day in three divided doses
- CrCl 30-59 mL/min: 400-1400 mg/day in two divided doses
- CrCl 15-29 mL/min: 200-700 mg/day as a single daily dose
- CrCl <15 mL/min: 100-300 mg/day as a single daily dose
Managing Side Effects
- The most common adverse effects are dizziness, somnolence, and sedation, which can be minimized by starting with lower doses and titrating cautiously 3, 1
- Side effects typically occur around the onset of dosing and may be transient, often subsiding within approximately 10 days from treatment initiation 5
- Some studies suggest that rapid initiation at 900 mg/day is well tolerated by most patients, except for a higher incidence of dizziness compared to slower titration 6
Common Pitfalls and Caveats
- Premature discontinuation before completing an adequate trial (3-8 weeks plus 2 weeks at maximum dose) may result in underestimating efficacy 1
- Failure to adjust dosing based on renal function can lead to excessive side effects 1, 2
- When discontinuing gabapentin, it should be done gradually over a minimum of 1 week to avoid withdrawal symptoms 2
- Divided doses should be administered at intervals not exceeding 12 hours to maintain therapeutic levels 3, 2
Practical Approach to Titration
- For neuropathic pain, evidence suggests starting at 900 mg/day (300 mg on day 1,600 mg on day 2, and 900 mg on day 3), with additional titration to 1800 mg/day for greater efficacy 5
- For epilepsy, higher maintenance doses up to 3600 mg/day may be necessary, particularly in drug-resistant patients 4
- Monitor for efficacy and side effects at each dose level before further titration 1