Gabapentin Dosing for Anxiety in a 17-Year-Old
Gabapentin is not FDA-approved for anxiety in adolescents, but when used off-label, should start at 100-300 mg at bedtime with careful titration to a maximum of 1800 mg/day in divided doses, with close monitoring for side effects.
Initial Dosing Considerations
- Start with a low dose of 100-300 mg at bedtime to minimize side effects such as dizziness and sedation 1, 2
- Gabapentin has nonlinear pharmacokinetics due to saturable absorption, requiring careful titration 1, 3
- For adolescents, a conservative approach similar to adult dosing is recommended, but with more cautious titration 2
Titration Schedule
- Increase dose gradually by 100-300 mg every 3-7 days as tolerated 3
- Divide doses throughout the day (typically three times daily) once beyond initial dosing 2
- Maximum recommended dose should not exceed 1800 mg/day for off-label anxiety use 3, 1
Monitoring and Adjustments
- Monitor for common side effects including somnolence (80% of patients), dizziness, and dry mouth 3, 1
- Assess response after 3-8 weeks of titration plus 2 weeks at maximum dose 3
- Clinical studies suggest efficacy for anxiety at doses between 300-900 mg/day 4, 5
- Lower doses (300 mg) may be effective for mild to moderate anxiety, while higher doses may be needed for severe anxiety 4
Special Considerations for Adolescents
- Pediatric patients may experience behavioral changes including hyperactivity, irritability, and agitation 6
- Avoid abrupt discontinuation; taper gradually over at least 1 week to prevent withdrawal symptoms 2
- Maximum time between doses should not exceed 12 hours to maintain therapeutic effect 2
Evidence for Anxiety Treatment
- A randomized controlled trial showed that gabapentin at both 300 mg and 900 mg was effective for anxiety compared to placebo, with effects persisting at 8 weeks 4
- Another study demonstrated that 800 mg of gabapentin attenuated anxiety in subjects during simulated public speaking 7
- In patients with more severe anxiety (panic disorder), gabapentin showed significant improvement compared to placebo 5
Important Caveats
- Gabapentin is primarily FDA-approved for epilepsy and postherpetic neuralgia, not anxiety 2
- Bioavailability decreases with increasing doses, which may necessitate more frequent dosing at higher doses 8
- If response is inadequate after appropriate trial, consider alternative treatments such as SSRIs or SNRIs 3
- The risk-benefit profile must be carefully considered given the off-label nature of this treatment in adolescents