Gabapentin Dosage for Anxiety
For anxiety management, start gabapentin at 300 mg daily (either at bedtime or divided into three times daily) and titrate upward by 100-300 mg every 1-7 days as tolerated, with most patients responding to doses between 300-900 mg daily. 1
Starting Dose and Titration Strategy
Begin with 100-300 mg at bedtime or 100-300 mg three times daily, which allows for assessment of tolerability while providing initial anxiolytic effects 1
The 300 mg daily dose is often sufficient for many patients with anxiety, particularly those with mild to moderate symptoms, as demonstrated in a randomized controlled trial of breast cancer survivors where 300 mg was as effective as 900 mg for most patients 2
Titrate by 100-300 mg increments every 1-7 days based on individual tolerance and response 1
Target Therapeutic Doses
For mild to moderate anxiety: 300-900 mg daily is typically effective 2, 3
- Single doses of 400 mg have shown anxiolytic effects in experimental anxiety models 3
- 800 mg single doses demonstrated stronger anxiety reduction in simulated public speaking tests 3
- In clinical trials, 300 mg daily was associated with the best treatment outcomes for all patients except those with the highest baseline anxiety 2
For severe anxiety or preoperative anxiety: 900-1200 mg may be required 2, 4
Maximum dose for neuropathic pain guidelines (which can inform anxiety dosing): up to 3600 mg daily in three divided doses, though this is rarely needed for anxiety alone 1
Treatment Duration and Assessment
Allow 4 weeks at the target dose to adequately assess therapeutic response 6, 7
Monitor for improvement using standardized anxiety assessment tools after 4 weeks 6
Anxiolytic effects typically persist with continued treatment, as demonstrated at 8-week follow-up in clinical trials 2
Critical Dosing Considerations
Renal impairment requires dose reduction since gabapentin is renally excreted—patients with eGFR <30 mL/min need significant dose adjustments 1, 7
Elderly patients should start at the lowest effective dose with slower titration due to increased risk of sedation and cognitive effects 7
Common dose-related side effects include somnolence, dizziness, and fatigue, which may limit dose escalation 5, 4
Clinical Context and Advantages
Gabapentin offers a non-controlled substance alternative for patients with substance use history or those reluctant to take benzodiazepines 2
For patients with comorbid conditions (hot flashes, neuropathic pain), gabapentin may address multiple symptoms simultaneously 2
The lower 300 mg dose provides optimal benefit-to-side-effect ratio for most patients, with higher doses reserved for treatment-resistant cases 2