Gabapentin for Anxiety in Adults
Gabapentin is not recommended as a first-line treatment for anxiety disorders in adults due to limited evidence supporting its efficacy and potential risks of tolerance, dependence, and withdrawal. 1, 2
First-Line Treatment Recommendations
The current evidence strongly supports using SSRIs or SNRIs as first-line pharmacological treatments for anxiety disorders:
- First-line medications:
- SSRIs (sertraline, escitalopram)
- SNRIs (venlafaxine, duloxetine)
- Combined with cognitive behavioral therapy (CBT) 1
Recommended Medication Dosing
| Medication | Starting Dose | Target Dose | Common Side Effects |
|---|---|---|---|
| Sertraline | 25-50 mg daily | 200 mg daily | Nausea, diarrhea, headache, insomnia, sexual dysfunction |
| Escitalopram | 10-20 mg daily | - | Dry mouth, nausea, diarrhea, headache, somnolence, insomnia |
| Venlafaxine | 37.5 mg daily | 225 mg daily | Different side effect profile than SSRIs |
| Duloxetine | 30 mg daily | 60 mg daily | Nausea, vomiting, headache, somnolence, insomnia, dizziness |
Evidence on Gabapentin for Anxiety
Limited Evidence Base
- There are no randomized controlled trials supporting gabapentin's use in generalized anxiety disorder 3
- Only case reports and small studies exist for gabapentin in anxiety disorders 3, 4
- Most evidence for gabapentin in psychiatric conditions is of low quality 3
Potential Risks
- Gabapentinoids (including gabapentin) have similar issues to benzodiazepines:
- Tolerance development
- Dependence
- Addiction potential
- Withdrawal symptoms 2
- Classified as controlled substances (Class C in the UK) due to these risks 2
Specific Anxiety Conditions Where Gabapentin May Have Limited Role
- Gabapentin may have some benefit for specific anxiety disorders, but evidence is limited 3
- More established evidence exists for gabapentin in:
- Alcohol withdrawal and craving
- Potentially as adjunctive treatment for opioid dependence 3
Treatment Algorithm for Anxiety Disorders
First-line: SSRI or SNRI + CBT
- Start with sertraline (25-50mg) or escitalopram (10mg)
- Titrate dose gradually over 4-8 weeks
- Monitor response using standardized assessment tools (HADS, STAI)
If inadequate response after 6-8 weeks:
- Increase dose of current medication to maximum tolerated dose
- OR switch to alternative SSRI/SNRI
If still inadequate response:
- Consider buspirone (15mg daily initially, target 20-30mg daily)
- Short-term benzodiazepine use may be considered in patients without history of substance abuse
Gabapentin consideration:
- Only consider gabapentin when first and second-line treatments have failed
- Should be used with caution and close monitoring due to risks of tolerance and dependence
- Not supported by high-quality evidence for most anxiety disorders
Monitoring and Maintenance
- Assess treatment response at 4 and 8 weeks using standardized tools
- Continue successful treatment for 12-24 months after achieving remission
- Monitor for side effects, particularly during first few weeks
- For patients under 24 years, monitor for suicidal ideation
Key Cautions About Gabapentin
- Pregabalin (similar to gabapentin) has been associated with rising death rates when combined with opioids or other drugs 2
- Evidence for gabapentinoids in anxiety comes from short-term trials with marginal differences from placebo 2
- Long-term effects including tolerance, dependence, and withdrawal are not well-studied 2
Human clinical studies with high-quality evidence supporting gabapentin for generalized anxiety disorder are notably absent, making it difficult to recommend as anything other than a last-line option after evidence-based treatments have failed.