Is gabapentin (Neurontin) effective for treating anxiety?

Gabapentin for Anxiety: Limited Evidence for Efficacy

Gabapentin is not recommended as a first-line treatment for anxiety disorders due to limited high-quality evidence supporting its efficacy and increasing concerns about its potential for misuse and dependence. While it may have some benefit in specific anxiety conditions, particularly preoperative anxiety, the evidence does not support its routine use for generalized anxiety disorder or other anxiety conditions 1.

Current Evidence and Guidelines

Efficacy in Anxiety Disorders

• The Canadian Clinical Practice Guidelines list gabapentin as a second-line treatment option specifically for social anxiety disorder, not as a first-line therapy 2
• A 2022 meta-analysis found only "moderate evidence" for gabapentin's efficacy in anxiety states, with inconsistent results across different anxiety conditions 1
• For preoperative anxiety, both pregabalin and gabapentin showed better efficacy than placebo, but this represents a very specific, short-term anxiety scenario 1

Concerns and Limitations

• Gabapentin has been reclassified as a controlled substance (Class C) in some countries due to risks of tolerance, dependence, addiction, and withdrawal 3
• There are no randomized controlled trials supporting gabapentin's use in generalized anxiety disorder, only case reports 4
• Short-term trials show only marginal differences from placebo and don't account for long-term effects of tolerance and dependence 3
• Rising prescription rates have been accompanied by increasing mortality, with 244 pregabalin-related poisoning deaths recorded in 2019 3

Treatment Algorithm for Anxiety Disorders

First-line Options (Preferred):

1. SSRIs/SNRIs: Better established efficacy and safety profile for long-term anxiety management
2. Cognitive Behavioral Therapy (CBT): Strong evidence as first-line treatment for chronic anxiety
3. Pregabalin: For specific cases where indicated by guidelines (e.g., social anxiety disorder)

Second-line Options (Consider when first-line fails):

1. Benzodiazepines: For short-term use only, with careful monitoring
2. Gabapentin: May be considered in specific scenarios:
   • Patients with comorbid neuropathic pain 5
   • Patients with history of substance use who cannot take benzodiazepines 6
   • Patients experiencing both anxiety and hot flashes (e.g., breast cancer survivors) 6

Dosing and Monitoring if Used

If gabapentin is prescribed for anxiety despite limited evidence:

• Starting dose: 300 mg daily, which showed efficacy in breast cancer survivors with anxiety 6
• Titration: May increase to 900 mg daily if needed and tolerated
• Renal adjustment: Critical for safety (see table below)

Creatinine Clearance (mL/min)	Total Daily Dose Range (mg/day)	Dose Regimen
≥60	900-3600	300-1200 mg TID
30-59	400-1400	200-700 mg BID
15-29	200-700	200-700 mg QD
≤15	100-300	100-300 mg QD

Monitoring Requirements

• Regular assessment for peripheral edema
• Monitoring for depression or suicidal ideation
• Vigilance for signs of misuse or dependence
• Particular caution in elderly patients and those with cardiovascular disease

Important Caveats

• Gabapentin may have addictive potential and should be used with caution in patients with history of substance use disorders 5
• The risk-benefit ratio is unfavorable for long-term use given the lack of evidence for sustained efficacy
• Withdrawal symptoms can occur with abrupt discontinuation, requiring gradual tapering

In conclusion, while gabapentin has shown some benefit for specific anxiety conditions in limited studies, its use for general anxiety disorders should be restricted due to insufficient evidence for efficacy, potential for misuse, and safety concerns. Other evidence-based treatments should be prioritized for anxiety management.