Are Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) effective for treating Binge Eating Disorder?

SNRIs for Binge Eating Disorder

SNRIs are effective for treating binge eating disorder, with duloxetine showing significant reduction in binge eating frequency and associated depressive symptoms in obese patients with BED. 1

Evidence for SNRIs in Binge Eating Disorder

The evidence supporting the use of SNRIs for binge eating disorder (BED) is promising, though somewhat limited compared to the data available for SSRIs:

• A 12-week open trial with duloxetine (60-120 mg/day) demonstrated significant reductions in:

  • Number of binges per week
  • Binge eating scale scores
  • Depressive symptoms
  • Weight and BMI 1

• Pharmacological research indicates that both SSRIs and SNRIs effectively reduce bulimic crises and purging episodes in patients with eating disorders 2

• The mechanism of action appears related to the restoration of serotonergic and noradrenergic tone, which is often reduced in the active phase of eating disorders 2

Comparison with Other Medication Options

SSRIs

SSRIs have more robust evidence for BED treatment:

• Fluoxetine and sertraline have demonstrated significant reduction in binge eating frequency compared to placebo 3
• Fluoxetine appears particularly effective in reducing depressive symptoms associated with BED 3
• High-dose fluoxetine has shown good evidence in treating bulimia nervosa and binge eating 4

Anticonvulsants

• Topiramate has consistently shown effectiveness in decreasing binge eating in BED with the added benefit of weight reduction 5, 4
• Single RCTs suggest zonisamide may be effective in BED 5

Other Options

• Atomoxetine (a selective norepinephrine reuptake inhibitor) has shown potential in a single RCT for BED 5, though its effectiveness for anxiety as a primary disorder has not been established 6

Clinical Considerations for SNRI Use

Dosing

• For duloxetine, effective dosing ranges from 60-120 mg/day 1
• Duloxetine and venlafaxine extended release have sufficiently long half-lives to permit once-daily dosing 6

Adverse Effects

SNRIs may cause:

• Diaphoresis, dry mouth
• Gastrointestinal effects (abdominal discomfort, nausea, vomiting, diarrhea)
• Neurological effects (dizziness, headache, tremor)
• Sleep disturbances (insomnia, somnolence)
• Decreased appetite and weight loss
• Cardiovascular effects (hypertension, increased pulse) 6

Monitoring

When prescribing SNRIs:

• Monitor height, weight, pulse, and blood pressure
• Be aware of potential serious adverse effects:
  • Suicidal thinking and behavior (through age 24)
  • Behavioral activation/agitation
  • Hypomania/mania
  • Sexual dysfunction
  • Seizures
  • Abnormal bleeding
  • Serotonin syndrome 6

Specific SNRI Considerations

• Duloxetine: Monitor for hepatic dysfunction; discontinue if jaundice or other evidence of liver dysfunction develops
• Venlafaxine: May be associated with greater suicide risk than other SNRIs; both venlafaxine and desvenlafaxine have been associated with overdose fatalities 6

Treatment Approach

1. Consider SNRIs (particularly duloxetine) for BED patients, especially when comorbid depression is present
2. Start with standard dosing and titrate as needed
3. Monitor for clinical response and side effects
4. Continue treatment for at least 4-9 months after satisfactory response 7
5. Consider longer treatment duration for patients with multiple episodes 7
6. Implement slow discontinuation taper to prevent withdrawal symptoms 6, 7

While SNRIs show promise for BED treatment, the evidence base remains smaller than for SSRIs. Duloxetine appears to be the most studied SNRI for this indication, with positive preliminary results in reducing binge eating and associated symptoms.