What are the considerations for switching a patient from amitriptyline (tricyclic antidepressant) to trazodone (antidepressant) for insomnia?

Switching from Amitriptyline to Trazodone for Insomnia

Switching from amitriptyline to trazodone for insomnia is not recommended as the American Academy of Sleep Medicine specifically suggests against using trazodone for either sleep onset or sleep maintenance insomnia. 1

Evidence-Based Recommendations for Insomnia Treatment

The American Academy of Sleep Medicine's clinical practice guideline provides clear recommendations regarding medication choices for insomnia:

• Trazodone is explicitly not recommended for treating either sleep onset or sleep maintenance insomnia, based on trials of 50 mg doses 1
• Doxepin (another tricyclic antidepressant) is suggested for sleep maintenance insomnia at low doses (3-6 mg) 1
• More effective FDA-approved options include:
  • Eszopiclone for both sleep onset and maintenance insomnia
  • Zolpidem for both sleep onset and maintenance insomnia
  • Suvorexant for sleep maintenance insomnia

Efficacy Considerations

Despite trazodone's widespread off-label use for insomnia, the evidence does not support this practice:

• Clinical trials show minimal benefits: trazodone only reduced sleep latency by 10 minutes and wake after sleep onset by 8 minutes compared to placebo 1
• No improvement in subjective sleep quality was reported in controlled trials 1
• While some research suggests low-dose trazodone may have some efficacy 2, the highest quality guideline evidence contradicts this finding

In contrast, amitriptyline has shown effectiveness for sleep maintenance:

• 73.9% of patients reported improvement in sleep maintenance with low-dose amitriptyline (10-20 mg) 3
• 45.8% reported satisfaction with treatment results 3

Safety and Side Effect Profile

When considering a switch between these medications, note the following:

• Trazodone:

  • Initial dose for depression is 150 mg/day in divided doses 4
  • For off-label insomnia use, lower doses (50 mg) are typically used
  • Common side effects include drowsiness, dizziness, and dry mouth
  • Risk of priapism (rare but serious)
  • Potential for orthostatic hypotension

• Amitriptyline:

  • Has more anticholinergic effects than trazodone
  • Greater risk of cardiac conduction abnormalities
  • 66.1% of patients on low-dose amitriptyline report at least one side effect 3

Practical Switching Considerations

If switching is still necessary despite the evidence against trazodone for insomnia:

1. Gradually taper amitriptyline to avoid withdrawal symptoms
2. Start trazodone at a low dose (25-50 mg) taken shortly after a meal or light snack 4
3. Monitor for effectiveness and side effects
4. Consider that trazodone requires dose adjustment with strong CYP3A4 inhibitors or inducers 4

Alternative Approaches

Based on the evidence, better alternatives to consider include:

• Doxepin at low doses (3-6 mg) for sleep maintenance insomnia 1
• FDA-approved insomnia medications (eszopiclone, zolpidem, suvorexant) 1
• Non-pharmacological approaches like cognitive behavioral therapy for insomnia

Special Considerations

• Bipolar disorder: Screen for bipolar disorder before starting trazodone 4, though low-dose trazodone appears to have a low risk for inducing mania when used with mood stabilizers 5
• Depression: If insomnia is secondary to depression, treating the underlying depression may be more appropriate than focusing solely on the insomnia 6