What is the recommended protocol for switching from Wellbutrin (bupropion) to Lexapro (escitalopram)?

Switching from Wellbutrin (Bupropion) to Lexapro (Escitalopram)

When switching from Wellbutrin (bupropion) to Lexapro (escitalopram), the recommended protocol is a cross-taper approach with gradual reduction of bupropion over 10-14 days while simultaneously introducing escitalopram at a low dose of 10 mg daily, increasing to the target dose of 20 mg daily as tolerated.

Rationale for Switching

Switching between these antidepressants may be indicated due to:

• Inadequate treatment response to bupropion
• Unacceptable side effects from bupropion
• Need for a different neurotransmitter profile (bupropion affects primarily norepinephrine and dopamine, while escitalopram affects serotonin) 1, 2

Cross-Taper Protocol

Week 1-2:

• Begin reducing bupropion dose by approximately 25-50% of the original dose
• Simultaneously start escitalopram at 10 mg once daily 1, 3
• Monitor for side effects and withdrawal symptoms

Week 3-4:

• Continue tapering bupropion until discontinued
• Maintain escitalopram at 10 mg daily
• After bupropion is fully discontinued, escitalopram can be increased to 20 mg daily if needed 1, 3

Important Monitoring Considerations

• Withdrawal symptoms: Monitor for symptoms such as irritability, anxiety, fatigue, and headaches from bupropion discontinuation 4
• Serotonin syndrome: Although risk is low with this specific switch, monitor for signs including agitation, confusion, rapid heart rate, dilated pupils, and muscle rigidity 3
• Side effect profile changes:
  • Bupropion side effects (insomnia, dry mouth, headache) may resolve
  • New escitalopram side effects may emerge (nausea, sexual dysfunction, drowsiness) 3, 2

Special Considerations

1. Seizure history: If bupropion was prescribed with caution due to seizure risk, escitalopram may be safer 3, 2

2. Sexual dysfunction: Escitalopram has higher rates of sexual side effects compared to bupropion. If this was a reason for switching, consider:

   • Lower escitalopram dosing (10 mg instead of 20 mg)
   • Monitoring sexual function during transition 2

3. Sleep issues:

   • If insomnia was a problem with bupropion, escitalopram may help
   • If daytime sedation occurs with escitalopram, consider morning dosing 3

4. Therapeutic onset: Expect 2-4 weeks before full therapeutic effect of escitalopram is achieved 3, 2

Contraindications and Cautions

• Do not combine with MAOIs (requires 14-day washout period)
• Use caution in patients with hepatic impairment (escitalopram may require dose adjustment) 1
• Maximum escitalopram dose is 20 mg daily 1, 3

Common Pitfalls to Avoid

1. Abrupt discontinuation: Never stop bupropion suddenly as this increases risk of withdrawal symptoms and potential relapse 4

2. Inadequate follow-up: Schedule follow-up within 1-2 weeks of initiating the switch to monitor for adverse effects and treatment response

3. Overlooking drug interactions: Escitalopram has fewer drug interactions than some other SSRIs, but still requires monitoring 3

4. Ignoring breakthrough symptoms: Depression symptoms may temporarily worsen during transition; have a plan for managing this

The evidence suggests this cross-taper approach minimizes discontinuation effects while maintaining therapeutic coverage during the transition period 3, 4.