What are the precautions when removing Strattera (atomoxetine) and adding Wellbutrin (bupropion) to a regimen including Prazosin (prazosin) and Lamictal (lamotrigine)?

Precautions When Switching from Strattera to Wellbutrin with Prazosin and Lamictal

When switching from atomoxetine (Strattera) to bupropion (Wellbutrin) in a regimen that includes prazosin and lamotrigine (Lamictal), a careful tapering approach of atomoxetine followed by gradual introduction of bupropion is necessary to minimize withdrawal effects and potential drug interactions.

Discontinuing Atomoxetine (Strattera)

Atomoxetine should be tapered rather than abruptly discontinued:

• Gradually reduce the dose over 1-2 weeks to minimize discontinuation effects
• Monitor for potential withdrawal symptoms including:
  • Mood changes
  • Irritability
  • Return of ADHD symptoms
  • Fatigue or lethargy

Starting Bupropion (Wellbutrin)

Begin bupropion only after atomoxetine has been tapered down:

• Initial dosing: Start with 37.5 mg every morning, then increase by 37.5 mg every 3 days 1
• Target dose: 150 mg twice daily (maximum recommended dose) 1
• Use extended-release formulation (XL): Start with 150 mg once daily, may increase to 300 mg once daily after 4 days 2
• To minimize insomnia risk: If using twice-daily dosing, administer second dose before 3 p.m. 1

Key Precautions and Monitoring

Drug Interactions

1. Bupropion with Lamotrigine (Lamictal):

   • Both medications lower seizure threshold
   • Monitor closely for signs of increased seizure risk
   • Consider lower initial bupropion dose (e.g., 150 mg daily) 2

2. Bupropion with Prazosin:

   • Prazosin can cause orthostatic hypotension
   • Bupropion may increase blood pressure 2
   • Monitor blood pressure regularly, especially during the transition period

Contraindications for Bupropion

Bupropion should NOT be used in patients with:

• Seizure disorders
• Current or prior diagnosis of bulimia or anorexia nervosa
• Abrupt discontinuation of alcohol, benzodiazepines, barbiturates, or antiepileptic drugs
• Concurrent use of MAOIs 2

Specific Side Effects to Monitor

1. Seizure Risk:

   • Risk is dose-related
   • Limit daily dose to maximum 450 mg
   • Increase dose gradually
   • Discontinue if seizure occurs 2

2. Cardiovascular Effects:

   • Monitor blood pressure before and during treatment
   • Bupropion can increase blood pressure 2
   • Prazosin lowers blood pressure, creating potential for unpredictable BP changes

3. Neuropsychiatric Effects:

   • Watch for activation of mania/hypomania
   • Monitor for anxiety, agitation, or insomnia
   • Bupropion is activating and may worsen anxiety 1, 2

Timing Considerations

• Allow at least 24 hours between the last dose of atomoxetine and first dose of bupropion
• Start bupropion at a low dose in the morning
• Increase dose gradually while monitoring for side effects
• Consider administering prazosin at bedtime to minimize potential orthostatic hypotension during the day

Follow-up Schedule

• First follow-up: 1 week after starting bupropion
• Monitor vital signs, mood, anxiety, sleep, and any side effects
• Subsequent follow-ups: Every 2 weeks until stable on target dose
• Once stable: Monthly follow-ups for 3 months, then quarterly

Common Pitfalls to Avoid

1. Abrupt discontinuation of atomoxetine - can lead to withdrawal symptoms
2. Starting bupropion at too high a dose - increases seizure risk
3. Not monitoring for drug interactions - especially with lamotrigine
4. Ignoring sleep disturbances - bupropion can cause insomnia if taken late in the day
5. Overlooking blood pressure changes - the combination of bupropion and prazosin requires careful BP monitoring

By following these precautions and monitoring guidelines, the transition from atomoxetine to bupropion can be managed safely while maintaining the benefits of prazosin and lamotrigine in the treatment regimen.