Can I add Buspar (buspirone) or clonidine to the treatment regimen of a patient taking Wellbutrin XL (bupropion) 150mg daily and Vyvanse (lisdexamfetamine) 30mg daily who is experiencing anxiety?

Managing Anxiety in a Patient on Wellbutrin XL and Vyvanse

Buspirone (BuSpar) is the recommended addition for managing anxiety in a patient taking Wellbutrin XL 150mg and Vyvanse 30mg daily. 1

Rationale for Medication Selection

Buspirone is specifically indicated for the management of anxiety disorders and has several advantages in this clinical scenario:

• FDA-approved for generalized anxiety disorder (GAD) 1
• Non-sedating anxiolytic that works through 5-HT1A serotonin receptors rather than GABA receptors 2
• Lacks the dependence potential and withdrawal concerns associated with benzodiazepines 3
• Has demonstrated efficacy in patients with coexisting depressive symptoms 1
• Can be safely used long-term (up to 1 year) without development of tolerance 4

Dosing Recommendations

• Start with 5mg twice daily for 7 days
• Increase to 7.5mg twice daily for another 7 days if needed
• Target dose: 15mg twice daily (BID dosing has similar safety profile to TID dosing and may improve compliance) 5
• Maximum dose: 30mg daily (divided doses)

Advantages of Buspirone over Clonidine

1. Mechanism compatibility: Buspirone works through serotonergic pathways 2, complementing Wellbutrin (dopamine/norepinephrine) and Vyvanse (dopamine) without direct overlap in mechanisms.

2. Specific anxiety indication: Buspirone is specifically indicated for anxiety disorders 1, while clonidine is primarily used for hypertension with off-label use for ADHD symptoms.

3. Fewer hemodynamic effects: Buspirone has minimal impact on blood pressure and heart rate compared to clonidine, which can cause hypotension and bradycardia.

4. Better side effect profile: Buspirone causes fewer sedative effects than clonidine, making it more compatible with the patient's current stimulant therapy.

Monitoring Recommendations

• Assess response after 2-4 weeks (full effect may take 3-4 weeks)
• Monitor for common side effects: dizziness, headache, nausea 5
• Less common side effects include nervousness and lightheadedness 3
• No need for laboratory monitoring

Important Precautions

• Avoid concurrent use with MAOIs due to risk of elevated blood pressure 1
• Be aware of potential for serotonin syndrome, especially if other serotonergic medications are added in the future 1
• Buspirone does not have established antipsychotic activity and should not be used for psychotic conditions 1
• Drug interactions: Buspirone levels may be increased by CYP3A4 inhibitors (e.g., erythromycin, ketoconazole) and decreased by CYP3A4 inducers 1

Alternative Considerations

If buspirone proves ineffective, bupropion XL has demonstrated comparable anxiolytic efficacy to escitalopram in GAD in a small pilot study 6, suggesting the current dose of Wellbutrin XL could potentially be optimized before adding other agents.

Patient Education

• Explain that buspirone differs from benzodiazepines:
  • No immediate relief (takes 2-4 weeks for full effect)
  • No sedation or cognitive impairment
  • No risk of dependence or withdrawal
• Advise that buspirone can be taken with or without food, but should be taken consistently
• Reassure that buspirone has been safely used for extended periods (up to 1 year) 4