What dose of Wellbutrin (bupropion) should be initiated after a 2-week hiatus from a previous dose of 300mg?

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Last updated: December 23, 2025View editorial policy

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Restart at Lower Dose After 2-Week Bupropion Hiatus

After a 2-week discontinuation of Wellbutrin 300mg ER, you should restart at the lower dose of 150mg once daily and titrate back up to 300mg after 4 days, following the standard initiation protocol. 1

Rationale for Dose Reduction

The FDA label explicitly states that bupropion XL should be started at 150mg once daily in the morning, with dose escalation to 300mg after 4 days of dosing to minimize seizure risk. 1 This gradual titration is necessary even in patients previously tolerating higher doses because:

  • Seizure risk minimization is paramount - The primary safety concern with bupropion is dose-related seizure risk, which requires gradual dose escalation regardless of prior exposure. 1
  • Two weeks represents sufficient washout - After 2 weeks off medication, the patient's system has cleared the drug and its metabolites, effectively resetting their tolerance profile. 1
  • No exception exists for previously stable patients - The FDA labeling makes no distinction between treatment-naive patients and those restarting after a hiatus; the same initiation protocol applies. 1

Specific Dosing Protocol

Week 1 (Days 1-4):

  • Administer 150mg once daily in the morning. 1
  • Take with or without food. 1
  • Swallow whole; do not crush, divide, or chew. 1

Week 1 (Day 5 onward):

  • Increase to 300mg once daily in the morning if the 150mg dose is well tolerated. 1
  • This represents the target maintenance dose for major depressive disorder. 1

Critical Safety Considerations

Seizure threshold protection requires:

  • Adherence to the gradual titration schedule, as abrupt initiation at 300mg bypasses the safety buffer built into the dosing protocol. 1
  • Maximum daily dose must not exceed 450mg to maintain seizure risk at approximately 0.1%. 2, 3
  • Screening for new seizure risk factors that may have developed during the 2-week hiatus (alcohol withdrawal, new benzodiazepine use, head trauma, etc.). 4

Monitor for neuropsychiatric effects:

  • Increased suicide risk is highest during the first 1-2 months of treatment, particularly in patients under 24 years old. 4
  • Begin monitoring within 1-2 weeks of reinitiation for worsening depression, suicidal ideation, or behavioral changes. 4

Common Pitfalls to Avoid

Do not restart at 300mg directly - Even though the patient previously tolerated this dose, the 2-week gap necessitates retitration. The FDA provides no exemption for previously stable patients, and the seizure risk reduction strategy depends on gradual dose escalation. 1

Do not assume tolerance persists - Medication tolerance can diminish after discontinuation, and adverse effects like insomnia, dry mouth, or anxiety may reemerge during reinitiation. 2, 5

Timing matters for the second dose consideration - If the patient were on SR formulation (twice daily), the second dose must be given before 3 PM to minimize insomnia risk, though this patient is on XL (once daily). 4

Expected Timeline for Response

  • Early monitoring (1-2 weeks): Assess for adverse effects and neuropsychiatric symptoms. 4
  • Therapeutic assessment (6-8 weeks): Evaluate for adequate antidepressant response at the target dose before considering treatment modification. 4
  • Energy improvement may occur earlier: Some patients experience improvement in energy levels within the first few weeks, though full antidepressant effect requires 6-8 weeks. 4

References

Guideline

Bupropion Dosing and Administration

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

15 years of clinical experience with bupropion HCl: from bupropion to bupropion SR to bupropion XL.

Primary care companion to the Journal of clinical psychiatry, 2005

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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