Wellbutrin Starting Dosage
For major depressive disorder in adults, start Wellbutrin XL at 150 mg once daily in the morning, which can be increased to the target dose of 300 mg once daily after 4 days if tolerated. 1
Formulation-Specific Starting Doses
Wellbutrin XL (Extended Release)
- Initial dose: 150 mg once daily in the morning 1
- After 4 days, may increase to target dose of 300 mg once daily 1
- Swallow whole—do not crush, divide, or chew 1
- Can be taken with or without food 1
Wellbutrin SR (Sustained Release)
- Initial dose: 150 mg once daily for 3 days 2
- Then increase to 150 mg twice daily (300 mg total daily) 2
- The American College of Obstetricians and Gynecologists also recommends starting at 100-150 mg once daily, with maintenance at 150 mg twice daily 2
Special Population Adjustments
Older Adults (≥65 years)
- Start at 37.5 mg every morning 2
- Gradually increase by 37.5 mg every 3 days as tolerated 2
- Maximum dose: 150 mg twice daily (300 mg total) 2
- Administer second dose before 3 p.m. to minimize insomnia 2
- Lower starting doses (approximately 50% of standard dose) are appropriate due to increased risk of adverse reactions 2
Hepatic Impairment
- Moderate to severe (Child-Pugh 7-15): Maximum 150 mg every other day 1
- Mild (Child-Pugh 5-6): Consider reducing dose and/or frequency 1
- Total daily dose should not exceed 150 mg daily 2
Renal Impairment
- GFR <90 mL/min: Reduce total daily dose by half 2
- Consider reducing dose and/or frequency 1
- Close monitoring required as bupropion and metabolites are cleared renally 2
Critical Safety Considerations
Seizure Risk Minimization
- Always increase dose gradually to minimize seizure risk 1
- Maximum dose should not exceed 450 mg per day for XL formulation 2
- Maximum dose for SR is 400 mg per day 2
- Contraindicated in patients with seizure disorders 2
- Avoid in patients with bulimia or anorexia nervosa due to increased seizure risk 2
Drug Interactions
- Allow at least 14 days between discontinuing an MAOI and starting bupropion 1
- Conversely, allow at least 14 days after stopping bupropion before starting an MAOI 1
- Do not start in patients taking reversible MAOIs (linezolid, IV methylene blue) 1
- Contraindicated in patients taking tamoxifen 2
Monitoring Requirements
Initial Phase
- Monitor for neuropsychiatric adverse effects, especially in patients <24 years 2
- Monitor blood pressure—avoid in uncontrolled hypertension 2
- Assess for emergence of suicidal thoughts and behaviors 1
Efficacy Assessment
- If no response after 6-8 weeks at adequate dose, consider alternative treatment 2
- Periodically reassess need for maintenance treatment 1
Common Pitfalls to Avoid
- Do not crush, divide, or chew XL tablets—this destroys the extended-release mechanism and increases seizure risk 1
- Do not exceed recommended maximum doses—seizure risk increases dose-dependently 2
- Do not skip the gradual titration—rapid dose escalation increases adverse effects and seizure risk 1
- Screen carefully for seizure risk factors before initiating therapy 2