What is the appropriate dosage of Wellbutrin XL (bupropion XL)?

Wellbutrin XL Dosage

For major depressive disorder, start Wellbutrin XL at 150 mg once daily in the morning, then increase to the target dose of 300 mg once daily as early as day 4 if tolerated, with a maximum dose of 450 mg once daily for patients without clinical improvement after several weeks at 300 mg. 1

Standard Dosing Algorithm

Major Depressive Disorder

Initial dosing:

• Start at 150 mg once daily in the morning
• Increase to 300 mg once daily (target dose) as early as day 4 if adequately tolerated
• Maintain at least 24 hours between doses 1

Dose escalation for inadequate response:

• If no clinical improvement after several weeks at 300 mg/day, increase to maximum 450 mg once daily
• Full antidepressant effect may not be evident until 4 weeks or longer 1

Seasonal Affective Disorder

Prophylactic dosing:

• Start at 150 mg once daily in autumn before symptom onset
• Increase to 300 mg once daily after 1 week if tolerated
• Continue through winter season
• Taper to 150 mg daily for 2 weeks before spring discontinuation 1

Note: Doses above 300 mg/day have not been studied for seasonal affective disorder 1

Smoking Cessation

When used for smoking cessation (off-label), the NCCN guidelines recommend:

• Days 1-3: 150 mg once daily
• Day 4 through 7-12 weeks: 150 mg twice daily if tolerated
• Maximum 300 mg per day
• Initiate dosing 1-2 weeks prior to quit date 2

Critical Dosing Considerations

Hepatic Impairment

• Severe hepatic cirrhosis: Maximum 150 mg every other day (use with extreme caution)
• Mild-to-moderate hepatic impairment: Reduced frequency and/or dose required 1

Renal Impairment

• Use with caution; reduced frequency and/or dose should be considered 1

Administration Requirements

• Swallow tablets whole - do not crush, divide, or chew (increases seizure risk) 1
• May be taken without regard to meals 1
• Avoid bedtime dosing to minimize insomnia 1

Important Safety Warnings

Seizure risk management:

• Gradual dose escalation is essential to minimize seizure risk 1
• Bupropion lowers seizure threshold - contraindicated in patients with seizure disorders, brain metastases, or stroke 2
• Avoid in patients taking MAO inhibitors (within 14 days) 2

Common side effects requiring management:

• Agitation, motor restlessness, and insomnia are common during initial days
• May require temporary dose reduction or short-term sedative-hypnotic (usually not needed beyond first week) 1
• Monitor for neuropsychiatric adverse effects including suicidal thoughts, especially in patients under 24 years 3

Duration of Treatment

Maintenance therapy:

• Acute depression episodes require several months or longer of sustained treatment beyond initial response 1
• Periodically reassess need for continued treatment 1
• For smoking cessation, therapy may be extended to 6 months-1 year while attempting to avoid longer periods 2

Switching from Other Bupropion Formulations

When switching from immediate-release or SR formulations to XL:

• Give the same total daily dose when possible
• Patients on 300 mg/day of immediate-release (100 mg three times daily) or SR (150 mg twice daily) may switch to 300 mg once daily of XL 1