Bupropion (Wellbutrin) Dosing Guidelines
The recommended dosing for Wellbutrin (bupropion) varies by formulation, with SR (sustained release) starting at 150 mg once daily for 3 days then increasing to 150 mg twice daily (300 mg total), and XL (extended release) starting at 150 mg once daily and increasing to 150-300 mg once daily, with a maximum dose of 450 mg per day. 1, 2, 3
Formulation-Specific Dosing
Bupropion SR (Sustained Release)
- Initial dose: 100-150 mg once daily 1, 2
- Titration: After 3 days, increase to 150 mg twice daily 2
- Maintenance dose: 150 mg twice daily (300 mg total daily) 1, 2
- Maximum dose: 400 mg per day 4
- Administration: Divided into two daily doses 1
Bupropion XL (Extended Release)
- Initial dose: 150 mg once daily in the morning 1, 2
- Maintenance dose: 150-300 mg once daily 1, 2
- Maximum dose: 450 mg per day 1, 3
- Administration: Once daily dosing, preferably in the morning 1, 2
Indication-Specific Dosing
For Major Depressive Disorder (MDD)
- SR formulation: Start with 150 mg once daily for 3 days, then increase to 150 mg twice daily 2
- XL formulation: Start with 150 mg once daily, may increase to 300 mg once daily after several weeks if needed 2, 3
- Clinical trials have demonstrated efficacy at doses of 300-450 mg daily 3, 5
For Smoking Cessation
- SR formulation: 150 mg twice daily (300 mg total) 1, 2
- Begin treatment 1-2 weeks before target quit date 1, 2
- Typical duration: 7-12 weeks 1, 2
- Monitor efficacy after 7-12 weeks of treatment 2
Dose Adjustments for Special Populations
Hepatic Impairment
- For moderate to severe hepatic impairment: Do not exceed 150 mg daily (one tablet) 2
- Consider using SR formulation for more flexible dosing in patients requiring dose adjustments 2
Renal Impairment
- For moderate to severe renal impairment: Reduce total daily dose by half 2
Safety Considerations and Monitoring
Seizure Risk
- Maximum dose should not exceed 450 mg per day to minimize seizure risk 1, 3, 6
- Contraindicated in patients with seizure disorders 1, 2
- Incidence of seizures is approximately 0.1% at recommended doses 6
- Gradual dose titration is essential to minimize seizure risk 4
Drug Interactions
- Avoid use with monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOIs 1, 2
- Contraindicated in patients taking tamoxifen 1
Common Side Effects
- Most common: insomnia, headache, dry mouth, nausea, and anxiety 6
- Only insomnia and dry mouth occur significantly more frequently than with placebo 6
- Most side effects are transient and often resolve quickly without intervention 6
- Side effects can be managed by dose reduction if necessary 6
Clinical Pearls
- Onset of action is typically 1-2 weeks with full efficacy at 4-6 weeks 4
- Bupropion has minimal sexual side effects compared to SSRIs 5
- Weight loss rather than weight gain may occur with bupropion treatment 7
- Particularly beneficial for patients with depression who also want to quit smoking 2
- Monitor for neuropsychiatric adverse effects, especially in individuals younger than 24 years 2
- Monitor vital signs, particularly blood pressure, as bupropion should be avoided in patients with uncontrolled hypertension 2