What is the recommended dosage of bupropion (Wellbutrin) for treating major depressive disorder and smoking cessation?

Bupropion Dosage for Major Depressive Disorder and Smoking Cessation

For major depressive disorder, bupropion XL should be started at 150 mg once daily in the morning for 4 days, then increased to the target dose of 300 mg once daily, while for smoking cessation, bupropion SR should be started at 150 mg once daily for 3 days, then increased to 150 mg twice daily. 1

Major Depressive Disorder (MDD) Dosing

Initial Dosing and Titration

• Start with bupropion XL 150 mg once daily in the morning 1
• After 4 days, increase to target dose of 300 mg once daily in the morning 1
• Bupropion should be swallowed whole, not crushed, divided, or chewed 1
• May be taken with or without food 1

Maintenance Treatment

• Long-term treatment beyond acute response is generally recommended 1
• Periodically reassess the need for maintenance treatment and appropriate dosing 1
• When discontinuing, taper from 300 mg to 150 mg once daily prior to full discontinuation 1

Smoking Cessation Dosing

Initial Dosing and Titration

• Start with bupropion SR 150 mg once daily 2, 3
• After 3 days, increase to 150 mg twice daily 3, 4
• Set a target quit date 1-2 weeks after initiating treatment 3
• Continue treatment for 7-12 weeks 3, 4

Efficacy for Smoking Cessation

• Bupropion SR has demonstrated efficacy for smoking cessation, even in patients with a history of depression or alcoholism 4
• Studies show 32% abstinence rates after 9 weeks of treatment 3

Maximum Dosage and Safety Considerations

Maximum Dosage

• Maximum daily dose should not exceed 450 mg per day 2
• Exceeding 450 mg/day significantly increases seizure risk 2

Dosage Adjustments for Special Populations

• Hepatic Impairment:

  • Moderate to severe impairment: Maximum 150 mg every other day 1
  • Mild impairment: Consider reducing dose and/or frequency 1

• Renal Impairment:

  • Consider reducing dose and/or frequency 1
  • For moderate to severe renal impairment, reduce total daily dose by half 5
  • Avoid in end-stage renal disease 5

Common Side Effects and Monitoring

Common Side Effects

• Insomnia (avoid taking late in the day) 5, 2
• Dry mouth 2, 6
• Anxiety/jitteriness 2
• Decreased appetite 2
• Headache 2
• Potential for increased blood pressure and heart rate 2

Seizure Risk

• Bupropion may lower seizure threshold 5, 6
• Avoid in patients with epilepsy or history of seizures 5, 2
• Seizure risk is comparable to other antidepressants when dosage is maintained at ≤450 mg/day 6

Drug Interactions

• Allow at least 14 days between discontinuing MAOIs and starting bupropion 1
• Allow at least 14 days after stopping bupropion before starting an MAOI 1
• Avoid use with linezolid or intravenous methylene blue due to risk of hypertensive reactions 1

Formulation Differences

Available Formulations

• Immediate Release (IR): Administered three times daily 7, 8
• Sustained Release (SR): Administered twice daily 7, 8
• Extended/Modified Release (XL/XR): Administered once daily 7, 8
• All three formulations are bioequivalent in terms of systemic exposure to bupropion 7, 8

Advantages of Newer Formulations

• Reduced frequency of daily administration 7, 8
• Improved adherence potential 7, 8

Clinical Pearls

• Bupropion has less sexual dysfunction compared to SSRIs 7, 8
• May be particularly beneficial for patients with depression who need to quit smoking 3
• Minimal weight gain observed during treatment 3, 7
• Less somnolence than some TCAs and SSRIs 7, 8
• Monitor for neuropsychiatric symptoms, especially in patients younger than 24 years 5