What is the proper dosage and administration of Wellbutrin (bupropion) for treating depression and seasonal affective disorder?

Bupropion (Wellbutrin) Dosage and Administration for Depression and Seasonal Affective Disorder

For treating depression and seasonal affective disorder, Wellbutrin (bupropion) should be started at 150 mg once daily in the morning for several days, then increased to the target dose of 300 mg once daily (or 150 mg twice daily for SR formulation), with careful monitoring for seizure risk and other adverse effects. 1, 2

Dosing for Major Depressive Disorder (MDD)

• For Wellbutrin XL (extended-release): Start with 150 mg once daily in the morning for 4 days, then increase to the target dose of 300 mg once daily in the morning 2
• For Wellbutrin SR (sustained-release): Start with 150 mg once daily for 3 days, then increase to 150 mg twice daily (300 mg total daily dose) 1
• Administer the second dose of SR formulation before 3 p.m. to minimize risk of insomnia 1
• Maximum dose for SR formulation is 400 mg per day, while maximum dose for XL formulation is 450 mg per day 1

Dosing for Seasonal Affective Disorder (SAD)

• Start with 150 mg once daily in the morning 2
• After 7 days, increase to the target dose of 300 mg once daily in the morning 2
• Doses above 300 mg were not assessed in SAD clinical trials 2
• Initiate treatment in autumn before onset of depressive symptoms and continue through winter 2
• When discontinuing in early spring, taper from 300 mg to 150 mg once daily before stopping completely 2

Administration Guidelines

• Bupropion XL tablets should be swallowed whole, not crushed, divided, or chewed 2
• May be taken with or without food 2
• To minimize seizure risk, increase dose gradually according to the recommended schedule 2

Special Population Considerations

Hepatic Impairment

• For moderate to severe hepatic impairment: Maximum dose is 150 mg every other day 2
• For mild hepatic impairment: Consider reducing the dose and/or frequency 2

Renal Impairment

• Consider reducing dose and/or frequency in patients with glomerular filtration rate less than 90 mL/min 2

Older Adults

• Start with lower doses (approximately 50% of standard dose) 1
• For older adults, consider starting at 37.5 mg every morning, then gradually increase by 37.5 mg every 3 days as tolerated 1
• Maximum recommended dose for older adults is 150 mg twice daily 1

Drug Interactions and Contraindications

• Allow at least 14 days between discontinuing MAOIs and starting bupropion, and vice versa 2
• Do not start bupropion in patients being treated with reversible MAOIs such as linezolid or intravenous methylene blue 2
• Bupropion inhibits CYP2D6 and may increase levels of drugs metabolized by this enzyme 3
• Avoid in patients with seizure disorders as bupropion lowers seizure threshold 1, 2

Monitoring and Safety Considerations

• Monitor closely for worsening depression and emergence of suicidal thoughts, especially when initiating therapy or changing doses 2
• Common side effects include nervousness, insomnia, headache, dry mouth, and nausea 3
• Bupropion has less sexual dysfunction compared to other antidepressants 3
• Seizure risk increases with doses above 450 mg per day 4
• Recent data suggests monitoring for potential adverse reactions including electrocardiogram QRS complex prolongation and false positive amphetamine tests 5

Efficacy Assessment

• Acute episodes of depression typically require several months of antidepressant treatment beyond the initial response 2
• If no response is seen after 6-8 weeks at an adequate dose, consider alternative treatment 1
• Periodically reassess the need for maintenance treatment and appropriate dosing 2

Clinical Pearls

• Bupropion may be particularly beneficial for patients with depression who also want to quit smoking 1
• May be effective for depression with decreased energy, pleasure, and interest 6
• Doses of 2.7g and higher in overdose can lead to seizures and cardiovascular effects 7

Remember that the goal of treatment is to achieve remission of depressive symptoms while minimizing side effects, with careful attention to seizure risk which is dose-dependent.