What is the starting dose of Bupropion (Wellbutrin XL) for an adult patient with major depressive disorder?

Starting Dose for Wellbutrin XL

For major depressive disorder in adults, start Wellbutrin XL at 150 mg once daily in the morning, then increase to the maintenance dose of 300 mg once daily after one week. 1

Initial Dosing Protocol

• Begin with 150 mg once daily for the first week to assess tolerability and minimize seizure risk 1
• Increase to 300 mg once daily after the first week if tolerated 1
• Administer in the morning to leverage bupropion's activating properties and minimize insomnia risk 1

Dose Titration and Maximum Dosing

• The maintenance dose is typically 300 mg once daily, which is effective for most patients with major depressive disorder 1
• The maximum dose is 450 mg once daily for Wellbutrin XL, though this should not be exceeded to maintain seizure risk at approximately 0.1% 1
• Allow 6-8 weeks at an adequate dose before determining treatment response 1

Special Population Adjustments

Older Adults

• Start with 37.5 mg every morning (using immediate-release formulation if XL not available in this strength) 1
• Gradually increase by 37.5 mg every 3 days as tolerated 1
• Maximum dose of 150 mg twice daily (300 mg total) for older adults 1

Hepatic Impairment

• Moderate to severe hepatic impairment: maximum 150 mg daily (one tablet) 1
• Consider using every-other-day dosing for severe impairment 1

Renal Impairment

• Moderate to severe renal impairment (GFR <90 mL/min): reduce total daily dose by 50% 1
• Close monitoring required as bupropion and metabolites are cleared renally 1

Critical Safety Screening Before Prescribing

Absolute contraindications that must be ruled out before starting: 1

• History of seizure disorder or any condition lowering seizure threshold
• Current or recent (within 14 days) MAOI use
• Eating disorders (bulimia or anorexia nervosa)
• Abrupt discontinuation of alcohol, benzodiazepines, or antiepileptic drugs
• Uncontrolled hypertension
• Current opioid use (if considering naltrexone-bupropion combination)

Monitoring Parameters

• Monitor blood pressure and heart rate periodically, especially during the first 12 weeks, as bupropion can elevate both 1
• Screen for neuropsychiatric symptoms including agitation, suicidal ideation, and behavioral changes, particularly in patients under 24 years old 1
• Assess treatment response at 1-2 weeks for early adverse effects and worsening depression 1
• Formal efficacy assessment at 6-8 weeks before considering treatment modification 1

Clinical Pearls

• Bupropion XL has lower rates of sexual dysfunction and weight gain compared to SSRIs, making it advantageous for patients concerned about these side effects 1
• Particularly beneficial for patients with depression characterized by low energy, apathy, or hypersomnia due to its activating dopaminergic/noradrenergic properties 1
• May provide dual benefit for patients who also want to quit smoking, addressing both depression and nicotine dependence 1
• The XL formulation is bioequivalent to SR and IR formulations under steady-state conditions, though once-daily dosing improves adherence 2, 3

Common Pitfalls to Avoid

• Do not exceed 450 mg/day to maintain seizure risk at 0.1% 1
• Do not switch between brand and generic formulations without close monitoring due to historical bioequivalence issues that may lead to loss of antidepressant effect 1
• Do not discontinue prematurely before 6-8 weeks unless significant adverse effects occur 1
• Do not prescribe late in the day as this increases insomnia risk 1