What is the maximum dose of bupropion (Wellbutrin) XL (extended release)?

Maximum Dose of Bupropion XL

The maximum dose of bupropion XL is 450 mg per day, administered as a single daily dose. 1, 2

Standard Dosing for Bupropion XL

• Initial dose: 150 mg once daily in the morning 1
• Maintenance dose: 150-300 mg once daily 1
• Maximum dose: 450 mg per day 1, 2

The 450 mg maximum is critical to minimize seizure risk, which is the most serious adverse effect of bupropion. 2, 3 This ceiling dose applies specifically to the XL (extended-release) formulation and should never be exceeded. 1

Dose Adjustments for Special Populations

Hepatic impairment:

• Moderate to severe hepatic impairment (Child-Pugh score 7-15): Maximum dose is 150 mg every other day 2
• Mild hepatic impairment (Child-Pugh score 5-6): Consider reducing dose and/or frequency 2

Renal impairment:

• Moderate to severe renal impairment (GFR <90 mL/min): Reduce total daily dose by half 4, 1
• Bupropion and metabolites are cleared renally and may accumulate, requiring close monitoring for adverse reactions 2

Older adults:

• Start with lower doses (approximately 50% of standard dose) due to increased risk of adverse reactions 1
• Maximum dose for older adults is 300 mg total daily (150 mg twice daily for SR formulation) 1
• Consider age-related decline in renal function when selecting dose 2

Critical Safety Considerations

Seizure risk is dose-dependent:

• The risk of seizures increases substantially above 450 mg/day 1, 3, 5
• At recommended doses (≤450 mg/day for immediate-release, ≤400 mg/day for SR), seizure incidence is approximately 0.1%, comparable to other antidepressants 5, 6
• Overdoses of 2.7g and higher can lead to seizures, encephalopathy, and cardiovascular effects 7

Absolute contraindications:

• Seizure disorders or conditions that lower seizure threshold 1, 2
• Concurrent MAOI use or within 14 days of discontinuing MAOIs 1, 2
• Bulimia or anorexia nervosa (increased seizure risk) 4

Formulation Differences

The maximum dose differs by formulation:

• Bupropion XL (extended-release): 450 mg per day 1, 3
• Bupropion SR (sustained-release): 400 mg per day 3
• Bupropion immediate-release: 450 mg per day in divided doses 3

For the XL formulation specifically, the entire daily dose is taken once in the morning, unlike SR which is dosed twice daily. 1

Monitoring Requirements

• Monitor for neuropsychiatric adverse effects, especially in patients younger than 24 years 1
• Monitor blood pressure, as bupropion should be avoided in uncontrolled hypertension 1
• Assess efficacy after 6-8 weeks at an adequate dose; if no response, consider alternative treatment 1