Can a patient start with once daily 100mg of bupropion (Wellbutrin) in the morning?

Starting Bupropion at 100mg Once Daily

No, a patient should not start bupropion at 100mg once daily in the morning—this dose is below the recommended starting dose and is not supported by FDA labeling or clinical guidelines. 1

FDA-Approved Starting Doses

The FDA label for bupropion XL (extended-release) specifies:

• Starting dose: 150 mg once daily in the morning 1
• After 4 days, may increase to target dose of 300 mg once daily 1
• The medication should be swallowed whole and not crushed, divided, or chewed 1

For bupropion SR (sustained-release), guidelines recommend:

• Starting dose: 150 mg once daily for 3 days, then increase to 150 mg twice daily 2
• Maximum dose for SR formulation is 400 mg per day 2

Why 100mg is Problematic

A 100mg starting dose is only mentioned in specific contexts:

For older adults with special considerations:

• The American Academy of Family Physicians suggests starting at 37.5 mg every morning for older adults, gradually increasing by 37.5 mg every 3 days 2
• This lower starting approach is reserved for geriatric patients at higher risk of adverse reactions 2

For bupropion SR formulation only:

• The American College of Obstetricians and Gynecologists mentions 100-150 mg once daily as an initial dose for bupropion SR specifically 2
• However, the standard recommendation remains 150 mg 2

Clinical Considerations

Seizure risk management:

• Gradual dose titration is essential to minimize seizure risk, which is approximately 0.1% at the recommended 300 mg/day dose 3
• The maximum daily dose should not exceed 450 mg per day for XL formulation to keep seizure risk below 0.1% 2, 1
• Patients with seizure disorders should not receive bupropion 2, 1

Therapeutic efficacy:

• Starting below 150 mg may delay therapeutic benefit, as onset of action is typically 2 weeks with full efficacy at 4 weeks 4
• Subtherapeutic dosing may lead to inadequate treatment response 5

Special Population Exceptions

Hepatic impairment:

• Moderate to severe hepatic impairment (Child-Pugh 7-15): maximum 150 mg every other day 1
• Mild hepatic impairment (Child-Pugh 5-6): consider dose/frequency reduction 1

Renal impairment:

• For GFR <90 mL/min: reduce total daily dose by half 2
• Consider reducing dose and/or frequency 1

Recommended Approach

For standard adult patients without contraindications:

• Start bupropion XL at 150 mg once daily in the morning 1
• After 4 days, increase to 300 mg once daily if tolerated 1
• Monitor for insomnia (give second dose before 3 p.m. if using SR formulation) 6

Common adverse effects to monitor:

• Insomnia, dry mouth, nausea, headache, and anxiety are most common 3
• These are generally transient and resolve without intervention 3
• Blood pressure monitoring is important as bupropion should be avoided in uncontrolled hypertension 2

Contraindications to verify before starting:

• Seizure disorders 2, 1
• Current or recent (within 14 days) MAOI use 2, 1
• Bulimia or anorexia nervosa (increased seizure risk) 2
• Patients taking tamoxifen 2