What is the dosing regimen for bupropion (Zyban) for smoking cessation?

Bupropion Dosing Regimen for Smoking Cessation

The recommended dosing regimen for bupropion (Zyban) for smoking cessation is to initiate 1-2 weeks prior to the quit date at 150 mg orally once daily for days 1-3, then increase to 150 mg orally twice daily from day 4 through 12 weeks, with a maximum dose of 300 mg per day. 1

Administration Timeline

• Start date: Begin 1-2 weeks before planned quit date
• Days 1-3: 150 mg once daily
• Day 4 through 12 weeks: 150 mg twice daily (if tolerated)
• Maximum duration: Typically 12 weeks, though therapy may be extended up to 6 months-1 year to promote continued cessation 1

Mechanism and Efficacy

Bupropion works by inhibiting nicotinic acetylcholinergic receptors and affecting the dopaminergic and adrenergic systems. It has demonstrated effectiveness for smoking cessation with a relative risk of 1.62 compared to placebo 1. While its efficacy is similar to nicotine replacement therapy, it appears less effective than varenicline 1.

Patient Selection Considerations

Potential Benefits

• May be particularly beneficial for patients with depression 1
• Extended pre-quit bupropion treatment (4 weeks vs. standard 1 week) may lead to greater pre-quit reductions in smoking and improved short-term abstinence rates 2

Contraindications

• Seizure disorders or increased seizure risk (stroke, brain metastases)
• Patients taking MAO inhibitors (risk of hypertensive reactions)
• Patients taking tamoxifen
• Closed-angle glaucoma
• History of eating disorders (anorexia/bulimia)
• History of bipolar disorder 1, 3

Monitoring and Follow-up

• Assess smoking status and medication side effects within 2-3 weeks of initiating therapy
• Continue periodic assessment at no more than 12-week intervals
• Follow-up approximately 12 weeks after completing pharmacotherapy 1

Side Effects and Safety

• Common side effects: dry mouth, sleep disturbance, insomnia, headache 4
• Serious but rare side effects:
  • Seizures (estimated risk: 0.1%) 1
  • Neuropsychiatric effects (depression, hostility, suicidal behavior)
  • Anaphylactic/hypersensitivity reactions (estimated 1 in 1,000) 4

Important Clinical Considerations

• Dose adjustments may be needed for patients with renal or hepatic impairment 3
• For patients who continue to smoke or relapse, consider switching to combination nicotine replacement therapy or varenicline before trying bupropion with combination NRT 1
• Combining bupropion with behavioral support significantly increases cessation success rates 4
• Recent evidence from the EAGLES trial showed no significant increase in neuropsychiatric events for bupropion compared to nicotine patch or placebo, even in patients with psychiatric disorders 1

Treatment for Persistent Smoking or Relapse

If the patient continues to smoke or relapses:

1. Consider continuing initial pharmacotherapy
2. Switch to alternative therapy (combination NRT or varenicline)
3. Consider combination NRT with bupropion as a subsequent option
4. Extend duration of pharmacotherapy if needed
5. Always pair with continued behavioral therapy 1