What is the recommended dosage of bupropion (Zyban) for smoking cessation?

Bupropion Dosage for Smoking Cessation

The recommended dosage of bupropion (Zyban) for smoking cessation is 150 mg once daily for the first 3 days, then 150 mg twice daily (300 mg total daily) for 7-12 weeks, starting 1-2 weeks before the target quit date. 1

Dosing Schedule

• Initiation phase: Begin 1-2 weeks prior to target quit date
  • Days 1-3: 150 mg orally once daily
  • Day 4 onward: 150 mg orally twice daily (maximum 300 mg per day)
• Duration: 7-12 weeks is standard, but may be extended up to 6 months to 1 year to promote continued cessation 2, 1

Efficacy

Bupropion significantly improves smoking cessation rates compared to placebo. Clinical trials have demonstrated that bupropion can more than double the chances of successful long-term smoking cessation compared to placebo, with 12-month abstinence rates of approximately 30% for bupropion versus 15% for placebo 3.

Contraindications

Bupropion is contraindicated in patients with:

• Seizure disorders or risk factors for seizures (stroke, brain metastases)
• Patients taking MAO inhibitors (risk of hypertensive reactions)
• Patients taking tamoxifen
• Closed-angle glaucoma 2, 1
• History of eating disorders 1

Side Effects and Safety

• Common side effects: Insomnia, dry mouth, headache, and nausea 4
• Serious but rare side effects:
  • Seizures (risk approximately 1 in 1000) 5, 4
  • Hypersensitivity reactions (approximately 1 in 1000) 4
  • Neuropsychiatric symptoms (depression, hostility, suicidal behavior) 2

Special Considerations

• Bupropion may help reduce weight gain commonly associated with smoking cessation 3
• The medication appears to be effective and well-tolerated in patients with COPD 6
• Combination therapy with nicotine replacement therapy may provide higher abstinence rates than bupropion alone, though the difference may not be statistically significant 3
• Dose adjustments may be considered if clinically indicated, particularly in patients with moderate to severe hepatic or renal impairment 1

Clinical Pearls

• Patients should be advised to take the second daily dose at least 8 hours after the first dose to minimize the risk of insomnia
• The most common reason for treatment discontinuation is adverse events (approximately 12% of patients) 4
• Behavioral support in addition to medication therapy significantly improves cessation rates 5
• Monitor for neuropsychiatric symptoms, particularly in patients with a history of psychiatric disorders

By following this dosing regimen and monitoring for potential side effects, bupropion can be an effective pharmacological aid for smoking cessation.