Recommended Dosage and Treatment Regimen for Zyban (Bupropion) for Smoking Cessation
The recommended dosage of Zyban (bupropion SR) for smoking cessation is 150 mg once daily for the first 3 days, followed by 150 mg twice daily (300 mg total) for 7-12 weeks, starting 1-2 weeks before the target quit date. 1
Detailed Dosing Schedule
- Initial phase: 150 mg once daily for the first 3 days
- Maintenance phase: Increase to 150 mg twice daily (300 mg total)
- Duration: 7-12 weeks total, with possible extension up to 6 months to 1 year for continued cessation support
- Timing: Begin treatment 1-2 weeks before the planned quit date 1
Administration Considerations
- The maximum recommended daily dose is 300 mg to maintain the risk of seizure at approximately 0.1% 2
- For patients with moderate to severe hepatic or renal impairment, dose reduction should be considered 1
- The medication should be taken at least 8 hours apart to minimize insomnia risk
- Day 8 of treatment is typically recommended as the target quit date 3
Efficacy and Mechanism
Bupropion SR significantly improves 12-month abstinence rates compared to placebo:
- Studies show 23.1% abstinence at one year with 300 mg daily dosing versus 12.4% with placebo 4
- Works by reducing nicotine withdrawal symptoms through modulation of dopamine and norepinephrine reuptake 1
- Efficacy appears independent of its antidepressant effects 1
Contraindications
Bupropion SR is contraindicated in patients with:
- Seizure disorders or risk factors for seizures
- Concurrent use of MAO inhibitors
- Patients taking tamoxifen
- Closed-angle glaucoma
- History of eating disorders
- History of bipolar disorder 1, 5
Side Effects and Monitoring
Common side effects include:
- Insomnia (most common)
- Dry mouth
- Headache
- Nausea
- Anxiety 2
Serious but rare side effects (approximately 0.1% incidence):
Combination Therapy
- Combining bupropion with nicotine replacement therapy (NRT) may enhance efficacy for patients who have difficulty quitting with monotherapy
- One study showed 35.5% abstinence at 12 months with combination therapy versus 30.3% with bupropion alone, though this difference was not statistically significant 3
- Combination therapy may also help reduce weight gain associated with smoking cessation 1, 3
Clinical Pearls
- Evidence on effectiveness is primarily in medium to heavy smokers (15+ cigarettes per day) receiving behavioral support 1
- Bupropion helps limit weight gain during cessation (1.5-1.7 kg with bupropion vs 2.1 kg with placebo) 3, 4
- Behavioral support should ideally accompany medication therapy to boost success rates 5
- Monitor carefully for neuropsychiatric symptoms, particularly in patients with history of psychiatric disorders 1