From the Guidelines
Varenicline (Chantix) is the preferred treatment over bupropion (Zyban) for smoking cessation due to its superior efficacy, as evidenced by a recent study published in the Journal of the National Comprehensive Cancer Network 1. The study found that varenicline increases the odds of smoking cessation by almost 3-fold compared with placebo, and is more efficacious than bupropion, with an odds ratio of 1.59. Some key points to consider when using varenicline include:
- Starting dose: 0.5 mg once daily for days 1-3, then 0.5 mg twice daily for days 4-7, then 1 mg twice daily for the remainder of the 12-week treatment period
- Common side effects: nausea, insomnia, and abnormal dreams
- Contraindications: pregnancy, and requires dose adjustment in renal impairment
- Mechanism of action: partially activates nicotine receptors while blocking nicotine binding, reducing both withdrawal symptoms and smoking satisfaction In contrast, bupropion is an acceptable alternative, but has a lower efficacy rate compared to varenicline, as shown in a study published in the same journal 1. It is dosed at 150 mg once daily for 3 days, then 150 mg twice daily for 7-12 weeks, also starting 1-2 weeks before the quit date. Bupropion works by inhibiting dopamine and norepinephrine reuptake, decreasing withdrawal symptoms. Both medications should be combined with behavioral counseling for optimal results. Another study published in the Journal of the National Comprehensive Cancer Network also found that varenicline is safe and has a favorable risk/benefit ratio for use in patients with cancer who smoke 1. Overall, the evidence suggests that varenicline is the preferred treatment for smoking cessation due to its superior efficacy and safety profile.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Comparison of Bupropion and Varenicline for Smoking Cessation
- Varenicline has been shown to be more effective than bupropion in achieving smoking cessation, with higher continuous abstinence rates at weeks 9-12 and weeks 9-52 2, 3, 4.
- Studies have demonstrated that varenicline is associated with significantly higher odds of remaining abstinent compared to bupropion, with odds ratios ranging from 1.69 to 3.85 2, 4.
- Varenicline has been found to attenuate the urge to smoke, negative affect withdrawal symptoms, and the reinforcing effects of smoking, making it a valuable new agent for smoking cessation treatment 2, 5.
- Common adverse events associated with varenicline include nausea, insomnia, and headache, while bupropion is associated with a higher discontinuation rate due to adverse events 6, 3, 4.
Efficacy of Varenicline vs Bupropion
- A randomized controlled trial found that varenicline had a higher continuous abstinence rate at weeks 9-12 (43.9%) compared to bupropion (29.8%) and placebo (17.6%) 4.
- Another study found that varenicline demonstrated both short-term and long-term efficacy, with continuous quit rates significantly higher than placebo and bupropion at weeks 4-52 3.
- Varenicline has been shown to be effective in reducing the rewarding effects of nicotine and relieving nicotine withdrawal symptoms, making it a promising treatment for smoking cessation 5, 4.
Safety and Tolerability
- Varenicline is generally well tolerated, with the most common adverse events being nausea, insomnia, and headache 6, 4.
- Bupropion is associated with a higher discontinuation rate due to adverse events, with 12.6% of participants discontinuing treatment compared to 10.5% for varenicline and 7.3% for placebo 4.
- Varenicline has been linked to an increase in neuropsychiatric symptoms, such as seizures, suicidal attempts, and depression, in certain high-risk populations, including patients with mental illness and operators of commercial vehicles or heavy machinery 6.