What is the efficacy of Champix (varenicline)?

From the Guidelines

Champix, also known as varenicline, is the most effective single pharmacotherapy option for smoking cessation, with a higher success rate compared to bupropion and nicotine replacement therapy (NRT) 1. The standard treatment regimen begins with a one-week titration: 0.5mg once daily for days 1-3, then 0.5mg twice daily for days 4-7, followed by 1mg twice daily for the remainder of the 12-week treatment period. You should set a quit date for 1-2 weeks after starting the medication and continue taking Champix even if you slip up and smoke. Common side effects include nausea, sleep disturbances, headache, and vivid dreams. Champix is effective because it addresses both the physical and psychological aspects of nicotine addiction by managing withdrawal symptoms while reducing the reinforcing effects of smoking. It's essential to combine this medication with behavioral support, such as counseling or support groups, for the best chance of quitting successfully, as even brief advice to quit tobacco smoking provided by a clinician increases the rate of quitting in persons who smoke 1. Those with certain psychiatric conditions or kidney problems should discuss these with their doctor before starting treatment. Additionally, varenicline may also be efficacious for smoking reduction, and an additional 12 weeks of varenicline maintenance therapy can help sustain continued abstinence in those who successfully quit during initial treatment 1. Behavioral therapy, including group and individual in-person counseling, telephone-based support, interactive internet-based interventions, and text message–based interventions, can also increase quit rates, with a meta-analysis of 37 RCTs showing a 22% increase in abstinence rates at 6 to 12 months 1. Some key resources for smoking cessation include the National Cancer Institute's Smokefree.gov, the Asian Smokers’ Quitline, and the BecomeAnEX program, which offer a range of support services, including counseling, text messaging, and online communities 1. Overall, varenicline is a highly effective medication for smoking cessation, and its use in combination with behavioral support can significantly increase the chances of quitting successfully.

From the FDA Drug Label

Varenicline (1 mg twice daily) did not alter the steady-state pharmacokinetics of bupropion (150 mg twice daily) in 46 smokers The efficacy of varenicline in smoking cessation was demonstrated in six clinical trials in which a total of 3659 chronic cigarette smokers (≥10 cigarettes per day) were treated with varenicline.

• Varenicline is used for smoking cessation.
• The drug has been shown to be effective in aiding smoking cessation in multiple clinical trials.
• Varenicline can be used in combination with other drugs for smoking cessation, such as bupropion, but the incidence of adverse reactions may be greater when combined with NRT 2.

From the Research

Overview of Champix (Varenicline)

• Champix, also known as varenicline, is a medication used to aid in smoking cessation therapy 3, 4, 5, 6, 7.
• It is an orally administered alpha4beta2 nicotinic acetylcholine (ACh) receptor partial agonist 3, 5, 7.

Efficacy of Champix

• Studies have shown that varenicline is an effective aid to smoking cessation, with higher continuous abstinence rates compared to placebo, bupropion, and nicotine replacement therapy 3, 4, 5, 6, 7.
• Varenicline has been shown to attenuate the urge to smoke, negative affect withdrawal symptoms, and the reinforcing effects of smoking 3, 5.
• Extending varenicline therapy by an additional 12 weeks has been shown to increase the likelihood of long-term abstinence 3, 5, 6.

Safety and Tolerability of Champix

• Varenicline is generally well tolerated, with nausea being the most commonly occurring adverse event 3, 5, 6.
• Other adverse events include insomnia, sleep disorder, and neuropsychiatric events, although these are usually mild to moderate and can be managed 5, 6, 7.
• The safety profile of varenicline has been assessed in several studies, with no major concerns identified 5, 6.

Comparison with Other Smoking Cessation Therapies

• Varenicline has been compared to bupropion and nicotine replacement therapy in several studies, with varenicline showing superior efficacy in maintaining abstinence and reducing craving 4, 5, 7.
• Varenicline has also been shown to be cost-effective compared to other smoking cessation therapies, with acceptable incremental costs per QALY gained 5.