Chantix (varenicline) is a new prescription drug designed to help smokers quit by stimulating the release of small amounts of dopamine, the brain chemical that mediates pleasure. A lack of dopamine is responsible for the irritability and other withdrawal symptoms that people addicted to tobacco feel when they try to quit and that drive so many of them to light up again. Nicotine replacement products (the patch, gum, lozenges and the drug Zyban) all work by prompting the release of low levels of dopamine. The purported advantage of Chantix is that also makes smoking less pleasurable by blocking nicotine receptors in the brain.
You may have read claims that Chantix works better than Zyban or a placebo. Clinical trials showed that of those who took Chantix for 12 weeks, 44 percent quit smoking compared to 30 percent of those who took Zyban and 17 percent of those who received a placebo. That means, of course, that even during a 12-week trial, 56 percent of those who took Chantix were not able to quit smoking. Less well publicized is the fact that over the course of a year, only 14 to 23 percent of those who used Chantix in the study remained smoke-free. Side effects of the drug included nausea (affecting about 30 percent of all study participants), headache, vomiting, gas, insomnia, abnormal dreams and changes in taste perception. Chantix can also affect kidney function and probably should be avoided by anyone with kidney problems, especially those on dialysis.
Chantix (or any other drug) wouldn't be my first choice of a strategy to stop smoking. I don't underrate the difficulty of quitting. Tobacco in the form of cigarettes is the most addictive drug in the world, and nicotine is one of the strongest stimulants known. Most smokers who manage to quit do it on their own after one or more unsuccessful attempts, and most find that stopping cold turkey is better than trying to cut down gradually.
If you're determined to quit, you have many options – acupuncture, hypnosis, nicotine gum, and support groups. All can help, but no single method works for everyone. Whatever method you choose, if you don't immediately succeed, recognize that very few people do, and keep trying. The best predictor for eventual success is making repeated attempts to break the habit. Good luck!
Andrew Weil, M.D.