FDA OKs New Quit-Smoking Drug

Chantix Eases Withdrawal Symptoms and Blocks Nicotine's Effects

Medically Reviewed by Ann Edmundson, MD, PhD on May 11, 2006
From the WebMD Archives

May 11, 2006 -- The FDA has approved a new drug to help cigarette smokers quit smokingquit smoking.

The drug is called Chantix. It comes in tablet form and is not recommended for pregnant smokers, smokers younger than 18, or use with other smoking-cessation products, the FDA's Curt Rosebraugh, MD, MPH, told reporters at a teleconference.

Rosebraugh is the deputy director of the Office for Drug Evaluation II at the FDA's Center for Drug Evaluation and Research.

The active ingredient in Chantix, varenicline tartrate, is a new drug that got a priority FDA review; it took six months for approval instead of the usual 10 months for routine reviews.

"We did a priority review because at the time the application was filed, a preliminary review of the efficacy studies indicated that smokers treated with Chantix may have a superior rate of smoking cessationsmoking cessation compared to another currently approved smoking-cessation product, which was Zyban," Rosebraugh says.

12 Weeks of Treatment

The approved course of Chantix treatment is 12 weeks, but longer treatment may help some patients. In addition to Chantix, counseling is also recommended as part of the treatment program.

"The way that the label is written is that if you take 12 weeks of therapy and successfully stop smoking at the end of that 12 weeks, an additional 12-week course of treatment is recommended to further increase the likelihood of long-term smoking cessation," Rosebraugh says.

Chantix acts at the same sites in the brain as nicotine. It may help people who want to quit smoking in two ways: by providing some nicotine effects to ease withdrawal symptoms and by blocking the effects of nicotine from cigarettes if they resume smoking.

"Cigarette smoking is a very difficult habit to break due in large part to nicotine dependence or addiction," says Steven Galson, MD, MPH, in the FDA news release. Galson directs the FDA's Center for Drug Evaluation and Research.

"Chantix therapy has proven to be effective in smokers motivated to quit and will provide another tool for physicians to use for the millions of smokers who want to quit," Galson says.

Chantix Trials

The effectiveness of Chantix in smoking cessationsmoking cessation was demonstrated in six clinical trials, which included 3,659 chronic cigarette smokers who were treated with Chantix.

Five of the six studies were randomized, controlled clinical trials in which Chantix was shown to be superior to placebo in helping people quit smokingquit smoking. These smokers had previously averaged 21 cigarettes a day for about 25 years.

In two of the five placebo-controlled studies, Chantix-treated patients were also more successful in giving up smoking than patients treated with Zyban, states the FDA's news release.

In those two studies, both Chantix and Zyban were superior to placebo. After 12 weeks of treatment, a bigger proportion of Chantix users had quit smoking.

But 50 weeks after treatment stopped, the differences between the percentage of people who had used Chantix or Zyban and were still smoke-free weren't statistically significant, meaning they may have been due to chance, notes Rosebraugh.

In clinical trials, the most common adverse effects of Chantix were nausea, headache, vomiting, flatulence (gas), insomniainsomnia, abnormal dreams, and dysgeusia (change in taste perception), according to the FDA.

Chantix is made and distributed by the drug company Pfizer.

American Cancer Society's Comments

The American Cancer Society issued a statement on Chantix. The statement is attributed to Thomas J. Glynn, PhD, the American Cancer Society's director for cancer and science trends and for international tobacco programs.

In the statement, Glynn calls the drug's approval "very welcome news."

While noting that long-term results in real-life settings aren't yet clear, Glynn says "if smokers comply with the Chantix treatment regimen and take advantage of an accompanying behavioral treatment program, we would expect success rates to be high and, equally important, that smokers and those who treat them will have an important new tool to call upon."

Show Sources

SOURCES: Curt Rosebraugh, MD, MPH, deputy director, Office of Drug Evaluation II, Center for Drug Evaluation and Research, FDA. News release, FDA. American Cancer Society statement attributed to Thomas J. Glynn, PhD, American Cancer Society director for cancer science and trends, American Cancer Society director for international tobacco programs.
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