Meta-Study Researchers To Pfizer: Quit Chantix

A meta-analysis that looks at 14 clinical trials involving 8,216 patients of Pfizer's smoking-cessation drug Chantix finds that its use can be linked to a 72% increase in risk of cardiovascular problems -- including stroke and congestive heart failure -- according to findings published this morning in the Canadian Medical Association Journal.

"I stopped prescribing Chantix several months ago, as soon as we found out about this data," says Sonal Singh, a lead author of the study and a doctor and professor at Johns Hopkins University School of Medicine. "I'm not saying that nobody should use it, but I think people should have this information. They should decide whether the risk is acceptable to them."

Co-author Curt D. Furberg of Wake Forest says, "The sum of all serious adverse effects of Chantix clearly outweighs the most positive effect of the drug," Thomas M. Burton writes in the Wall Street Journal. He called for its removal from the market.

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"Pfizer disagrees with the interpretation of the data," its vp of medical affairs, Gail Cawkwell, emails Bloomberg's Tom Randall. "The health benefits of quitting smoking are immediate and substantial. Pfizer strongly believes in and supports Chantix as an important treatment option." She tells the Journal's Burton "about one in 100 people in the studies had cardiovascular problems."

Pfizer and the Food and Drug Administration also respond that they have been planning to conduct a joint analysis of clinical trials on whether Chantix posed heart risks, Duff Wilson reports in the New York Times. "This would have raised a red flag for us if the flag hadn't already been flying," Dr. Celia Winchell, a team leader with the FDA's Center for Drug Evaluation and Research, tells Wilson. The report is due next year.

Chantix is non-nicotine prescription medicine that works in two ways, according to Pfizer. It targets nicotine receptors in the brain, attaches to them, and blocks nicotine from reaching them. Pfizer also believes that Chantix activates these receptors, causing a reduced release of dopamine compared to nicotine.

"There are lots of other options to help people stop smoking that don't involve drugs," Dr. Yoon Loke of the University of East Anglia, who worked on the review, told the BBC. While admitting that the numbers are small, Loke says that's probably because the studies looked at healthy people. Loke believes that the risk could be greater for smokers who already have heart problems.

Matt McMillen, writing in WebMD Health News, points out that the FDA last month issued a notice that Chantix may be associated with a small, increased risk of heart attacks and other cardiovascular problems among smokers with cardiovascular disease.

And Fair Warning's Lilly Fowler reports that Pfizer never tested Chantix on the mentally ill or those with a recent history of depression during clinical trails "even though millions of smokers suffer from psychiatric problems." Since the drug was approved in May 2006, thousands of Chantix users have suffered serious psychiatric events, including suicides and depression, Fowler writes. As a result, the drug has carried a black box warning, the FDA's strongest safety alert, since 2009 that begins: "Some people have had changes in behavior, hostility, agitation, depressed mood, suicidal thoughts or actions while using Chantix to help them quit smoking..."

Chantix' sales of $755 million last year were down 14% from its high of $883 million in 2007, according to data compiled by Bloomberg.

The risk of suffering cardiovascular problems was 1.06% among those taking Chantix, according to the data compiled in the study, compared with 0.82% among those given a placebo.

Tina Kaufman, an assistant professor of medicine and smoking cessation coordinator at Oregon Health and Science University who was not involved with the study, tells WebMD's McMillen that doctors should discuss with patients the issues the study raises but she believes cardiologists will still continue to prescribe the treatment.

"We're talking about a small risk compared to the huge benefits of quitting," Kaufman says. "It's far more dangerous for them to continue smoking."

On a side note, Chantix' marketing materials makes interesting use of the word "quit" as a state of being in and of itself. Copy for its "Chantix Challenge," which offers full refunds to anyone who has not stopped smoking after 12 weeks of using the product, as well as its GETQUIT program of telephone and online support, feature variations on the theme of "if you are not quit."

Copywriters being the copycats that they are, will we soon be seeing "If you are not lose" for Weight Watchers or Jenny Craig?

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