Keep in mind that Zyban is Wellbutrin and Chantix is almost identical to Zoloft.
Chantix Gets Boxed In
Matthew Herper, 07.01.09, 05:20 PM EDT
The FDA says patients taking Chantix or Zyban need to be watched for suicide and other psychiatric problems.
The Food and Drug Administration will require a “black box” warning–the agency’s most urgent–that patients taking Chantix, the anti-smoking drug made by Pfizer, should be watched for suicide attempts and other side effects.
In a surprise move, the FDA will require the same prominent warning for Zyban, for GlaxoSmithKline ( GSK – news -people ), the other non-nicotine pill approved to help patients stop smoking. Nicotine-releasing patches and gums will not carry this warning.
The warning will appear in a black box atop the package inserts for both products and must be included in any advertisements. The FDA emphasized that it is not saying that the drugs should not be used, but that doctors and patients should take care to look for changes in behavior when they are prescribed.
“We don’t think people should stop using smoking cessation [products],” said Robert Temple, director of the FDA’s office of drug evaluation on a conference call with reporters. “Smoking is really bad for you. What you want is that people don’t [use the drugs] casually.”
The more prominent warnings are a blow to Pfizer ( PFE -news – people ), which has struggled to invent enough new drugs to replace aging blockbusters like Lipitor and Viagra, and for which Chantix was a rare hit. It is much less of a problem for GlaxoSmithKline, which makes little profit from Zyban, which is available as a generic.
Designed to hug the nicotine receptor so patients don’t get either cravings or pleasure from cigarettes, Chantix generated $700 million in U.S. sales in 2007, its first full year on the market. Wall Street analysts expected sales of $1 billion. But then stories started to emerge about the drug causing strange behavior and even suicide. The FDA has changed the warnings on the product’s labeling four times. U.S. sales dropped 30% to $489 million in 2008, and analysts at J.P. Morgan forecast U.S. sales of only $383 million this year.
Issues with Zyban emerged as a surprise when the FDA started looking into the alleged problems with Chantix, FDA officials said. Zyban, a re-branded version of the antidepressant Wellbutrin, was approved as a stop-smoking aid in 1997. The drug already has a boxed warning about suicidal thinking, as do other antidepressants.
Over the lifetimes of the products, the FDA received 98 reports of suicide with Chantix, along with 188 suicide attempts. For Zyban, there were 14 suicides and 17 attempts. FDA officials say that the reason for the big disparity in how many suicides were reported might be partly the result of all the bad publicity Chantix has received, as well as the fact that Zyban is used less often.
Such reports are notoriously inexact and don’t give researchers an idea of how often a problem occurs. Analysis of other types of reports, as well as a look at the specifics of some of the cases, led the agency to believe that patients needed to be warned loudly.
Temple said “it almost doesn’t matter” whether Chantix and Zyban are causing psychiatric issues or the problems are the result of nicotine withdrawal. What is important, he said, is that patients need to be watched for changes in behavior.
The FDA is also requiring Pfizer and GlaxoSmithKline to conduct new clinical trials of Chantix and Zyban to help figure out what the risks from the products are. The design of these studies has yet to be ironed out. Although Glaxo won’t benefit financially from clearing Zyban’s name, the FDA has powers under a recent law to compel the company to conduct a study. “We intend to work with the FDA to learn more about their requirements for a clinical trial that is in the best interest of patients and prescribers,” says Kevin Colgan, a GlaxoSmithKline spokesman.
When Chantix was approved, no large studies of the drug in mentally ill patients had been conducted, even though patients with psychiatric illnesses not only smoke, they smoke a lot. Eight of 10 schizophrenics smoke, and patients with mental illness consume 40% of all cigarettes. Pfizer is now conducting a 120-patient study of Chantix in schizophrenics. But Pfizer executives and the FDA indicated that larger studies might be needed to define what risks Chantix has. Pfizer says it stands behind the safety and efficacy of its drug.
Many prescription drugs have been implicated in rare increases in suicidality, including anti-epilepsy drugs, some antibiotics and the acne drug Accutane. Exactly why this would be so is not clear, the FDA said.