Chantix raises the risk of depression or suicidal behavior and should be a drug of last resort, according to a study co-authored by Dr. Curt Furberg, professor of public health sciences at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina. The findings directly contradict a recent Food and Drug Administration review that found no difference in psychiatric hospitalizations between Chantix and nicotine patches.
Furberg called the FDA’s research “flawed” saying in a statement that the FDA studies could not capture serious psychiatric side effects such as suicide, depression, aggression and assaults because while such events can be catastrophic, they do not usually result in hospitalization.
Chantix, also called varenicline, already carries a black box warning because of reports of depression or suicidal behavior associated with the product. With the research revealing increased risks, the scientists now say that the drug should be the last choice among smoking cessation products.
“We found that Chantix is associated with more suicidal behavior reports than any other smoking-cessation drug on the U.S. market,” Furberg said. “The risks simply outweigh the benefits.”
Furberg said the scientists “strongly recommend” that the FDA revise the black box warning to say that varenicline has higher risks for depression and suicidal behavior than other quit smoking products.
Wake Forest researchers were joined in the study by the Institute for Safe Medication Practices, Harvard Medical School and Johns Hopkins University School of Medicine. The study is published in PLoS One, an online publication of the Public Library of Science.
In a statement to Reuters, Pfizer criticized the study’s reliance on reports of adverse events after the drug was marketed. Pfizer said that such reports “often lack important medical information,” which makes them unsuitable for study.
“These same authors persist in publishing analyses based on a review of spontaneous reports,” Pfizer said. “It is important to remember that post-marketing reports do not establish a cause and effect relationship between a medicine and a reported adverse event.”
The scientists studied 3,249 case reports of serious injury included in the FDA’s Adverse Event Reporting System from 1998 through September 2010. The study compared Chantix, GlaxoSmithKline (NYSE:GSK) smoking-cessation drug Zyban and nicotine replacement products. Of all the reported suicides related to smoking-cessation drugs in that nearly 13 year period, the researchers attribute 90 percent of them to Chantix even if the drug was only on the market for four years of the study period. Zyban was connected to only 7 percent of cases; nicotine replacement products with 3 percent. The researchers also found that varenicline was eight times more likely to result in a reported case of suicidal behavior or depression than nicotine replacement products.
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