Pfizer Updates Chantix Warnings

The world’s leading pharmaceutical company, Pfizer Inc. announced on Friday that it has added stronger warnings to its popular anti-smoking drug Chantix, including language about depression and suicidal behavior. The company had been under pressure from regulators for over a year to do the same.

Patient advocacy groups, health bloggers, and the U.S. Food and Drug Administration have been consistently asking Pfizer to update warnings of the drug over the past year as patients have reported erratic behavior and serious mood symptoms while taking Chantix.

Pfizer said that it had enacted a label change for Chantix last year also after working with the U.S. Food and Drug Administration. Pfizer officials said that the new label offers a similar recommendation to monitor patients, but the language is more prominently located to better get the attention of doctors.

Ponni Subbiah, Vice President of Pfizer said, "By putting this information in a more prominent location we're hoping it will be included in the dialogue between patients and physicians." He added that the revised section is not a “black box,” a warning reserved for what the FDA deems the most dangerous potential adverse events.

The new label includes a warning that patients who are attempting to quit smoking by taking Chantix should be observed by a physician for serious neuropsychiatric symptoms like changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior.

Pfizer stressed on the fact that a direct link between Chantix and the problems has not yet been established, but it also cannot be ruled out. Subbiah said that because nicotine withdrawal alone increases the risk of suicide, it may never be possible to sort out whether Chantix aggravates dangerous behavior.

Last month only, European regulators had said that they would conduct their own investigation into the drug's safety, and had asked the company for more information about behavioral changes. The drug is sold by the name of Champix in European markets.

Chantix was approved in May 2006 and has since been prescribed more than 4.0 million times in the U.S. alone. The drug has been a success story for Pfizer having generated sales of $241 million in the most recent quarter compared to older drugs which face stiff competition from cheaper generics.

Chantix is a twice-daily tablet that works by binding to nicotine receptors in the brain, reducing the symptoms of withdrawal. The FDA is currently also reviewing the drug’s safety.