Pfizer toughens Chantix label on depression

Based upon post-marketing reports first reflected in a November 2007 labeling update, global drug giant Pfizer updated the labeling of its smoke-cessation drug Chantix (varenicline) in the USA to include a warning that patients who are attempting to quit smoking with the product should be observed for serious neuropsychiatric symptoms, including changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior.

The current update, based on Pfizer and the Food and Drug Administration's ongoing safety review of post-marketing reports, is provided to better ensure that health care providers and patients will appropriately consider this information in their discussions about (Marketletter November 11, 2007). A causal relationship between the drug and these reported symptoms has not been established, says Pfizer. In some reports, however, an association could not be excluded. More specifically, some reports may have been complicated by the symptoms of nicotine withdrawal in patients who stopped smoking, but not all people with these symptoms had quit smoking. Some with pre-existing psychiatric illness experienced a worsening of their conditions. By heightening awareness of these post-marketing events and facilitating this discussion, patients and doctors can play an important role in mitigating potential risk and ensuring the full benefits of CHANTIX can be realized, Pfizer noted.

Chantix was approved by the FDA in May 2006 and has been prescribed around four million times, generatin turnover of some $240.0 million in third-quarter 2007.