New York: Pfizer, the manufacturer of anti-smoking drug Chantix, has updated its label to include a warning on mental health symptoms.

CHANTIX® was approved in the US in May of 2006 as an aid to smoking cessation. Since then there have been a number of cases of suicide and suicidal behaviour by those taking Chantix. A causal relationship between the drug and these symptoms has not been established.

But the manufacturer has now included a warning on the CHANTIX label in the US that patients who are attempting to quit smoking with CHANTIX 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 FDA’s ongoing safety review of post-marketing reports, is provided to better ensure that healthcare providers and patients will appropriately consider this information in their discussions about CHANTIX.

A causal relationship between CHANTIX and these reported symptoms has not been established. 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 patients with these symptoms had quit smoking. Some patients 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.

In the controlled clinical trial program of more than 5,000 patients treated with CHANTIX, changes in behavior, agitation, depressed mood, suicidal ideation, and suicidal behavior occurred at a rate comparable to placebo-treated patients. There were no suicides attributed to CHANTIX in clinical trials. Patients with serious psychiatric illness such as schizophrenia, bipolar disorder, and major depressive disorder did not participate in the controlled clinical trial program.

CHANTIX, a selective nicotinic acetylcholine receptor partial agonist, is the first non-nicotine prescription treatment for smoking cessation in almost a decade. It has been prescribed to more than 4 million patients in the United States since approval.