NEW YORK (AP) - Pfizer Inc. said Thursday it believes its anti-smoking drug Chantix, which has been linked to depression and suicidal thoughts, can be prescribed to patients with mental illness.
In an interview with The Associated Press, Pfizer Senior Medical Director Dr. Martina Flammer, who is also the medical team leader for Chantix, said that patients with a history of mental illness who are considering taking Chantix should let their doctors know of their condition.
But, 'there is no indication that there is any reason why Chantix should not be taken in this population,' Flammer said.
In November, the Food and Drug Administration began investigating reports of psychiatric events such as suicidal thoughts associated with Chantix. That prompted Pfizer to update the drug's labeling that patients should be monitored for unusual behavior.
Last month, the Federal Aviation Administration banned use of Chantix by pilots and air traffic controllers after a non-profit group's report warned of serious side effects.
Chantix works by binding to the same spots in the brain that nicotine does when people smoke, blocking nicotine from those spots but causing release of a 'feel-good' chemical, dopamine.
During a Thursday media briefing, Pfizer said it is conducting additional studies in several patient populations, including people suffering from schizophrenia, heart disease, emphysema, as well as adolescents. Also, the company plans on publishing the results later this year of an in-depth analysis of the psychiatric events seen in patients taking Chantix.
Pfizer also said it has funded grants to independent scientists to investigate severe adverse events of Chantix in patients with depression, schizophrenia and alcoholics.
During its own key trials, Pfizer said that it did not see an increase in psychiatric events in patients taking Chantix compared with placebo.
However, David Gonzales, co-director of Oregon Health & Science University's Smoking Cessation Center and who led the trials, told The AP that patients who reported schizophrenia and other mental illness were deliberately excluded from the trials so that adverse events couldn't be attributed to a pre-existing condition.
Dr. John Spangler, who has a family medicine practice in Winston-Salem, N.C., and is director of tobacco control programs at Wake Forest University Baptist Medical Center, said that following the initial reports of psychiatric events with Chantix, he decided not to give the drug as an initial treatment to patients with mental illness.
For those patients, he prefers to start them on GlaxoSmithKline's anti-smoking drug Zyban, which is also sold as an antidepressant.
Zyban, unlike Chantix, does not target nicotine receptors, but works on naturally occurring chemicals in the brain.
Dr. Kristen Santos, an internist in Troy, N.Y., said that her patients prescribed Chantix 'have done wonderfully on it.' However, she added that in patients with mental illness, she would likely not give Chantix as a first-line treatment.
Chantix is one of Pfizer's best-selling new drugs. For full-year 2007, the drug had sales of $883 million, while annual pharmaceutical revenue totaled $44.6 billion.
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