Feb. 1, 2008 -- Federal officials warned Friday that a popular antismoking drug may be linked to suicides in some patients.
The drug, called Chantix, has been used by more than 5 million patients as a smoking cessation aid, according to manufacturer Pfizer Inc. The drug will now carry new labels warning doctors and consumers of reports of suicidal thoughts and behaviors.
FDA officials said they had received nearly 500 reports of suicidal thoughts, behaviors, and completed suicides, 420 of which were in U.S. patients. Thirty-four cases of completed suicide were recorded in the U.S., along with five cases overseas.
The reports don't prove that Chantix was the cause of the suicide. But FDA officials say their investigation showed several suicide cases in patients with no history of psychiatric problems.
"We've become increasingly concerned as we've seen that there are a number of compelling cases that truly look as though they are the result of exposure to the drug," said Bob Rappaport, MD, director of the FDA's Division of Anesthesia, Analgesia and Rheumatology Products.
"Clearly these are very concerning findings for this product, which is being very widely used," he told reporters on a telephone conference call.
The agency asked Pfizer to increase the prominence of warnings on the Chantix label. The company made similar changes to the label two weeks ago.
The drug was approved in May 2006 as a smoking cessation agent. It is different from the variety of nicotine gums, patches, and lozenges on the market. While those products help replace nicotine when patients quit, Chantix acts directly on brain centers affected by nicotine.
In a statement issued two weeks ago, Pfizer said any risks associated with Chantix should be balanced with the known risks of smoking.
"Chantix is a real breakthrough medicine that has helped many smokers who want to quit. We hope that today's labeling change will further facilitate the important dialogue that should always occur between patients and their doctors when considering any prescription medication," a release from the company stated.
Rappaport said the FDA considers Chantix "extremely important and extremely effective" in helping people quit smoking. But he said patients taking the drug and their doctors should be on the lookout for any behavior or mood changes.
"They should discuss with their health care provider as soon as possible whether they should continue with the drug or not" if mood changes occur, he said.
The FDA's public health advisory emphasizes the following safety information on Chantix:
- Patients should tell their doctor about any history of psychiatric illness prior to starting Chantix. Chantix may cause worsening of a current psychiatric illness even if it is currently under control and may cause an old psychiatric illness to reoccur.
- Health care professionals, patients, patients' families, and caregivers should be alert to and monitor for changes in mood and behavior in patients treated with Chantix. Symptoms may include anxiety, nervousness, tension, depressed mood, unusual behaviors, and thinking about or attempting suicide. In most cases, neuropsychiatric symptoms developed during Chantix treatment, but in others, symptoms developed following withdrawal of Chantix.
- Patients taking Chantix should immediately report changes in mood and behavior to their doctor.
- Patients taking Chantix may experience vivid, unusual, or strange dreams.
- Patients taking Chantix may experience impairment of the ability to drive or operate heavy machinery.
The FDA is working with Pfizer to finalize a medication guide for patients.