October 24, 2011 — A review by the US Food and Drug Administration (FDA) of 2 epidemiological studies evaluating the risk for neuropsychiatric adverse events associated with varenicline (Chantix, Pfizer) and nicotine replacement therapy suggests there is no difference between the 2 smoking cessation therapies.
However, importantly, the FDA notes that both studies had a number of limitations, including the fact that they only assessed neuropsychiatric events that resulted in hospitalization and do not have a large enough sample size to detect rare adverse events.
"Although these 2 studies did not suggest an increased risk of neuropsychiatric events that resulted in hospitalization they do not rule out an increased risk of other neuropsychiatric events with Chantix," according to an FDA release.
The FDA added that healthcare professionals should continue to follow the recommendations on the physician label and the patient medication guide and to monitor for neuropsychiatric symptoms when prescribing or using Chantix.
According to the FDA, Pfizer is conducting a large safety trial of varenicline to assess neuropsychiatric adverse events. However, the results are not expected until 2017.
In the meantime, "based on FDA's assessment of currently available data, the Agency continues to believe that the drug's benefits outweigh the risks and the current warnings in the Chantix drug label are appropriate," the release notes.
However, neuropsychiatric events aside, a meta-analysis published in the Canadian Medical Association Journal in July 2011 and reported then by heartwire, a sister publication of Medscape Medical News, raised concerns about the drug's cardiovascular risk.
At that time, lead investigator Carl Furberg, MD, from Wake Forest Baptist Medical Center, Winston-Salem, North Carolina, told heartwire that the findings highlight "yet again how dangerous this drug is. It has only a very modest benefit. But it is associated with some very real and scary side effects, and there are other things available to help people stop smoking."
In contrast, Taylor Hays, MD, from the Mayo Clinic, Rochester, Minnesota, who has been involved in clinical trials of the drug, told heartwire that although the study's findings "suggest a measure of caution should be taken in prescribing varenicline for tobacco dependence treatment, the small absolute risk of cardiovascular events associated with varenicline treatment is outweighed by the enormous benefit for reducing cardiovascular morbidity and mortality that can be achieved with successful smoking abstinence."
Medscape Medical News © 2011 WebMD, LLC
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Cite this: FDA Update for Neuropsychiatric Events With Varenicline - Medscape - Oct 24, 2011.