Individuals taking Chantix to help the quit smoking may face an increased risk of experiencing serious heart problems, according to the findings of new research, which renews safety concerns about the popular medication.
In a study published online this week by the American Journal of Respiratory and Critical Care Medicine, researchers indicate that some smokers who use Chantix to try to kick the habit are a third more likely to be hospitalized or visit an emergency room for cardiovascular problems than smokers who do not use the drug. The study also saw a small increase in the risk of neurological problems, but indicated that the number was only marginally significant.
Canadian researchers looked at medical records of 57,000 new Chantix users in Ontario, Canada, from September 2011 through February 2015. The subjects were observed for a year before they began taking Chantix to one year after they ceased using the drug.
According to the findings, those taking the drug were 34% more likely to have to visit an emergency room or be hospitalized for cardiovascular events than the year before they began taking the drug. When the researchers broke the numbers down further, they saw that those who had never had heart problems of any kind were about 12% more likely to suffer heart problems, and said that the true risk increase likely lies between those two numbers.
The findings also indicated that there was a six percent increase in the risk of hospitalization or emergency room visits from neurological side effects, such as suicide. However, the increase was only marginally significant and did not show up in all analyses of the data, leading the researchers to determine that the risks were not overall significant.
“Varenicline (Chantix) appears to be associated with an increased risk of cardiovascular but not neuropsychiatric events,” the researchers concluded.
The findings come almost exactly a year after the FDA announced that it was removing a black box warning from Chantix and Zyban, which indicated that they carried an increased risk of major psychological side effects, including suicidal thoughts and behaviors.
Chantix (varenicline) is a prescription medication introduced by Pfizer in 2006, designed to help people quit smoking. However, less than three years later, the FDA required Pfizer to add a “black box” warning, following a number of reports involving suicide and other unusual behavior among users.
A black box is the strongest label warning the FDA can require a drug maker to apply, alerting doctors and patients to a potential link between use of the Chantix or Zyban and the emergence of suicidal or homicidal thoughts.
Pfizer, the manufacturer, fought to get the label warning removed, and succeeded in December 2016.