The warning label on Pfzier’s smoking cessation drug Chantix (varencline) is being updated to reflect a risk of seizures. The revised label will also state that some patients who drink alcohol have experienced blacking out and aggressive behavior. The U.S. Food and Drug Administration (FDA) has also decided to not remove the drug’s boxed warning of suicidal thoughts.
The label update was approved in September, Reuters reports. A public notice is now being released so that patients are aware of this information “and can consider this new information when making prescribing decisions.” The FDA said most of the seizures occurred in the first month.
“Until patients know how Chantix affects their ability to tolerate alcohol, they should decrease the amount of alcohol they drink. Patients who have a seizure while taking Chantix should stop the medicine and seek medical attention immediately,” the FDA said in a release.
In 2006, Chantix was approved as a drug to help patients quit smoking. In 2009, the FDA added a “black box” warning, which is reserved for the most serious side effects, for neuropsychiatric side effects such as suicidal thoughts, suicidal actions, depression, hostility and agitation. Pfizer wants this warning to be removed from the label, and cited its own studies in arguing that there is no link. According to Reuters, an FDA advisory committee said in October that the warning should stay pending the outcome of an ongoing safety study.
In deciding that the boxed warning should stay, the FDA said on Monday that current studies were too limited to make a conclusive decision, including a study conducted by Pfizer. The warning will stay until the results of Pfizer’s second study on Chantix, the results of which are expected by late 2015.