While Pfizer has been pushing federal drug regulators to ease warning requirements for the stop-smoking drug Chantix, the FDA announced this week that existing warnings about the risk of neurological and psychological side effects of Chantix will remain and ordered additional information to be provided about the potential risks associated with the drug.
In a drug safety communication issued March 9, the FDA indicated that new Chantix warnings will be required about the risk of seizures and potential side effects that may result from combining Chantix with alcohol.
“Until patients know how Chantix affects their ability to tolerate alcohol, they should decrease the amount of alcohol they drink,” the agency warned. “Patients who have a seizure while taking Chantix should stop the medicine and see medical attention immediately.”
The FDA said that new information will also be added to the label about a recent study by Pfizer, which contradicts previous studies indicating that Chantix can increase the risk of neurological and psychological side effects, such as suicide and violent aggressive behavior. However, the agency noted that studies claiming Chantix did not carry these side effects had limitations that prevented reliable conclusions.
Chantix (varenicline) is a prescription medication introduced by Pfizer in 2006, designed to help people quit smoking. However, in 2009, the FDA required Pfizer to add a “black box” warning for Chantix, alerting doctors and patients to a potential link between use of the drug and the emergence of unusual behavior, including suicidal or homicidal thoughts.
Last year, Pfizer tried to get those Chantix warnings removed, arguing that new studies raise questions about whether there are any psychological side effects from the medication.
FDA reviewers looked at Pfizer’s data and found it lacking, indicating that the data was “insufficient in quality” and determined that the Chantix boxed warning should stay.
Two FDA advisory panels met in October 2014 and agreed with the agency’s reviewers.
New concerns over seizures and alcohol interaction were the result of an analysis of the FDA Adverse Event Reporting System (FAERS) database. An FDA review of FAERS found 48 adverse events linked to aggressive behavior and decreased tolerance in Chantix users who consumed alcohol. Most involved Chantix users becoming aggressive when drinking, when this was not their reaction to alcohol before using the drug.
“In more than half of these cases, the patients described their behavior as a significant change from their behavior prior to Chantix treatment. Twenty-two cases reported harm to person or property.”
The FDA also reported that there were numerous cases where those who behaved aggressively suffered amnesia or impaired memory of their experiences while drinking and taking Chantix.
The FDA found 64 cases of patients suffering seizures after taking Chantix, with a median onset after taking the drug for two to three weeks. In 37 of the cases reported to FAERS, the patients had no history of seizures.
Chantix Suicidal Side Effects
While Chantix was originally viewed as a potential blockbuster medication to help people quit smoking, sales have been slowed by concerns about the risk of severe psychological side effects and unusually violent or aggressive behavior among users.
The public first began to become aware of the potential Chantix side effects after the 2007 shooting death of Jeffrey Carter Albrecht, former keyboardist for the folk band Edie Brickell and the New Bohemians, who allegedly was suffering a violent psychotic episode sparked by Chantix when he was shot to death by a neighbor. Albrecht thought the neighbor’s house was his girlfriend’s, and was reportedly trying to kick the door down when he was shot.
Reports of Chantix rage ballooned after that, and some studies appeared to verify that the drug caused aggression, and sometimes homicidal tendencies, in some users. It also caused suicidal tendencies as well as vivid and horrific nightmares. There were skits on Saturday Night Live and the term Chantix Nightmare became a pop culture reference.
Pfizer was hit with nearly 3,000 Chantix lawsuits after the FDA added the black box warning. All of the claims alleged that inadequate warnings were provided for users of the medication prior to July 2009. Rather than fighting the claims, the drug maker agreed last year to pay about $300 million as part of a global Chantix settlement agreement that resolved the litigation.