Quitting smoking with Chantix®? Watch your alcohol intake

Chantix® (varenicline), a prescription smoking cessation medicine manufactured by Pfizer, can change the way people react to alcohol, including decreased tolerance to alcohol, increased drunkenness, unusual or aggressive behavior, or blackout memory loss. There have also been rare accounts of individuals with no history of seizures experiencing seizures while taking Chantix. In a safety announcement, the FDA updated the Warnings and Precautions section of the drug label and the patient Medication Guide for Chantix to tell patients to decrease their alcohol intake until they know how the drug affects their ability to tolerate alcohol, and patients who have a seizure while taking Chantix should stop taking the medication immediately.


According to the Centers for Disease Control and Prevention (CDC), tobacco use is the leading preventable cause of death, disease, and disability in the United States. Around 443,000 Americans die from smoking or exposure to secondhand smoke each year. Approximately 46.6 million American adults smoke, exposing 88 million nonsmokers to secondhand smoke. In May 2006, the FDA approved Chantix as a smoking cessation drug. The medication acts at sites in the brain affected by nicotine, and may help those who wish to stop smoking by providing some nicotine effects to ease withdrawal symptoms. It can also block the effects of nicotine from cigarettes if users resume smoking. Clinical trials show that Chantix increases the likelihood of abstinence from smoking for as long as one year compared to placebo treatment.

Safety announcement

The FDA reviewed information about adverse reactions to alcohol experienced by patients taking Chantix from a case series submitted by Pfizer and cases in the FDA Adverse Event Reporting System (FAERS) database. The FDA also reviewed FAERS and medical literature for cases of seizures in Chantix users, particularly those who had no history of seizures or who had a well-controlled seizure disorder prior to taking the drug. In most cases, seizures occurred within the first month of starting Chantix. Information about these risks was added to the drug labeling and patient Medication Guide.

The FDA also updated the Warnings and Precautions section of the label to include information about several studies that investigated the risk of neuropsychiatric side effects on mood, behavior, or thinking occurring with Chantix. Available observational studies and analyses conducted by Pfizer of randomized controlled clinical trial data did not show an increased risk of neuropsychiatric side effects with Chantix; however, the studies did not examine all types of neuropsychiatric side effects, and had limitations that prevented the FDA from drawing reliable conclusions. The FDA previously noted that possible serious neuropsychiatric side effects may occur from Chantix use; Pfizer is conducting a large clinical safety trial to investigate the risk, and expects results from that study in late 2015.

Report side effects

The FDA urges health care professionals and patients to report side effects involving Chantix to the FDA MedWatch program, using the information in the “Contact FDA” box at the bottom of the page.