Drugs to quit smoking can affect mental and physical health: the truth about Chantix and Zyban

Sharon Cannistra, Jackie Britz, and Sarah Pedersen

Everyone knows that smoking harms health and that the habit is difficult to quit. Unfortunately, some products that help people stop smoking can also be harmful – perhaps too harmful to consider using.

In June 2011, the U.S. Food and Drug Administration (FDA) announced new concerns about the safety of Chantix.  Their announcement came in the months after two reports by independent researchers that there were more reports of deaths and violence from taking Chantix than any other drug.

These new reports add to concerns about two stop-smoking drugs, Chantix and Zyban.  In July 2009, the FDA had already announced “black box” warning labels on both drugs.  A “black box” warning is the FDA’s most serious caution and indicates that a drug carries significant health risks.  The black box warnings for Chantix and Zyban warn of the mental health risks associated with their use, which can include changes in behavior, depressed mood, hostility, and suicidal thoughts.

These warnings were recommended as the result of information gathered from clinical trials, as well as a series of reports to the FDA’s Adverse Event Reporting System.  Zheng-Xiong Xi, MD, PhD, a researcher at the National Institute on Drug Abuse, found that Chantix was associated with incredibly dangerous side effects in many individuals, including suicide attempts and seizures, as well as psychosis, depression, and serious injuries resulting from dizziness, loss of consciousness, movement disorders, and visual disturbances. These problems have been noted among individuals with a history of mental illness but also have occurred among individuals with no prior history of mental illness.

Analysis from reports to the FDA’s Adverse Event Reporting System similarly shows that some people who used Chantix and Zyban began experiencing changes in behavior, depressed mood, and suicidal thoughts shortly after starting the medication.  The symptoms usually ended shortly after the medication was stopped, but some people still reported symptoms after stopping the medications, while still others did not even begin developing the symptoms until after they stopped taking the drug.

Neither Chantix nor Zyban contains nicotine, unlike other smoking cessation aids such as chewing gum and the patch.  Nicotine withdrawal can also cause mental health problems similar to those caused by Chantix and Zyban, such as depression, anxiety, irritability, restlessness, and sleep disturbance. However, the mental health risks of these two drugs far exceed the symptoms suffered by people with nicotine withdrawal.

Zyban is another name for Wellbutrin, an anti-depressant.  Its marketing as a smoking-cessation drug came about after researchers noticed that smokers who took Wellbutrin for depression had less desire to smoke. GlaxoSmithKline carried out additional research in order to get approval to sell Wellbutrin under a different name as a medication to quit smoking. However, like most anti-depressants, the pills–whether they are called Wellbutrin or Zyban–can cause an increase in suicidal thoughts.  Antidepressants have carried black box warnings about suicide risks since 2004.

Chantix: News about increased risk of suicide, violent behavior, and other mental health problems

From the approval of Chantix in May 2006 until July 2009, the drug was linked to reports of approximately 100 suicides, 200 suicide attempts, and almost 5,000 serious psychiatric events. Doctors are not required to report deaths or serious complications to the companies that make the medication or the FDA, although drug companies are required to do so.  Because most doctors don’t report, it is assumed that the numbers are much higher and that those problems have continued since 2009.  In fact, in May 2011, the Institute for Safe Medication Practices (ISMP) revealed that hundreds of cases of suicides, psychotic reactions, hostility, aggression and other serious problems tied to Chantix had not been properly reported to the FDA by Pfizer, the drug’s manufacturer.  Among the 589 delayed reports of severe problems, there were more than 150 suicides-almost doubling those previously known.  Thomas J. Moore, the ISMP senior scientist who analyzed the data, stated that, based on the FDA’s adverse event reports, Chantix is the riskiest of all drugs sold in the U.S. In the third quarter of 2010, it ranked first in reported deaths, with twice as many fatalities recorded as any other drug.

The discovered reports coincide with a study by Moore released in December 2010 examining all of the most serious adverse drug events reported to the FDA since 1968. Chantix had the largest number of reported cases of violence (408).

2011: Increased risk of heart attack for patients with cardiovascular disease

Research has shown, however, that these stop-smoking drugs affect not only mental health, but can also jeopardize physical health.  In June 2011, the FDA warned that Chantix may be associated with an increased risk of certain cardiovascular adverse events in patients who have cardiovascular disease. After reviewing a randomized clinical trail of 700 smokers with stable cardiovascular disease, the FDA found that certain events, including heart attacks, were reported more frequently in patients treated with Chantix than in patients treated with placebo (2.0% vs. 0.9%).

The question remains whether the risks of taking one of these drugs outweigh the benefits. Quitting smoking is usually a step towards improving one’s health, but doing so at the risk of mental or heart health is not a good compromise.  Instead, there are other, safer ways to quit smoking.

The unreported deaths and serious injuries for people taking Chantix raises questions about whether other information is also being withheld.  Since most doctors don’t report adverse reactions to the FDA, it is likely that Chantix has caused many more deaths and injuries than reported.  For that reason, we believe that Chantix is not a safe choice.  At the very least, the mental health of anyone taking Chantix or Zyban should be closely monitored by a health care professional.  Additionally, if you have a history of cardiovascular disease, consult your doctor before taking Chantix, and if you experience new or worsening symptoms of cardiovascular disease, contact your doctor immediately.

If you or someone you know is trying to quit smoking, be aware of the symptoms associated with quitting, and if symptoms develop, a health care professional should be consulted.

The current black box warning, which will soon include information on cardiovascular risks, starts with the following statements (from the product Web sites):


Serious neuropsychiatric events, including but not limited to depression, suicidal ideation, suicide attempt, and completed suicide have been reported in patients taking ZYBAN for smoking cessation. Some cases may have been complicated by the symptoms of nicotine withdrawal in patients who stopped smoking. Depressed mood may be a symptom of nicotine withdrawal. Depression, rarely including suicidal ideation, has been reported in smokers undergoing a smoking cessation attempt without medication. However, some of these symptoms have occurred in patients taking ZYBAN who continued to smoke.


Some people have had changes in behavior, hostility, agitation, depressed mood, suicidal thoughts or actions while using CHANTIX to help them quit smoking. Some people had these symptoms when they began taking CHANTIX, and others developed them after several weeks of treatment or after stopping CHANTIX. If you, your family, or caregiver notice agitation, hostility, depression, or changes in behavior, thinking, or mood that are not typical for you, or you develop suicidal thoughts or actions, anxiety, panic, aggression, anger, mania, abnormal sensations, hallucinations, paranoia, or confusion, stop taking CHANTIX and call your doctor right away. Also tell your doctor about any history of depression or other mental health problems before taking CHANTIX, as these symptoms may worsen while taking CHANTIX.

Xi ZX. Preclinical Pharmacology, Efficacy and Safety of Varenicline in Smoking Cessation and Clinical Utility in High Risk Patients. Drug, Healthcare and Patient Safety. 2010;2:39-48. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/21278851

U.S. Food and Drug Administration. “Boxed Warning on Serious Mental Health Events to be Required for Chantix and Zyban.” Press release. FDA: Boxed Warning on Serious Mental Health Events to be Required for Chantix and Zyban. 1 July 2009.

Riley K. Transcript for FDA’s Media Briefing on the Serious Mental Health Risks Associated With The Drugs Chantix And Zyban. Briefing presented at U.S. Food and Drug Administration Briefing. 1 July 2009.

Moore TJ, Glenmullen J, Furberg CD (2010) Prescription Drugs Associated with Reports of Violence Towards Others. PLoS ONE 5(12): e15337. Retrieved 27 May 2011 at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015337

U.S. Food and Drug Administration. FDA Drug Safety Communication: Chantix (varenicline) may increase the risk of certain cardiovascular adverse events in patients with cardiovascular disease. 6 June 2011. Retrieved 6 July 2011 at http://www.fda.gov/Drugs/DrugSafety/ucm259161.htm