Chantix for smoking cessation side effects, caution, danger, risk, Varenicline anti smoking medication by Ray Sahelian, M.D.
April 3 2015


Chantix ( varenicline ) can be effective in helping a smoker give up cigarettes successfully, but it has side effects. Chantix is more effective than Zyban (bupropion). The chances of having a relapse during the first six months after giving up are reduced when a smoker is on Chantix. All studies are funded by the makers of Chantix, Pfizer. A JAMA editorial is skeptical of all the hype surrounding this new smoking cessation drug. Robert Klesges, University of Tennessee Health Science Center, Memphis, USA, says enthusiasm for a new smoking-cessation drug is always high when it first comes onto the market. Even though Chantix has better results than either a placebo or Zyban, this does not necessarily mean it is the holy grail for smoking addicts.


Chantix side effects, caution, danger, risk for suicide
Thousands of patients taking Pfizer Inc's anti-smoking drug Chantix (varenicline), have reported serious accidents, vision problems and heart trouble. There is a higher risk for heart attacks. Varenicline use results in an increased risk for heart attacks and other heart problems among people with cardiovascular disease.

Hepatology. 2015. Varenicline-induced acute liver injury with jaundice.

The FDA changed the labeling in 2015 on the quit-smoking drug Chantix to reflect concerns that it may lower tolerance to alcohol and is linked to a rare risk of seizures.


Patients taking two popular stop-smoking drugs should be watched closely for signs of serious mental illness, as reported suicides among the drugs’ users mount. The smoking-cessation medicines include Chantix, made by Pfizer, and Zyban, made by GlaxoSmithKline.


Chantix will carry prominent warnings that patients be monitored for unusual side effects including agitation, depression and suicidal behavior.


Warnings for doctors and patients are needed to increase awareness of cases of suicidal thoughts linked to Pfizer Inc's new smoking cessation pill. Pfizer has been asked to submit changes to the marketing information for the product -- sold as Champix in Europe and Chantix in the United States.

November 2007 - The U.S. Food and Drug Administration issued an early warning  about Pfizer Inc's anti-smoking drug, Chantix. There have been reports of suicidal thoughts and behavior, aggressive behavior, and at least one death potentially linked to the anti smoking medication, sometimes within days of starting the anti smoking drug.

Chantix is the new kid on the block

Cigarette smoking remains an important risk factor for premature cardiovascular disease and its complications. There are clear benefits of cigarette smoking cessation on the rate of clinical outcomes, and in addition to behavioral therapies, various pharmacologic strategies have been developed to help achieve this goal. First-line therapies include nicotine replacement and/or bupropion. Second-line treatments include clonidine and nortriptyline. Additional treatment strategies, with less proven efficacy, include monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, opioid receptor antagonists, bromocriptine, antianxiety drugs, nicotinic receptor antagonists (eg, mecamylamine), and glucose tablets. Various approaches under investigation include the use of partial nicotine agonists (eg, varenicline), inhibitors of the hepatic P-450 enzyme (eg, methoxsalen), and cannaboid-1 receptor antagonists (eg, rimonabant), and nicotine vaccines.
     Dr. Sahelian says: I am quite cautious when new medicines are introduced because it is not uncommon that unforseen side effects could come up after a medicine is marketed to the public. At this point it is difficult to know whether Chantrix has side effects of any significant nature.

Chantrix Mechanism of action

Chantix works in a different way from Zyban or nicotine-replacement therapies. Nicotine-replacement therapies give you a small dose of nicotine - the aim is to provide the smoker with his/her drug while he/she overcomes the enormous psychological problems that come with giving up. Zyban undermines the reuptake of addiction-linked brain chemicals by neurons - dopamine and norepinephrine. Chantix makes the patient produce more dopamine, which is supposed to help lower the cravings - at the same time brain cell receptors that help perpetuate addiction are blocked. However, another researcher adds a different twist to the mechanism of action of Chantix. Perhaps Chantix is also a partial agonist at the alpha4beta2 nicotinic acetylcholine receptor.


New Smoking Stopper?
FDA announced in May 2006 the approval of Chantix (varenicline tartrate) tablets, to help cigarette smokers stop smoking. The active ingredient in Chantix, varenicline tartrate, is a new molecular entity that received a priority FDA review because of its significant potential benefit to public health. Chantix acts at sites in the brain affected by nicotine and may help those who wish to give up smoking in two ways: by providing some nicotine effects to ease the withdrawal symptoms and by blocking the effects of nicotine from cigarettes if they resume smoking.


Chantix Research
Varenicline, an alpha4beta2 nicotinic acetylcholine receptor partial agonist, vs sustained-release bupropion and placebo for smoking cessation: a randomized controlled trial.
JAMA. 2006. Smoking Cessation Center, Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
The alpha4beta2 nicotinic acetylcholine receptors (nAChRs) are linked to the reinforcing effects of nicotine and maintaining smoking behavior. Varenicline ( Chantix ), a novel alpha4beta2 nAChR partial agonist, may be beneficial for smoking cessation. To assess efficacy and safety of Chantix for smoking cessation compared with sustained-release bupropion (bupropion SR) and placebo. Chantix was significantly more efficacious than placebo for smoking cessation at all time points and significantly more efficacious than bupropion SR at the end of 12 weeks of drug treatment and at 24 weeks.


Q. I have a friend who took Chantix to quit smoke last March. Handled it very well! My question is: what could happen if you take this drug and drink wine?
   A. We do not have any feedback on this combination yet.