Varenicline (brand name Chantix)

How it works: 1

  • Varenicline is a non-nicotine medication that was approved by the FDA for the treatment of tobacco dependence in 2006.
  • It is presumed to work by acting as a partial nicotine receptor agonist and antagonist. 
  • Varenicline has a very specific dosage recommendation.  It is recommended that to be most effective, it should be started 1 week before the quit date at .5 mg once a day for 3 days, followed by .5 mg twice daily for 4 days.  The quit day should be on day 8 and then Varenicline should be taken at 1 mg twice daily for 3 months.  It is approved for a maintenance indication up to 6 months.

What the evidence says:

  • Strength of Evidence: A The Clinical Practice Guide states that Varenicline is, “appropriate as a first-line medication for treating tobacco use” (DHHS, 2008, p. 53).  This medication comes with several precautions.  Pregnant smokers should be encouraged to quit smoking without medication.  Use this medication with caution in patients with significant kidney disease or who are on dialysis. 
  • In March 2015 the Food and Drug Administration (FDA) revised its black box warning label for Chantix to include potential negative interactions with alcohol and the possibility of seizure.  The FDA alerts Chantix users that they should decrease their alcohol use until they know how Chantix affects their tolerance, and to seek medical attention if a seizure were to occur.  This warning adds to the original 2009 FDA Chantix black box warning, resulting from consumer reports of depressed mood, suicidal thoughts, hostility, and agitation.  While these side effects are quite uncommon, they should be monitored when taking Chantix.  Users are also recommended to keep ongoing communication with their physician.  For more information please refer to the official FDA warning shown here.

    • Because of the more severe nature of these side effects reported, numerous studies have been conducted to further evaluate the validity of these reports.  Some research has indicated this relationship is minor and only found in minimal numbers while other studies have indicated a direct relationship between severe emotional disturbances and taking Varenicline.4,5
    • A controlled trial since the warning included over 3,000 participants indicated that there was not an increase in overall psychiatric disorders compared with placebo except in sleep disturbances.6
    • It would seem the rule of thumb is that the warning should be seriously considered by prescribing clinicians due to the more severe nature of the side effects reported. 
  • More recent research suggests that Varenicline may increase the risk of cardiovascular adverse events in patients with cardiovascular disease.2
  • Quitting Rates
    • Studies report higher rates of cessation than bupropion.  Reports indicate it has a 12 week abstinence rate of up to 44% and a 12 month abstinence rate of about 22%.3

Possible Side Effects:

  • Nausea
  • Gas
  • Constipation
  • Vomiting
  • Difficulties sleeping (trouble sleeping or vivid, unusual, or strange dreams)

Where to get it:

  • Varenicline is available through prescription only.
  • Commercial brands include:
    • Chantix or Champix
  1. Fiore, M. C., Jaen, C. R., Baker, T. B., & al., e. (2008). Treating Tobacco Use and Dependence 2008 Update.  Clinical Practice Guideline. In U.S. Department of Health and Human Services (Ed.). Rockville, MD: U.S. Department of Health and Human Services.
  3. Gonzales, D., Rennard, S. I., Nides, M., Oncken, C., Azoulay, S., Billing, M. S., et al. (2006). Varenicline, an α4β2 nicotinic acetylcholine receptor partial agonist, vs. sustained-release bupropion and placebo for smoking cessation. Journal of the American Medical Association, 296(1), 47–55.
  4. McClure, J. B., Swan, G. E., Jack, L., Catz, S. L., Zbikowski, S. M., McAfee, T. A., & ... Javitz, H. (2009). Mood, Side-effects and Smoking Outcomes Among Persons With and Without Probable Lifetime Depression Taking Varenicline. JGIM: Journal Of General Internal Medicine, 24(5), 563-569.
  5. Williams, J., Steinberg, M., Steinberg, M., Gandhi, K., Ulpe, R., & Foulds, J. (2011). Varenicline for tobacco dependence: panacea or plight?. Expert Opinion On Pharmacotherapy, 12(11), 1799-1812.
  6. Tonstad, S., Davies, S., Flammer, M., Russ, C., & Hughes, J. (2010). Psychiatric Adverse Events in Randomized, Double-Blind, Placebo-Controlled Clinical Trials of Varenicline: A Pooled Analysis. Drug Safety, 33(4), 289-301.