Varenicline (Tradename: Champix) is a partial nicotine receptor agonist and antagonist, used for smoking cessation.

  • Varenicline is a partial agonist and antagonist at the alpha-4 beta-2 nicotinic receptor (α4β2 or a4b2) nicotinic acetylcholine receptor (nAChR)[1]
  • Plays a significant role in the nicotine reward pathway[2]
  • Varenicline is safe, tolerable, and efficacious for tobacco cessation in individuals with alcohol use disorder, and might have secondary benefits in reducing alcohol use.[3]
  • Start 1 week before quitting
  • 0.5mg PO qAM x 3 days
  • Increase to 0.5mg PO BID x 4 days
  • Then 1mg PO BID x 3 months
    • Up to 6 months
  • For those with gastrointestinal upset, consider taking medication after eating or with a large glass of water
  • For those with insomnia, consider taking medication earlier in the day.
  • For those who experience side effects, consider reduced dosage (0.5 mg BID)
  • Reports of increased rates of depressed mood, agitation, changes in behaviour, suicidal thoughts and behaviour exist with use of varenicline
  • Clinicians should elicit a psychiatric history prior to using this medication and monitor any changes in mood and behaviour during use
  • From the information available to date, it is not possible to determine whether varenicline increases the risk of heart or stroke events in people who have cardiovascular disease

Varenicline was previously thought to increase the risk for neuropsychiatric symptoms, and the FDA applied a black box warning on the medication for this. However, a subsequent 2016 randomized control trial found no significant differences in outcomes between varenicline and placebo, and the warning was removed in 2016.[4][5]