Varenicline: An α₄ Β₂ nicotinic acetylcholine receptor partial agonist as an aid to smoking cessation

Based on evidence that the actions of nicotine in humans are likely related to a combination of agonist and antagonist effects and that effective treatments for nicotine dependence may be developed using combinations of nicotinic receptor agonism and antagonism, there has been considerable interest in the development of nicotinic receptor partial agonists. Varenicline tartarate is the first nicotinic receptor partial agonist to be developed for use as a pharmacological aid for smoking cessation. The results of phase II and III trials are very promising, and evidence suggests that this agent is safe and efficacious in both abstinence initiation and relapse-prevention trials and that it may have superior efficacy to bupropion SR. The authors discuss the potential for this agent, which when approved will clearly add to the repertoire of available medications for the treatment of nicotine dependence.