Varenicline: An oral partial nicotine agonist for smoking cessation
Varenicline (Chantix, Pfizer) is a partial nicotine receptor agonist with a high affinity for the alpha-4 beta-2 nicotinic acetylcholine receptors, modulating dopamine levels associated with nicotine addiction and aiding in smoking cessation. Clinical studies have demonstrated favorable cessation rates compared with placebo and sustained-release bupropion, with an encouraging safety profile. The most common adverse effect seen in clinical trials was mild-to-moderate nausea. In November 2005, a New Drug Application (NDA) was submitted for varenicline, and the drug was subsequently granted a 6-month priority review. On May 10,2006, varenicline became the first oral medication approved for smoking cessation since buprapion, representing an agent with a novel mechanism of action for smoking cessation.