Varenicline (Molecule of the Month for May 2007)
Champix, non-nicotine, Stop-smoking
Varenicline is a prescription medication used to treat smoking addiction. This medication is the first approved nicotinic receptor partial agonist. In this respect it reduces cravings for and decreases the pleasurable effects of cigarettes and other tobacco products, and through these mechanisms may assist some patients in smoking cessation. In May 2006, it was approved for sale in the United States. On August 1, 2006, Pfizer announced that Chantix was available for sale in the United States, and on September 29, 2006, it was approved for sale in the European Union, and in May 2007 has been given approval for use by the National Health Service (NHS).
Varenicline, produced by Pfizer, is unusual as it both stimulates and blocks specific nicotinic receptors in the brain. It is thought that by stimulating the receptor it mimics the effects of nicotine to reduce cravings. At the same time, it partially blocks the receptor preventing nicotine from binding to it, resulting in a weaker response in people who give in to temptation and have a cigarette.
Trials have shown the drug was effective after a 12-week course, with 44% of smokers managing to stop. This compares with 18% of those given a placebo and 30% of those taking another anti-smoking drug, bupropion, which is also available on the NHS.
Update by Karl Harrison
(Molecule of the Month for May 2007 )