Varenicline

Varenicline is a prescription medication used to treat smoking addiction. This medication is the first approved nicotinic receptor partial agonist. Specifically, varenicline is a partial agonist of the alpha4/beta2 subtype of the nicotinic acetylcholine receptor. In addition it acts on alpha3/beta4 and weakly on alpha3beta2 and alpha6-containing receptors. A full agonism was displayed on alpha7-receptors.

On March 9, 2015, the U.S. Food and Drug Administration warned that Varenicline, in the form of Pfizer Inc's quit-smoking drug, Chantix, has been associated with seizures and that some patients who drink while taking the drug may become aggressive or black out. Pfizer is conducting an additional safety study of the drug, results of which are expected in late 2015. The FDA said it is keeping the black box in place at least until the results of the trial are announced.