Varenicline: An α4β2 Nicotinic Receptor Partial Agonist for Smoking Cessation

Herein we describe a novel series of compounds from which varenicline (1, 6,7,8,9-tetrahydro-6,10-methano-6H-pyrazino[2,3-h][3]benzazepine) has been identified for smoking cessation. Neuronal nicotinic acetylcholine receptors (nAChRs) mediate the dependence-producing effects of nicotine. We have pursued α4β2 nicotinic receptor partial agonists to inhibit dopaminergic activation produced by smoking while simultaneously providing relief from the craving and withdrawal syndrome that accompanies cessation attempts. Varenicline displays high α4β2 nAChR affinity and the desired in vivo dopaminergic profile.