Various formulations of nicotine are used as adjuncts in the discontinuation of smoking. They enable the psychological addiction of the smoking habit to be dealt with separately from the physical addiction to nicotine. Bupropion inhibits reuptake of noradrenaline and dopamine, increasing levels of these transmitters in areas of the brain involved with the symptoms of withdrawal and the development of dependence. This reduces the craving and withdrawal symptoms so may increase the chances of complete cessation. Varenicline binds to nicotinic acetylcholine receptors to alleviate symptoms of craving and withdrawal and competes with nicotine at the receptor binding sites resulting in a reduction of the rewarding and reinforcing effects of smoking. Nicotine replacement therapy, bupropion and varenicline should be used in conjunction with a patient support programme.