Varenicline for smoking cessation

Tobacco dependence is a complex process characterised by repeated cycles of stimulation, followed after a period of time by withdrawal and relief of withdrawal symptoms from the next cigarette providing a further stimulatory effect. Chemically, a surge in brain nicotine levels after smoking activates specific nicotine receptors within the so-called ‘brain reward system’ that functions as the common central pathway for pleasurable experiences such as sexual activity and satiety from eating. Dopamine is the critical mediator in this process and nicotine, cocaine, opiates and amphetamines all act on their own specific receptors in the ‘brain reward system’.