Cigarette smoking is the leading cause of morbidity and mortality worldwide, contributing to an estimated more than 6 million deaths annually. Combining pharmacotherapy with behavioral interventions is the most effective way to help smokers sustain abstinence. Pharmacological therapies help smokers adapt to the absence of nicotine after quitting smoking by reducing nicotine withdrawal symptoms. In the general population of smokers, varenicline or a combination of prolonged- and short-acting nicotine replacement therapy (NRT) are the first-line agents for smoking cessation therapy.