A Review of Smoking Cessation Interventions

Ashish Maseeh, MD, and Gagandeep Kwatra, MD

In This Article


Nicotine is the most widely used substance of abuse.[8] The cigarette rapidly delivers nicotine to the brain to produce an almost instantaneous rewarding effect. Worse, most smokers are dependent on the ritual of smoking[7] (opening of the packet, the lighting process, and the sight and smell of smoke) rather than just on nicotine.[9] The stimulation of the nicotinic receptors by nicotine results in enhanced alertness and mild euphoria. The rewarding effects of nicotine are mediated through the same pathway involved in other pleasurable activities (eg, sexual activity, eating, etc.), namely increased dopamine release.[10] Exogenous nicotine binds to these receptors more avidly and for a longer time than does the endogenous neurotransmitter,[11] thus producing a chronic secondary antagonism.

Upregulation of the nicotinic receptors in the central nervous system (CNS) occurs as a result of the secondary antagonism, and the normal amounts of endogenous acetylcholine are no longer sufficient to sustain the normal physiological activity of these receptors, leading to tolerance.[4] Similarly, dependence develops because the body cannot release any more neurotransmitter, and consequently, periodic and repetitive doses of nicotine are essential to support normal levels of functioning.

Dependence is the outcome of an exquisite amalgam of diverse factors. A temporal association of rituals and sensory inputs in concert with repeated stimulation and relief from withdrawal encourages dependence.[12] Subtle variations in different alleles may predispose an individual to taking up smoking[13] or protect him from persistent smoking,[14,15] produce greater craving[14] or modify the rate of metabolism of nicotine.[16] Environmental conditions (eg, lifestyle, stress), socioeconomic status, peer pressure, adolescent dissension, and psychiatric disorders[7,17] all may directly or indirectly influence to variable degrees the eventual decision to smoke.

Nicotine dependence may produce an abstinence syndrome characterized primarily by symptoms related to the CNS (eg, irritability, anger, impatience, difficulty concentrating), although a diverse spectrum of nonspecific symptoms may also occur, varying in intensity and duration. The symptoms usually develop within a few hours of abstinence, peak after 2-3 days, and may last for weeks or months.[18] Craving plays an important role in maintaining regular smoking patterns and may lead to relapses in smokers trying to quit.


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