Rene Maximiliano Gomez, MD Head, Allergy & Asthma Unit Hospital San Bernardo, Salta - Argentina.

Rene Maximiliano Gomez, MDHead, Allergy & Asthma Unit

Hospital San Bernardo, Salta - Argentina

The causes of death in order of incidence are cardiovascular diseases (43%), all forms of tobacco-caused cancer (36%), respiratory diseases (20%), and all other smoking-caused deaths (1%).

The three primary causes of mortality are similar for men and women: heart disease, cancer, and stroke

“Addiction" has been more broadly used to refer to compulsive use of psychoactive drugs in which tolerance and physiological dependence may also be present.

The term physiological dependence will be used to refer to the physiological adaptation manifested by the emergence of withdrawal symptoms after cessation of use.

The patho-physiological consequences of tobacco smoke exposure include tissue destruction contributing to lung disease, cellular changes contributing to cancer, and the cellular and molecular reinforcing effects leading to dependence.

Most smokers identify smoking as harmful and express a desire to reduce or stop smoking, and nearly 20 million of them (more than one-third of all smokers) make a serious attempt to quit each year.

Unfortunately, less than 7% of these smokers attempting to quit (or less than 3% of all smokers) achieve 1-year abstinence each year

Approximately 50% of the survivors of myocardial infarctions, lung removal, and tracheostomy resume smoking.

This illustrates two important points. First, powerful motivational incentives can lead to cessation; no widely used formal treatment reliably establishes 50% rates of long-term abstinence. Second, this powerful motivational contingency (i.e., threat of death) is inadequate for 50% of cigarette smokers; they may also require medications, behavior modification procedures, or both.

Nicotine dependence is a "progressive," "chronic," "relapsing" disorder.

Mean age of cigarette smoking onset is 13-14 years.

The level of nicotine dependence in adults is inversely related to the age of smoking initiation when measured by diagnostic criteria of the American Psychiatric Association

Continued smoke intake is accompanied by the development of tolerance and physiological dependence. After smoking a few cigarettes, estimates of people who progress to dependence ranges from roughly 33% to 50% (USA – UK).

Surveys differ in their criteria for initial smoking and dependent smoking.

Nicotine tolerance appears to be substantially acquired during youth as smokers progress from a few to many cigarettes to obtain same effects

There are several physiological mechanisms of nicotine tolerance, including decreased responsiveness to the drug at the site of drug action and increased nicotine receptor number and some degree of increased metabolism

The rapid pharmacodynamic development of tolerance may contribute to the disappointment with nicotine replacement systems expressed by many patients.

Abstinence is usually short-lived; most individuals resume smoking within 3 days. Providing minimal assistance prolongs the remission by at least a few more days, and providing nicotine replacement can extend the mean remission duration by 6 months or more. One year later, nearly one-third of those surveyed had relapsed, a testament to the persistence of the dependence

A Gallup Survey of cigarette smoking and markers of dependence indicated that

40% of teenage smokers begin smoking within 1 hr of awakening (sign of dependence);

50% of teenage smokers had tried to quit but relapsed;

70% would not start smoking if they could "do it again"; and

38% of teenage smokers would be interested in smoking cessation programs targeted to their needs

38% were smoking at the time of the survey and reported that they needed tobacco or felt dependent at the time the survey was conducted, and approximately 80% of people who smoked at least a pack per day felt that they were dependent.

By contrast, among people who had consumed alcoholic beverages in the past year, 30% had consumed at least once in the past week; and among those who had binged (five or more drinks in a row) in the past 30 days, 17% reported they felt they needed to drink or were dependent.

It has been widely assumed that moderate daily use of tobacco over an extended period of time is a prerequisite for nicotine dependence. The Development and Assessment of Nicotine Dependence in Youth (DANDY) study contradicts this view, with results indicating that the first symptoms of nicotine dependence can appear within a matter of days or weeks of the onset of intermittent tobacco use. These first symptoms were strongly predictive of long term tobacco use, indicating that the loss of autonomy over tobacco can occur very rapidly with minimal exposure to nicotine.

Chronic use is highly resistant to modification. For example, efforts to reduce intake by smoking fewer cigarettes or cigarettes with lower nicotine delivery ratings are usually partially or completely thwarted by compensatory changes in how the cigarettes are smoked

Accelerated decline in lung function, more severe symptoms, impairment in quality of life and diminished therapeutic response to steroids.

Can influence innate immunity diminishing innate production of antigen presenting cells cytokines, as well as an impaired response to toll-like receptor ligands.

Associated with current symptoms of asthma and rhinitis, and risk factor for developing new asthma in patients with rhinitis.

Inducer of nasal obstruction and decreased muco-ciliary clearance in nonallergic rhinitis.