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Nicotine is a highly addictive drug found in tobacco and is a major component of cigarette smoke. This drug stimulates the brain reward system activated during pleasurable activities in a manner similar to that of most other addictive drugs (see Drug Use and Dependence). People smoke to feed their nicotine addiction but simultaneously inhale hundreds of carcinogens, noxious gases, and chemical additives that are a part of cigarette smoke. These components are responsible for the multiple health consequences of smoking.
Epidemiology
Smoking:
The percentage of people in the US who smoke cigarettes has declined since 1964, when the Surgeon General first publicized the link between smoking and ill health. Nevertheless, about 45 million adults (nearly 23%) still smoke. Smoking is most prevalent in men, people with < 12 yr of education, people living at or below the poverty income level, non-Hispanic whites, non-Hispanic blacks, American Indians, and Alaska natives. Smoking is least common among Asian Americans.
Most smokers start during childhood. Children as young as 10 yr experiment with cigarettes. Over 2000 start daily, 31% before age 16 and over ½ before age 18, and age of initiation continues to decrease. Risk factors for childhood initiation include parental, peer, and role model (eg, celebrity) smoking; poor school performance; high-risk behavior (eg, excessive dieting among boys or girls, physical fighting, drunk driving); and poor problem-solving abilities.
Smoking harms nearly every organ in the body and is, as of 2000, the leading cause of mortality in the US, accounting for an estimated 435,000 deaths/yr. About ½ of all current smokers will die prematurely of a disease directly caused by smoking, losing 10 to 14 yr of life (7 min/cigarette) on average. Sixty-five percent of smoking-attributable deaths are from ischemic heart disease, lung cancer, and chronic lung disease; the rest are from non-cardiac vascular diseases (eg, stroke, aortic aneurysm), other cancers (eg, bladder, cervical, esophageal, kidney, laryngeal, oropharyngeal, pancreatic, stomach, throat), pneumonia, and perinatal conditions (eg, preterm birth, low birth weight, SIDS). In addition, smoking is a risk factor for other conditions that convey profound morbidity and disability, such as acute myelocytic leukemia, frequent URIs, cataracts, reproductive effects (eg, infertility, spontaneous abortion, ectopic pregnancy, premature menopause), and periodontitis.
Quitting:
More than 70% of smokers present to a primary care setting every year, yet only a minority leaves having received counseling and medications to assist them in quitting. Most smokers < 18 yr believe they will not be smoking in 5 yr, and over ½ report having tried to quit in the previous year. However, longitudinal studies show that 73% of daily smokers in high school remain daily smokers 5 to 6 yr later.
Passive smoking:
Passive exposure to cigarette smoke (secondhand smoke, environmental tobacco smoke) has grave health implications for children and adults. Risks to neonates, infants, and children include low birth weight, SIDS, asthma and other related respiratory illnesses, and otitis media. Children exposed to cigarette smoke lose more school days to illness than non-exposed children. Smoking-related fires kill 80 children each year and injure almost 300 more; they are the leading cause of deaths resulting from unintentional fires in the US. Treating children for smoking-related illnesses is estimated to cost $4.6 billion/yr. In addition, 43,000 children each year lose one or more caretakers who die from smoking-related diseases.
Exposure in adults is linked to the same neoplastic, respiratory, and cardiovascular diseases that threaten active smokers. Overall, secondhand smoke is estimated to be responsible for 50,000 to 60,000 deaths each year in the US. These findings have led 6 states and municipalities across the US to ban smoking within workplaces in an effort to protect the health of workers and others from the substantive risks of environmental tobacco smoke.
Symptoms and Signs
Smoking cessation often causes intense withdrawal symptoms, primarily a craving for cigarettes but also anxiety, depression (mostly mild, sometimes major), inability to concentrate, irritability, restlessness, insomnia, drowsiness, impatience, hunger, tremor, sweating, dizziness, headaches, and digestive disturbances. These symptoms are worst in the 1st wk and subside within 3 to 4 wk, but many patients resume smoking as symptoms peak. An average weight gain of 4 to 5 kg is common and is another reason for recidivism. Smokers with ulcerative colitis often experience an exacerbation soon after quitting.
Treatment
The addiction and withdrawal symptoms are powerful enough that, even with knowledge of the many health risks, many smokers thinking of quitting are often unwilling to try, and those attempting to quit are often unsuccessful. A minority quits permanently in initial attempts, but most go on to smoke for many years, cycling through multiple periods of relapse and remission. The optimal evidence-based approach to patients, particularly those unwilling to quit or those who have not yet considered quitting, should be guided by the same principles that guide chronic disease management, namely:
Effective interventions require 3 core components: counseling, drug therapy (in patients without contraindications), and consistent identification of and intervention with smokers. (See also information about tobacco
cessation from the US Department of Health and Human Services.)
The counseling approach for children is similar to that for adults. (See also the Centers for Disease Control and Prevention guide for Youth
Tobacco Cessation.) Children should be screened for smoking and risk factors by age 10. Parents should be advised to maintain smoke-free households and to communicate the expectation to their children that they will remain nonsmokers. Cognitive-behavioral therapy that involves establishing awareness of tobacco use, providing motivations to quit, preparing to quit, and providing strategies to maintain abstinence after cessation are effective in treating nicotine -dependent adolescents. Alternative approaches to smoking cessation, such as hypnosis and acupuncture, have been inadequately studied and cannot be recommended for routine use.
Counseling:
Counseling efforts begin with the 5 A's: ask at every visit if a patient smokes and document the response; advise all smokers to quit in clear, strong language they will understand; assess a smoker's willingness to quit within the next 30 days; assist those willing to make a quit attempt with brief counseling and medications; and arrange a follow-up, preferably within the 1st wk of the quit date.
For smokers willing to quit, clinicians should establish a quit date, preferably within 2 wk, and stress that total abstinence is better than reduction. Past quitting experiences can be reviewed to identify what helped and what did not, and smoking triggers or challenges to quitting should be planned for in advance. For example, alcohol use is associated with relapse, so alcohol restriction or abstinence should be discussed. In addition, quitting is more difficult with another smoker in the household; spouses and housemates can be encouraged to quit together. In general, patients should be instructed to develop social support among family and friends for their quit attempt, and clinicians should reinforce their availability and assistance in support of the attempt. Although these counseling strategies make good sense and provide important patient support, little scientific evidence supports their use in preventing relapse.
About 40 states in the US have telephone quitlines that can provide additional support to smokers trying to quit. Phone numbers for these can be obtained locally or from the American Cancer Society (1-800-ACS-2345; www.cancer.org) .
Drugs:
Drugs proven effective and safe for smoking cessation include bupropion SR and nicotine (in the form of gum, lozenge, inhaler, nasal spray, or patch; see Table 1: Smoking Cessation: Drug Therapies for Smoking Cessation ). Some evidence suggests bupropion is more effective than nicotine replacement. All forms of nicotine are equivalent as monotherapy, but the combination of a nicotine patch with gum or nasal spray increases long-term abstinence compared to any one form alone. Nortriptyline 25 to 75 mg po at bedtime may be an effective 2nd-line alternative for smokers with depression. Drug choice is guided by the clinician's familiarity with the drug, patient preference and previous experience (positive or negative), and contraindications.
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Table 1
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Drug Therapies for Smoking
Cessation
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Drug Therapy
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Dosage
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Duration
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Adverse Effects
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Comments
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Bupropion SR
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150 mg every morning for 3 days, then 150 mg twice/day (begin treatment 1–2 wk before quitting)
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7–12 wk initially; may continue up to 6 mo
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Insomnia; dry mouth
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Prescription only; contraindicated with history of seizure, eating disorder, MAO inhibitor use within past 2 wk
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Nicotine gum
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If smoking 1–24 cigarettes/day, 2 mg gum (up to 24 pieces/day)
If smoking 25 + cigarettes/day, 4 mg gum (up to 24 pieces/day)
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Up to 12 wk
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Mouth soreness; dyspepsia
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OTC only
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Nicotine lozenge
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If smoking > 30 min after waking, 2 mg; if smoking < 30 min after waking, 4 mg
Schedule for both dosage strengths is 1 q 1–2 h for wk 1–6; 1 q 2–4 h for wk 7–9; 1 q 4–8 h for wk 10–12
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Up to 12 wk
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Nausea; insomnia
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OTC only
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Nicotine inhaler
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6–16 cartridges/day for wk 1–12, then taper down over next 6–12 wk
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3–6 mo
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Local irritation of mouth and throat
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Prescription only
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Nicotine nasal spray
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8–40 doses/day
1 dose = 2 sprays
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14 wk
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Nasal irritation
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Prescription only
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Nicotine patch
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21 mg/24 h for 6 wk, then 14 mg/24 h for 2 wk, then 7 mg/24 h for 2 wk
If smoking > 10 cigarettes/day, start with 21-mg dose; if smoking < 10 cigarettes/day, start with 14-mg dose
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10 wk
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Local skin reaction; insomnia
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OTC and prescription
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or
15 mg/16 h if smoking > 10 cigarettes/day
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6 wk
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Contraindications to bupropion include a history of seizures, eating disorder, and MAO inhibitor use within 2 wk. Nicotine replacement should be used cautiously in patients with certain cardiovascular risks (those within 2 wk of an MI, with serious arrhythmias, or with serious angina). Nicotine gum is contraindicated in patients with temporomandibular joint syndrome, and nicotine patches are contraindicated in patients with severe topical sensitization. All these drugs should be used cautiously, if at all, in pregnant and breastfeeding women and adolescents and, because nicotine toxicity is possible and evidence of benefit is lacking, in patients who smoke < 10 cigarettes/day. These drugs delay but do not prevent weight gain.
Despite their proven efficacy, smoking cessation drugs are used by < 25% of smokers attempting to quit. Reasons include low rates of insurance coverage, clinician concerns about the safety of simultaneous smoking and nicotine replacement, and discouragement because of past unsuccessful quit attempts.
Therapies under investigation for smoking cessation include a vaccine that intercepts nicotine before the nicotine reaches its specific receptors and rimonabant, a cannabinoid CB1 receptor antagonist.
Prognosis
More than 90% of the about 20 million smokers in the US who try to quit each year relapse within days, weeks, or months. Almost ½ report having tried to quit in the last year, usually by using a “cold turkey” or other approach that did not work. Success rates are 20 to 30% among smokers who use cessation counseling or drugs.
Other Kinds of
Tobacco
Cigarette smoking is the most harmful form of tobacco use, although pipe, cigar, and smokeless tobacco use results in similar ominous consequences. Exclusive pipe smoking is relatively rare in the US (< 1% of people ≥ 12 yr), although it has increased among middle and high school students since 1999. About 5.4% of persons > 12 yr smoke cigars. Although this percentage has declined since 2000, people < 18 yr comprise the largest group of new cigar smokers. Risks of pipe and cigar smoking include cardiovascular disease; COPD; cancers of the oral cavity, lung, larynx, esophagus, colon, pancreas; and periodontal disease and tooth loss.
About 3.3% of persons ≥ 12 yr use smokeless tobacco (chewing tobacco and snuff). Toxicity of smokeless tobacco varies by brand. Risks include cardiovascular disease, oral disorders (eg, cancers, gum recession, gingivitis, periodontitis and its consequences), and teratogenicity. Smoking cessation for smokeless tobacco users and pipe and cigar smokers is accomplished similarly as that for cigarette smokers. Success rates are higher among smokeless tobacco users. However, success rates for pipe and cigar smokers are not well documented and are impacted by concurrent use of cigarettes and whether or not smokers inhale.
Last full review/revision November 2005
Content last modified April 2007
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