Smoking cessation interventions 2

Sustained-release bupropion (Zyban)
Initially marketed as an atypical antidepressant,
sustained-release bupropion is hypothesized to pro-
mote smoking cessation by inhibiting the reuptake
of dopamine and norepinephrine in the central
nervous system [116] and acting as a nicotinic
acetylcholine receptor antagonist [117]. These neu-
rochemical effects are believed to modulate the
dopamine reward pathway and reduce the cravings
for nicotine and symptoms of withdrawal [112].
Because seizures are a dose-related toxicity
associated with bupropion, this medication is
contraindicated in patients with underlying seizure
disorders and in patients receiving concurrent ther-
apy with other forms of bupropion (Wellbutrin,
Wellbutrin SR, and Wellbutrin XL). Bupropion also
is contraindicated in patients with anorexia or bu-
limia nervosa and in patients who are undergo-
ing abrupt discontinuation of alcohol or sedatives
(including benzodiazepines) due to the increased
risk for seizures. The concurrent administration
of bupropion and a monoamine oxidase (MAO)
inhibitor is contraindicated and at least 14 days
should elapse between discontinuation of an MAO
inhibitor and initiation of treatment with bupro-
pion [118]. Although seizures were not reported in
the smoking cessation clinical trials, the incidence
of seizures with the sustained-release formulation
(Wellbutrin) used in the treatment of depression
was 0.1% among patients without a previous his-
tory of seizures [119]. For this reason, bupropion
should be used with extreme caution in patients
with a history of seizure, cranial trauma, patients
receiving medications known to lower the seizure
threshold, and patients with underlying severe hep-
atic cirrhosis. Bupropion is classified as a pregnancy
category C drug, meaning that either (a) animal
studies have demonstrated that the drug exerts ani-
mal teratogenic or embryocidal effects, but there are
no controlled studies inwomen, or (b) no studies are
available in either animals or women. Correspond-
ingly, themanufacturer recommends that this agent
be used during pregnancy only if clearly necessary
[118].Varenicline tartrate (Chantix)
The efficacy of varenicline, a partial agonist selec-
tive for the a4b2 nicotinic acetylcholine receptor
[120,121), is believed to be the result of sustained,
low-level agonist activity at the receptor site com-
bined with competitive inhibition of nicotine bind-
ing. The partial agonist activity induces mod-
est receptor stimulation, which leads to increased
dopamine levels, thereby attenuating the symptoms
of nicotine withdrawal. In addition, by competi-
tively blocking the binding of nicotine to nicotinic
acetylcholine receptors in the central nervous sys-
tem, varenicline inhibits the surges of dopamine
release that occur following the inhalation of to-
bacco smoke. The latter effect might be effective in
preventing relapse by reducing the reinforcing and
rewarding effects of smoking [120]. The FDA classi-
fies varenicline as a pregnancy category C drug, and
themanufacturer recommends that thismedication
be used during pregnancy only if the potential ben-
efit justifies the potential risk to the fetus [121].
Summary
Tobacco use remains prevalent among the popula-
tion and represents a matter of special public health
concern. It is the primary risk factor for the devel-
opment of lung cancer. It has been shown to cause
malignancies in other locations, aswell as numerous
other diseases. The body of knowledge of various
aspects of smoking behavior has largely increased
over the past two decades. Studies of factors predis-
posing to smoking initiation among youthmay pro-
vide important clues for the development of feasi-
ble and effective smoking prevention activities. The
knowledge of biobehavioral factors leading to devel-
opment of nicotine dependence may assist in pro-
vidingmore effective treatments to patientswho use
tobacco products. The five A’s approach (Ask about
tobacco use,Advise patients to quit,Assess readiness
to quit, Assist with quitting, and Arrange follow-
up) is described in the US Public Health Service
Clinical Practice Guideline for Treating Tobacco Use and
Dependence. Health care providers are encouraged to
implement at least brief interventions at each en-
counter with a patient who uses tobacco.