Understanding
the Bio-behavioral Basis of Smoking
September / October 2004
A recent Penn and Georgetown University Transdisciplinary
Tobacco Use Research Center (TTURC) study evaluated the
comparative
efficacy of transdermal nicotine and nicotine nasal spray
to identify pre-treatment clinical characteristics that predict
treatment outcome. Caryn Lerman, PhD, professor of medicine
and associate director for cancer control and population
science at the Abramson Cancer Center of the University
of Pennsylvania,
led a research team that examined 299 treatment-seeking smokers
enrolled in a clinical trial of transdermal nicotine versus
nicotine nasal spray.
Researchers found that race, weight, and level of nicotine
dependence may help identify a smoker’s likelihood to
quit using either method. For example, transdermal nicotine
may be a more effective treatment for non-obese, Caucasian,
and low-nicotine dependent smokers while the nicotine nasal
spray may be more beneficial for smokers who are obese, highly
nicotine dependent, and members of a minority group. “This
study, which was published in the March 2004 Annals of Internal
Medicine, is an important step towards helping clinicians
and patients individualize the choice of nicotine replacement
therapy,” explains Dr. Lerman.
This research also uses information about smokers’
genetic backgrounds to predict the effectiveness of different
treatments. Previous research has shown that bupropion is
an effective smoking cessation aid, but there is substantial
variability between smokers in response to this drug with
only 30 to 45 percent of participants remaining abstinent.
As part of the emerging field of pharmacogenetics, Dr. Lerman
and her colleagues examined 426 smokers enrolled in a randomized
clinical trial of bupropion for smoking cessation. Participants
provided blood samples and received bupropion (or a placebo)
plus behavioral group counseling. The study concluded that
participants with a decreased activity variant of the CYP2B6
gene reported greater increases in cravings for cigarettes
following the quit date. They were about one-and-a-half times
more likely to relapse during the treatment plan.
“The study provides an important first step toward
utilizing genotype to identify smokers who are more vulnerable
to relapse and who may benefit most from more intensive smoking
cessation treatment,” adds Dr. Lerman. The study was
published in the publication Pharmacogenetics.
Typically, the most effective approach to smoking cessation
combines pharmocologic therapies with behavioral counseling.
This allows practitioners to address the biological basis
of the addiction and the behavioral habit that contributes
to it. “We are currently investigating how different
genetic factors might influence response to treatment and
we hope in the future that this information could be integrated
into clinical practice,” says Dr. Lerman.
Transdisciplinary
Tobacco Use Research Center |
The Transdisciplinary Tobacco Use
Research Center (TTURC) of the University of Pennsylvania
School of Medicine supports a broad program of research
related to tobacco control. It is one of seven sites
in the country to receive a $10 million grant from the
National Cancer Institute and the National Institute
on Drug Abuse.
“The theme of our center is to understand the
bio-behavioral basis of nicotine addiction and improve
treatment to help people quit smoking. We are studying
novel therapies including medications that could have
been used for other indications such as drug abuse or
depression,” says Caryn Lerman, PhD. “Another
major thrust of our clinical research is moving toward
individualizing tobacco dependence treatment.”
The current practice for tobacco dependence treatment
is a “one size fits all” model. A health
care provider typically recommends the nicotine patch
to a smoker who wants to quit and, if that is not successful,
the provider will prescribe Zyban™, the anti-depressant
drug bupropion. “There is no model in which physicians
and other providers can base choices about which treatment
might be best for which smoker, and even going further,
the individual dose of treatment, duration of therapy,
and more,” adds Dr. Lerman. |
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or refer a patient, contact PennHealth through the secure online
referral form or by calling
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(7366). |
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