|NIH Scientists Demonstrate Genetic Variant is
Linked to Greater Effectiveness of Smoking Cessation Medication
Finding Is a Step toward Personalized Approach to Treatment
A genetic variant present in nearly half of Americans of European
ancestry is linked to greater effectiveness of the smoking cessation
medication bupropion (Zyban), according to research by scientists
supported by the National Institute on Drug Abuse (NIDA) and the
National Cancer Institute (NCI), part of the National Institutes
of Health (NIH). People with this variant were less likely than
those without it to have resumed smoking six months after treatment
The study, published in the September issue of the journal Biological
Psychiatry, is a step toward the goal of being able to tailor smoking
cessation treatment to individuals based on their unique genetic
"This study is part of our ongoing commitment to develop
more accurate and personalized approaches to medicine," said
NIH Director Dr. Elias A. Zerhouni. "This kind of genetic
research is helping us to better understand why some people respond
to certain smoking cessation treatments, and others don't."
The study involved more than 300 smokers who had been randomly
assigned to treatment with either bupropion or a placebo (sugar
pill) for 10 weeks. Participants were genetically tested for the
presence of a variant form of the CYP2B6 gene. The study
was co-led by Dr. Rachel F. Tyndale of the Center for Addiction
and Mental Health at the University of Toronto, Canada, and Dr.
Caryn Lerman of the Transdisciplinary Tobacco Use Research Center
at the University of Pennsylvania (TTURC) in Philadelphia.
"After 10 weeks of treatment, participants with this variant
had significantly better quit rates on bupropion than on placebo,
whereas those without it did equally well on both placebo and bupropion," says
Dr. Tyndale. "Additionally, among all participants who took
bupropion, those with this variant were less likely than those
without it to have resumed smoking at the six month follow-up."
"This is another step towards improving the success rates
of smoking cessation programs," says NIDA Director Dr. Nora
D. Volkow. "We are that much closer to being able to choose
the treatment that will most benefit the individual patient, based
on their genetic make-up."
Previous studies have shown that about 45 percent of Americans
of European ancestry have this variant form of the CYP2B6 gene.
This variant is also found in about 50 percent of African Americans
and 25 percent of Asian Americans. The current study looked only
at people of European ancestry, but the author and her colleagues
have begun a similar study in African American smokers. They hypothesize
that this variant of the CYP2B6 gene will influence the
effectiveness of bupropion treatment in the same way in African
Americans as in those of European descent.
The Transdisciplinary Tobacco Use Research Centers are funded
by NIDA, NCI and the National Institute on Alcohol Abuse and Alcoholism
(NIAAA). Additional support for this study was provided by the
Canadian Institute of Health Research.
The National Institute on Drug Abuse is a component of the National
Institutes of Health, U.S. Department of Health and Human Services.
NIDA supports most of the world’s research on the health aspects
of drug abuse and addiction. The Institute carries out a large
variety of programs to inform policy and improve practice. Fact
sheets on the health effects of drugs of abuse and information
on NIDA research and other activities can be found on the NIDA
home page at www.drugabuse.gov.
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at http://www.cancer.gov or
call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
The National Institute on Alcohol Abuse and Alcoholism, part of
the National Institutes of Health, is the primary U.S. agency for
conducting and supporting research on the causes, consequences,
prevention, and treatment of alcohol abuse, alcoholism, and alcohol
problems and disseminates research findings to general, professional,
and academic audiences. Additional alcohol research information
and publications are available at www.niaaa.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.