Smokers who quit with drug may gain less weight
CHICAGO, Aug 8 (Reuters) - Smokers who use the prescription smoking cessation pill Zyban may gain less weight than those who quit using a placebo, according to data presented at the 11th World Congress on Tobacco or Health.
The differences in weight gain were most marked in women.
``Public health advocates have long considered weight gain to be a concern of smokers trying to quit,'' said Dr. Nancy Rigotti of the Tobacco Research and Treatment programme of Massachusetts General Hospital.
Rigotti, the lead investigator of the study, analysed data from a multicenter study originally designed to evaluate maintenance use of Zyban, which has the generic name of bupropion. In that study, 784 smokers were placed on seven weeks of therapy with Zyban, the only non-nicotine smoking cessation aid approved by the Food and Drug Administration.
At week seven, 432 patients who had not smoked in the past seven days continued for 45 weeks on either the drug or placebo. At the end of the study, 97 smokers who had abstained from smoking for 24 months were evaluated for weight gain.
Those quitters who had continued on Zyban gained an average of 9.02 pounds less than those who took the placebo.
The difference was statistically significant through 18 months, when the difference between the two groups lessened to 5.5 pounds, the study said.
The analysis also found a difference in the amount of weight that women gained versus men.
At 52 weeks, women in the group treated with Zyban gained an average of 13.86 pounds less than the women in the placebo group. At 18 months, women in the group treated with Zyban gained an average of 8.14 pounds less than the women in the placebo group.
Smaller differences occurred in men. The study noted a 3.96 pound difference at 52 weeks and a 2.86 pound difference at 18 months.
Other research suggests that people often gain weight when they quit smoking because of the effect nicotine can have on the body's metabolism.
Once smokers quit and no longer get nicotine, they may move toward their natural weight, gaining 8 to 12 pounds, Rigotti said. Some studies suggest it is closer to 13 pounds.
``Smokers tend to weigh less than nonsmokers. Once they quit, they go back to what they would have weighed,'' she added.
Zyban, manufactured by Glaxo Wellcome, is not indicated for weight loss, and Glaxo Wellcome said the effect of bupropion on weight has not thoroughly been evaluated. Further study is necessary to determine conclusively the short-term and long-term effect of bupropion on weight, the company said.
Bupropion is also marketed under the name Wellbutrin, the antidepressant drug.
The study was based on data from a previous study funded by Glaxo Wellcome, a company spokesman said.