Data presented today at the 11th World Congress on Tobacco or Health suggests that smokers who use the smoking cessation aid ZYBAN (bupropion HCl) Sustained Release 150 mg Tablets may gain less weight than people who quit using a placebo, with marked differences among women. "Public health advocates have long considered weight gain to be a concern of smokers trying to quit," said Nancy Rigotti, MD, of the Tobacco Research & Treatment Program of Massachusetts General Hospital, and the lead investigator on this study.

Dr. Rigotti analyzed data retrospectively from a multicenter study that was originally designed to evaluate maintenance use of Zyban, the only non- nicotine smoking cessation aid approved by FDA. In that study, 784 smokers were placed on seven weeks of therapy with Zyban and given brief counseling. At week seven, the 432 patients who had not smoked in the past seven days then continued for 45 weeks on either the drug or placebo. At the end of the study, 97 smokers who had been continuously abstinent 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 randomized to placebo. This difference was statistically significant through 18 months, when the difference between the two groups lessened to 5.5 pounds. The analysis also found a difference, though not a statistically significant one, 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 (3.96 pound difference at 52 weeks; 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 towards their natural weight.(1) It is generally stated that successful quitters may gain eight to 10 pounds, but some studies suggest it is closer to 13 pounds.(2) However, Zyban is not indicated for weight loss, and the effect of bupropion SR on weight has not thoroughly been evaluated. Further study is necessary to determine conclusively the short-term and long-term effect of bupropion SR on weight.

Zyban should only be taken as directed by a doctor. The most common side effects associated with Zyban are dry mouth and insomnia. The use of bupropion is associated with a dose-dependent risk of seizure. Therefore, higher than recommended doses should not be prescribed and Zyban should not be used in people who are already taking Wellbutrin, or Wellbutrin SR, or any other medications containing bupropion. Zyban should be used with extreme caution in patients with severe liver disease; in these patients, a reduced frequency of dosing may be required. Zyban should also not be used in patients who have or have had a seizure disorder or who have a history of or are currently diagnosed with bulimia or anorexia nervosa. It should also not be used in people who are taking or have recently taken a monoamine oxidase inhibitor (MAO-I).

Zyban is the first nicotine-free prescription medicine available as an aid to quitting smoking and was cleared by the Food and Drug Administration (FDA) for this use in May 1997. Zyban and the Zyban Advantage Plan, a free counseling and personalized patient support program, are to be used as part of an overall plan recommended by a healthcare professional to help patients quit smoking.

• (1) American Lung Association Seven Steps to a Smoke-Free Life, Edwin B. Fisher Jr., PhD with Toni Goldfarb, John Wiley & Sons, Inc. 1998. (p. 41-42)
• (2) Ockene JK et al, Relapse and Maintenance Issues for Smoking Cessation, Health Psychology, 2000, vol. 19, no. 1 (supplement, p. 24)