Pharmacologic treatment such as nicotine replacement therapy has been shown to help some people stop smoking. The idea of using a non-nicotine product such as an antidepressant as an aid for smoking cessation has been intriguing, since people who smoke are more likely to have a history of depression than nonsmokers. However, results of clinical trials of antidepressant therapy as aids for smoking cessation, such as those involving doxepin and selective serotonin reuptake inhibitors, have been mixed. Hurt and associates conducted a randomized, double-blind, placebo-controlled study to evaluate the effectiveness of a sustained-release form of bupropion as an aid to smoking cessation.

Patients were recruited for the study through advertisements and press releases. To be eligible, patients had to be at least 18 years of age, to have smoked at least 15 cigarettes per day for the past year, to be motivated to quit smoking and to be in generally good physical health. Exclusion criteria included a personal or family history of seizures, current use of psychotropic medications, current use of any nicotine-replacement products, a history of alcohol dependence, and pregnancy. Patients who currently had depression as determined by the physician were excluded; however, those with a history of stable major depression were allowed to participate.

At baseline, patients were randomized to one of four treatment groups and were then given a sustained-release form of bupropion at dosages of either 100 mg, 150 mg or 300 mg per day, or placebo. The patients were followed weekly during the seven weeks of the treatment phase. They were then evaluated at eight, 12, 26 and 52 weeks for further follow-up.

A total of 615 patients were included in the study, but 219 did not complete the 12-month study period. By the end of the seven-week treatment phase, 19 percent of patients in the placebo group had stopped smoking, compared with 28.8 percent of patients receiving 100 mg of bupropion, 38.6 percent of patients receiving 150 mg of bupropion and 44.2 percent of patients receiving 300 mg of bupropion daily. At one year, the rate of smoking cessation was 12.4 percent in the placebo group, 19.6 percent in the group receiving 100 mg, 22.9 percent in the group receiving 150 mg and 23.1 percent in the group receiving 300 mg. Results in the groups receiving 150 and 300 mg were significantly different from those in the groups receiving placebo or 100 mg per day of buproprion.

The study also evaluated weight gain in all participants and found that the mean weight gain was inversely associated with the dosage of bupropion. Patients receiving 300 mg of bupropion daily had an average weight gain of 1.5 kg at one year compared with 2.9 kg in the placebo group. Adverse events associated with bupropion resulted in treatment cessation by 29 patients. The most common adverse reactions included tremor, headaches, rash and urticaria. Other adverse effects included insomnia and dry mouth.

The authors conclude that sustained-release bupropion is an effective aid for smoking cessation with minimal side effects. Dosages of 150 and 300 mg of bupropion per day are more effective than a 100-mg dosage. An additional advantage appears to be a diminished weight gain, avoiding what is often a deterrent for people who attempt to quit smoking.