Bupropion SR enhances weight loss: a 48-week double-blind, placebo- controlled trial.

OBJECTIVE To critically examine the efficacy of bupropion SR for weight loss. RESEARCH METHODS AND PROCEDURES This 24-week multicenter, double-blind, placebo-controlled study randomized obese adults to placebo, bupropion SR 300, or 400 mg/d. Subjects were counseled on energy-restricted diets, meal replacements, and exercise. During a 24-week extension, placebo subjects were randomized to bupropion SR 300 or 400 mg/d in a double-blinded manner. RESULTS Of 327 subjects enrolled, 227 completed 24 weeks; 192 completed 48 weeks. Percentage losses of initial body weight for subjects completing 24 weeks were 5.0%, 7.2%, and 10.1% for placebo, bupropion SR 300, and 400 mg/d, respectively. Compared with placebo, net weight losses were 2.2% (p = 0.0468) and 5.1% (p < 0.0001) for bupropion SR 300 and 400 mg/d, respectively. The percentages of subjects who lost >or=5% of initial body weight were 46%, 59%, and 83% (p vs. placebo < 0.0001) for placebo, bupropion SR 300, and 400 mg/d, respectively; weight losses of >or=10% were 20%, 33%, and 46% (p vs. placebo = 0.0008) for placebo, bupropion SR 300, and 400 mg/d, respectively. Withdrawals, changes in pulse and blood pressure did not differ significantly from placebo at 24 weeks. Subjects who completed 48 weeks maintained mean losses of initial body weight of 7.5% and 8.6% for bupropion SR 300 and 400 mg/d, respectively. DISCUSSION Bupropion SR 300 and 400 mg/d were well-tolerated by obese adults and were associated with a 24-week weight loss of 7.2% and 10.1% and sustained weight losses at 48 weeks.