Pharmacological and Surgical Treatment of Obesity

OBJECTIVES: To assess the efficacy and safety of the weight loss medications sibutramine, orlistat, fluoxetine, phentermine, and diethylpropion; to assess the evidence for other medications that have been used for weight loss; and to assess the efficacy and safety of various types of bariatric surgery. DATA SOURCES: MEDLINE and EMBASE. The authors also contacted experts in the field. REVIEW METHODS: They screened 1,063 articles. The authors reviewed 78 medication studies that reported on sertraline (1 article), zonisamide (1 article), orlistat (49), bupropion (5), topirmate (9), and fluoxetine (13). Meta-analysis was performed for all medications except sertraline and zonisamide. The authors reviewed 147 surgery studies, of which, 89 contributed to weight loss analysis, 134 to mortality analysis, and 128 to complications analysis. The authors abstracted information about study design, intervention, co-interventions (diet, exercise), population, and outcomes. They abstracted weight loss, control of comorbidities, and adverse events. RESULTS: Sibutramine treatment resulted in a weight loss (compared to placebo) of 3.43 kg at 6 months, and 4.45 kg at 12 months, and orlistat resulted in a mean weight loss of 2.51 kg at 6 months, and 2.75 kg at 12 months. Subjects treated with phentermine lost on average 3.6 additional kg of weight at 6 months, while subjects treated with diethylpropion lost on average 3.0 additional kg of weight. Fluoxetine studies showed a mean weight loss of 4.74 kg at 6 months and 3.05 kg at 12 months. Bupropion studies showed a pooled result of weight loss of 2.8 kg at 6 to 12 months, and topiramate studies showed a pooled result of an additional 6.5 percent of pretreatment weight lost at 6 months. Surgery results in greater weight loss than does medical treatment in obese individuals with a BMI of 40 kg/m2 or greater. Surgery resulted in a 20 to 30 kg weight loss, maintained up to 8 years and accompanied by significant improvements in several comorbidities. Bariatric surgical procedures in current use have been performed with an overall postoperative mortality rate of less than 1 percent. CONCLUSIONS: Sibutramine, orlistat, phentermine, diethylpropion (probably), bupropion, fluoxetine, and topiramate all promote weight loss. Sibutramine and orlistat are the two most-studied drugs. All of these drugs have side effects. Surgical treatment is more effective than nonsurgical treatment but associated with a substantial number of complications and adverse events, although most of these are minor. There is no data regarding either pharmaceutical or surgical treatment of adolescent and pediatric patients