Background: The primary goal of weight loss is to prevent or reduce obesity-associated morbidity and mortality by improving cardiovascular and metabolic risk factors. We conducted a systematic review to assess the efficacy and safety of sibutramine hydrochloride for weight loss.
Methods: In April 2002, we searched MEDLINE, EMBASE, the Cochrane Library, and 7 other computerized bibliographic search tools using the keywords "sibutramine," "Meridia," and "Reductil" (in all languages and all available years). The authors and the manufacturer were contacted. We reviewed randomized placebo-controlled trials of sibutramine, 10 to 20 mg/d, in obese adults. Methodological quality was assessed.
Results: A total of 29 trials had sufficient data for analysis after including unpublished data from 10 authors. The summary mean differences in weight loss, sibutramine minus placebo, for the 3-month and 1-year trials were -2.78 kg (95% confidence interval, -2.26 to -3.29 kg) and -4.45 kg (95% confidence interval, -3.62 to -5.29 kg), respectively. The 6-month trials were statistically heterogeneous, and evidence of publication bias was found. One trial found that sibutramine maintains weight loss better than placebo at 2 years. Weight loss with sibutramine was associated with modest increases in heart rate and blood pressure, small improvements in high-density lipoprotein cholesterol and triglycerides levels, and, among diabetic patients, small improvements in glycemic control. There was no direct evidence that sibutramine reduces obesity-associated morbidity or mortality.
Conclusions: Sibutramine is effective in promoting weight loss. Weight loss with sibutramine is associated with both positive and negative changes in cardiovascular and metabolic risk factors. There is insufficient evidence to accurately determine the long-term risk-benefit profile for sibutramine.