Authors' objectives:

This review aims to assess the available evidence on the effectiveness of pharmacological approaches to weight loss in adults.

Authors' recommendations: With regard to pharmacological approaches to weight loss, the ICSI Technology Assessment Committee finds: Sibutramine is safe for most patients. However, due to concerns about hypertension and cardiovascular disease related to sibutramine use, blood pressure and pulse rate should be monitored at regular intervals to identify those patients who experience clinically significant increases in blood pressure or pulse rate during treatment. Orlistat is safe for most patients. Gastrointestinal side effects are common but the frequency and severity decrease over time (typically after 1 week) and can be reduced by careful attention to the dietary fat content. As an adjunct to intensive nutritional and lifestyle changes, both orlistat and sibutramine are associated with greater weight loss than placebo. With sibutramine, patients can expect a weight loss of 2.4-16.6 kg after 12-52 weeks of treatment. A weight loss of at least 5% of initial body weight at up to 1 year is reported by 27%-88%; a weight loss of at least 10% of initial body weight at up to 1 year is reported by 6%-76%. With orlistat, patients can expect a weight loss of 3.9-10.3 kg after 1 year and 5.0-7.4 kg after 2 years of treatment. A weight loss of at least 5% of initial body weight at 1 year is reported by 33-69%; a weight loss of at least 10% of initial body weight at 1 year is reported by 10-39%. With both drugs, 5%-25% fail to complete the run-in phase of the study; of those who are randomized, 9%-54% of both the active treatment and placebo groups fail to complete the treatment phase of the study. The greatest benefit may be in patients with comorbid conditions such as diabetes. While patients with a comorbid condition may not experience as great a weight loss as patients without the condition, the physiological benefits are important. (Conclusion Grade I) Programs in which >50% of patients lose >5% of initial body weight and >30% of patients lose >10% of initial body weight are characterized by a placebo run-in period that identified individuals willing and able to make changes in their nutritional and activity patterns; information on behavior modification, changing nutritional choices, and increasing physical activity; regular monitoring in a clinic setting; and exclusion criteria that exclude patients with serious disease, major depression, and substance abuse. To date, the longest reported follow-up is 2 years. There is little published evidence to suggest that orlistat or sibutramine are effective in maintenance of weight loss for longer than 2 years or in decreasing long-term morbidity or mortality. Possible harms associated with long-term use of orlistat or sibutramine are unknown.

Authors' methods: Review

Project Status: Completed

URL for project: http://www.icsi.org/index.asp

Year Published: 2003

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Institute for Clinical Systems Improvement

Contact Address: 8009 34th Avenue South, Suite 1200, Bloomington, MN, USA. Tel: +1 952 814 7060; Fax: +1 952 858 9675

Contact Name: icsi.info@icsi.org

Contact Email: icsi.info@icsi.org

Copyright: Institute for Clinical Systems Improvement (ICSI)