Does Sibutramine Help People Lose Weight? Is It Safe?

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Arterburn DE, Crane PK, Veenstra DL: The efficacy and safety of sibutramine for weight loss. Arch Intern Med 164:994-1003, 2004.

What is the problem and what is known about it so far?

Sibutramine is a weight-loss drug that has caused concern over its safety. It has been found to have some side effects on the cardiovascular (heart and blood vessel) system.

In March 2002, Italian regulators took sibutramine off the market for a little while. Later, a European committee on medical product safety found that the benefits of sibutramine were greater than its risks.

In this study, researchers searched for evidence of the risks and benefits of sibutramine.

Who was studied?

Researchers looked at 29 clinical trials (including 10 trials that were not yet published in medical journals). Participants were obese adults in generally good health. Some studies included people with medical conditions like high blood pressure or diabetes.

How was the study done?

Participants were put into one of two groups: sibutramine or placebo. A placebo is a "fake" pill whose ingredients don't affect the body. Participants did not know if they were getting the real medicine or a placebo.

Participants on sibutramine were given one of these daily doses: 10 mg, 15 mg, or 20 mg.

Seven trials lasted from 8 to 12 weeks. Twelve trials lasted 16 to 24 weeks. Five trials lasted 44 to 54 weeks.

What did the researchers find?

Weight Loss

Overall, people who took sibutramine lost an average of 6 pounds within 3 months, and 9.8 pounds after a year.

It didn't make much difference if participants took a high or low dose of sibutramine.

According to one study, those who took sibutramine kept more weight off after 2 years than the participants who took a placebo.

Safety

Sibultramine was linked to slight increases in heart rate and blood pressure.

One study followed adults with type 2 diabetes for 1 year. People who took sibutramine had an average increase in systolic blood pressure of 4.4 mmHg. On average, they had an increase in diastolic blood pressure of 3.3 mmHg.

In 11 studies, participants on sibutramine had an average increase in heart rate of 3.76 beats per minute.

Nobody died during follow-up in any of the studies.

What were the limitations of the study?

There were not enough high-quality studies to determine long-term risks and benefits of sibutramine. The clinical trials in this study didn’t have many participants.

What are the implications of the study?

Sibutramine helps obese adults lose weight. More information is needed on the cardiovascular effects of sibutramine.