Long-Term Sibutramine Use Linked to Nonfatal Strokes and MIs
Major Finding: The nonfatal MI rate in patients randomized to receive placebo or 10 mg/day of sibutramine for a mean of 3.4 years was 4.1% in the active drug group and 3.2% in the placebo group. The nonfatal stroke rate was 2.6% among those on sibutramine and 1.9% among those on placebo. There was no difference in the risks of cardiovascular death or death from any cause.
Data Source: The Sibutramine Cardiovascular Outcomes (SCOUT) study was a double-blind, placebo-controlled study conducted in 16 countries in Europe, South America, Central America and Australia. Cardiovascular outcomes were compared in 9,804 older (mean age 63 years) obese or overweight men and women with preexisting cardiovascular disease, type 2 diabetes, or both.
Disclosures: The study was funded by sibutramine manufacturer Abbott Laboratories. Author disclosures included having received lecture fees and travel reimbursement from Abbott. Abbott employees were among the authors of the study. The lead author has served on advisory boards for and has received travel reimbursements from GlaxoSmithKline, the manufacturer of orlistat, another weight loss drug. The authors of the editorial declared no conflicts of interest.
The mean pulse rate among those on sibutramine was also “consistently higher” than among those on placebo, with mean differences of 2.2 to 3.7 beats per minute.
The SCOUT authors cite several limitations of the study. The enrollment of mostly high-risk patients meant that most of the study patients did not meet the treatment criteria in the drug’s label, which warns against the use of sibutramine in patients with preexisting cardiovascular disease.
The editorialists observed that after 1 year, those on sibutramine gained back about 0.5 kg, so had a net weight loss of about 4 kg – almost 9 pounds – from an average of 96 kg (211 pounds) at baseline. “Thus, in exchange for an average weight loss of less than 4 kg, a subject had a 1 in 70 chance (or a 1 in 52 chance for those with known cardiovascular disease) of having a myocardial infarction or stroke – an unattractive benefit-to-risk ratio,” they wrote.
The study was funded by sibutramine manufacturer Abbott Laboratories. Author disclosures included having received lecture fees and travel reimbursement from Abbott. Abbott employees were among the authors of the study. The lead author has served on advisory boards for and has received travel reimbursements from GlaxoSmithKline, the manufacturer of orlistat, another weight loss drug.
The coauthors of the editorial were Stephen Morrissey, Ph.D., and Dr. Jeffrey Drazen. The authors of the editorial declared no conflicts of interest.
