The FDA has warned that a review of additional data indicates an increased risk of heart attack and stroke in patients with a history of cardiovascular disease using sibutramine (Meridia, Abbott Laboratories), a drug used to curb obesity and enhance weight loss.
Based on the serious nature of the review findings, the agency requested and the manufacturer agreed to add a new contraindication to the sibutramine drug label stating that sibutramine is not to be used in patients with a history of cardiovascular disease, including:
- History of coronary artery disease (e.g., heart attack, angina);
- History of stroke or transient ischemic attack;
- History of heart arrhythmias;
- History of congestive heart failure;
- History of peripheral arterial disease; and
- Uncontrolled hypertension (e.g., more than 145/90 mmHg).
Simultaneous to the FDA announcement, the European Medicines Agency has finalized a safety review of sibutramine, and the agency’s Committee for Medicinal Products for Human Use (CHMP) voted to recommend the suspension of marketing authorizations for all anti-obesity medicines containing sibutramine.
In the United Kingdom, sibutramine-containing drugs have been authorized for use since 1999 and are available under the following tradenames: Afibon, Ectiva, Lindaxa, Meissa, Meridia, Minimacin, Minimectil, Obesan, Reductil, Reduxade, Sibutral, Sibutril, Siluton, Sitrane, Zelium and Zelixa.
According to the FDA, patients currently using sibutramine should talk with their healthcare professional to determine if continued use of sibutramine is appropriate. Also, healthcare professionals should regularly monitor the blood pressure and heart rate of patients using sibutramine and if sustained increases in blood pressure and/or heart rate are observed, sibutramine should be discontinued.
The SCOUT (Sibutramine Cardiovascular Morbidity/Mortality Outcomes in Overweight or Obese Subjects at Risk of a Cardiovascular Event) study was designed to show that weight loss with sibutramine and standard care was more effective in reducing the number of cardiovascular events compared to weight loss from a placebo and standard care. Patients included in the study were 55 years of age or older, overweight or obese, and had a history of cardiovascular disease or type 2 diabetes plus one additional cardiovascular risk factor. Patients who recently had a heart attack or stroke, or had poorly controlled congestive heart failure were not included in the study. Approximately 10,000 patients enrolled in the study.
In November 2009, the FDA issued preliminary results from the SCOUT study indicating cardiovascular events occurred in 11.4 percent of patients using sibutramine compared to 10 percent of patients using a placebo. This difference was higher than expected, suggesting that sibutramine was associated with an increased cardiovascular risk in the study population.
The additional data from the SCOUT study, according to the FDA, indicate that the increased risk for cardiovascular events with sibutramine occurred only in patients with a history of cardiovascular disease.