On Thursday, the Food and Drug Administration (FDA) added tougher warnings to the prescription weight loss medication sibutramine, marketed in the U.S. as Meridia, further highlighting its increased risk of cardiovascular events—heart attack, stroke, resuscitated cardiac arrest, or death—in patients with a history of heart problems. Agency officials say they requested, and Meridia’s manufacturer Abbott Laboratories agreed, to add the new contraindications after reviewing additional data from the Sibutramine Cardiovascular Morbidity/Mortality Outcomes in Overweight or Obese Subjects at Risk of a Cardiovascular Event (SCOUT) study. However, European regulators took a decidedly harsher stance, advising doctors and pharmacists to stop using sibutramine and recommending that the drug’s marketing license be suspended, saying “the risks of these medicines are greater than their benefits.”
The current sibutramine label cautions against its use in patients with a history of cardiovascular disease, but the warning will now be more specific, including those with a history of coronary artery disease, heart attack, or angina; stroke or transient ischemic attack; arrhythmia (irregular heart beat); congestive heart failure; peripheral arterial disease; or uncontrolled hypertension more than 145/90 mmHg. Additionally, the FDA says patients currently using sibutramine should talk with their healthcare provider to determine if continued use of the drug is appropriate and discuss any questions or concerns they may have.
The SCOUT study, which began in 2002, 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. About 10,000 overweight or obese people, 55 years of age or older, who had a history of heart disease or type 2 diabetes plus one additional cardiovascular risk factor were enrolled in the study. Patients who recently had a heart attack or stroke, or had poorly controlled congestive heart failure were not included.
Half of the participants took sibutramine along with standard medical care for five years, while the other half received a sugar pill (placebo) and got standard medical care. During that time, serious cardiovascular events occurred in 11.4 percent of those taking sibutramine, compared to 10 percent of patients taking the placebo. These results suggest that instead of reducing cardiovascular risk, sibutramine is associated with an increased risk. However, additional data from the SCOUT study indicates that the increased risk for cardiovascular events with sibutramine occurred only in patients with a history of heart disease.
Abbott spokesman Kurt Ebenhoch says Meridia is safe when used as prescribed in the appropriate group of people. He argues that the SCOUT study not only included high-risk patients, but that participants took the drug much longer than the one-year maximum use recommended. “Sibutramine is not recommended or approved for use in more than 90 percent of the patients in the SCOUT study,” Ebenhoch said. Approved by the FDA in 1997, Meridia is intended for use by obese people with a body mass index (BMI) of 30 or higher in conjunction with a reduced calorie diet and regular exercise. It is also prescribed for some people with BMIs as low as 27 when they have weight-related conditions such as diabetes, high cholesterol, controlled hypertension or sleep apnea.