Diet Drug Rimonabant Tied to Depression, Anxiety

In June, rimonabant's maker, French pharmaceutical giant Sanofi-Aventis, said in a statement that despite the FDA's decision, the company "is confident in the positive benefit-risk ratio of rimonabant 20 milligrams when used in the appropriate population."

Another expert said more data on the safety of rimonabant is needed.

"Rimonabant is potentially beneficial in some patients, but we really need long-term data demonstrating reductions in major obesity-related comorbidities such as heart attack, stroke and sleep apnea and/or mortality, to be completely certain," said Dr. Raj Padwal, an assistant professor of general internal medicine at the University of Alberta in Edmonton, Canada.

The drug needs to be avoided in anyone who has a mood disorder, Padwal added. "Since many patients with weight issues have depression, this means that the drug cannot be used in a large number of people. In the remaining individuals in whom the drug is used, the patient and physician must be cognizant of the risk of a mood disorder and monitor accordingly," he said.

In a related study in the Nov. 16 issue of theBritish Medical Journal, Padwal's team found that long-term users of weight-loss drugs such as orlistat (Xenical), sibutramine (Meridia) and rimonabant experienced only modest weight loss -- less than 11 pounds, which was less than 5 percent of their total body weight.

Padwal's team also noted that the U.S. National Institute for Clinical Excellence recommends stopping the use of weight-loss drugs if 5 percent of total body weight is not lost after three months.

Commenting on Padwal's study, Dr. Gareth Williams, dean of the Faculty of Medicine & Dentistry at the University of Bristol in the U.K., wrote in an accompanying editorial: "Selling anti-obesity drugs over the counter will perpetuate the myth that obesity can be fixed simply by popping a pill and could further undermine the efforts to promote healthy living, which is the only long-term escape from obesity."

More information

For more information on obesity, visit the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

SOURCES: Philip Mitchell, M.B., M.D., professor and head, School of Psychiatry, University of New South Wales, Sydney, Australia; Raj Padwal, M.D., assistant professor, general internal medicine, University of Alberta, Edmonton, Canada; Nov. 17, 2007,The Lancet; Nov. 16, 2007,British Medical Journalonline; June 29, 2007, statement, Sanofi-Aventis, Paris