FDA issues special alert for obesity drugs

Despite a lack of conclusive research results, the Food and Drug Administration alerted physicians that treating women for obesity with a combination of fenfluramine and phentermine may be linked to valvular heart disease.

According to a letter mail-ed to physicians, the FDA has received reports of 33 cases of unusual abnormalities in mitral, aortic and tricuspid heart valves in women who had been taking fenfluramine and phentermine for one month to 28 months. The women were between the ages of 30 and 72 and were healthy aside from obesity.

The FDA said it has found no conclusive evidence of a cause-and-effect relationship between use of the products and the development of valvular disease, but the agency stated that the seriousness of the cardiac problems prompted it to notify physicians. Researchers at the Mayo Clinic and Mayo Foundation, Rochester, MN, announced that they will publish the results of a study on the combined drugs and valvular disease in the August issue of the New England Journal of Medicine.

Both drugs were individually approved more than 20 years ago as single-drug, short-term obesity treatments. In recent years, however, doctors have paired the two for the long-term management of obesity. The FDA has never indicated that the drugs should be combined for that use.

Manufacturers of the products, including American Home Products, Madison, NJ, and SmithKline Beecham, Philadelphia, have been asked to meet with the FDA to discuss possible labeling changes.

In addition, the agency asked that all health care professionals report any cases of cardiac valvular disease or other serious toxicities associated with use of fenfluramine, phentermine or dexfenfluramine to the manufacturers or to the FDA at, (800) FDA-1088. PR