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Date: November 13, 1997
FOR IMMEDIATE RELEASE
Contact: FOOD AND DRUG ADMINISTRATION, Lawrence Bachorik: (301) 827­6250, Broadcast Media:(301) 827­3434, Consumer Hotline(800) 532­4440

Interim Recommendations Issued for Patients Exposed to Fenfluramine and Dexfenfluramine

"Since these drugs were withdrawn from the U.S. market last September, many people who took them have been asking what they should do," said FDA's lead deputy commissioner Michael Friedman, M.D. "We in the government, together with the medical community, have developed these recommendations to provide guidance based on the best information we have at this time."

The recommendations are based on current knowledge about the association of these drugs with the development of heart valvular disease. The valvular damage can cause regurgitation­­a backflow of blood into a heart chamber­­that may in some cases lead to heart and lung disease.

Of immediate concern for patients with valvular disease is the possible increased risk of bacterial endocarditis­­an often serious and potentially fatal infection of the heart's lining­­following certain invasive medical and dental procedures.

Until more complete information is available, HHS recommends the following measures for people who have taken fenfluramine or dexfenfluramine.

• Anyone who has taken fenfluramine or dexfenfluramine for any period of time, either alone or with another drug or drugs, should see their doctor for a medical history and physical examination to determine whether there are signs or symptoms of heart or lung disease.

• Anyone who has taken these drugs for any period of time, either alone or with another drug or drugs, who has signs or symptoms of heart or lung disease, such as a new heart murmur or shortness of breath, should have an echocardiogram performed.

• An echocardiogram should be strongly considered for any patient who has taken these drugs, either alone or with another drug or drugs ­­ regardless of whether they have signs and symptoms of the heart or lung diseases ­­ BEFORE having any invasive procedure for which the American Heart Association recommends antibiotic prophylactic treatment to prevent the development of bacterial endocarditis. This will provide an accurate determination of whether or not the person needs the antibiotic treatment.

On September 15, at the request of the Food and Drug Administration, Wyeth­Ayerst Laboratories and Interneuron Pharmaceuticals, which manufactured and marketed fenfluramine ­ under the brand name Pondimin and dexfenfluramine under the brand name Redux, voluntarily withdrew these products from the market. The withdrawal was based on initial echocardiographic findings in five surveys indicating that approximately 30 percent of patients in these surveys who took these drugs had valvular abnormalities, even though most had no symptoms. This is apparently much higher than would be expected in the general population, where additional preliminary reports suggest that significant valvular regurgitation occurs in less than five percent of the general population of young and middle­aged adults in the United States.

Studies are underway and others planned to learn more about the clinical significance of these findings, the natural course of the valvular lesions (that is, whether they generally disappear, become worse, or stay the same once the drugs are stopped), and what factors, if any, may increase an individual's susceptibility to their development.