Dealing with legacy of Pondimin and Redux

In a Sept. 15 letter to health care providers, the Pondimin and Redux manufacturer, Philadelphia, PA-based Wyeth-Ayerst, a subsidiary of American Home Products of Madison, NJ, stated that 92 abnormal echo-cardiograms were found among 291 asymptomatic patients seen in five centers.

The letter specifies that most of the patients had used fenfluramine or dexfenfluramine, most often with phentermine, for up to 24 months. (For a free copy, call the Wyeth-Ayerst provider inquiries line listed in resources, p. 139.) Fen-phen is the combination of Pondimin (fenfluramine) and phentermine. Dexfen-phen is the combination of Redux (dexfenfluramine) and phentermine.

Though all three of the drugs were approved by the U.S. Food and Drug Administration (FDA) for solo use, there was no approval for combined use. Such nonapproved use is often dubbed "off-label."

The voluntary recall came on the heels of FDA warnings about the impaired heart valve function among diet drug users. Wyeth-Ayerst responded to the FDA’s appeal to pull Pondimin and Redux off the market.

In most cases where women used diet medications, "I would recommend they get a baseline echocardiogram," explains Nancy Carteron, MD, FACR, chair of the advisory council of the women’s program at the California Pacific Medical Center in San Francisco. She says the cardiac findings are preliminary. Controlled studies still are needed to determine how much damage is due to the medication and how much is attributable to other causes. ß