The weight-loss drug often referred to as “Fen-Phen” – though it actually was sold under the brand names of Pondimin and Redux – has been associated with an increased risk for heart damage – specifically conditions known as heart valve disease and Primary Pulmonary Hypertension (PPH). Fen-Phen was a popular type of appetite suppressant prescribed to those wanting to slim down, until it was recalled about 16 years ago. However, those who ingested the drug when it was on the market are still getting diagnosed with heart conditions, even if they took it for only a short time. These heart conditions can take 10 to 20 years to show up, according to medical experts.
Fen-Phen a Combination of Two Weight Loss Drugs Sold Under Different Brands
Fen-phen is a generic name for branded medication that consisted of a combination of two drugs, fenfluramine and dexfenfluramine. Each suppresses appetite. Fenfluramine, specifically, depresses the central nervous system and raises serotonin levels, leaving those who ingest it tired. Dexfenfluramine also decreases hunger but acts more like a stimulant. The FDA had approved dexfenfluramine for short-term weight-loss in 1959 and fenfluramine for the same thing in 1973. The FDA, however, did not approve a combination of the two drugs, which is what Fen-Phen was – so basically, it could be termed an off-label drug.
After a 1992 research study revealed fenfluramine and dexfenfluramine combined resulted in fewer unwanted side effects than when taken separately, companies began to market a diet drug combination under the brand names Pondimin and Redux, and many doctors began prescribing fenfluramine and dexfenfluramine to be taken together.
Then in July 1997, researchers at the Mayo Clinic and Mayo Foundation reported 24 cases of rare valvular disease in women who took Fen-Phen drugs. Subsequently, the FDA received 66 additional reports of heart valve disease associated mainly with Fen-Phen. There were also reports of cases seen in patients taking only fenfluramine or dexfenfluramine.
First the FDA requested that manufacturers stress the potential risk to the heart in the drugs- labeling and patient package inserts. Clearly, the drugs would prove to be too dangerous even for that to be enough.
FDA Issued Recall in 1997
The FDA issued a recall in September 1997, urging both doctors and patients to stop using the diet pill combination. The agency asked the manufacturers to voluntarily withdraw both treatments for obesity from the market. Dexfenfluramine was manufactured for Interneuron Pharmaceuticals and marketed under the name of Redux by Wyeth-Ayerst Laboratories, a subsidiary of American Home Products Corp. of Madison, N.J., which also manufactured and marketed fenfluramine under the brand name Pondimin. Both companies agreed to voluntarily withdraw the drugs.
After additional testing, the FDA stated that in findings from doctors evaluated with echo-cardiograms patients who took fenfluramine and dexfenfluramine, finding that approximately 30 percent had abnormal echo-cardiograms, even though they showed no symptoms, an exceedingly high percentage of abnormal test results.
Additionally, a Mayo Clinic study published in the New England Journal of Medicine on August 28, 1997, suggested that as many as one-third of the people who took Fen-Phen showed evidence of heart valve disease. The study found a high incidence of heart valve disease among patients taking the diet pills; these cases show no other known reason for developing valve disease. In addition fenfluramine and dexfenfluramine were found to increase the risk of developing Primary Pulmonary Hypertension or (PPH), a rare disease that causes the progressive narrowing of the blood vessels of the lungs. Studies estimate that treatment with certain appetite suppressant drugs tends to increase the chances of developing PPH by approximately 25% to 30%.