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| |  Valvular Heart Disease Associated With Commonly Prescribed Diet Pills ROCHESTER, Minn. -- July 8, 1997 -- Mayo Clinic today reports a clinical observation of unusual valvular heart disease in 24 patients who had taken the weight-loss medications fenfluramine and phentermine (fen-phen). Last year, doctors wrote a total of 18 million monthly prescriptions for these drugs. "We recommend that patients who are currently taking or considering fen-phen therapy discuss these findings with their physicians, who can help them weigh the benefits and risks of weight reduction therapy," says Dr. Heidi Connolly, Mayo cardiologist and primary author of the paper. "We believe that these cases raise significant concern that this combination of appetite suppressants can have important implications regarding valvular heart disease," she continues, "but more comprehensive study, which we are planning, is needed to make a definitive statement about the association." Physicians identified the patients in this report -- all women with an average of 43 years -- during routine medical visits. All 24 patients had cardiovascular symptoms or a heart murmur. Subsequent testing showed that one or more heart valves in each patient was thickened and blood was regurgitating (or "leaking" backwards), making the heart work harder to pump blood throughout the body. Eight of the women had newly documented pulmonary hypertension, a serious and sometimes fatal disease of the heart and lungs. Five patients needed heart surgery to repair or replace damaged valves. No patients in the report have died to date. "We don't know how fen-phen may cause injury to the heart valves," says Dr. Connolly. "We do know that fenfluramine and phentermine alter the way the brain chemical serotonin is metabolized, and serotonin that circulates in the blood can cause valve injury. Again, more study is needed to identify mechanisms and risk factors." The 24 women in this report, who had used fen-phen for an average of one year, had been free of heart disease when they began taking these weight-loss medications. Physicians and surgeons at Mayo noted the first case of valvular heart disease following fen-phen therapy about a year ago. Since then, Mayo physicians and Dr. Jack Crary, a cardiologist at MeritCare, in Fargo, N.D., have identified an increasing number of patients with similar problems, which led to this report. "We began to notice that otherwise healthy young women, presenting with this unusual form of valve disease, were also on fen-phen," Dr. Connolly added. "This caused us to further evaluate the possible correlation between fen-phen and valve disease." In a letter to doctors, the U.S. Food and Drug Administration (FDA) noted that as of July 8, 1997, the agency has received reports of 33 cases of unusual abnormalities in mitral, aortic, and tricuspid heart valves in women between the ages of 30 and 72 who had been taking fenfluramine and phentermine for 1 month to 28 months. The course of the disease when the drugs are stopped is unknown at this time. Wyeth-Ayerst, maker of Redux (dexfenfluramine), has reviewed the case reports from the Mayo Clinic and is concerned about the potential association of valvular disorders with the combination use of two separate medications, phentermine and fenfluramine, sometimes referred to as "phen/fen." Because the data from the Mayo Clinic are limited and therefore inconclusive, additional scientific investigation must be conducted before any possible link can be confirmed, the company said in a statement. Obesity is associated with serious health disorders. Patients taking "phen/fen" should not be alarmed, but are advised to consult their doctors if they have any concerns. Wyeth-Ayerst is working with Mayo Clinic to develop a rigorous, prospective study which will provide clinical data to properly examine this issue. Because the addition of phentermine to fenfluramine is not an FDA-approved use, potential safety concerns related to such a combination have not been systematically evaluated in large, multicenter, placebo-controlled trials. In a recent letter to all prescribers, Wyeth-Ayerst stated that concomitant use of fenfluramine with other weight-loss agents is not recommended. The letter reiterated that fenfluramine is indicated only for short-term use and that the combination of phentermine with fenfluramine has not been adequately studied. Further research is necessary because this data cannot rule out a number of potential biases and other external factors which could influence the findings, the company stated. For example, all reported cases originated in a limited, specific geographical region, which indicates that the study results may be subject to some as yet undetermined selection bias. Other potential regional factors, such as environmental, lifestyle or occupational links, may have also affected the results. In some cases, the results may have been related to dosage, since some of the patients in question were taking very large doses which are well outside of the recommended dosage range. A recent large European case control study which showed an association between the use of anorexigens and an increased risk of primary pulmonary hypertension did not report these specific valvular abnormalities. Obesity is a serious medical condition, which now afflicts one in three adult Americans and has grown at alarming rates in recent years. Today obesity is the second leading preventable cause of death in America after tobacco use, and is linked to an estimated 300,000 deaths each year. Anorexigens; such as fenfluramine can play an important role in treating clinically obese patients when properly prescribed as part of a program that also includes a regulated diet and increased physical exercise. Although, as stated by the Mayo Clinic, the initial findings are not conclusive, Wyeth-Ayerst is committed to working closely with the Clinic in conducting further research. More information on: Wyeth-Ayerst
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