Cardiac Problems Related to Dexfenfluramine and Phentermine Combined with Fenfluramine ("Phen/Fen")
Since the initial report on the valvular heart disease problems being associated with dexfenfluramine (brand name REDUX) and the use of "phen/fen" many people are confused and frightened. Valvular Heart Disease refers to abnormalities of one of the four valves (aortic, mitral, pulmonic, and tricuspid) that are inside the heart and which direct the flow of blood. These valves, which are normally smooth and composed of connective tissue, open and close in response to the pumping action of the heart. If one of the valves malfunctions, it can lead to either insufficient blood flow to the body or result in a "back pressure," which may result in fluid accumulating in the lungs or lower portions of the body. Symptoms of valvular heart disease can vary from no symptoms in the early stages to chest pain, shortness of breath or swelling in the legs as the disease progresses.If an individual was on these medications for any length of time, there is concern. Many studies have been performed with conflicting results. The largest controlled study (that is, having echocardiograms done before, during, and after treatment with fenfluramine or dexfenfluramine and phentermine or mazindol) was published in July, 1999 (OR 1999;7:313-322). In that study, 16.5% of the individuals developed valvular heart disease. The average use of the medications was 17 months in this study. Other, less well controlled studies have shown an incidence of valvular heart disease of 22% for individuals who utilized the medications (dexfenfluramine or fenfluramine either alone or in combination with other medications such as phentermine) for less than 6 months. The incidence increased to 35 % of all individuals who utilized the medications for more than 6 months. Overall, there may be upwards of a million Americans afflicted with valvular heart disease related to these medications.
What to do?
If you have taken any fenfluramine or dexfenfluramine, you should undergo a thorough examination by your physician with particular attention to the pulmonary and cardiac examination. You should undergo a specialized test called an echocardiogram if any of the following are present:-- A new heart murmur (extra heart sound) is discovered on examination
-- New cardiac symptoms, such as shortness of breath, chest pain, or leg swelling develop
-- You are anticipating undergoing a medical or dental procedure that may result in bacteria entering your bloodstream which could result in bacterial endocarditis (infection of the heart valves)
-- You have taken the medications for 3 months or longer since the majority of heart valve problems cannot be heard on physical examination
There are many medical and dental procedures that can result in bacteria getting into the bloodstream. Physicians and dentists routinely give antibiotics to prevent patients with valvular heart disease (e.g., rheumatic fever related heart disease or someone with an artificial heart valve) from developing endocarditis. The reason for the 3 rd recommendation (above) is that individuals who were on the medications and who were determined by echocardiogram to have significant valvular heart disease confirmed by echocardiogram, fully 83% had normal physical examinations (no clinical history or physical finding to suggest such disease being present)!
Unfortunately, the long-term prognosis of valvular heart disease related to the medications is unknown at this time. There are ongoing studies that (hopefully) will give us more answers.
What about studies that state there is no increased incidence of Valvular Heart Disease in people treated with Redux?
Unfortunately, each study that has been published has had errors that have accounted for the benign results. For example, a study sponsored by the manufacturer of Redux (American Home Products) was presented at a meeting of the American College of Cardiology in Atlanta on March 31, 1998. That study, which was only 77 days long, compared placebo pills with regular Redux and a sustained release Redux in looking at the incidence of valvular heart disease. The results are as follows:|
Aortic
Valve Leakage (>mild)
|
Mitral
Valve Leakage
(> moderate) |
Total %
with Heart Valve Problems (may have more than one valve involved)
|
|
|
Placebo Group
|
3.6 %
|
1.2 %
|
4.5 %
|
|
Regular
Redux
|
5 %
|
1.7 %
|
6.5 %
|
|
Sustained
Release Redux
|
5.8 %
|
1.8 %
|
7.3 %
|
DISCLAIMER STATEMENT
The above information is for general
purposes only and should not be construed as definitive or binding medical advice.
Because each person is medically different, individuals should consult their
own personal physicians for specific information and/or treatment recommendations.
It should be noted that the incidence of valvular heart disease in the placebo group was at least twice as high as previously reported in other studies. This may be because the placebo group allowed for inclusion of people who had previously been on the medication as long as it was more than 6 months prior to the start of this study.
As 1999 ends, the best scientific evidence is that dexfenfluramine and phentermine combined with fenfluramine is associated with valvular heart disease and that the longer you were on the medication(s), the greater the risk of these complications. If you do have valvular heart disease or suspect that you do, please see your physician.
Content written: July 1999.
Last modified: August 2001.
Copyright © 1996 -2001
Michael D. Myers M.D. Inc.
All rights reserved.
The above information is for general purposes only and should not be construed as definitive or binding medical advice. Because each person is medically different, individuals should consult their own personal physicians for specific information and/or treatment recommendations.