DIET
DRUG & FEN-
PHEN HISTORY EXPLAINED
While dieters since the mid
1950's had used amphetemine types of diet aids it was not until in 1973, Pondimin (fenfluramine)
first was approved by the FDA (Food & Drug Administration) to
fight obesity for "single drug, short-term use." Pondimin promoted a
feeling of fullness in users that caused them to have a decreased appetite. The
problem with Pondimin is that it had side effects such as include diarrhea,
drowsiness, and dry mouth.
Phentermine
is another diet drug that also had a long history behind it, being approved for
sale in 1959 by the FDA. Despite the side effects of insomnia and irritability,
phentermine also spent its time on the market without event. Both of these
drugs, Pondimin and Phentermine were not very popular because of their side
effects.
FEN PHEN IS BORN
In 1992, a
study was published that showed that by using Pondimin
(fenfluramine) with Phentermine, that
side effects of dry mouth could be reduced while maintaining effective weight
loss with both drugs being taken. However, since the doses were lower, the
doctor performing the study lengthened the duration of administering the drugs.
A critical note by the FDA at that time of approval for fenfluramine, was that
safety of use beyond one year had not been established in clinical trials.
Within weeks of a July 1997 Mayo Clinic
paper being published, the drugs were withdrawn. The Mayo
report showed heart valve damage in about one third (1/3) of those studied
who had been taking Fen-Phen comdination, Pondimin or Redux. Additionally
eveidence was presented of an increase likelihood of primary pulmonary
hypertension cases as well. Immediately the FDA announces it's withdrawal
(see below)
PRIMARY PULMONARY HYPERTENSION (PPH)
FDA Announces
Withdrawal Fenfluramine and
Dexfenfluramine (Fen-Phen)
P97-32
FOR IMMEDIATE RELEASE
September 15, 1997 |
FOOD AND DRUG ADMINISTRATION
Lawrence Bachorik: (301) 827-6250
Broadcast Media: (301) 827-3434
Consumer Hotline: (800) 532-4440 |
FDA ANNOUNCES WITHDRAWAL OF FENFLURAMINE AND
DEXFENFLURAMINE
The Food and Drug Administration, acting on
new evidence about significant side-effects associated with fenfluramine and
dexfenfluramine, has asked the manufacturers to voluntarily withdraw both
treaents for obesity from the market. Dexfenfluramine is 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 manufactures and markets fenfluramine under the brand
name Pondimin.
Both companies have agreed to voluntarily withdraw their drugs. The FDA is not
requesting the withdrawal of phentermine, the third widely used medication for
obesity.
The action is based on new findings from
doctors who have evaluated patients taking these two drugs with echocardiograms,
a special procedure that can test the functioning of heart valves. These
findings indicate that approximately 30 percent of patients who were evaluated
had abnormal echocardiograms, even though they had no symptoms. This is a much
higher than expected percentage of abnormal test results.
"These
findings call for prompt action, " said Michael A. Friedman, M.D., the Lead
Deputy Commissioner of the FDA. "The
data we have obtained indicate that fenfluramine, and the chemically closely
related dexfenfluramine, present an unacceptable risk at this time to patients
who take them."
FDA recommends
that patients using either of these products stop taking them. Users of these
two products should contact
their doctors to discuss their treaent.These new findings suggest fenfluramine
and dexfenfluramine are the likely cause of heart valve problems of the type
that prompted FDA's two earlier warnings concerning "fen-phen, " a
combination of fenfluramine and phentermine. "Fen-phen" has been widely used
off-label in recent years for the long-term management of obesity.
In July, researchers at the Mayo Clinic and
Mayo Foundation reported 24 cases of rare valvular disease in women who took the
"fen-phen" combination therapy. FDA alerted medical doctors that it had
received nine additional reports of the same type, and requested all health care
professionals to report any such cases to the agency's MedWatch program
(1-800-FDA-1088/fax 1-800-FDA- 0178) or to the respective pharmaceutical
manufacturers.
Subsequently, 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. FDA requested that the manufacturers of fenfluramine and
dexfenfluramine stress the potential risk to the heart in the drugs' labeling
and patient package inserts. FDA continues to receive reports of cardiac
valvular disease in persons who have taken these drugs.
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Legal Assistance
for PPH & Diet Drug Victims since 1997
