|
FDA Withdrawal of Fenfluramine and Dexfenfluramine
(Fen Phen) Announcement
FOR IMMEDIATE RELEASE
September 15, 1997
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 treatments
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 treatment.
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.
top
|
