LIKE I'VE BEEN SAYING: (CAN YOU SAY SQUEEEEZE?)
Study Shows No Significant Increase in Valve Abnormalities in
Patients Taking Redux
/ADVANCE FOR RELEASE AT 5:00 P.M. EST, TODAY, MARCH 31/
/ADVANCE/ ATLANTA, March 31 /PRNewswire/ -- Results of a clinical study
presented today at the annual meeting of the American College of Cardiology
show no significant increase in the prevalence of clinically relevant heart
valve regurgitation after two to three months of taking Redux
(dexfenfluramine). These results were presented by Neil J. Weissman,
assistant professor of medicine and director of clinical echocardiography at
Georgetown University Medical Center's Cardiovascular Institute.
The randomized, double-blinded, multi-center study involved 1,072 patients
who were part of a trial of a new sustained-release form of Redux, which was
never marketed. The trial of this new drug compared the sustained-release
formula to both Redux and placebo. The administration of drug was stopped in
September 1997 following reports of valvular abnormalities among users of
fenfluramine (part of the phen/fen combination) and Redux. At the same time,
Redux and Pondimin (fenfluramine) were both voluntarily withdrawn from the
market by Wyeth-Ayerst. The protocol of the study was then modified to
include echocardiographic evaluation of these patients.
At the time the trial was stopped, patients had been treated with drug or
placebo for a median of 77 days. Market research indicates that while Redux
was on the market, 76 percent of Redux patients used the drug for 60 days or
less, while 86 percent used it for 90 days or less.
The echocardiograms of the 1,072 participants were interpreted at
Georgetown University Medical Center by cardiologists who did not know whether
patients had taken Redux, sustained-release dexfenfluramine or placebo. The
echocardiograms were studied for evidence of valvular regurgitation and
valvular leaflet abnormalities. Valvular regurgitation is the leakage of
blood backwards which may decrease blood flow to the rest of the body and may
increase the workload of the heart.
The study focused primarily on mild or greater aortic regurgitation and
moderate or greater mitral regurgitation, which were the focus of the Food and
Drug Administration's previously reported "case definition" of valvular
abnormalities among diet drug users.
The principal findings of the study included:
-- Mild or greater aortic regurgitation occurred in 5.0 percent of Redux,
5.8 percent of sustained-release dexfenfluramine, and 3.6 percent of
the placebo-treated patients.
-- Moderate or greater mitral regurgitation occurred in 1.7 percent,
1.8 percent, and 1.2 percent, respectively.
-- Mild or greater aortic, moderate or greater mitral regurgitation, or
both occurred in 6.5 percent, 7.3 percent, and 4.5 percent,
respectively.
None of these differences between drug and placebo groups were
statistically significant.
Other notable findings included the following:
-- When all degrees of regurgitation (physiologic, mild, moderate,
severe) were compared, there was a higher prevalence of mitral
regurgitation in treated than in placebo patients. This was due to a
slightly increased prevalence of physiologic or mild mitral
regurgitation.
-- Decreased posterior mitral leaflet mobility of any degree occurred
more frequently in treated than in placebo patients. Moderate or
severe restricted mobility was rarely seen (Redux 2.0 percent,
sustained-release dexfenfluramine 1.5 percent, placebo 0.3 percent).
-- There were no differences among treatment groups for tricuspid or
pulmonary regurgitation, aortic or tricuspid leaflet morphology,
estimated pulmonary artery pressure, or serious cardiovascular adverse
events.
"This study demonstrates that any difference in prevalence or severity of
valvular regurgitation between patients who took Redux and those that took
placebo is very small," says Weissman. "While this is reassuring for the
patients who have taken Redux for two to three months, it needs to be
confirmed for other diet drugs and should not preclude appropriate evaluation
of patients who took diet drugs and display signs or symptoms of heart valve
disease. Future studies should explore combination therapy and the duration
of therapy."
The study was sponsored by Wyeth-Ayerst Research. A full report of the
findings has been submitted for publication.
The Georgetown Cardiovascular Institute was formed to provide patients in
the Washington, D.C. area and around the world with a comprehensive center
dedicated to diagnosis, treatment, research, education and prevention of
cardiovascular illnesses.
SOURCE Georgetown University Medical Center; Wyeth-Ayerst Laboratories
CONTACT: Amy Pianalto of Georgetown Univ. Med. Ctr.,
202-687-5100; Doug Petkus of Wyeth-Ayerst at ACC, 404-222-3664 or
Audrey Ashby, 610-971-5823 |
