HEALTH ADVISORY ON
FENFLURAMINE/PHENTERMINE FOR OBESITY July 8, 1997
FDA today alerted physicians to reports of valvular heart
disease in women treated for obesity with a combination of
fenfluramine and phentermine. The drugs were approved
individually more than 20 years ago for single-drug, short-term
obesity therapy. Recently, however, they have been widely used
"off-label" in combination and for long-term
management of obesity. FDA is unaware of studies adequately
demonstrating the safety and effectiveness of these products
when used in combination.
"These are drugs that should be taken only by obese
patients in conjunction with a weight loss regimen that includes
a reduced-calorie diet and an exercise program, in accordance
with approved labeling" said lead deputy FDA Commissioner
Michael Friedman.
In a letter to doctors, 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.
Researchers at the Mayo Clinic and Mayo Foundation,
Rochester, Minn., today also announced results of a study of
valvular disease in women who took the combination of
fenfluramine and phentermine for management of obesity, to be
published in the New England Journal of Medicine next month.
There is no conclusive evidence of a cause-effect
relationship between use of the drugs and the development of
valvular disease. However, because of the seriousness of the
cardiac problems and their rare occurrence in otherwise healthy
obese women in this age range, FDA believes patients and health
care professionals should be notified of this information. In
addition, the agency is notifying manufacturers to meet with FDA
to discuss possible labeling changes.
FDA will continue to monitor adverse events reports from all
sources. The agency encourages all health care professionals to
report any cases of cardiac valvular disease or other serious
toxicities associated with the use of fenfluramine,
dexfenfluramine, or phentermine to the FDA's MEDWATCH program at
1-800-FDA-1088/fax 1-800-FDA-0178; or to the respective drug
manufacturers. Of particular interest would be information from
such patients on the dosage and duration of therapy with the
drug product(s), whether there were any other medications being
taken by the patient on a chronic basis, whether there was any
history of pre-existent cardiac disease, the results of the
patient's cardiac evaluation, and the degree of obesity at the
time drug therapy was started. |
