Food and Drug Administration
"PHEN/FEN" AND VALVULAR HEART DISEASE
July 8, 1997
QUESTIONS AND ANSWERS
1. WHAT IS "PHEN/FEN" ?
Phentermine ("phen") and fenfluramine ("fen") are prescription
medications approved by the FDA as single medicines for short-term
(a few weeks) use as appetite suppressants in the management of
obesity. Some physicians have prescribed them recently to be used
in combination with each other and to be used for extended periods
of time in weight loss programs. Such use of the products is
called "off label" because there have been no studies presented to
the FDA to demonstrate either the effectiveness or safety of the
two drugs taken together or for longer periods of time (greater
than a few weeks).
"Phen" is short for phentermine, an amphetamine-like drug marketed
under various trade names such as Ionamin® and Fastin®, as well as
several generic forms of phentermine. It is approved for
short-term use as an appetite suppressant.
"Fen" is short for fenfluramine, a drug affecting serotonin,
marketed as Pondimin®. It is approved for short-term use as an
appetite suppressant.
2. WHAT IS VALVULAR HEART DISEASE?
There are four major valves controlling the flow of blood into,
out of, and between the four chambers of the heart. Several
disease processes, including infection and toxicity, may damage
the valves, causing them to malfunction, and may produce severe
heart and/or lung disease.
3. WHAT IS THE RELATIONSHIP OF "PHEN/FEN" TO HEART DISEASE?
Recently, the FDA has received reports of confirmed valvular heart
disease in the United States in at least 33 women between ages 35
and 72 who had taken the drug combination for time periods ranging
between 1 and greater than 16 months (average 9.5 months). A
direct causal relationship between the use of the drugs and the
valve disease has not been established; however, the occurrence of
a severe and usually rare disease in an otherwise healthy
population of young obese women is a matter of serious public
health concern. It is not known at present how the damage to the
heart valves develops: whether it is due to either phentermine or
fenfluramine alone, to the combination of products, or to other
factors.
4. WHAT ARE THE SIGNS OF VALVULAR HEART DISEASE?
The occurrence of a new heart murmur (abnormal sound as the blood
flows over a valve) is usually the first indication of the
development of valvular heart disease. Abnormal valve function may
then be evaluated by a painless, non-invasive test called
echocardiography, usually performed by a cardiologist. More severe
symptoms of the disease include shortness of breath, loss of
tolerance to physical activity, and fluid retention in the legs
and lungs.
5. IS THE VALVE DISEASE REVERSIBLE?
Presently, good data are not available to answer this question.
6. HOW IS VALVULAR DISEASE TREATED?
In some instances, medication can control the heart failure
associated with valvular damage. In others, surgery to replace the
valves with artificial valves may be necessary.
7. IS VALVULAR HEART DISEASE RELATED TO PRIMARY PULMONARY HYPERTENSION?
Primary pulmonary hypertension is a disease of the heart and lungs
caused by narrowing of blood vessels in the lungs. It has been
reported to occur in about 1 in 25,000 people using appetite
suppressants for more than 3 months. This disorder results in
death in about 40% of affected individuals within 4 years. Primary
pulmonary hypertension may also occur in association with valvular
heart disease. More research is needed to determine if there is
some relationship between the disease of the heart valves and the
primary pulmonary hypertension also seen in certain patients who
use these appetite suppressants.
8. SHOULD I STOP TAKING "PHEN/FEN" RIGHT NOW?
You should discuss with your health care provider what is the best
course of action for your individual case.
9. WHAT DRUGS CAN BE USED IN PLACE OF PHEN/FEN?
You need to discuss with your health care provider whether
alternative approaches to appetite suppression and weight control
would be appropriate for your individual case. No currently
available weight-loss drugs have been studied adequately in
combinations to permit a recommendation by FDA for combined use.
None of the currently available weight-loss drugs except
dexfenfluramine has been studied for more than a few weeks use.
10. IS THIS JUST A DISEASE OF WOMEN?
To date, all 33 cases of which FDA is aware are women. However,
there is no reason at present to believe that men could not also
be affected. Most of the use of these products is in women, so
what we are presently seeing could be only a reflection of the
usage patterns of the products. FDA advises that male and female
patients and their health care professionals should all be aware
of this information; FDA encourages reporting to FDA or the
manufacturers any case of valvular problems in male or female
patients suspected of being associated with the use of these
products.http://www.fda.gov/cder/phenfenqa.htm
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