Home » Drug Information » FDA Approved Drugs » 1996
Medical Areas: Endocrinology | Neurology | Psychiatry/Psychology | Nutrition and Weight Loss
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Redux (dexfenfluramine hydrochloride)
The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
Approval Status: Approved May 1996
Treatment Area: obesity
Redux, when combined with a reduced-calorie diet, has been
indicated for the management of obesity, including weight loss and
maintenance of that weight loss. The safety and effectiveness of
Redux beyond one year have not been determined at this time.
Redux is recommended for obese subjects with an initial body
mass index (BMI) of at least 30 kg/m2 (which is approximately 30%
over desirable weight) or a BMI of at least 27 kg/m2 (which is
approximately 20% over desirable weight) in the presence of other
risk factors (e.g., hypertension, diabetes, or hyperlipidemia).
Redux is available by physician's prescription in 15 mg
capsules to be taken twice daily.
In clinical trials, Redux therapy was associated with decreased
appetite and may make people feel full and lessen their desire to
In a large, one-year clinical trial of more than 900 subjects,
individuals taking Redux in conjunction with a reduced-calorie diet
loss significantly more weight than subjects on diet and placebo.
Redux helped produce a significant reduction in weight during the
first four to six months. This response was maintained during a
year of therapy. At the end of the year, 64% of all subjects lost
at least 5% of their initial total weight, 40% lost at least 10%,
and 21% lost at least 15%. In a study of 60 obese subjects who had
successfully lost weight by dieting alone (i.e., lost at least ten
pounds in the previous year), the addition of Redux to their
regimen resulted in the further loss of 26% of initial excess
The most commonly reported side effects in clinical trials
included drowsiness, diarrhea, and dry mouth. These side effects
were usually mild and disappeared in a few weeks.
There is a low incidence of a serious, potentially
life-threatening cardiovascular condition, primary pulmonary
hypertension (PPH), associated with the use of all types of
prescription weight loss drugs (anorexigens). A two-year study
looked to investigate all incidences of PPH in Europe and
identified 95 cases: 20 of these had been exposed to anorexigens in
the past. Eighteen of the 20 cases identified a history of
dexfenfluramine use. In an initial review of these cases (excluding
ten additional cases where the specific drug or dates of use were
unknown), the use of anorexigens for longer than three months was
associated with a nine-fold increase in the risk of PPH. Therefore,
the risk of PPH in obese subjects was estimated to be at least 18
cases per 1,000,000 subjects per year. The authors of the initial
review are continuing to analyze the data. In the general
population, the yearly occurrence of PPH is one to two cases per
one million people.
Redux should not be used in subjects hypersensitive to
dexfenfluramine or related compounds, in subjects with diagnosed
pulmonary hypertension, or in subjects taking (or without 14 days
of discontinuing) monoamine oxidase (MAO) inhibitors. Redux should
not be administered to patients using other serotoninergic drugs.
Redux is not recommended for women who are pregnant or nursing or
for pediatric subjects.
Mechanism of Action
The mechanism of action of Redux is based upon its effects on
serotonin, a neurotransmitter in the brain. Redux works primarily
by decreased caloric intake associated with increased activity of
serotonin in the brain.