Dexfenfluramine
Encyclopedia
Dexfenfluramine, marketed as dexfenfluramine hydrochloride under the name Redux, is a serotoninergic
anorectic
drug: it reduces appetite by increasing the amount of extracellular serotonin
in the brain. It is the d-enantiomer
of fenfluramine
and is structually similar to amphetamine
, but lacks any psychologically stimulating effects.
Dexfenfluramine was for some years in the mid-1990s approved by the United States Food and Drug Administration
for the purposes of weight loss
. However, following multiple concerns about the cardiovascular side-effects of the drug, such approval was withdrawn and it was retired from the market in 1997. After it was removed in the US, dexfenfluramine was also pulled out in other global markets. It was later superseded by sibutramine
, which although initially considered a safer alternative to both dexfenfluramine and fenfluramine
, was also removed from the US market in 2010.
The drug was manufactured by Interneuron Pharmaceuticals, a company co-founded by Richard Wurtman
, aimed at marketing discoveries by Massachusetts Institute of Technology
scientists. In the case of Redux, Interneuron's manufacture was under licence to Wyeth-Ayerst Laboratories. Although at the time of its release, some optimism prevailed that it might herald a new approach, there remained some reservations amongst neurologists, twenty-two of whom petitioned the FDA to delay approval. Their concern was based on the work of George A. Ricaurte
whose techniques and conclusions were later questioned.
In actuality, most conversant with the discussion felt that dexfenfuramine's only advantage was patent protection for its licensed companies. Racemic
fenfluramine was far cheaper.
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
anorectic
Anorectic
An anorectic or anorexic , also known as anorexigenic or appetite suppressant, is a dietary supplement and/or drug which reduces appetite, food consumption, and as a result, causes weight loss to occur.-List of anorectics:Numerous pharmaceutical compounds are marketed as appetite suppressants.The...
drug: it reduces appetite by increasing the amount of extracellular serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
in the brain. It is the d-enantiomer
Enantiomer
In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...
of fenfluramine
Fenfluramine
Fenfluramine is a drug that was part of the Fen-Phen anti-obesity medication . Fenfluramine was introduced on the U.S. market in 1973. It is the racemic mixture of two enantiomers, dextrofenfluramine and levofenfluramine...
and is structually similar to amphetamine
Amphetamine
Amphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...
, but lacks any psychologically stimulating effects.
Dexfenfluramine was for some years in the mid-1990s approved by the United States Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
for the purposes of weight loss
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
. However, following multiple concerns about the cardiovascular side-effects of the drug, such approval was withdrawn and it was retired from the market in 1997. After it was removed in the US, dexfenfluramine was also pulled out in other global markets. It was later superseded by sibutramine
Sibutramine
Sibutramine is an oral anorexiant. Until 2010 it was marketed and prescribed as an adjunct in the treatment of exogenous obesity along with diet and exercise...
, which although initially considered a safer alternative to both dexfenfluramine and fenfluramine
Fenfluramine
Fenfluramine is a drug that was part of the Fen-Phen anti-obesity medication . Fenfluramine was introduced on the U.S. market in 1973. It is the racemic mixture of two enantiomers, dextrofenfluramine and levofenfluramine...
, was also removed from the US market in 2010.
The drug was manufactured by Interneuron Pharmaceuticals, a company co-founded by Richard Wurtman
Richard Wurtman
Richard Wurtman, M.D., is the Cecil H. Green Distinguished Professor at the Massachusetts Institute of Technology and a Professor of Neuroscience in MIT’s Department of Brain & Cognitive Sciences, and of Neuropharmacology in the Harvard – MIT Division of Health Sciences & Technology.His research...
, aimed at marketing discoveries by Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
scientists. In the case of Redux, Interneuron's manufacture was under licence to Wyeth-Ayerst Laboratories. Although at the time of its release, some optimism prevailed that it might herald a new approach, there remained some reservations amongst neurologists, twenty-two of whom petitioned the FDA to delay approval. Their concern was based on the work of George A. Ricaurte
George A. Ricaurte
George A. Ricaurte is a controversial neurology researcher who works at the Johns Hopkins School of Medicine in the Department of Neurology. He received his MD from Northwestern University Medical School and his Ph.D. from the University of Chicago.His research focuses on Parkinson's disease and...
whose techniques and conclusions were later questioned.
In actuality, most conversant with the discussion felt that dexfenfuramine's only advantage was patent protection for its licensed companies. Racemic
Racemic
In chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...
fenfluramine was far cheaper.
External links
- FDA Announces Withdrawal Fenfluramine and Dexfenfluramine (Fen-Phen)
- Drug description
- Dexfenfluramine hydrochloride
- Questions and Answers about Withdrawal of Fenfluramine (Pondimin) and Dexfenfluramine (Redux)
- Frontline: Dangerous prescriptions - Interview with Leo Lutwak, M.D. in which he discuses the side effects of fenfluramine, its successor Redux, and the Fen-PhenFen-phenThe drug combination fenfluramine/phentermine, usually called fen-phen, is an anti-obesity treatment that utilizes two anorectics. Fenfluramine, its S-enantiomer dexfenfluramine, and a few other serotonin agonists were shown to cause potentially fatal pulmonary hypertension and heart valve...
combination