Oxandrolone
Encyclopedia
Oxandrolone is a drug
created by Raphael Pappo while at Searle Laboratories, now Pfizer Inc.
under the trademark Anavar, and introduced into the US in 1964.
Oxandrolone is a synthetic anabolic steroid
derived from dihydrotestosterone
by substituting 2nd carbon atom for oxygen (O). It is widely known for its exceptionally small level of androgenicity accompanied by moderate anabolic effect. Although oxandrolone is a 17-alpha alkylated steroid, its liver toxicity is very small as well. Studies have showed that a daily dose of 20 mg oxandrolone used in the course of 12 weeks had only a negligible impact on the increase of liver enzymes. As a DHT derivative, oxandrolone does not aromatize
(convert to estrogen, which causes gynecomastia
or male breast tissue). It also does not significantly influence the body's normal testosterone production (HPTA axis) at low dosages (10 mg). When dosages are high, the human body reacts by reducing the production of LH (luteinizing hormone
), thinking endogenous
testosterone production is too high; this in turn eliminates further stimulation of Leydig cells in the testicles, causing testicular atrophy
(shrinking). Oxandrolone used in a dose of 80 mg/day suppressed endogenous testosterone by 67% after 12 weeks of therapy.
The drug was prescribed to promote muscle regrowth in disorders which cause involuntary weight loss. It had also been shown to be partially successful in treating cases of osteoporosis
. However, in part due to bad publicity from its abuses by bodybuilders
, production of Anavar was discontinued by Searle Laboratories in 1989. It was picked up by Bio-Technology General Corporation, now Savient Pharmaceuticals who, following successful clinical trials in 1995, released it under the tradename Oxandrin. As of 2009, it is the only drug marketed by the company.
It was subsequently approved for orphan drug
status by the Food and Drug Administration
(FDA) for treating alcoholic hepatitis, Turner syndrome
, and HIV
-induced weight loss. It is also indicated as an offset to protein catabolism
caused by long-term administration of corticosteroids. In addition, the drug has shown positive results in treating anemia
and hereditary angioedema
. Because of its potential for abuse, it is categorized as a Schedule III
controlled substance in the US.
In a randomized, double-blind study, patients with 40% total body surface area burn
s were selected to receive standard burn care plus oxandrolone, or without oxandrolone. Those treated with oxandrolone showed improved body composition, preserved muscle mass and reduced hospital stay time.
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
created by Raphael Pappo while at Searle Laboratories, now Pfizer Inc.
Pfizer
Pfizer, Inc. is an American multinational pharmaceutical corporation. The company is based in New York City, New York with its research headquarters in Groton, Connecticut, United States...
under the trademark Anavar, and introduced into the US in 1964.
Oxandrolone is a synthetic anabolic steroid
Anabolic steroid
Anabolic steroids, technically known as anabolic-androgen steroids or colloquially simply as "steroids", are drugs that mimic the effects of testosterone and dihydrotestosterone in the body. They increase protein synthesis within cells, which results in the buildup of cellular tissue ,...
derived from dihydrotestosterone
Dihydrotestosterone
Dihydrotestosterone is an androgen or male sex hormone. The enzyme 5α-reductase synthesises DHT in the prostate, testes, hair follicles, and adrenal glands...
by substituting 2nd carbon atom for oxygen (O). It is widely known for its exceptionally small level of androgenicity accompanied by moderate anabolic effect. Although oxandrolone is a 17-alpha alkylated steroid, its liver toxicity is very small as well. Studies have showed that a daily dose of 20 mg oxandrolone used in the course of 12 weeks had only a negligible impact on the increase of liver enzymes. As a DHT derivative, oxandrolone does not aromatize
Aromaticity
In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...
(convert to estrogen, which causes gynecomastia
Gynecomastia
Gynecomastia or Gynaecomastia, , is the abnormal development of large mammary glands in males resulting in breast enlargement. The term comes from the Greek γυνή gyné meaning "woman" and μαστός mastós meaning "breast"...
or male breast tissue). It also does not significantly influence the body's normal testosterone production (HPTA axis) at low dosages (10 mg). When dosages are high, the human body reacts by reducing the production of LH (luteinizing hormone
Luteinizing hormone
Luteinizing hormone is a hormone produced by the anterior pituitary gland. In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone , it stimulates Leydig cell...
), thinking endogenous
Endogenous
Endogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...
testosterone production is too high; this in turn eliminates further stimulation of Leydig cells in the testicles, causing testicular atrophy
Testicular atrophy
Testicular atrophy is a medical condition in which the male reproductive organs diminish in size and may be accompanied by loss of function. This does not refer to temporary changes, such as those brought on by cold.Some medications can cause testicular atrophy...
(shrinking). Oxandrolone used in a dose of 80 mg/day suppressed endogenous testosterone by 67% after 12 weeks of therapy.
The drug was prescribed to promote muscle regrowth in disorders which cause involuntary weight loss. It had also been shown to be partially successful in treating cases of osteoporosis
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
. However, in part due to bad publicity from its abuses by bodybuilders
Bodybuilding
Bodybuilding is a form of body modification involving intensive muscle hypertrophy. An individual who engages in this activity is referred to as a bodybuilder. In competitive and professional bodybuilding, bodybuilders display their physiques to a panel of judges, who assign points based on their...
, production of Anavar was discontinued by Searle Laboratories in 1989. It was picked up by Bio-Technology General Corporation, now Savient Pharmaceuticals who, following successful clinical trials in 1995, released it under the tradename Oxandrin. As of 2009, it is the only drug marketed by the company.
It was subsequently approved for orphan drug
Orphan drug
An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease...
status by the 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...
(FDA) for treating alcoholic hepatitis, Turner syndrome
Turner syndrome
Turner syndrome or Ullrich-Turner syndrome encompasses several conditions in human females, of which monosomy X is most common. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent...
, and HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
-induced weight loss. It is also indicated as an offset to protein catabolism
Protein catabolism
Protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerisation into new proteins via the use of ribonucleic acids and ribosomes...
caused by long-term administration of corticosteroids. In addition, the drug has shown positive results in treating anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
and hereditary angioedema
Hereditary angioedema
Hereditary angioedema presents in the second to fourth decade, and is characterized by local swelling in subcutaneous tissues....
. Because of its potential for abuse, it is categorized as a Schedule III
Controlled Substances Act
The Controlled Substances Act was enacted into law by the Congress of the United States as Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970. The CSA is the federal U.S. drug policy under which the manufacture, importation, possession, use and distribution of certain...
controlled substance in the US.
In a randomized, double-blind study, patients with 40% total body surface area burn
Burn
A burn is an injury to flesh caused by heat, electricity, chemicals, light, radiation, or friction.Burn may also refer to:*Combustion*Burn , type of watercourses so named in Scotland and north-eastern England...
s were selected to receive standard burn care plus oxandrolone, or without oxandrolone. Those treated with oxandrolone showed improved body composition, preserved muscle mass and reduced hospital stay time.
Chemistry
http://dx.doi.org/10.1016/S0040-4039(00)70883-5External links
- Oxandrin Homepage, savientpharma.com (retrieved 23 October 2009)* Oxandrin Label, fda.gov (retrieved 23 October 2009)