Oxandrolone

Oxandrolone has been researched and prescribed as a treatment for a wide variety of conditions. It is FDA-approved for treating bone pain associated with osteoporosis, aiding weight gain following surgery or physical trauma, during chronic infection, or in the context of unexplained weight loss, and counteracting the catabolic effect of long-term corticosteroid therapy.[13][14]As of 2016, it is often prescribed off-label to quicken recovery from severe burns, aid the development of girls with Turner syndrome, and counteract HIV/AIDS-induced wasting. Oxandrolone improves both short-term and long-term outcomes in people recovering from severe burns and is well-established as a safe treatment for this indication.[5][6] It is also used in the treatment of idiopathic short stature, anemia, hereditary angioedema, alcoholic hepatitis, and hypogonadism.[15][16]

Medical research has established the effectiveness of oxandrolone in aiding the development of girls with Turner syndrome. Although oxandrolone has long been used to accelerate growth in children with idiopathic short stature, it is unlikely to increase adult height, and in some cases may even decrease it . Oxandrolone has, therefore, largely been replaced by growth hormone for this use.[17] Children with idiopathic short stature or Turner syndrome are given doses of oxandrolone far smaller than those given to people with burns to minimize the likelihood of virilization and premature maturation.[17][18]

Many bodybuilders and athletes use oxandrolone illicitly for its muscle-building effects.[4] It is much more anabolic than androgenic, so women and those seeking less intense steroid regimens use it particularly often.[4] Many also value oxandrolone's low hepatotoxicity relative to most other orally active AASs.[4]

Like other AASs, oxandrolone may worsen hypercalcemia by increasing osteolytic bone resorption.[13] When taken by pregnant women, oxandrolone may have unintended effects such as masculinization on the fetus.[13]

Women who are administered oxandrolone may experience virilization, irreversible development of masculine features such as voice deepening, hirsutism, menstruation abnormalities, male-pattern hair loss, and clitoral enlargement.[17][13][18] Oxandrolone may disrupt growth in children, reducing their adult height.[19] Because of these side effects, doses given to women and children are minimized and people are usually monitored for virilization and growth abnormalities.[17][18] Like other androgens, oxandrolone can cause or worsen acne and priapism (unwanted or prolonged erections).[13][19] Oxandrolone can also reduce males' fertility, another side effect common among androgens.[19] In an attempt to compensate for the exogenous increase in androgens, the body may reduce testosterone production via testicular atrophy and inhibition of gonadotropic activity.[13]

Unlike some AASs, oxandrolone does not generally cause gynecomastia because it is not aromatized into estrogenic metabolites.[20] However, although no reports of gynecomastia were made in spite of widespread use, oxandrolone was reported in a publication in 1991 to have been associated with 33 cases of gynecomastia in adolescent boys treated with it for short stature.[21][22] The gynecomastia developed during oxandrolone therapy in 19 of the boys and after the therapy was completed in 14 of the boys, and 10 of the boys had transient gynecomastia, while 23 had persistent gynecomastia that necessitated mastectomy.[21][22] Though transient gynecomastia is a natural and common occurrence in pubertal boys, the gynecomastia associated with oxandrolone was of a late/delayed onset and was persistent in a high percentage of the cases.[21][22] As such, the researchers stated, "although oxandrolone cannot be implicated as stimulatory [in] gynecomastia", a possible relationship should be considered in clinicians using oxandrolone in adolescents for growth stimulation.[21][22]

Uniquely among 17α-alkylated AASs, oxandrolone shows little to no hepatotoxicity, even at high doses.[23] No cases of severe hepatotoxicity have been singularly attributed to oxandrolone.[23] However, elevated liver enzymes have been observed in some people, particularly with high doses and/or prolonged treatment, although they return to normal ranges following discontinuation.[23]

Oxandrolone greatly increases warfarin's blood-thinning effect, sometimes dangerously so.[24] In April 2004, Savient Pharmaceuticals published a safety alert through the FDA warning healthcare professionals of this.[25] Oxandrolone can also inhibit the metabolism of oral hypoglycemic agents.[13] It may worsen edema when taken alongside corticosteroids or adrenocorticotropic hormone.[13]

Oxandrolone is a synthetic androstane steroid and a 17α-alkylated derivative of DHT.[28][29][4] It is also known as 2-oxa-17α-methyl-5α-dihydrotestosterone (2-oxa-17α-methyl-DHT) or as 2-oxa-17α-methyl-5α-androstan-17β-ol-3-one, and is DHT with a methyl group at the C17α position and the C2 carbon replaced with an oxygen atom.[28][29][4] Closely related AASs include the marketed AAS mestanolone (17α-methyl-DHT), oxymetholone (2-hydroxymethylene-17α-methyl-DHT), and stanozolol (a 2,3-pyrazole A ring-fused derivative of 17α-methyl-DHT) and the never-marketed/designer AAS desoxymethyltestosterone (3-deketo-17α-methyl-δ²-DHT), methasterone (2α,17α-dimethyl-DHT), methyl-1-testosterone (17α-methyl-δ¹-DHT), and methylstenbolone (2,17α-dimethyl-δ¹-DHT).[28][29][4]

Oxandrolone was first made by Raphael Pappo and Christopher J. Jung while at Searle Laboratories (now part of Pfizer). The researchers first described the drug in 1962.[4][30][31] They were immediately interested in oxandrolone's very weak androgenic effects relative to its anabolic effects.[30][4] It was introduced as a pharmaceutical drug in the United States in 1964.[4]

The drug was prescribed to promote muscle regrowth in disorders which cause involuntary weight loss, and is used as part of treatment for HIV/AIDS.[4] It had also been shown to be partially successful in treating cases of osteoporosis.[4] However, in part due to bad publicity from its illicit use by bodybuilders, production of Anavar was discontinued by Searle Laboratories in 1989.[4] It was picked up by Bio-Technology General Corporation, which changed its name to Savient Pharmaceuticals, which following successful clinical trials in 1995, released it under the brand name Oxandrin.[4] BTG subsequently won approvals for orphan drug status by the Food and Drug Administration for treating alcoholic hepatitis, Turner syndrome, and HIV-induced weight loss.[4] It is also indicated as an offset to protein catabolism caused by long-term administration of corticosteroids.[4]

• Oxandrin Homepage, savientpharma.com (via archive.org)
• Oxandrin Label, fda.gov (retrieved 23 October 2009)
• "Oxandrolone Side Effects, Interactions and Information". drugs.com.