Ethynerone (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

, USAN), also known as 17α-(2-chloroethynyl)estra-4,9-dien-17β-ol-3-one, is a

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

progestin A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural product, natural female sex hormone progesterone in the body. A progestin is a ''synthetic co ...

of the

19-nortestosterone Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...

group that was first reported in 1961 but was never marketed. Under the developmental code name MK-665, it was studied in combination with

mestranol Mestranol, sold under the brand names Enovid, Norinyl, and Ortho-Novum among others, is an estrogen medication which has been used in birth control pills, menopausal hormone therapy, and the treatment of menstrual disorders. It is formulated in c ...

as an oral contraceptive. Development of the drug was discontinued due to concerns surrounding toxicity findings in dogs. It is a chloroethynylated derivative of

norethisterone Norethisterone, also known as norethindrone and sold under many brand names, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in both ...

. In 1966, during its

clinical development Drug development is the process of bringing a new pharmaceutical drug to the market once a lead compound has been identified through the process of drug discovery. It includes preclinical research on microorganisms and animals, filing for regu ...

, ethynerone was found to produce

mammary gland A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primat ...

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s in dogs treated with it at very high doses for prolonged periods of time. Subsequent investigation found that

17α-hydroxyprogesterone 17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many ot ...

derivatives included anagestone acetate, chlormadinone acetate,

medroxyprogesterone acetate Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in injectable form and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. It is used as a method of bi ...

, and megestrol acetate produced similar mammary gland tumors, and that their ability to do so correlated directly with their progestogenic actions. In contrast, the non-halogenated

derivatives

norgestrel Norgestrel, sold under the brand name Ovral among others, is a progestin medication which is used in birth control pills and in menopausal hormone therapy. It is available both in combination with an estrogen and alone. It is taken by mouth. S ...

, noretynodrel, and

etynodiol diacetate Etynodiol diacetate, or ethynodiol diacetate, sold under the brand names Demulen and Femulen among others, is a progestin medication which is used in birth control pills. The medication is available only in combination with an estrogen. It is tak ...

, which are much less potent as progestogens, did not produce such effects at the dosages tested. Clinical development of ethynerone was discontinued, and many of the 17α-hydroxyprogesterone derivatives were withdrawn for the indication of

hormonal contraception Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The origin ...

. Research later on revealed species differences between dogs and humans and established that there is no similar risk in humans.

Synthesis

References

Estranes Organochlorides Progestogens {{steroid-stub

Synthesis

See also

References