Ethisterone, also known as ethinyltestosterone, pregneninolone, and anhydrohydroxyprogesterone and formerly sold under the brand names Proluton C and Pranone among others, is 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 female sex hormone progesterone in the body. A progestin is a '' synthetic'' progestogen. Pro ...
medication which was used in the treatment of
gynecological disorder
Gynaecology or gynecology (see spelling differences) is the area of medicine that involves the treatment of women's diseases, especially those of the reproductive organs. It is often paired with the field of obstetrics, forming the combined ar ...
s but is now no longer available.
It was used alone and was not formulated in combination with an
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...
.
The medication is taken
by mouth
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...
.
Side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s of ethisterone include
masculinization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
among others.
Ethisterone is a progestin, or a
synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to:
Science
* Synthetic chemical or compound, produced by the process of chemical synthesis
* Synthetic o ...
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
, and hence is an
agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
of the
progesterone receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone.
In humans, PR is encoded by a single ''PGR'' gene res ...
, the
biological target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...
of progestogens like
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
.
It has some
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...
ic and
anabolic
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-d ...
activity and no other important
hormonal
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required fo ...
activity.
Ethisterone was discovered in 1938 and was introduced for medical use in
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
in 1939 and in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
in 1945.
It was the second
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
to be marketed, following
injected progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
in 1934, and was both the first
orally active
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are in ...
progestogen and the first progestin to be introduced.
Ethisterone was followed by the improved and much more widely used and known progestin
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 ...
in 1957.
Medical uses
Ethisterone was used in the treatment of
gynecological disorder
Gynaecology or gynecology (see spelling differences) is the area of medicine that involves the treatment of women's diseases, especially those of the reproductive organs. It is often paired with the field of obstetrics, forming the combined ar ...
s such as
irregular menstruation
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of ...
,
amenorrhea
Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of mense ...
, and
premenstrual syndrome
Premenstrual syndrome (PMS) refers to emotional and physical symptoms that regularly occur in the one to two weeks before the start of each menstrual period. Symptoms resolve around the time menstrual bleeding begins. Different women experienc ...
.
Available forms
Ethisterone was available in the form of 5, 10, and 25 mg
oral
The word oral may refer to:
Relating to the mouth
* Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid
**Oral administration of medicines
** Oral examination (also known as an oral exam or ora ...
and
sublingual
Sublingual ( abbreviated SL), from the Latin for "under the tongue", refers to the pharmacological route of administration by which substances diffuse into the blood through tissues under the tongue.
The sublingual glands receive their pr ...
tablet
Tablet may refer to:
Medicine
* Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill"
Computing
* Tablet computer, a mobile computer that is primarily operated by touching the s ...
s, as well as 50 , 100 , and 250 mg oral
capsule
Capsule may refer to:
Anatomy
* Articular capsule (joint capsule), an envelope surrounding a synovial joint
* Bowman's capsule (glomerular capsule), a sac surrounding a glomerulus in a mammalian kidney
* Glisson's capsule, a fibrous layer covering ...
s.
The usual dosage was 25 mg, up to four times per day.
Side effects
Side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s of ethisterone reportedly include
symptom
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...
s of
masculinization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
such as
acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
and
hirsutism
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin ''hirsutus'' meaning "hairy". It usually refers to a "male" pattern of hair growth in a female that ...
among others.
Findings are mixed on the
anabolic
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-d ...
effects of high doses of ethisterone.
Pharmacology
Pharmacodynamics
Ethisterone has weak
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
ic activity and weak
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...
ic activity, but does not seem to have
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...
ic activity.
Ethisterone is a major
active metabolite An active metabolite is an active form of a drug after it has been processed by the body.
Metabolites of drugs
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...
of
danazol
Danazol, sold as Danocrine and other brand names, is a medication used in the treatment of endometriosis, fibrocystic breast disease, hereditary angioedema and other conditions. It is taken by mouth.
The use of danazol is limited by masculi ...
(2,3-isoxazolethisterone), and is thought to contribute importantly to its effects.
Progestogenic activity
Ethisterone is a
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
, or an
agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
of the
progesterone receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone.
In humans, PR is encoded by a single ''PGR'' gene res ...
s.
It has about 44% of the
affinity
Affinity may refer to:
Commerce, finance and law
* Affinity (law), kinship by marriage
* Affinity analysis, a market research and business management technique
* Affinity Credit Union, a Saskatchewan-based credit union
* Affinity Equity Part ...
of
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
for the progesterone receptor.
The medication is described as a relatively weak progestogen, similarly to its analogue
dimethisterone
Dimethisterone, formerly sold under the brand names Lutagan and Secrosteron among others, is a progestin medication which was used in birth control pills and in the treatment of gynecological disorders but is now no longer available. It was used ...
.
Its total
endometrial transformation
Decidualization is a process that results in significant changes to cells of the endometrium in preparation for, and during, pregnancy. This includes morphological and functional changes (the decidual reaction) to endometrial stromal cells (ESCs), ...
dosage per 10 to 14 days in women is 200 to 700 mg.
Ethisterone has about 20-fold lower
potency
Potency may refer to:
* Potency (pharmacology), a measure of the activity of a drug in a biological system
* Virility
* Cell potency, a measure of the differentiation potential of stem cells
* In homeopathic dilutions, potency is a measure of how ...
as a progestogen relative to
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 ...
.
It is said to have minimal
antigonadotropic
An antigonadotropin is a drug which suppresses the activity and/or downstream effects of one or both of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This results in an inhibition of the hypothalamic-pituita ...
effect and to not suppress
ovulation
Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilize ...
, which has precluded its use in
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 origi ...
.
Androgenic activity
Based on ''
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and ...
'' research, ethisterone and norethisterone are about equipotent in their values for activation of the
androgen receptor (AR), whereas, conversely, norethisterone shows markedly increased potency relative to ethisterone in terms of its EC
50 for the
progesterone receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone.
In humans, PR is encoded by a single ''PGR'' gene res ...
.
As such, there is a considerable separation in the ratios of androgenic and progestogenic activity for ethisterone and norethisterone.
Moreover, at the larger dosages in which it is used to achieve equivalent progestogenic effect, ethisterone has more androgenic effect relative to norethisterone and other
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 ...
progestins.
However, the androgenic activity of ethisterone has in any case been described as weak.
Due to its androgenic activity, ethisterone has been associated with the
masculinization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
of female
fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal develo ...
es in women who have taken it during
pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ...
.
The
5α-reduced metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, ...
of ethisterone,
5α-dihydroethisterone
5α-Dihydroethisterone (5α-DHET; developmental code name HE-3562) is an active metabolite of the formerly clinically used but now-discontinued progestin ethisterone and the experimental and never-marketed hormonal antineoplastic agent 17α-Ethyn ...
, has been found to show reduced androgenic activity relative to ethisterone.
Interestingly, ethisterone showed
antiandrogen
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the ...
ic activity when co-administered with
dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues incl ...
(DHT) in animals, whereas 5α-dihydroethisterone did not.
Estrogenic activity
Testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteris ...
is
aromatized
Aromatization is a chemical reaction in which an aromatic system is formed from a single nonaromatic precursor. Typically aromatization is achieved by dehydrogenation of existing cyclic compounds, illustrated by the conversion of cyclohexane into ...
into
estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...
, and
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 ...
, 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 ...
analogue of ethisterone, has similarly been shown to be aromatized into
ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological dis ...
.
In accordance, high doses of norethisterone have been found to be associated with marked increases in
urinary
The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, con ...
estrogen
excretion
Excretion is a process in which metabolic waste
is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks afte ...
(due to
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
into ethinylestradiol), as well as with high rates of
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...
ic
side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s such as
breast enlargement Breast enlargement is the enlargement of the breasts. It may occur naturally as in mammoplasia or may occur artificially through active intervention. Many women regard their breasts, which are female secondary sex characteristics, as important to t ...
in women and
gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ...
in men and improvement of
menopausal
Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often d ...
symptoms in postmenopausal women.
In contrast, ethisterone and other progestogens such as
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
and
hydroxyprogesterone caproate
Hydroxyprogesterone caproate (OHPC), sold under the brand names Proluton and Makena among others, is a progestin medication which is used to prevent preterm birth in pregnant women with a history of the condition and to treat gynecological diso ...
do not increase estrogen excretion and are not associated with estrogenic effects, indicating that they have little or no estrogenic activity.
Similarly, although ethisterone showed estrogenic effects in the
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
and
vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hy ...
in rats, few or no such effects were observed in women treated with the medication, even at very high doses.
As such, ethisterone does not appear to share the estrogenic activity of norethisterone, at least in humans.
Aside from ethinylestradiol,
17α-ethynyl-3α-androstanediol
17α-Ethynyl-3α-androstanediol (developmental code names HE-3235, Apoptone), also known as 17α-ethynyl-5α-androstane-3α,17β-diol, is a synthetic androstane steroid and a 17α-substituted derivative of 3α-androstanediol which was never mar ...
and
17α-ethynyl-3β-androstanediol
17α-Ethynyl-3β-androstanediol (developmental code HE-3539; also known as 17α-ethynyl-5α-androstane-3β,17β-diol) is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
17α-Ethynyl-3β-and ...
may be estrogenic metabolites of ethisterone.
Pharmacokinetics
Absorption
Ethisterone is active both
orally
The word oral may refer to:
Relating to the mouth
* Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid
**Oral administration of medicines
** Oral examination (also known as an oral exam or oral ...
and
sublingual
Sublingual ( abbreviated SL), from the Latin for "under the tongue", refers to the pharmacological route of administration by which substances diffuse into the blood through tissues under the tongue.
The sublingual glands receive their pr ...
ly in humans.
Good oral
bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. ...
of ethisterone has been observed in rats.
The medication was the first orally active progestin to be discovered and introduced for clinical use.
Distribution
Ethisterone has relatively high
affinity
Affinity may refer to:
Commerce, finance and law
* Affinity (law), kinship by marriage
* Affinity analysis, a market research and business management technique
* Affinity Credit Union, a Saskatchewan-based credit union
* Affinity Equity Part ...
for
sex hormone-binding globulin
Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it has also been called androgen-bi ...
, about 14% of that of
dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues incl ...
and 49% of that of
testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteris ...
in one study.
Metabolism
In terms of
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
, ethisterone is not converted into
pregnanediol
Pregnanediol, or 5β-pregnane-3α,20α-diol, is an inactive metabolic product of progesterone. A test can be done to measure the amount of pregnanediol in urine, which offers an indirect way to measure progesterone levels in the body.
From the ur ...
in humans.
This indicates that it is not
metabolized
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
into
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
.
No
aromatization
Aromatization is a chemical reaction in which an aromatic system is formed from a single nonaromatic precursor. Typically aromatization is achieved by dehydrogenation of existing cyclic compounds, illustrated by the conversion of cyclohexane into ...
of ethisterone has been detected ''
in vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...
'', and no
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...
ic
metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, ...
s were observed ''
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and ...
'' upon
incubation of ethisterone in
placenta
The placenta is a temporary embryonic and later fetal organ (anatomy), organ that begins embryonic development, developing from the blastocyst shortly after implantation (embryology), implantation. It plays critical roles in facilitating nutrien ...
l
homogenate
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, si ...
s.
This suggests that ethisterone may not be transformed into
ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological dis ...
(17α-ethynylestradiol).
5α-Dihydroethisterone
5α-Dihydroethisterone (5α-DHET; developmental code name HE-3562) is an active metabolite of the formerly clinically used but now-discontinued progestin ethisterone and the experimental and never-marketed hormonal antineoplastic agent 17α-Ethyn ...
(5α-dihydro-17α-ethynyltestosterone), formed by
5α-reductase
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes ...
, is an
active metabolite An active metabolite is an active form of a drug after it has been processed by the body.
Metabolites of drugs
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...
of ethisterone.
17α-Ethynyl-3α-androstanediol
17α-Ethynyl-3α-androstanediol (developmental code names HE-3235, Apoptone), also known as 17α-ethynyl-5α-androstane-3α,17β-diol, is a synthetic androstane steroid and a 17α-substituted derivative of 3α-androstanediol which was never mar ...
and
17α-ethynyl-3β-androstanediol
17α-Ethynyl-3β-androstanediol (developmental code HE-3539; also known as 17α-ethynyl-5α-androstane-3β,17β-diol) is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
17α-Ethynyl-3β-and ...
, also formed via 5α-reductase, as well as other
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
s, are also potential metabolites of ethisterone.
Chemistry
Ethisterone is a
synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to:
Science
* Synthetic chemical or compound, produced by the process of chemical synthesis
* Synthetic o ...
androstane
Androstane is a C19 steroidal hydrocarbon with a gonane core. Androstane can exist as either of two isomers, known as 5α-androstane and 5β-androstane.
File:androstane.png, 5α-Androstane
File:androstane 5beta.png, 5β-Androstane
Pharmacolo ...
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 ...
which was derived from
testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteris ...
and is also known by the following synonyms:
* 17α-Ethynyltestosterone (or simply ethinyltestosterone or ethynyltestosterone)
* 17α-Ethynylandrost-4-en-17β-ol-3-one
* 17α-Pregn-4-en-20-yn-17β-ol-3-one (or simply pregneninolone or pregnenynolone)
* 20,21-Anhydro-17β-hydroxyprogesterone (or simply anhydrohydroxyprogesterone)
Closely related
analogues of ethisterone include
dimethisterone
Dimethisterone, formerly sold under the brand names Lutagan and Secrosteron among others, is a progestin medication which was used in birth control pills and in the treatment of gynecological disorders but is now no longer available. It was used ...
(6α,21-dimethylethisterone),
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 ...
(19-norethisterone), and
danazol
Danazol, sold as Danocrine and other brand names, is a medication used in the treatment of endometriosis, fibrocystic breast disease, hereditary angioedema and other conditions. It is taken by mouth.
The use of danazol is limited by masculi ...
(the 2,3-''d''-
isoxazole
Isoxazole is an electron-rich azole with an oxygen atom next to the nitrogen. It is also the class of compounds containing this ring. Isoxazolyl is the univalent radical derived from isoxazole.
Occurrence
Isoxazole rings are found in some natur ...
ring
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
-fused
derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...
of ethisterone), as well as
vinyltestosterone,
allyltestosterone
Allyltestosterone, or 17α-allyltestosterone, also known as 17α-allylandrost-4-en-17β-ol-3-one, is a steroid derived from testosterone that was first synthesized in 1936 and was never marketed. Along with propyltestosterone (topterone), it h ...
,
methyltestosterone
Methyltestosterone, sold under the brand names Android, Metandren, and Testred among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, at low ...
,
ethyltestosterone
Ethyltestosterone, or 17α-ethyltestosterone, also known as 17α-ethylandrost-4-en-17β-ol-3-one or 17α-pregn-4-en-17-ol-3-one, is a synthetic, orally active anabolic–androgenic steroid (AAS) of the 17α-alkylated group related to methyltesto ...
, and
propyltestosterone. Other ethisterone analogues include
ethinylandrostenediol
Ethinylandrostenediol (developmental code name SKF-2856), also known as 17α-ethynyl-5-androstenediol, is a synthetic estrogen, progestogen, and androgen which was never marketed.Tan, V. Y. (2010). Characterization of the estrogenic activity of a ...
(17α-ethynyl-5-androstenediol),
ethandrostate
Ethandrostate, also known as ethinylandrostenediol 3β-cyclohexanepropionate, is a synthetic steroidal estrogen and ester of ethinylandrostenediol (17α-ethynyl-5-androstenediol) which was developed and studied in people with certain cancers like ...
(17α-ethynyl-5-androstenediol 3β-cyclohexylpropionate),
17α-ethynyl-3α-androstanediol
17α-Ethynyl-3α-androstanediol (developmental code names HE-3235, Apoptone), also known as 17α-ethynyl-5α-androstane-3α,17β-diol, is a synthetic androstane steroid and a 17α-substituted derivative of 3α-androstanediol which was never mar ...
, and
17α-ethynyl-3β-androstanediol
17α-Ethynyl-3β-androstanediol (developmental code HE-3539; also known as 17α-ethynyl-5α-androstane-3β,17β-diol) is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
17α-Ethynyl-3β-and ...
.
Synthesis
Chemical syntheses
As a topic of chemistry, chemical synthesis (or combination) is the artificial execution of chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In mode ...
of ethisterone have been published.
History
Ethisterone was
synthesized in 1938 by Hans Herloff Inhoffen, Willy Logemann, Walter Hohlweg, and Arthur Serini at
Schering AG
Schering AG was a research-centered German multinational pharmaceutical company headquartered in Wedding, Berlin, which operated as an independent company from 1851 to 2006. In 2006, it was bought by Bayer AG and merged to form the Bayer subsi ...
in
Berlin
Berlin is Capital of Germany, the capital and largest city of Germany, both by area and List of cities in Germany by population, by population. Its more than 3.85 million inhabitants make it the European Union's List of cities in the European U ...
.
It was derived from testosterone via
ethynyl In organic chemistry, the term ethynyl designates a functional group with a double bond with 2 carbon atoms both with
sp hybridisation and a triple bond(1 sigma and 2 pi bond) . It is a species similar to acetylene (or in IUPAC ethyne ) with a less ...
ation at the C17α position, and it was hoped, that, analogously to
estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...
and
ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological dis ...
, ethisterone would be an orally active form of testosterone.
However, the androgenic activity of ethisterone was attenuated and it showed considerable progestogenic activity.
As such, it was developed as a progestogen instead and was introduced for medical use in
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
in 1939 as Proluton C and by
Schering in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
in 1945 as Pranone.
Ethisterone remained in use as late as 2000.
Society and culture
Generic names
''Ethisterone'' is the
generic name of the drug and its , , and , while ''ethistérone'' is its .
It has also been referred to as ''ethinyltestosterone'', ''pregneninolone'', and ''anhydrohydroxyprogesterone''.
Brand names
Ethisterone has been marketed under a variety of brand names including Amenoren, Cycloestrol-AH Progestérone, Duosterone, Estormon, Etherone, Ethisteron, Luteosterone, Lutocyclin, Lutocylol, Lutogynestryl, Menstrogen, Nugestoral, Oophormin Luteum, Ora-Lutin, Orasecron, Pranone, Pre Ciclo, Prodroxan, Produxan, Progestab, Progesteron lingvalete, Progestoral, Proluton C, Syngestrotabs, and Trosinone among others.
Availability
Ethisterone was previously available in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...
,
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
,
Japan, the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
, and the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
, among other countries.
It is no longer marketed and hence is no longer available in any country.
References
Further reading
*
*
* Kugener, André (2004)
Tabletten der Fa. ScheringTablets of Schering AG ''Proluton C'' tablets c. 1939
*
*
*
{{Progesterone receptor modulators
Ethynyl compounds
Abandoned drugs
Androgens and anabolic steroids
Androstanes
Human drug metabolites
Enones
Progestogens