Noretynodrel, or norethynodrel, sold under the brand name Enovid 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. ...

medication which was previously used in

birth control pill The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. It is the oral form of combined hormonal contra ...

s and in the treatment of

gynecological disorder Gynaecology or gynecology (see American and British English spelling differences) is the area of medicine concerned with conditions affecting the female reproductive system. It is often paired with the field of obstetrics, which focuses on pre ...

s but is now no longer marketed. It was available both alone and in combination with an

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

. The medication is taken

by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

. Noretynodrel is a progestin, or a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

progestogen Progestogens, also sometimes written progestins, 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 progestoge ...

, and hence is an

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

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 resi ...

, 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 is a relatively weak progestogen. The medication has weak

ic activity, no or only very weak

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

ic 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 or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...

activity. It is a

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

of various

active metabolite An active metabolite, or pharmacologically active metabolite is a biologically active metabolite of a xenobiotic substance, such as a drug or environmental chemical. Active metabolites may produce therapeutic effects, as well as harmful effects. ...

s in the body, such as

norethisterone Norethisterone, also known as norethindrone and sold under the brand name Norlutin among others, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medicatio ...

among others. Noretynodrel was introduced for medical use in 1957. It was specifically approved at this time in combination with mestranol for the treatment of gynecological and

menstrual disorder A menstrual disorder is characterized as any abnormal condition with regards to a woman's menstrual cycle. There are many different types of menstrual disorders that vary with signs and symptoms, including pain during menstruation, heavy bleeding, ...

s. Subsequently, in 1960, this formulation was approved for use as a birth control pill. It was the first birth control pill to be introduced, and was followed by birth control pills containing norethisterone and other progestins shortly thereafter. Due to its nature as a relatively weak progestogen, noretynodrel is no longer used in medicine. As such, it is no longer marketed.

Medical uses

Noretynodrel was formerly used in combination with the

mestranol in the treatment of gynecological and

s and as a combined birth control pill. It has also been used in the treatment of

endometriosis Endometriosis is a disease in which Tissue (biology), tissue similar to the endometrium, the lining of the uterus, grows in other places in the body, outside the uterus. It occurs in women and a limited number of other female mammals. Endomet ...

at high dosages of 40 to 100 mg/day. The medication has been discontinued, and is no longer marketed or used medically.

Contraindications

No adverse effects have been observed in

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

infants whose mothers were treated with noretynodrel. Because of this, the

American Academy of Pediatrics The American Academy of Pediatrics (AAP) is the largest professional association of pediatricians in the United States. It is headquartered in Itasca, Illinois, and maintains an office in Washington, D.C. The AAP has published hundreds of poli ...

has considered noretynodrel to be usually compatible with breastfeeding.

Side effects

There is a reported case of signs 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 a medical term commonly used in three medical a ...

in a female infant whose mother was treated with noretynodrel for threatened miscarriage during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

Overdose

Interactions

Pharmacology

Pharmacodynamics

Noretynodrel has weak

ic activity, weak

ic activity, and no or only very weak

ic activity. It is considered to be a

, and for this reason, the

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, c ...

s of noretynodrel play an important role in its

biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

. As such, the

pharmacodynamics Pharmacodynamics (PD) is the study of the biochemistry, biochemical and physiology, physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or comb ...

of noretynodrel cannot be understood without reference to its

metabolism Metabolism (, from ''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 cellular processes; the co ...

. Noretynodrel is closely related to norethisterone and tibolone, which are the δ⁴-isomer and the 7α-

methyl In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated as ...

derivative of noretynodrel, respectively. It is metabolized in a very similar manner to tibolone, whereas the metabolism of norethisterone differs. Both noretynodrel and tibolone are transformed into 3α- and 3β-hydroxylated metabolites and a δ⁴-isomer metabolite (in the case of noretynodrel, this being norethisterone), whereas norethisterone is not 3α- or 3β-hydroxylated (and of course does not form a δ⁴-isomer metabolite). The major

s of noretynodrel are 3α-hydroxynoretynodrel and to a lesser extent 3β-hydroxynoretynodrel, formed respectively by 3α- and 3β-hydroxysteroid dehydrogenases ( AKR1C1– 4), while the δ⁴-isomer norethisterone is a minor metabolite formed in small amounts. Tibolone is considered to be a prodrug of both its 3α- and 3β-hydroxylated and δ⁴-isomerized metabolites. Noretynodrel is also thought to be a prodrug, as it is rapidly metabolized and cleared from circulation and shows very weak relative affinity for the

(PR), although it appears to form norethisterone in only minor quantities.

Progestogenic activity

Noretynodrel is a relatively weak

, with only about one-tenth of the progestogenic activity of norethisterone. The

ovulation Ovulation is an important part of the menstrual cycle in female vertebrates where the egg cells are released from the ovaries as part of the ovarian cycle. In female humans ovulation typically occurs near the midpoint in the menstrual cycle and ...

-inhibiting dosage of noretynodrel is 4.0 mg/day, relative to 0.4 mg/day in the case of norethisterone. Conversely, the endometrial transformation dosage of noretynodrel is 150 mg per cycle, relative to 120 mg per cycle for norethisterone. In terms of the PR, noretynodrel possesses only about 6 to 19% 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 Pa ...

of norethisterone for the PR_A, whereas the affinity of the two drugs for the PR_B is similar (noretynodrel possesses 94% of the affinity of norethisterone for the PR_B). Tibolone and the δ⁴-isomer metabolite of tibolone have similar affinity for the PRs as noretynodrel and norethisterone, respectively, whereas the 3α- and 3β-hydroxylated metabolites of tibolone are virtually devoid of affinity for the PRs. Since the structurally related

anabolic steroid Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolism, Anaboli ...

trestolone (7α-methyl-19-nortestosterone) is known to be a potent progestogen, suggesting that a 7α-methyl substitution does not interfere with progestogenic activity, 3α- and 3β-hydroxynoretynodrel likely are devoid of affinity for the PR similarly to the 3α- and 3β-hydroxylated metabolites of tibolone.

Androgenic activity

Noretynodrel has been said to possess no or only very weak

ic activity. This is in contrast to norethisterone, which shows mild but significant androgenicity. Relative to norethisterone, noretynodrel has 45 to 81% lower affinity for the

androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

(AR). In accordance, no androgenic effects (such as

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 ma ...

, clitoral enlargement, or

voice change A voice change or voice mutation, sometimes referred to as a voice break or voice crack, commonly refers to the deepening of the voice of men as they reach puberty. Before puberty both sexes have roughly similar vocal pitches, but during puberty ...

s) have been observed with noretynodrel even when used in large dosages (e.g., 60 mg/day) for prolonged periods of time (9–12 months) in the treatment of women with

. Additionally, noretynodrel has not been found to virilize female

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

es, in contrast to many other

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

-derived progestins including

ethisterone Ethisterone, also known as ethinyltestosterone, pregneninolone, and anhydrohydroxyprogesterone and formerly sold under the brand names Proluton C and Pranone among others, is a progestin medication which was used in the treatment of gynecologica ...

, norethisterone, and

norethisterone acetate Norethisterone acetate (NETA), also known as norethindrone acetate and sold under the brand name Primolut-Nor among others, is a progestin medication which is used in birth control pills, menopausal hormone therapy, and for the treatment of gynec ...

. However, at least one case of

pseudohermaphroditism Pseudohermaphroditism is an outdated term for when an individual's gonads were mismatched with their internal reproductive system and/or external genitalia. The term was contrasted with "true hermaphroditism" (now known as ovotesticular syndrome), ...

(virilized genitalia) has been observed that may have been due to noretynodrel. The δ⁴-isomer metabolite of tibolone shows dramatically and disproportionately increased affinity for the AR relative to norethisterone and noretynodrel (5.7- to 18.5-fold greater than that of norethisterone), indicating that the 7α-methyl group of tibolone markedly increases its androgenic activity and is responsible for the greater androgenic effects of tibolone relative to noretynodrel.

Estrogenic activity

Noretynodrel, unlike most progestins but similarly to

etynodiol diacetate Etynodiol diacetate, or ethynodiol diacetate, sold under the brand name Ovulen 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 taken by mouth ...

, has some

ic activity. Relative to other 19-nortestosterone progestins, noretynodrel is said to possess much stronger estrogenic activity. In the Allen–Doisy test of estrogenicity in animals, noretynodrel has been reported to possess 100-fold greater estrogenic activity than norethisterone. Whereas norethisterone has virtually no affinity for the

estrogen receptor Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen ...

s (ERs), noretynodrel shows some, albeit very weak affinity for both the

ERα Estrogen receptor alpha (ERα), also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of two main types of estrogen receptor, a nuclear receptor (mainly found as a chromatin-binding protein) that is activated by the se ...

and the

ERβ Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by t ...

(in terms of relative binding affinity, 0.7% and 0.22% of that of

estradiol Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible ...

, respectively). The estrogenic activity of 3α- and 3β-hydroxynoretynodrel has never been assessed. However, while tibolone shows similar affinity for the ERs as noretynodrel, the 3α- and 3β-hydroxylated metabolites of tibolone have several-fold increased affinity for the ERs. As such, the 3α- and 3β-hydroxylated metabolites of noretynodrel may also show increased estrogenic activity, and this may account for the known estrogenic effects of noretynodrel. The δ⁴-isomer of tibolone, similarly to norethisterone, is virtually devoid of affinity for the ERs. Neither tibolone nor its metabolites are aromatized, whereas trestolone is readily aromatized similarly to testosterone and 19-nortestosterone, and for these reasons, it is unlikely that noretynodrel or its metabolites, aside from norethisterone, are aromatized either. As such, aromatization likely does not play a role in the estrogenic activity of tibolone or noretynodrel. However, controversy on this matter exists, and other researchers have suggested that tibolone and noretynodrel may be aromatized in small amounts to highly potent estrogens (

ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. Ethinylestradiol was widely used for various indications such as the treatment of menopausal symptoms, gynecological ...

and its 7α-methyl derivative, respectively).

Pharmacokinetics

Noretynodrel is rapidly absorbed upon

oral administration Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

and is rapidly

metabolized Metabolism (, from ''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 cellular processes; the co ...

, disappearing from the circulation within 30 minutes. In terms of

plasma protein binding Plasma protein binding refers to the degree to which medications attach to blood proteins within the blood plasma. A drug's efficacy may be affected by the degree to which it binds. The less bound a drug is, the more efficiently it can traverse o ...

, noretynodrel is bound to

albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All of the proteins of the albumin family are water- soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Alb ...

, and show no

itself 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 is called androgen-binding prot ...

corticosteroid-binding globulin Transcortin, also known as corticosteroid-binding globulin (CBG) or serpin A6, is a protein produced in the liver in animals. In humans it is encoded by the SERPINA6 gene. It is an alpha-globulin. Function This gene encodes an alpha-globulin ...

. The plasma protein binding of its

s, such as

, may differ however. The major metabolites of noretynodrel in the circulation are 3α-hydroxynoretynodrel (formed by ) and to a lesser extent 3β-hydroxynoretynodrel (formed by ), and more minor metabolites of noretynodrel are

(formed by δ^5-4-isomerase) and possibly

(formed by

aromatase Aromatase (), also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily, which are monooxygenases that catalyze man ...

or possibly other

cytochrome P450 Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for examp ...

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s, most likely

monooxygenase Monooxygenases are enzymes that incorporate one hydroxyl group (−OH) into substrates in many metabolic pathways. In this reaction, the two atoms of dioxygen are reduced to one hydroxyl group and one H2O molecule by the concomitant oxidation of ...

s). Due to its very short

elimination half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma. ...

and its low affinities for

steroid hormone receptor Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells. They are generally intracellular receptors (typically cytoplasmic or nuclear) and initiate signal transduction for steroid hormones which ...

s in receptor binding assays, noretynodrel is considered to be a

which is rapidly transformed into its

s in the

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

s and

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

following oral administration. Some researchers have stated that it is specifically a prodrug of norethisterone. According to other researchers however, there is, due to a lack of research, insufficient data to unequivocally show this to be the case at present. About 1% of an oral dose of noretynodrel is detected in

breast milk Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by the mammary glands in the breasts of women. Breast milk is the primary source of nutrition for newborn infants, comprising fats, proteins, carbohydrates, and a var ...

. The

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to describing how the body affects a specific su ...

of noretynodrel have been reviewed.

Chemistry

Noretynodrel, also known as 17α-ethynyl-δ⁵⁽¹⁰⁾-19-nortestosterone or as 17α-ethynylestr-5(10)-en-17β-ol-3-one, is a

estrane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

and a

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

. It is specifically a derivative of testosterone that has been

ethynyl In organic chemistry, an ethynyl group is a functional group with the formula −C≡CH, representing an acetylene molecule with one fewer hydrogen atom. * Ethynyl group (HC≡C–), also designated as an acetylenic group (from acetylene), is refer ...

ated at the C17α position, demethylated at the C19 position, and dehydrogenated (i.e., has a

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

) between the C5 and C10 positions). As such, noretynodrel is also a combined derivative of

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

(19-nortestosterone) and

(17α-ethynyltestosterone). In addition, it is an

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

of norethisterone (17α-ethynyl-19-nortestosterone) in which the C4 double bond has been replaced with a double bond between the C5 and C10 positions. For this reason, noretynodrel is also known as 5(10)-norethisterone. Few other 19-nortestosterone progestins share the C5(10) double bond of noretynodrel, but examples of a couple that do include tibolone, the C7α

derivative of noretynodrel (i.e., 7α-methylnoretynodrel), and norgesterone, the C17α

vinyl Vinyl may refer to: Chemistry * Polyvinyl chloride (PVC), a particular vinyl polymer * Vinyl cation, a type of carbocation * Vinyl group, a broad class of organic molecules in chemistry * Vinyl polymer, a group of polymers derived from vinyl ...

analogue of noretynodrel.

Synthesis

Chemical syntheses of noretynodrel have been published.

History

Noretynodrel was first synthesized by Frank B. Colton of G. D. Searle & Company in 1952, and this was preceded by the synthesis of norethisterone by

Luis E. Miramontes Luis Ernesto Miramontes Cárdenas (March 16, 1925 – September 13, 2004) was a Mexican chemist known as co-inventor and the first to synthesize an oral contraceptive, progestin norethisterone. Career summary Miramontes was born in Tepic, Nayar ...

and

Carl Djerassi Carl Djerassi (October 29, 1923 – January 30, 2015) was an Austrian-born Bulgarian-American pharmaceutical chemist, novelist, playwright and co-founder of Djerassi Resident Artists Program with Diane Wood Middlebrook. He is best known for his ...

Syntex Laboratorios Syntex SA (later Syntex Laboratories, Inc.) was a pharmaceutical company formed in Mexico City in January 1944 by Russell Marker, Emeric Somlo, and Federico Lehmann to manufacture therapeutic steroids from the Mexican yams called ''c ...

in 1951. In 1957, both noretynodrel and norethisterone, in combination with mestranol, were approved in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

for the treatment of

s. In 1960, noretynodrel, in combination with mestranol (as ''Enovid''), was introduced in the United States as the first oral contraceptive, and the combination of norethisterone and mestranol followed in 1963 as the second oral contraceptive to be introduced. In 1988, Enovid, along with other oral contraceptives containing high doses of estrogen, was discontinued. Noretynodrel was first studied in the treatment of

in 1961 and was the first progestin to be investigated for the treatment of the condition.

Society and culture

Generic names

''Noretynodrel'' is the of the drug while ''norethynodrel'' is its and . It is also known by its developmental code name ''SC-4642''.

Brand names

Noretynodrel has been marketed by alone under the brand names Enidrel, Orgametril, and Previson and in combination with mestranol under the brand names Conovid, Conovid E, Enavid, Enavid E, Enovid, Enovid E, Norolen, and Singestol.

Availability

Noretynodrel is no longer available in any formulation in the U.S., nor does it appear to still be marketed in any other country.
/ref>

References

{{Navboxes , title =

Pharmacodynamics Pharmacodynamics (PD) is the study of the biochemistry, biochemical and physiology, physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or comb ...

, titlestyle = background:#ccccff , list1 = {{Androgen receptor modulators {{Progesterone receptor modulators {{Estrogen receptor modulators Abandoned drugs Ethynyl compounds Alkene derivatives Anabolic–androgenic steroids Estranes Hormonal contraception Ketones Progestogens Synthetic estrogens