Altrenogest, sold under the brand names Swinemate and Altren manufactured by Aurora Pharmaceutical and Regumate manufactured by Merck, 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 ...

of the 19-nortestosterone group which is widely used in

veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in animals. Along with this, it deals with animal rearing, husbandry, breeding, research on nutri ...

to suppress or synchronize

estrus The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million ...

s and pigs.
/ref> It is available for veterinary use in both

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

(as Regumate) 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 ...

(as Matrix).

Uses

Veterinary

Altrenogest is used in

Pharmacology

Pharmacodynamics

An ''

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 ...

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to consti ...

structure–activity relationship The structure–activity relationship (SAR) is the relationship between the chemical structure of a molecule and its biological activity. This idea was first presented by Crum-Brown and Fraser in 1865. The analysis of SAR enables the determination o ...

bioassay A bioassay is an analytical method to determine the concentration or potency of a substance by its effect on living animals or plants (''in vivo''), or on living cells or tissues(''in vitro''). A bioassay can be either quantal or quantitative, dir ...

study found that altrenogest was the most potent

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 both 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 ...

(PR) and the androgen receptor (AR) of a large selection of other

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 ...

s as well as

anabolic–androgenic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects ...

s (AAS). The observed potency of altrenogest even exceeded that of metribolone (methyltrienolone, R-1881), which was the second most potent compound. In the study, it showed an EC₅₀ of 0.64 nM for the AR and 688% of the relative activational potency 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 ...

and an EC₅₀ of 0.3 nM and 1,300% of the relative activational potency 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 ...

, with an AR/PR activational potency ratio of 0.53. Although very potent in both activities ''in vitro'', the AR/PR activational potency ratio of altrenogest was in the same range as that of other 19-nortestosterone progestins such as

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 ...

noretynodrel Noretynodrel, or norethynodrel, sold under the brand name Enovid among others, is a progestin medication which was previously used in birth control pills and in the treatment of gynecological disorders but is now no longer marketed. It was availa ...

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. ...

, and allylestrenol (ratio for all < 1.0), whereas the AR/PR activational potency ratio of its 17α-deallylated AAS analogue trenbolone was, at 64, profoundly increased (although the ratio of metribolone (the 17α-methylated variant of altrenogest), at 0.56, was almost the same as that of altrenogest). According to its

manufacturer Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to a ...

Roussel Uclaf, altrenogest has weak

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 ...

and

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 equivalent to 1/20th of that of

. However, no significant androgenic effects have been observed in young

stallion A stallion is a male horse that has not been gelded (castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cresty" nec ...

s or mature

mare A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than f ...

s, and altrenogest has notably been used to maintain

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 ...

in mares (similarly to the use of allylestrenol to maintain pregnancy in women) with no incidence of

virilization 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 ...

or other abnormalities in

filly A filly is a female horse that is too young to be called a mare. There are two specific definitions in use: *In most cases, a ''filly'' is a female horse under four years old. *In some nations, such as the United Kingdom and the United States, t ...

offspring In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...

. On the other hand, minor potential anabolic/androgenic effects have been suggested for altrenogest in pigs.

Chemistry

Altrenogest, also known as 17α-allyl-19-nor-δ^9,11-testosterone or as 17α-allylestra-4,9,11-trien-17β-ol-3-one, 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 ...

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 ...

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 ...

and

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 19-nortestosterone and 17α-allyltestosterone, or of 17α-allyl-19-nortestosterone. It is one of only two marketed progestins that possesses a 17α-allyl group, the other being allylestrenol. Most other progestins possess a 17α- ethynyl group, while AAS, if they are 17α-substituted, are usually 17α-alkylated (with a methyl or

ethyl group In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula , derived from ethane (). ''Ethyl'' is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturat ...

). Altrenogest is the 17α-allylated derivative of the AAS

trenbolone Trenbolone is an androgen and anabolic steroid (AAS) of the nandrolone group which itself was never marketed. Trenbolone ester prodrugs, including trenbolone acetate (brand names Finajet, Finaplix, others) and trenbolone hexahydrobenzylcarbo ...

(and hence can also be referred to as allyltrenbolone or allyltrienolone), which itself is the 9,11-didehydro analogue of the AAS

nandrolone 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). Nandrol ...

(19-nortestosterone). Altrenogest is also closely related to norgestrienone.

History

Altrenogest has been marketed as Regumate since the early 1980s.

Society and culture

Generic names

''Altrenogest'' is the generic name of the drug and its , , and , while ''altrénogest'' is its .

Brand names

Altrenogest is marketed under the brand names Regumate and Matrix among others.

References

{{Progesterone receptor modulators Tertiary alcohols Allyl compounds Estranes Enones Progestogens Veterinary drugs Polyenes