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

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 yea ...

s and

pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...

s.
/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 entirel ...

(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 states, a federal district, five major unincorporated territori ...

(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 ...

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 constit ...

structure–activity relationships

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 of both the progesterone receptor (PR) and the androgen receptor (AR) of a large selection of other progestogens as well as anabolic–androgenic steroids (AAS). The observed potency of altrenogest even exceeded that of

metribolone Metribolone (developmental code R1881, also known as methyltrienolone) is a synthetic and orally active anabolic–androgenic steroid (AAS) and a 17α-alkylated nandrolone (19-nortestosterone) derivative which was never marketed for medical ...

(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 characteristi ...

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

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, 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 ...

Roussel Uclaf Roussel Uclaf S.A. was a French pharmaceutical company and one of several predecessor companies of today's Sanofi. It was the second largest French pharmaceutical company before it was acquired by Hoechst AG of Frankfurt, Germany in 1997, with p ...

, 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 ...

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 stallions 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 fo ...

s, and altrenogest has notably been used to maintain

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

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

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

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, fo ...

steroid 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 anabolic steroid, 17α-alkylated (with a methyl group, methyl or ethyl group). Altrenogest is the 17α-allylated derivative of the AAS trenbolone (and hence can also be referred to as allyltrenbolone or allyltrienolone), which itself is the 9,11-didehydro analogue of the AAS nandrolone (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 term, 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