Quinestrol, also known as ethinylestradiol cyclopentyl ether (EECPE), sold under the brand name Estrovis among others, is 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 acti ...

medication which has been used in

menopausal hormone therapy Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. These symptoms can include hot flashes, vagina ...

hormonal birth control 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 original ...

, and to treat

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

and

prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...

. It is taken once per week to once per month

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 ...

Medical uses

Quinestrol has been used as the estrogen component in

and in combined hormonal birth control. It has also occasionally been used in the treatment of

and

, as well as to suppress

lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...

. On its own as an estrogen, quinestrol was taken once per week

. As a

combined 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. The pill contains two important hormones: progesti ...

, it was used together with

quingestanol acetate Quingestanol acetate, sold under the brand names Demovis and Pilomin among others, is a progestin medication which was used in birth control pills but is no longer marketed. It is taken by mouth. Quingestanol acetate is a progestin, or a synt ...

and was taken once per month by mouth.

Pharmacology

Quinestrol is a

prodrug A prodrug is a 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 used to improve how the drug ...

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 disord ...

(EE), with no estrogenic activity of its own. It is taken orally and has prolonged activity following a single dose, with a very long

biological half-life Biological half-life (also known as elimination half-life, pharmacologic 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 bl ...

of more than 120 hours (5 days) due to enhanced

lipophilicity Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipop ...

and storage in

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers spec ...

. Because of its much longer half-life, quinestrol is two to three times as potent as EE. Also because of its long half-life, quinestrol can be taken once a week or once a month. Following administration, quinestrol is absorbed via the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid o ...

, is stored in

adipose tissue Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...

, and is gradually released from adipose tissue.

Chemistry

Quinestrol, also known as ethinylestradiol 3-cyclopentyl ether (EE2CPE), 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 A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

and a

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. F ...

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 of f ...

. It is an

estrogen ether An estrogen ester is an ester of an estrogen, most typically of estradiol but also of other estrogens such as estrone, estriol, and even nonsteroidal estrogens like diethylstilbestrol. Esterification renders estradiol into a prodrug of estradiol ...

, specifically the C3

cyclopentyl Cyclopentane (also called C pentane) is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occu ...

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be c ...

(17α-ethynylestradiol). Closely related estrogens include mestranol (ethinylestradiol 3-methyl ether) and

ethinylestradiol sulfonate Ethinylestradiol sulfonate (EES), sold under the brand names Deposiston and Turisteron among others, is an estrogen (medication), estrogen medication which has been used in birth control pills for women and in the treatment of prostate cancer in ...

(EES; Turisteron; ethinylestradiol 3-isopropylsulfonate).

History

Quinestrol was developed and introduced for medical use in the 1960s.

Society and culture

Generic names

''Quinestrol'' is the generic name of the drug and its , , and .
/ref> It is also known by its former developmental code name ''W-3566''.

Brand names

Quinestrol has been marketed under brand names including Agalacto-Quilea, Basaquines, Eston, Estrovis, Estrovister, Plestrovis, Qui-Lea, Soluna, and Yueketing, among others.

Availability

Quinestrol was marketed as ''Estrovis'' 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 states, a federal district, five major unincorporated territorie ...

Parke-Davis Parke-Davis is a subsidiary of the pharmaceutical company Pfizer. Although Parke, Davis & Co. is no longer an independent corporation, it was once America's oldest and largest drug maker, and played an important role in medical history. In 1970 ...

and as ''Qui-Lea'' in

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, but is reportedly not currently marketed. However, it does appear to still be available as an

oral contraceptive Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control. Female Two types of female oral contraceptive pill, taken once per day, are widely available: * The combin ...

in combination with

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

s in Argentina and

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

.
/ref> One tablet form available in China consists of 6 mg levonorgestrel and 3 mg quinestrol; it is used as a prescription "long-term" oral contraceptive, with one dose taken each month. It is sold under various brand names including Yuèkětíng () and Àiyuè (). A version with the racemic

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

in place of levonorgestrel also appears to be available.

Veterinary use

Rodents

The Chinese levonorgestrel/quinestrol 2:1 formula is known as EP-1 in veterinary practice. It is known to have some organ-specific effects on the

Mongolian gerbil The Mongolian gerbil or Mongolian jird (''Meriones unguiculatus'') is a small rodent belonging to the subfamily Gerbillinae. Their body size is typically , with a tail, and body weight , with adult males larger than females. The animal is us ...

as measured by receptor mRNA expression. Incorporated into baits at a concentration of 50 ppm, EP-1 has been used to control wild Mongolian gerbil populations with some success.

References

{{Estrogen receptor modulators Ethynyl compounds Antigonadotropins Cyclopentyl ethers Estranes Estrogen ethers Synthetic estrogens Tertiary alcohols