Combination of | |
---|---|
Estradiol enantate | Estrogen |
Algestone acetophenide | Progestogen |
Clinical data | |
Trade names | Perlutal, Topasel, Unalmes, Yectames, many others |
Other names | Estradiol enantate/dihydroxyprogesterone acetophenide; E2-EN/DHPA |
Routes of administration | Intramuscular injection |
Identifiers | |
CAS Number | |
PubChem CID | |
UNII |
Estradiol enantate/algestone acetophenide, also known as estradiol enantate/dihydroxyprogesterone acetophenide (E2-EN/DHPA) and sold under the brand names Perlutal and Topasel among others, is a form of combined injectable birth control which is used to prevent pregnancy. [1] [2] [3] It contains estradiol enantate (E2-EN), an estrogen, and algestone acetophenide (dihydroxyprogesterone acetophenide; DHPA), a progestin. [1] [2] [3] The medication is given once a month by injection into muscle. [1] [2] [3]
E2-EN/DHPA is used widely throughout Latin America, is also marketed in Hong Kong, and was previously available in Portugal and Spain as well but was discontinued in these countries. [1] [2] [3] [4]
E2-EN/DHPA is used in combination as a once-monthly combined injectable contraceptive to prevent pregnancy in women in Latin America and Hong Kong. [5] [3] [6] E2-EN/DHPA has been said to be used by "travestis" (a term for transgender women in some cultures, especially in South America) as a means of feminizing hormone therapy as well. [7]
The following forms of E2-EN/DHPA are or have been available for use: [3] [8] [9] [10] [5]
A 6 mg E2-EN and 90 mg DHPA formulation was also studied, but was never marketed. [11] [12] [13] The combination of E2-EN and DHPA has also been studied at other doses ranging from 5 to 50 mg E2-EN and 75 to 200 mg DHPA. [14]
Clinical studies have found that, on the basis of endometrial changes, E2-EN/DHPA appears, at the doses used, to be an estrogen-dominant combination. [15]
By intramuscular injection, the elimination half-life of E2-EN has been found to be 5.6 to 7.5 days, while the half-life of algestone acetophenide and its metabolites has been found to be 24 days. [16] [17] [18] [2] Following a single injection, E2-EN and DHPA are detectable in the circulation for up to 30 to 60 days. [19] [2]
E2-EN/DHPA was first studied as a combined injectable contraceptive in 1964. [10] It was developed by Squibb under the developmental code name and tentative brand name Deladroxate for potential use as a combined injectable contraceptive in the United States. [20] [2] Due to toxicological findings of DHPA of pituitary hyperplasia in rats, mammary tumors in beagle dogs, and "uterine swellings" in animals, as well as concerns about possible accumulation of DHPA, Squibb discontinued the development of E2-EN/DHPA in the late 1960s. [20] [10] [21] [2] Subsequently, in 1973, a pharmacokinetic study of E2-EN/DHPA in women generated concerns about potential accumulation of E2-EN with once-monthly use as well. [20] [10] [2] In spite of these concerns however, no toxicity or tumorigenicity has been observed with E2-EN/DHPA in humans in extensive clinical studies, and there are doubts about the relevance of the animal findings to humans. [21] [10] [2] In addition, only very limited accumulation of E2-EN has been found to occur with the preparation. [2]
Manufacturers in other countries, including EuroPharma, Farmitalia, and Promeco, resumed development of E2-EN/DHPA following the discontinuation of its development by Squibb, and introduced it for clinical use as a combined injectable contraceptive, under the brand names Perlutal and Topasel, in Spain and Latin America in the 1970s. [20] [15] [10] It was one of only two combined injectable contraceptives to have been marketed by 1976, and was one of only three combined injectable contraceptives with considerable clinical experience by 1976. [20] [15] The others were estradiol valerate/hydroxyprogesterone caproate (EV/OHPC; brand name Injectable No. 1), which had been marketed in China, and estradiol cypionate/medroxyprogesterone acetate (EC/MPA; code name Cyclo-Provera), which was still experimental by 1976 and did not become formally available for clinical use until the 1990s. [15] [10] By 1994, at which point EC/MPA (brand names Cyclofem and later Lunelle) and estradiol valerate/norethisterone enantate (EV/NETE; brand name Mesigyna) had been introduced, E2-EN/DHPA had been in use for many years. [15] [10]
E2-EN/DHPA and EV/OHPC have been referred to as first-generation combined injectable contraceptives, while EC/MPA and EV/NETE have been referred to as second-generation combined injectable contraceptives. [20]
E2-EN has been marketed under a wide variety of brand names. [4] [22] [23] [24] [3] [25] [9] [26] [10] [5] [1] It has been marketed in a few different preparations, with varying doses of E2-EN and DHPA. [9] [3] [25] [8] [10] [5] [1] These formulations all have different brand names, which include the following († = discontinued): [4] [22] [23] [24] [8] [9] [3] [25] [5] [27]
The combination of E2-EN 10 mg and DHPA 150 mg was developed under the developmental brand name Deladroxate, but this brand name was never used commercially. [10] [5]
DHPA has been marketed in combination with estradiol enantate (E2-EN) as a combined injectable contraceptive in at least 19 countries, mostly in Latin America. [3] [25] [9] [26] [4] [22] [23] [24] A few different preparations, with varying doses of E2-EN and DHPA and varying availability, have been introduced. [9] [3] [25] [8] [10] [5] [1] These formulations have the following approval and availability († = discontinued in this country): [4] [22] [23] [24] [8] [9] [3] [25] [5]
E2-EN/DHPA is the most widely used combined injectable contraceptive in Latin America. [28] It was estimated in 1995 that E2-EN/DHPA was used as a combined injectable contraceptive in Latin America by at least 1 million women. [9] However, combined injectable contraceptives like E2-EN/DHPA are unlikely to constitute a large proportion of contraceptive use in the countries in which they are available. [9]
Levonorgestrel is a hormonal medication which is used in a number of birth control methods. It is combined with an estrogen to make combination birth control pills. As an emergency birth control, sold under the brand names Plan B One-Step and Julie, among others, it is useful within 72 hours of unprotected sex. The more time that has passed since sex, the less effective the medication becomes, and it does not work after pregnancy (implantation) has occurred. Levonorgestrel works by preventing ovulation or fertilization from occurring. It decreases the chances of pregnancy by 57–93%. In an intrauterine device (IUD), such as Mirena among others, it is effective for the long-term prevention of pregnancy. A levonorgestrel-releasing implant is also available in some countries.
The Yuzpe regimen is a method of emergency contraception that uses a combination of ethinyl estradiol and levonorgestrel, specifically 1 mg of norgestrel and 100 mcg of ethinyl estradiol ASAP and again in 12 hrs. It is less effective and less commonly used than a larger dose of levonorgestrel alone, a dose of ulipristal acetate, or insertion of a copper intrauterine device. It is designed to be used within 72 hours of unprotected sexual intercourse because it works by inhibiting ovulation.
Estradiol valerate (EV), sold for use by mouth under the brand name Progynova and for use by injection under the brand names Delestrogen and Progynon Depot among others, is an estrogen medication. It is used in hormone therapy for menopausal symptoms and low estrogen levels, hormone therapy for transgender people, and in hormonal birth control. It is also used in the treatment of prostate cancer. The medication is taken by mouth or by injection into muscle or fat once every 1 to 4 weeks.
Desogestrel is a progestin medication which is used in birth control pills for women. It is also used in the treatment of menopausal symptoms in women. The medication is available and used alone or in combination with an estrogen. It is taken by mouth.
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 both low-dose and high-dose formulations and both alone and in combination with an estrogen. It is used by mouth or, as norethisterone enanthate, by injection into muscle.
Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy.
Algestone acetophenide, also known more commonly as dihydroxyprogesterone acetophenide (DHPA) and sold under the brand names Perlutal and Topasel among others, is a progestin medication which is used in combination with an estrogen as a form of long-lasting injectable birth control. It has also been used alone, but is no longer available as a standalone medication. DHPA is not active by mouth and is given once a month by injection into muscle.
Estradiol cypionate (EC), sold under the brand name Depo-Estradiol among others, is an estrogen medication which is used in hormone therapy for menopausal symptoms and low estrogen levels in women, in hormone therapy for trans women, and in hormonal birth control for women. It is given by injection into muscle once every 1 to 4 weeks.
Estradiol enantate, also spelled estradiol enanthate and sold under the brand names Perlutal and Topasel among others, is an estrogen medication which is used in hormonal birth control for women. It is formulated in combination with dihydroxyprogesterone acetophenide, a progestin, and is used specifically as a combined injectable contraceptive. Estradiol enantate is not available for medical use alone. The medication, in combination with DHPA, is given by injection into muscle once a month.
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 with increased resistance to first-pass metabolism, slightly improving its oral bioavailability. In addition, estrogen esters have increased lipophilicity, which results in a longer duration when given by intramuscular or subcutaneous injection due to the formation of a long-lasting local depot in muscle and fat. Conversely, this is not the case with intravenous injection or oral administration. Estrogen esters are rapidly hydrolyzed into their parent estrogen by esterases once they have been released from the depot. Because estradiol esters are prodrugs of estradiol, they are considered to be natural and bioidentical forms of estrogen.
Combined birth control pills that contain natural estradiol or an estradiol ester include:
Progestogen-only injectable contraceptives (POICs) are a form of hormonal contraception and progestogen-only contraception that are administered by injection and providing long-lasting birth control. As opposed to combined injectable contraceptives, they contain only a progestogen without an estrogen, and include two progestin preparations:
Estradiol benzoate butyrate (EBB), sold under the brand names Neolutin N, Redimen, Soluna, and Unijab and formerly known under the developmental code name Unimens, is an estrogen medication which is used in hormonal birth control for women. It is formulated in combination with dihydroxyprogesterone acetophenide, a progestin, and is used specifically as a combined injectable contraceptive. EBB is not available for medical use alone. The medication, in combination with DHPA, is given by injection into muscle once a month.
Estradiol/progesterone (E2/P4), sold under the brand name Bijuva among others, is a combined estrogen and progestogen medication which is used in the treatment of menopausal symptoms in postmenopausal women. It contains estradiol, an estrogen, and progesterone, a progestogen, and is available in both oral and intramuscular formulations. E2/P4 differs from other estrogen–progestogen formulations in that the sex-hormonal agents used are bioidentical.
Estradiol valerate/norethisterone enantate (EV/NETE), sold under the brand name Mesigyna among others, is a form of combined injectable birth control which is used to prevent pregnancy in women. It contains estradiol valerate (EV), an estrogen, and norethisterone enantate (NETE), a progestin. The medication is given once a month by injection into muscle.
Estradiol valerate/hydroxyprogesterone caproate (EV/OHPC), sold under the brand names Gravibinon and Injectable No. 1 among others, is a combined estrogen and progestogen medication which is used in the treatment of threatened miscarriage and other indications and as a form of combined injectable birth control to prevent pregnancy. It contains estradiol valerate (EV), an estrogen, and hydroxyprogesterone caproate (OHPC), a progestin. The medication is given by injection into muscle once a day to once a month depending on the indication.
Estradiol benzoate butyrate/algestone acetophenide, also known as estradiol benzoate butyrate/dihydroxyprogesterone acetophenide (EBB/DHPA) and sold under the brand names Neolutin N, Redimen, Soluna, and Unijab, is a form of combined injectable birth control which is used in Peru and Singapore. It contains estradiol benzoate butyrate (EBB), an estrogen, and algestone acetophenide, a progestin. The medication is given once per month by injection into muscle.
Estradiol benzoate/estradiol phenylpropionate (EB/EPP), sold under the brand name Dimenformon Prolongatum, is an injectable combination formulation of estradiol benzoate (EB), a shorter-acting estrogen, and estradiol phenylpropionate (EPP), a longer-acting estrogen, which has been used in menopausal hormone therapy for women in Europe but appears to no longer be available. It has also been used to suppress lactation in women and has been used in feminizing hormone therapy for transgender women. It has been provided in the form of 1 mL ampoules containing 2.5 mg EB and 10 mg EPP in oil solution and is administered by intramuscular injection at regular intervals.
Estradiol undecylate/norethisterone enanthate (EU/NETE) is a combination medication of estradiol undecylate (EU), an estrogen, and norethisterone enanthate (NETE), a progestin, which was developed by Schering for potential use as a combined injectable contraceptive in women but was ultimately never marketed. It contained 5 to 10 mg EU and 50 to 70 mg NETE in oil solution and was intended for use by intramuscular injection at regular intervals. Although never commercialized, EU/NETE was found to be effective and well tolerated.
Estradiol valerate/megestrol acetate (EV/MGA) is a combined injectable contraceptive which was developed in China in the 1980s but was never marketed. It is an aqueous suspension of microcapsules containing 5 mg estradiol valerate (EV) and 15 mg megestrol acetate (MGA). It was also studied at doses of EV ranging from 0.5 to 5 mg and at doses of MGA ranging from 15 to 25 mg.
Two additional monthly, combined injectable methods warrant mention. Deladroxate (commercially labelled as Perlutan, Topasel, Agurin, Horprotal and Uno-Ciclo in various countries), is a combination of 150 mg dihydroxyprogesterone acetophenide and 10 mg estradiol enanthate, and is available in many Latin American countries and Spain. The method is highly effective, without a single pregnancy reported in large clinical trials (Koetsawang 1994). Although available since the 1960s, the method has not been studied as extensively as Cyclofem or Mesigyna. The original manufacturer withdrew support due to toxicological concerns with dihydroxyprogesterone acetophenide, and clinical evaluations continue to be published. A recent dose-finding trial compared the standard available dose of 150/10 with a lower dose of 90/6, and concluded the lower dose was equally effective (Coutinho et al., 1997).